129 results on '"Zhi-Tao, Wang"'
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2. Temporal and spatial biosonar activity of the recently established uppermost Yangtze finless porpoise population downstream of the Gezhouba Dam: Correlation with hydropower cascade development, shipping, hydrological regime, and light intensity
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Zhi‐Tao Wang, Peng‐Xiang Duan, Tomonari Akamatsu, Ke‐Xiong Wang, and Ding Wang
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boat traffic ,Gezhouba dam ,hydrological regime ,hydropower cascade development ,light intensity ,Yangtze finless porpoises ,Ecology ,QH540-549.5 - Abstract
Abstract Numerous dams disrupt freshwater animals. The uppermost population of the critically endangered Yangtze finless porpoise has been newly formed below the Gezhouba Dam, however, information regarding the local porpoise is scarce. Passive acoustic monitoring was used to detect the behaviors of porpoises below the Gezhouba Dam. The influence of shipping, pandemic lockdown, hydrological regime, and light intensity on the biosonar activity of dolphins was also examined using Generalized linear models. Over the course of 4 years (2019–2022), approximately 848, 596, and 676 effective monitoring days were investigated at the three sites, from upstream to downstream. Observations revealed significant spatio‐temporal biosonar activity. Proportion of days that are porpoise positive were 73%, 54%, and 61%, while porpoise buzz signals accounted for 78.49%, 62.35%, and 81.30% of all porpoise biosonar at the three stations. The biosonar activity of porpoises was much higher at the confluence area, particularly at the MZ site, during the absence of boat traffic, and during the Pandemic shutdown. Temporal trends of monthly, seasonal, and yearly variation were also visible, with the highest number of porpoises biosonar detected in the summer season and in 2020. Significant correlations also exist between the hydrological regime and light intensity and porpoise activity, with much higher detections during nighttime and full moon periods. Hydropower cascade development, establishment of a natural reserve, fish release initiatives, and implementation of fishing restrictions may facilitate the proliferation of the porpoise population downstream of the Gezhouba Dam within the Yichang section of the Yangtze River. Prioritizing restoration designs that match natural flow regimes, optimize boat traffic, and reduce noise pollution is crucial for promoting the conservation of the local porpoises.
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- 2024
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3. Increased Yangtze finless porpoise presence in urban Wuhan waters of the Yangtze River during fishing closures
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Zhi‐Tao Wang, Peng‐Xiang Duan, Tomonari Akamatsu, Ke‐Xiong Wang, and Ding Wang
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boat traffic ,hydrological regime ,light intensity ,passive acoustic monitoring ,Wuhan ,Yangtze finless porpoises ,Ecology ,QH540-549.5 - Abstract
Abstract Wuhan, a highly urbanized and rapidly growing region within China's Yangtze Economic Zone, has historically been identified as a gap area for the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) based on daytime visual surveys. However, there has been a noticeable increase in porpoise sightings since 2020. This study employed passive acoustic monitoring to investigate porpoise distribution in Wuhan between 2020 and 2022. Generalized linear models were used to explore the relationship between shipping, hydrological patterns, light intensity, and porpoise biosonar activity. Over 603 days of effective monitoring, the daily positive rate for porpoise biosonar detection reached 43%, with feeding‐related buzz signals accounting for 55% of all porpoise biosonar signals. However, the proportion of minutes during which porpoise presence was detected was 0.18%, suggesting that while porpoises may frequent the area, their visits were brief and mainly focused on feeding. A significant temporal trend emerged, showing higher porpoise biosonar detection during winter (especially in February) and 2022. Additionally, periods without boat traffic correlated with increased porpoise activity. Hydrological conditions and light levels exhibited significant negative correlations with porpoise activity. Specifically, porpoise sonar detections were notably higher during the night, twilight, and new moon phases. It is highly conceivable that both fishing bans and COVID‐19 pandemic‐related lockdowns contributed to the heightened presence of porpoises in Wuhan. The rapid development of municipal transportation and shipping in Wuhan and resulting underwater noise pollution have emerged as a significant threat to the local porpoise population. Accordingly, it is imperative for regulatory bodies to effectively address this environmental stressor and formulate targeted protection measures to ensure the conservation of the finless porpoise.
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- 2024
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4. Editorial: Hearing research in cetaceans
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Zhi-Tao Wang and Dorian S. Houser
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cetaceans ,whales ,dolphins ,porpoises ,hearing research ,audiogram ,Science ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Published
- 2023
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5. Computed Tomography Features of Adnexal Torsion: A Meta-Analysis
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Ling-Shan, Chen, Jing, Li, Zheng-Qiu, Zhu, Pin, Wang, Zhi-Tao, Wang, Fu-Ting, Tang, Xu-Yu, Hu, and Zhong-Qiu, Wang
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- 2022
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6. Magnetic resonance imaging features for differentiating tuberculous from pyogenic spondylitis: a meta-analysis.
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Ling-Shan, Chen, Zheng-Qiu, Zhu, Jing, Li, Rui, Zhao, Li-Fang, Ling, Zhi-Tao, Wang, and Zhong-Qiu, Wang
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MAGNETIC resonance imaging ,SPONDYLITIS - Abstract
Objective: To perform a meta-analysis comparing the MRI features of tuberculous and pyogenic spondylitis, using histopathological results and/or blood culture as the standard reference. Materials and methods: PubMed, Embase, Web of Science, and Cochrane Library were searched for English-language studies on the MRI features of tuberculous and pyogenic spondylitis published between January 2010 and February 2023. Risk for bias and concerns regarding applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Pooled MRI features' proportions were calculated using a bivariate random-effects model. Results: Thirty-two studies met the inclusion criteria: 21 for tuberculous spondylitis, three for pyogenic spondylitis, and eight for both. Of the nine informative MRI features comparing tuberculous spondylitis to pyogenic spondylitis, involvement of ≥ 2 vertebral bodies (92% vs. 88%, P =.004), epidural extension (77% vs. 25%, P <.001), paravertebral collection (91% vs. 84%, P <.001), subligamentous spread (93% vs. 24%, P <.001), thin and regular abscess wall (94% vs. 18%, P <.001), vertebral collapse (68% vs. 24%, P <.001), and kyphosis (39% vs. 3%, P <.01) were more suggestive of tuberculous spondylitis, while disc signal change (82% vs. 95%, P <.001) and disc height loss (22% vs. 59%, P <.001) were more suggestive of pyogenic spondylitis. Conclusion: Involvement of ≥ 2 vertebral vertebral bodies, soft tissue attribution, thin and regular abscess wall, vertebral collapse, and kyphosis were MRI features more common in tuberculous spondylitis, while disc signal change and height loss were more common in pyogenic spondylitis. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Riverside underwater noise pollution threaten porpoises and fish along the middle and lower reaches of the Yangtze River, China
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Zhi-Tao Wang, Peng-Xiang Duan, Tomonari Akamatsu, Yu-Wei Chen, Xue An, Jing Yuan, Pei-Yu Lei, Jiao Li, Lu Zhou, Ming-Chao Liu, Yi-Ning Yang, Fei Fan, Ke-Xiong Wang, and Ding Wang
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Yangtze River ,Yangtze finless porpoises ,Underwater noise ,Fishes ,Sturgeon ,Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
The Yangtze River exhibits a high biodiversity and plays an important role in global biodiversity conservation. As the world's busiest inland river in regard to shipping, little attention has been paid to underwater noise pollution. In 2017, the underwater noise level in 25 riverside locations along the middle and lower reaches of the Yangtze River mainly at night time were investigated by using passive acoustic monitoring method. Approximately 88% and 40% of the sampled sites exhibit noise levels exceeding the underwater acoustic thresholds of causing responsiveness and temporary threshold shift, respectively, in cetacean. Noise pollution may impose a high impact on fish with physostomous swim bladders and Weberian ossicles, such as silver carp, bighead carp, goldfish and common carp, whereas it may affect fish with physoclistous swim bladders and without Weberian ossicles, such as lake sturgeon and paddlefish, to a lesser extent. Noise levels reductions of approximately 10 and 20 dB were observed in the middle and lower reaches, respectively, of the Yangtze River over the 2012 level. The green development mode of the ongoing construction of green shipping in the Yangtze River Economic Belt, including the development of green shipping lanes, ports, ships and transportation organizations, may account for the alleviated underwater noise pollution. Follow-up noise mitigation endeavors, such as the extension of ship speed restrictions and the study and implementation of the optimal navigation speed in ecologically important areas, are required to further reduce the noise level in the Yangtze River to protect local porpoises and fish.
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- 2021
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8. Auditory evoked potential in stranded melon-headed whales (Peponocephala electra): With severe hearing loss and possibly caused by anthropogenic noise pollution
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Zhi-Tao Wang, Alexander Ya Supin, Tomonari Akamatsu, Peng-Xiang Duan, Yi-Ning Yang, Ke-Xiong Wang, and Ding Wang
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Auditory evoked-potential ,Audiogram ,Melon headed whale ,Hearing loss ,Stranding ,Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
Highly concentrated live mass stranding events of dolphins and whales happened in the eastern coast of China between June and October 2021. The current study adopted the non-invasive auditory evoked-potential technique to investigate the hearing threshold of a stranded melon headed whale (Peponocephala electra) at a frequency range of between 9.5 and 181 kHz. It was found that, at the frequency range of from 10 to 100 kHz, hearing thresholds for the animal were between 20 and 65 dB higher than those of its phylogenetically closest species (Pygmy killer whale). The severe hearing loss in the melon headed whale was probably caused by transient intense anthropogenic sonar or chronic shipping noise exposures. The hearing loss could have been the cause for the observed temporal and spatial clustered stranding events. Therefore, there is need for noise mitigation strategies to reduce noise exposure levels for marine mammals in the coastal areas of China.
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- 2021
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9. Cycloaddition of Propargylic Amines and CO2 by Ni@Pd Nanoclusters Confined Within Metal–Organic Framework Cavities in Aqueous Solution
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Zhi-tao, Wang
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- 2020
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10. Comparison of the Clinical and Radiographical Outcomes of Regenerative Surgery and Open Flap Debridement in the Treatment of Shallow No-Contentive Periodontal Infra-Bony Defects
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Yan Jia, Xin-Yue Li, Yong-Qiang Ma, Zhi-Tao Wang, and Jian Kang
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Biomaterials ,Medicine (miscellaneous) ,Orthopedics and Sports Medicine ,Cell Biology ,General Dentistry ,Biochemistry - Published
- 2023
11. Association of high-resolution computed tomography score with ventilator weaning and 28-day mortality of patients with acute respiratory distress syndrome
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Kun Zhao, Shu-juan Bai, Zhi-tao Wang, Yu-he Zhang, Chao Liu, Hai-gang Song, Hai-bo Wang, Xin Li, and Wen-laing You
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Medicine (General) ,R5-920 - Abstract
Objective This study was performed to explore the association of the high-resolution computed tomography (HRCT) score with ventilator weaning and 28-day mortality of patients with acute respiratory distress syndrome (ARDS). Method In total, 197 patients treated for ARDS from October 2004 to December 2015 were retrospectively analyzed. Univariate analysis and multifactor regression analysis were used to determine the relationship of the HRCT score with ventilator weaning and 28-day mortality. Curve-fitting analysis and threshold analysis were further used to explore the association of the HRCT score with ventilator weaning and 28-day mortality. Results The multifactor regression analysis showed that the HRCT score was significantly associated with a lower rate of ventilator weaning and a higher risk of 28-day mortality in patients with ARDS. HRCT scores of 257.0 and 243.2 were the thresholds for ventilator weaning and 28-day mortality, respectively. When the HRCT score was below the threshold, every 1-point increase in the HRCT score was associated with a 4.6% decrease in the ventilator weaning rate and a 4.6% increase in the 28-day mortality rate. Conclusion The HRCT score was associated with ventilator weaning and 28-day mortality with a threshold of 257.0 and 243.2 points, respectively.
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- 2020
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12. Effect of Changes in Bolus Viscosity on Swallowing Muscles in Patients with Dysphagia after Stroke
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Shuang Wu, Lan Chu, Chun-Feng Liu, Qian Zhang, Yi-Fan Zhang, Teng-Fei Zhou, Zhi-Tao Wang, Rui-Han Ni, and Yuan Li
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Medicine - Published
- 2018
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13. Vocalization of Bryde's whales ( Balaenoptera edeni ) in the Beibu Gulf, China
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Zhi‐Tao Wang, Peng‐Xiang Duan, Mo Chen, Zhi‐Gang Mei, Xiao‐Dong Sun, Zhi‐Wen Nong, Mei‐Han Liu, Tomonari Akamatsu, Ke‐Xiong Wang, and Ding Wang
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Aquatic Science ,Ecology, Evolution, Behavior and Systematics - Published
- 2022
14. Anthropogenic activity, hydrological regime, and light level jointly influence temporal patterns in biosonar activity of the Yangtze finless porpoise at the junction of the Yangtze River and Poyang Lake, China.
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Peng-Xiang Duan, Zhi-Tao Wang, Tomonari Akamatsu, Tregenza, Nick, Guang-Yu Li, Ke-Xiong Wang, and Ding Wang
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PORPOISES ,ANTHROPOGENIC effects on nature ,WATER levels ,COVID-19 pandemic ,LAKES ,TEMPOROPARIETAL junction ,ACOUSTIC emission testing ,ANTHROPOGENIC soils - Abstract
Under increasing anthropogenic pressure, species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations. The critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), once commonly observed in the Yangtze River-Poyang Lake junction, is now rarely seen in the river-lake corridor. In this study, static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor. Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation, as well as environmental variables, including hydrological conditions and light levels. Over approximately three consecutive years of monitoring (2020–2022), porpoise biosonar was detected during 93% of logged days, indicating the key role of the corridor for finless porpoise conservation. In addition, porpoise clicks were recorded in 3.80% of minutes, while feeding correlated buzzes were detected in 1.23% of minutes, suggesting the potential existence of localized, small-scale migration. Furthermore, both anthropogenic and environmental variables were significantly correlated with the diel, lunar, monthly, seasonal, and annual variations in porpoise biosonar activities. During the pandemic lockdown period, porpoise sonar detection showed a significant increase. Furthermore, a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity. In addition to water level and flux, daylight and moonlight exhibited significant correlations with porpoise biosonar activities, with markedly higher detections at night and quarter moon periods. Ensuring the spatiotemporal reduction of anthropogenic activities, implementing vessel speed restrictions (e.g., during porpoise migration and feeding), and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Diversity of fish sound types in the Pearl River Estuary, China
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Zhi-Tao Wang, Douglas P. Nowacek, Tomonari Akamatsu, Ke-Xiong Wang, Jian-Chang Liu, Guo-Qin Duan, Han-Jiang Cao, and Ding Wang
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Indo-pacific humpback dolphins ,Hierarchical cluster analysis ,Pearl River Estuary ,Fish sound ,Passive acoustic monitoring ,Pulse train ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background Repetitive species-specific sound enables the identification of the presence and behavior of soniferous species by acoustic means. Passive acoustic monitoring has been widely applied to monitor the spatial and temporal occurrence and behavior of calling species. Methods Underwater biological sounds in the Pearl River Estuary, China, were collected using passive acoustic monitoring, with special attention paid to fish sounds. A total of 1,408 suspected fish calls comprising 18,942 pulses were qualitatively analyzed using a customized acoustic analysis routine. Results We identified a diversity of 66 types of fish sounds. In addition to single pulse, the sounds tended to have a pulse train structure. The pulses were characterized by an approximate 8 ms duration, with a peak frequency from 500 to 2,600 Hz and a majority of the energy below 4,000 Hz. The median inter-pulsepeak interval (IPPI) of most call types was 9 or 10 ms. Most call types with median IPPIs of 9 ms and 10 ms were observed at times that were exclusive from each other, suggesting that they might be produced by different species. According to the literature, the two section signal types of 1 + 1 and 1 + N10 might belong to big-snout croaker (Johnius macrorhynus), and 1 + N19 might be produced by Belanger’s croaker (J. belangerii). Discussion Categorization of the baseline ambient biological sound is an important first step in mapping the spatial and temporal patterns of soniferous fishes. The next step is the identification of the species producing each sound. The distribution pattern of soniferous fishes will be helpful for the protection and management of local fishery resources and in marine environmental impact assessment. Since the local vulnerable Indo-Pacific humpback dolphin (Sousa chinensis) mainly preys on soniferous fishes, the fine-scale distribution pattern of soniferous fishes can aid in the conservation of this species. Additionally, prey and predator relationships can be observed when a database of species-identified sounds is completed.
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- 2017
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16. Research on Simulink/Fluent Collaborative Simulation Zooming of Marine Gas Turbine
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Zhi-tao Wang, Jian Li, Tie-lei Li, and Shu-ying Li
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Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Based on the detailed analysis of collaborative running interface of Simulink/Fluent, a system simulation for the rated working condition as well as variable working condition of marine gas turbine has been achieved, which can improve the simulation efficiency of marine gas turbine by developing simulation model of combustor with Fluent and simulation models of other components with Simulink. The result shows that the Simulink/Fluent collaborative simulation zooming can make the inner working conditions of combustor be observed specifically, based on the overall performance matching analysis; thus an effective technical means for the structural optimization design of combustor has been provided.
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- 2017
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17. Syntheses, Crystal Structures and NBO Calculation of Two New Zn(II)/Co(II) Coordination Polymers
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Ya-Ru Pan, Valentin Valtchev, Xiu-Mei Li, and Zhi-Tao Wang
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chemistry.chemical_classification ,Materials science ,Hydrogen bond ,Intermolecular force ,Supramolecular chemistry ,Stacking ,Infrared spectroscopy ,02 engineering and technology ,General Chemistry ,Polymer ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Crystallography ,chemistry ,General Materials Science ,0210 nano-technology ,Natural bond orbital - Abstract
Two new Zn(II)/Co(II) coordination polymers, [Zn1.5(pmda)(OH)(bipy)]2n·2nH2O (1) and [Co(pmda)(bib)]n (2) (H2pmda = 4,4′-[1,2-phenylenebis(methyleneoxy)]dibenzoic acid, bipy = 4,4′-bipyridine, bib = 1,4-bis(imidazol-1-yl)-butane), have been prepared under hydrothermal conditions. Their structure were determined by single-crystal X-ray diffraction analysis, and further characterized by elemental analysis, IR spectra TG, and powder X-ray diffraction analysis. Complexes 1 and 2 both exhibit two-dimensional network structures and the intermolecular hydrogen bonding, π-π stacking interactions extend them into 3D supramolecular architectures, which play an important role in stabilizing them. The solid-state luminescent property of 1 and 2 were characterized and the results revealed that they exhibit fascinating photoluminescence properties. In addition, the sensing property of only 1 has been examined briefly. The quantum-chemical calculations of complex 1 have been performed on ‘molecular fragments’ extracted from the crystal structure using the PBE0/LANL2DZ method built in Gaussian 16 Program.
- Published
- 2021
18. Apparent source levels and active communication space of whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in the Pearl River Estuary and Beibu Gulf, China
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Zhi-Tao Wang, Whitlow W.L. Au, Luke Rendell, Ke-Xiong Wang, Hai-Ping Wu, Yu-Ping Wu, Jian-Chang Liu, Guo-Qin Duan, Han-Jiang Cao, and Ding Wang
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Active communication space ,Pearl River Estuary ,Sound propagation model ,Whistles ,Indo-Pacific Humpback dolphins ,Hydrophone arrays ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background. Knowledge of species-specific vocalization characteristics and their associated active communication space, the effective range over which a communication signal can be detected by a conspecific, is critical for understanding the impacts of underwater acoustic pollution, as well as other threats. Methods. We used a two-dimensional cross-shaped hydrophone array system to record the whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in shallow-water environments of the Pearl River Estuary (PRE) and Beibu Gulf (BG), China. Using hyperbolic position fixing, which exploits time differences of arrival of a signal between pairs of hydrophone receivers, we obtained source location estimates for whistles with good signal-to-noise ratio (SNR ≥10 dB) and not polluted by other sounds and back-calculated their apparent source levels (ASL). Combining with the masking levels (including simultaneous noise levels, masking tonal threshold, and the Sousa auditory threshold) and the custom made site-specific sound propagation models, we further estimated their active communication space (ACS). Results. Humpback dolphins produced whistles with average root-mean-square ASL of 138.5 ± 6.8 (mean ± standard deviation) and 137.2 ± 7.0 dB re 1 µPa in PRE (N = 33) and BG (N = 209), respectively. We found statistically significant differences in ASLs among different whistle contour types. The mean and maximum ACS of whistles were estimated to be 14.7 ± 2.6 (median ± quartile deviation) and 17.1± 3.5 m in PRE, and 34.2 ± 9.5 and 43.5 ± 12.2 m in BG. Using just the auditory threshold as the masking level produced the mean and maximum ACSat of 24.3 ± 4.8 and 35.7 ± 4.6 m for PRE, and 60.7 ± 18.1 and 74.3 ± 25.3 m for BG. The small ACSs were due to the high ambient noise level. Significant differences in ACSs were also observed among different whistle contour types. Discussion. Besides shedding some light for evaluating appropriate noise exposure levels and information for the regulation of underwater acoustic pollution, these baseline data can also be used for aiding the passive acoustic monitoring of dolphin populations, defining the boundaries of separate groups in a more biologically meaningful way during field surveys, and guiding the appropriate approach distance for local dolphin-watching boats and research boat during focal group following.
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- 2016
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19. Noise pollution disrupts freshwater cetaceans
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Zhi-Tao Wang, Peng-Xiang Duan, Ke-Xiong Wang, and Ding Wang
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Multidisciplinary ,Rivers ,Dolphins ,Population Dynamics ,Animals ,Fresh Water ,Porpoises ,Noise ,Ships - Published
- 2021
20. Visual acuity assessment after cataract surgery by pattern reversal visual evoked potential
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Yi-Chen Zheng, Xian-Zhi Bai, Gui-Gang Li, Zhi-Tao Wang, Jian Sun, Xin-Yu Li, and Jun Hu
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pattern reversal visual evoked potential ,cataract ,assessment of visual acuity ,Ophthalmology ,RE1-994 - Abstract
AIM: To discuss visual acuity assessment after cataract surgery by pattern reversal visual evoked potential. METHODS:Data of 72 adult cataract patients received PRVEP before and after phaco and IOL in Department of Ophthalmology, Tongji Hospital from October 2012 to May 2013 was analyzed retrospectively. A total of 114 eyes were studied, including 76 eyes with senile cataract and 38 eyes with complicated cataract. According to the degree of lens opacity and the hardness of lens nucleus, these data were divided into two groups: Group 1(gradeⅠ, Ⅱ, Ⅲ )and Group 2(grade Ⅳ, Ⅴ )and was statistically studied with correlation analysis. RESULTS: Group 1:(1)Preoperative: the average of visual acuity was 0.344, the incubation time of P100 wave was 107ms and the amplitude of N75- P100 wave was 4.633μV; postoperative: the average of visual acuity was 0.672, the incubation time of P100 wave was 104.37ms and the amplitude of N75- P100 wave was 4.400μV.(2)The visual acuity before and after operation were both significantly negatively correlated with the incubation time of P100 wave(P75- P100 wave(preoperative: PP100 wave. Group 2:(1)Preoperative: the average of visual acuity was 0.116,the incubation time of P100 wave was 118.905ms and the amplitude of N75-P100 wave was 1.650μV; postoperative: the average of visual acuity was 0.576, the incubation time of P100 wave was 108.429ms and the amplitude of N75- P100 wave was 5.132μV.(2)The visual acuity before operation was significantly negatively correlated with the incubation time of P100 wave(P100 wave; the visual acuity before and after operation showed no relationship with the amplitude of N75- P100 wave.(3)The improved rows of the visual acuity before and after operation showed no relationship with the change of the incubation time of P100 wave. CONCLUSION:According to the correlation among the visual acuity, the incubation time of P100 wave and the amplitude of N75- P100 wave, PRVEP is significantly affected by preoperative visual acuity(the degree of opacity in refractive media). PRVEP is not helpful as an indicator of visual prognosis after cataract surgery, and PRVEP before cataract surgery has no clinical significance.
- Published
- 2013
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21. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis) in the Pearl River Estuary, China.
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Zhi-Tao Wang, Paul E Nachtigall, Tomonari Akamatsu, Ke-Xiong Wang, Yu-Ping Wu, Jian-Chang Liu, Guo-Qin Duan, Han-Jiang Cao, and Ding Wang
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Medicine ,Science - Abstract
A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis). Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.
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- 2015
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22. Syntheses, Crystal Structures and NBO Calculation of Two New Zinc(II) Coordination Polymers
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Xiu-Mei Li, Valentin Valtchev, Zhi-Tao Wang, Ya-Ru Pan, and Qianrong Fang
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Chemistry ,Hydrogen bond ,Intermolecular force ,Stacking ,Supramolecular chemistry ,General Chemistry ,Covalent Interaction ,Crystal structure ,010402 general chemistry ,010403 inorganic & nuclear chemistry ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Crystallography ,Single crystal ,Natural bond orbital - Abstract
Two new Zn(II) coordination polymers based on bis(imidazol), namely, [Zn(hba)2(bib)]n(1) and [Zn(NAA)(bib)1.5]n·nNO3−·3nH2O (2) (Hhba = 3-hydroxybenzoic acid, HNAA = 1-naphthyl acetic acid, bib = 1,4-bis(imidazol-1-yl)-butane) have been successfully synthesized under hydrothermal conditions. Their structures have been determined by single crystal X-ray diffraction analyses, elemental analyses, IR, TG and fluorescence spectrums. Complex 1 shows a one-dimensional zigzag chain structure. Complex 2 exhibits two-dimensional network structure. The intermolecular hydrogen bonding and π–π stacking interactions extend the complexes 1 and 2 into supramolecular architectures and play an important role in stabilizing complexes 1 and 2. Furthermore, complex 1 exhibits intense blue luminescence and appears to be a good candidate for novel hybrid inorganic–organic photoactive materials, while no photoluminescent response was observed for complex 2. In addition, we analyzed the Natural Bond Orbitals (NBO) of 1 and 2 using the PBE0/LANL2DZ method in the Gaussian 09 Program. The calculations showed the obvious covalent interaction between the coordinated atoms and Zn(II) ion. Two new Zn(II) coordination polymers based on bis(imidazol), namely, [Zn(hba)2(bib)]n(1) and [Zn(NAA)(bib)1.5]n·nNO3−·3nH2O (2) have been successfully synthesized under hydrothermal conditions. Their structures have been determined by single crystal X-ray diffraction analyses, elemental analyses, IR, TG and fluorescence spectrum. Complex 1 shows a one-dimensional zigzag chain structure. Complex 2 exhibits two-dimensional network structure. The intermolecular hydrogen bonding and π–π stacking interactions extend the complex 1 and 2 into supramolecular architectures and play an important role in stabilizing complex 1 and 2. In addition, we analyzed Natural Bond Orbital (NBO) of 1 and 2 in using the PBE0/LANL2DZ method built in Gaussian 09 Program. The calculation results showed the obvious covalent interaction between the coordinated atoms and Zn(II) ion.
- Published
- 2019
23. Syntheses, Crystal Structures and Theoretical Calculations of Two Nickel, Zinc Coordination Polymers with 4-Nitrophthalic Acid and Bis(imidazol) Ligands
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Zhi-Tao Wang, Valentin Valtchev, Xiu-Mei Li, Qianrong Fang, and Ya-Ru Pan
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Polymers and Plastics ,Hydrogen bond ,Chemistry ,Stacking ,Supramolecular chemistry ,Infrared spectroscopy ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ring (chemistry) ,01 natural sciences ,0104 chemical sciences ,Crystallography ,Covalent bond ,Materials Chemistry ,0210 nano-technology ,Natural bond orbital - Abstract
Two new complexes [Ni(4-nph)(bix)(H2O)]n(1) and [Zn(4-nph)(mbix)]n·nH2O (2) (4-H2nph = 4-nitrophthalic acid, bix = 1,4-bis(imidazol-1-yl)-benzene, mbix = 1,3-bis(imidazol-1-yl)-benzene) have been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG, fluorescence spectroscopy, single-crystal and powder X-ray diffraction. Complex 1 exhibits two dimensional (2D) network structure contain 42-number ring and complex 2 shows one-dimensional ribbon, which were further extended into three-dimensional supramolecular structure through hydrogen bonds and π–π stacking interactions. Moreover, we analyzed the natural bond orbital using the PBE0/LANL2DZ method in the Gaussian 03 program of complexes 1 and 2. The calculation results indicated the obvious covalent interactions between the coordinated atoms and the NiII, ZnII ion respectively.
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- 2019
24. [Simulation and uncertainty analysis of natural regeneration for pine-oak forests.]
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Bin, Wang, Xiang-Lin, Tian, Zi-Yan, Liao, Zhi-Tao, Wang, Sheng-Lian, Geng, and Tian-Jian, Cao
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Quercus ,Uncertainty ,Bayes Theorem ,Forests ,Pinus ,Ecosystem - Abstract
The complexity and uncertainty of forest regeneration is crucial for predicting forest ecosystem dynamics. A natural regeneration model of pine-oak forests in Qinling Mountains was constructed with competition, climate and topography factors using Bayesian statistics and global sensitivity analysis (GSA). The alternative models were based on Poisson, negative binomial (NB), zero-inflated Poisson (ZIP), and zero-inflated negative binomial (ZINB) models. According to the uncertainty of model parameter transfer, the analysis results were quantified, and the dominant factors of small probability events affecting forest regeneration were explained. The results showed that the ZINB model was the best one in the simulation of森林天然更新的复杂性和不确定性是森林生态系统动态预测中的关键问题。本研究引入贝叶斯技术和全局敏感性分析,构建基于竞争、气候和地形3类因子的秦岭松栎林天然更新模型。备选模型形式以泊松(Poisson)模型、负二项(negative binomial,NB)模型、零膨胀泊松(zero-inflated Poisson,ZIP)模型和零膨胀负二项(zero-inflated negative binomial,ZINB)模型为基础。同时,根据模型参数传递的不确定性量化分析结果,阐释影响森林更新小概率事件的主导因子。结果表明: ZINB模型在油松和锐齿栎更新模拟中均优于其他模型。林分总断面积、光截留、坡位和生长季最低温是影响松栎林中油松天然更新的最关键因子;而林分总断面积、坡向与海拔的组合、年均温和最热季节降水量则是影响松栎林中锐齿栎天然更新的关键因子。油松更新模拟中,各类因子对模型输出的不确定性贡献率从小到大依次为: 竞争因子(25%)<气候因子(29%)<地形因子(46%);锐齿栎更新模拟中为: 气候因子(12%)<竞争因子(24%)<地形因子(64%)。油松天然更新数量对生长季最低温和最干季节降水量为正响应,对最干季节均温为负响应;锐齿栎天然更新数量对年均温、生长季最低温和最热季节降水量为正响应,对最干季节均温为负响应。基于贝叶斯技术的ZINB模型可以量化森林更新的影响因子,并解释参数传递的不确定性,是预测森林天然更新的有力工具。.
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- 2021
25. Association of high-resolution computed tomography score with ventilator weaning and 28-day mortality of patients with acute respiratory distress syndrome
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Zhi-Tao Wang, Shu-Juan Bai, Kun Zhao, Hai-Bo Wang, Yu-He Zhang, Chao Liu, Xin Li, Hai-Gang Song, and Wen-Laing You
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Male ,ARDS ,Medicine (General) ,retrospective study ,Computed tomography ,Biochemistry ,HRCT score ,0302 clinical medicine ,multifactor regression analysis ,Medicine ,Hospital Mortality ,030212 general & internal medicine ,Respiratory system ,Lung ,Aged, 80 and over ,Respiratory Distress Syndrome ,medicine.diagnostic_test ,General Medicine ,Middle Aged ,respiratory system ,Prognosis ,ventilator weaning ,Female ,28 day mortality ,musculoskeletal diseases ,China ,medicine.medical_specialty ,High-resolution computed tomography ,Acute respiratory distress ,03 medical and health sciences ,R5-920 ,Humans ,Aged ,Retrospective Studies ,Ventilator weaning ,business.industry ,28-day mortality ,Biochemistry (medical) ,030208 emergency & critical care medicine ,Retrospective cohort study ,Cell Biology ,medicine.disease ,Respiration, Artificial ,respiratory tract diseases ,Dyspnea ,Emergency medicine ,Tomography, X-Ray Computed ,business ,Retrospective Clinical Research Report - Abstract
Objective This study was performed to explore the association of the high-resolution computed tomography (HRCT) score with ventilator weaning and 28-day mortality of patients with acute respiratory distress syndrome (ARDS). Method In total, 197 patients treated for ARDS from October 2004 to December 2015 were retrospectively analyzed. Univariate analysis and multifactor regression analysis were used to determine the relationship of the HRCT score with ventilator weaning and 28-day mortality. Curve-fitting analysis and threshold analysis were further used to explore the association of the HRCT score with ventilator weaning and 28-day mortality. Results The multifactor regression analysis showed that the HRCT score was significantly associated with a lower rate of ventilator weaning and a higher risk of 28-day mortality in patients with ARDS. HRCT scores of 257.0 and 243.2 were the thresholds for ventilator weaning and 28-day mortality, respectively. When the HRCT score was below the threshold, every 1-point increase in the HRCT score was associated with a 4.6% decrease in the ventilator weaning rate and a 4.6% increase in the 28-day mortality rate. Conclusion The HRCT score was associated with ventilator weaning and 28-day mortality with a threshold of 257.0 and 243.2 points, respectively.
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- 2020
26. Potentials of an Integrated Levitation, Guidance, and Propulsion System by a Superconducting Transverse Flux Linear Motor
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Zhi-Tao Wang, Kun Liu, Chao Wang, Hangyu Qian, and Guangtong Ma
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Physics ,020208 electrical & electronic engineering ,Mechanical engineering ,02 engineering and technology ,Superconducting magnet ,Propulsion ,Linear motor ,01 natural sciences ,Magnetic field ,Nonlinear system ,Control and Systems Engineering ,Maglev ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Levitation ,Electrical and Electronic Engineering ,010306 general physics ,Magnetic levitation - Abstract
We devised a transverse flux linear motor (TFLM) that uses the superconductor-aluminum hybrid as the secondary to explore the potentials of integrating the propulsion with the levitation and guidance, which are generally separated in existing magnetic levitation (MAGLEV) systems. In this proposal, the hybrid secondary is made of aluminum plate and close-ended coated superconductor coils, with the latter placed over the former to achieve the stable levitation and self-propulsion. To validate the proposal, analytical formulations for describing the electromagnetic responses of such hybrid secondary were established, and the resultant magnetic forces were calculated and compared with a 3-D finite-element model, in which the actual geometry of the proposed TFLM and the nonlinear behavior of superconductor were represented. Afterward, the proposed TFLM was demonstrated and its 3-D forces were measured by a test rig developed for this paper. It was proven that the derived analytical formulations and built finite-element model are both able to reproduce the main feature of the measured results. Characteristic studies clearly display that, although the levitation capability is limited in the proof-of-concept demonstrator, the self-stability and self-propulsion could be integrated by the proposed TFLM, which provides a novel alternative to the scientific community of MAGLEV transit.
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- 2018
27. Diffusion and Photon-Stimulated Desorption of CO on TiO2(110)
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Greg A. Kimmel, Rentao Mu, Igor Lyubinetsky, Arjun Dahal, Nikolay G. Petrik, and Zhi-Tao Wang
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Materials science ,Annealing (metallurgy) ,Kinetics ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,General Energy ,Adsorption ,chemistry ,law ,Desorption ,Monolayer ,Irradiation ,Physical and Theoretical Chemistry ,Scanning tunneling microscope ,0210 nano-technology - Abstract
Thermal diffusion of CO adsorbed on rutile TiO2(110) was studied in the 20–110 K range using photon-stimulated desorption (PSD), temperature-programmed desorption (TPD), and scanning tunneling microscopy. During UV irradiation, CO desorbs from certain photoactive sites (e.g., oxygen vacancies). This phenomenon was exploited to study CO thermal diffusion in three steps: first, empty these sites during a first irradiation cycle, then replenish them with CO during annealing, and finally probe the active site occupancy in the second PSD cycle. The PSD and TPD experiments show that the CO diffusion rate correlates with the CO adsorption energy—stronger binding corresponds to slower diffusion. Increasing the CO coverage from 0.06 to 0.44 monolayer (ML) or hydroxylation of the surface decreases the CO binding and increases the CO diffusion rate. Relative to the reduced surface, the CO adsorption energy increases and the diffusion decreases on the oxidized surface. The CO diffusion kinetics can be modeled satisfa...
- Published
- 2018
28. Chemical shift magnetic resonance imaging for distinguishing minimal-fat renal angiomyolipoma from renal cell carcinoma: a meta-analysis
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Jing Li, Zhongqiu Wang, Zheng-Qiu Zhu, Zhi-Tao Wang, Ling-Shan Chen, Ji-yang Jin, and Li-Feng Liang
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medicine.medical_specialty ,Angiomyolipoma ,Urology ,Chromophobe cell ,Kidney ,urologic and male genital diseases ,030218 nuclear medicine & medical imaging ,Diagnosis, Differential ,03 medical and health sciences ,0302 clinical medicine ,Renal cell carcinoma ,Statistical significance ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Carcinoma, Renal Cell ,neoplasms ,Neuroradiology ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,General Medicine ,Publication bias ,medicine.disease ,Magnetic Resonance Imaging ,Kidney Neoplasms ,female genital diseases and pregnancy complications ,Adipose Tissue ,030220 oncology & carcinogenesis ,Meta-analysis ,Radiology ,business ,Clear cell - Abstract
To determine the performance of chemical shift signal intensity index (CS-SII) values for distinguishing minimal-fat renal angiomyolipoma (mfAML) from renal cell carcinoma (RCC) and to assess RCC subtype characterisation. We identified eligible studies on CS magnetic resonance imaging (CS-MRI) of focal renal lesions via PubMed, Embase, and the Cochrane Library. CS-SII values were extracted by lesion type and evaluated using linear mixed model-based meta-regression. RCC subtypes were analysed. Two-sided p value
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- 2017
29. Synthesis, Crystal Structure and Theoretical Calculations of Two Zinc, Cobalt Coordination Polymers with 5-Nitroisophthalic Acid and 1,4-Bis(1H-benzimidazolyl)butane Ligands
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Bo Liu, Zhi-Tao Wang, Ya-Ru Pan, Xiu-Mei Li, and Qing-Wei Wang
- Subjects
Polymers and Plastics ,Hydrogen bond ,Inorganic chemistry ,Supramolecular chemistry ,Stacking ,Infrared spectroscopy ,Butane ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallography ,chemistry ,Covalent bond ,Materials Chemistry ,0210 nano-technology ,Natural bond orbital - Abstract
Two new complexes [Zn(NIPH)(bbib)]2n·nbbib·nH2O (1) and [Co(NIPH)(bbib)]n (2) (H2NIPH = 5-nitroisophthalic acid, bbib = 1,4-bis(1H-benzimidazolyl)butane) have been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG, fluorescence spectroscopy, single-crystal and powder X-ray diffraction. Complex 1 exhibits a two-dimensional network structure and complex 2 shows a three-dimensional framework, which were further extended into three-dimensional supramolecular structure through hydrogen bonds and π–π stacking interactions. Moreover, we analyzed the natural bond orbital using the PBE0/LANL2DZ method in the Gaussian 03 program of complex 1 and 2. The calculation results indicated the obvious covalent interactions between the coordinated atoms and the ZnII, CoII ion respectively.
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- 2017
30. Dry Dehydrogenation of Ethanol on Pt–Cu Single Atom Alloys
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Robert A. Hoyt, E. Charles H. Sykes, Robert J. Madix, Efthimios Kaxiras, Mostafa El-Soda, and Zhi-Tao Wang
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Ethanol ,Hydrogen ,Inorganic chemistry ,Acetaldehyde ,chemistry.chemical_element ,Alcohol ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Reactivity (chemistry) ,Dehydrogenation ,0210 nano-technology - Abstract
The non-oxidative dehydrogenation of ethanol to acetaldehyde and hydrogen is an industrially relevant chemical conversion. Although Cu-based catalysts show high reactivity toward oxidative ethanol dehydrogenation, the flat Cu(111) surface is rather inactive for ethanol dehydrogenation in the absence of water, surface oxygen or defects. Herein we show, using experimental and theoretical studies of model systems, that adding 1% Pt into the surface of Cu(111) to form dilute Pt–Cu single atom alloys (SAAs) increases the activity of Cu(111) for ethanol dehydrogenation sixfold. The mechanism of ethanol dehydrogenation was investigated at the molecular level using scanning tunneling microscopy, temperature programmed experiments and density functional theory calculations. Our results demonstrate that Pt–Cu SAAs are much more active than Cu(111) for converting ethanol to acetaldehyde and hydrogen in the absence of surface oxygen and water. Specifically, the O–H bond of ethanol is activated at Pt sites below 160 K, followed by ethoxy spillover to Cu sites which results in a significant increase of the ethoxy intermediate yield. The C–H bond of ethoxy is then activated at 310 K, and the final product, acetaldehyde, desorbs from Cu(111) in a reaction rate limited process. Finally, we show that the Cu model surfaces exhibit stability with respect to poisoning as well as 100% selectivity in the alcohol dehydrogenation to acetaldehyde and hydrogen.
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- 2017
31. Cloning, expression ofCrocus sativus phytoene desaturase gene and preparation of antiserum against it
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Jie, Bai, Chen, Miao, Ying, Xu, Lin, Tang, Zhi-tao, Wang, and Fang, Chen
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- 2004
- Full Text
- View/download PDF
32. Adsorption and Photodesorption of CO from Charged Point Defects on TiO2(110)
- Author
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Igor Lyubinetsky, Greg A. Kimmel, Zhi-Tao Wang, Zdenek Dohnálek, Arjun Dahal, Rentao Mu, and Nikolay G. Petrik
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Chemistry ,Scattering ,Diffusion ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Crystallographic defect ,0104 chemical sciences ,law.invention ,Adsorption ,Rutile ,law ,Desorption ,General Materials Science ,Irradiation ,Physical and Theoretical Chemistry ,Scanning tunneling microscope ,0210 nano-technology - Abstract
The adsorption and photochemistry of CO on rutile TiO2(110) are studied with scanning tunneling microscopy (STM), temperature-programmed desorption, and angle-resolved photon-stimulated desorption (PSD) at low temperatures. Site occupancies, when weighted by the concentration of each kind of adsorption site on the reduced surface, show that the adsorption probability is the highest for the bridging oxygen vacancies (VO). The probability distribution for the different adsorption sites corresponds to very small differences in CO adsorption energies (
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- 2017
33. Surface Structure Dependence of the Dry Dehydrogenation of Alcohols on Cu(111) and Cu(110)
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E. Charles H. Sykes, Zhi-Tao Wang, Yun-Fei Xu, Mostafa El-Soda, Robert J. Madix, Felicia R. Lucci, and Cynthia M. Friend
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chemistry.chemical_classification ,Hydrogen ,Inorganic chemistry ,Acetaldehyde ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Aldehyde ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Catalysis ,chemistry.chemical_compound ,General Energy ,chemistry ,Alkoxide ,Anhydrous ,Dehydrogenation ,Methanol ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
The non-oxidative dehydrogenation of alcohols is considered as an important method to produce aldehydes for the chemical industry and hydrogen gas. However, current industrial processes are oxidative, meaning that the aldehydes are formed along with water, which, in addition to being less energy efficient, poses separation problems. Herein the production of aldehydes from methanol and ethanol on clean and dry Cu(111) and Cu(110) surfaces was investigated in order to understand the catalytic anhydrous dehydrogenation of alcohols. Both ethanol and methanol preferentially react under ultrahigh vacuum conditions at surface defects to yield acetaldehyde and formaldehyde, respectively, in the absence of surface oxygen and water. The amount of alkoxide reaction intermediates measured by scanning tunneling microscopy, and aldehyde and hydrogen products detected by temperature programmed reaction, are increased by inducing more defects in the Cu substrates with Ar ion sputtering. This work also reveals that the Cu...
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- 2017
34. Experiment and Simulation of REBCO Conductor Coils for an HTS Linear Synchronous Motor
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Guangtong Ma, Weihua Zhang, Kun Liu, Zhang Han, Zhi-Tao Wang, Chen Yang, Li Xingtian, and Tianyong Gong
- Subjects
Superconductivity ,Materials science ,Stator ,Acoustics ,020208 electrical & electronic engineering ,Thrust ,02 engineering and technology ,Linear motor ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Conductor ,law.invention ,Magnetic field ,law ,Electromagnetic coil ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,010306 general physics ,Excitation - Abstract
A high temperature superconducting (HTS) linear synchronous motor that uses REBCO-coated conductor as the secondary excitation system was recently demonstrated. Four series-connected REBCO-coated conductor coils were fabricated via the epoxy impregnation technique and the critical current of each coil can be retained by a percent of over 75% at 77 K after winding. Meanwhile, a three-dimensional (3-D) finite-element model was established to describe the coated superconductor coils subject to the traveling magnetic fields of a conventional copper-based stator. The comparison between experiment and simulation in terms of thrust has verified the developed 3-D numerical model, allowing the complex studies of HTS linear motor prior to fabrication. Our preliminary testing has shown that, when the coated superconductor coils were placed over a three-phase stator, the transport dc current in the coated conductor coils will exhibit a significant variation, depending on its magnitude and the operating frequency of stator current as well as the electromagnetic gap.
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- 2017
35. Numerical Modeling and Transient Analysis of a Linear Induction Motor With Close-Ended Coated Superconductor Coils as Secondary
- Author
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Tianyong Gong, Guangtong Ma, Yuan-Yuan Xu, Li Xingtian, Weihua Zhang, Kun Liu, Chang-Qing Ye, Pengbo Zhou, Zhang Han, Zhi-Tao Wang, and Chen Yang
- Subjects
010302 applied physics ,Flux pumping ,Computer science ,Superconducting electric machine ,Stator ,Mechanical engineering ,Thrust ,Superconducting magnet ,Superconducting magnetic energy storage ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Linear induction motor ,0103 physical sciences ,Electrical and Electronic Engineering ,010306 general physics ,Induction motor - Abstract
We devised a linear induction motor (LIM) that uses the close-ended coated superconductor coils as the secondary to explore the potential solutions of enhancing the thrust performance at large clearance, which is generally required for the linear propulsion of transit systems. In this proposal, the coated superconductor coils are embedded into a ferromagnetic yoke whose function is to guide and concentrate the travelling fields generated by the three-phase conventional stator. To make a preliminary study before the laboratory demonstration, we built a numerical model of this proposal by resorting to the finite-element software of MagNet, a recognized professional tool to simulate the electrical machines in the scientific community. Through a treatment of the power law, the developed numerical model has included the nonlinear constitutive law of superconductor, which is currently thought to be difficult in the MagNet environment. This general treatment takes a step forward toward the use of the professional software to perform complex simulations of the superconducting machines. Based on the numerical model, we carried out a set of transient studies on the proposed LIM to observe the distributions of travelling flux, the starting characteristics, and the time evolutions of thrust and speed. The achieved results clearly display that the proposed LIM has advantages over the conventional type and could be thereby regarded as a candidate for developing high thrust linear LIM with large clearance.
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- 2017
36. Probing equilibrium of molecular and deprotonated water on TiO 2 (110)
- Author
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Yeohoon Yoon, Rentao Mu, Igor Lyubinetsky, Zdenek Dohnálek, Yang-Gang Wang, Gregory K. Schenter, Zhi Tao Wang, Roger Rousseau, Arjun Dahal, and Vassiliki Alexandra Glezakou
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Multidisciplinary ,Chemistry ,Protonation ,Nanotechnology ,02 engineering and technology ,Reaction intermediate ,021001 nanoscience & nanotechnology ,01 natural sciences ,Dissociation (chemistry) ,law.invention ,Deprotonation ,Chemical physics ,law ,0103 physical sciences ,Bound water ,Molecule ,Scanning tunneling microscope ,010306 general physics ,0210 nano-technology ,Molecular beam - Abstract
Understanding adsorbed water and its dissociation to surface hydroxyls on oxide surfaces is key to unraveling many physical and chemical processes, yet the barrier for its deprotonation has never been measured. In this study, we present direct evidence for water dissociation equilibrium on rutile-TiO2(110) by combining supersonic molecular beam, scanning tunneling microscopy (STM), and ab initio molecular dynamics. We measure the deprotonation/protonation barriers of 0.36 eV and find that molecularly bound water is preferred over the surface-bound hydroxyls by only 0.035 eV. We demonstrate that long-range electrostatic fields emanating from the oxide lead to steering and reorientation of the molecules approaching the surface, activating the O–H bonds and inducing deprotonation. The developed methodology for studying metastable reaction intermediates prepared with a high-energy molecular beam in the STM can be readily extended to other systems to clarify a wide range of important bond activation processes.
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- 2017
37. Hydrothermal synthesis and crystal structure of three-dimensional supramolecular zinc, manganese coordination polymers
- Author
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Xiu-Mei Li, Qianrong Fang, Ya-Ru Pan, Zhi-Tao Wang, Valentin Valtchev, Laboratoire de Matériaux à Porosité Contrôlée (LMPC), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Ecole Nationale Supérieure de Chimie de Mulhouse-Centre National de la Recherche Scientifique (CNRS), Laboratoire catalyse et spectrochimie (LCS), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)
- Subjects
chemistry.chemical_classification ,Supramolecular chemistry ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,Zinc ,Polymer ,Manganese ,Pyrazole ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Hydrothermal synthesis ,[CHIM]Chemical Sciences ,Physical and Theoretical Chemistry ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience; Hydrothermal Synthesis and Crystal Structure of Three-dimensional Supramolecular Zinc, Manganese Coordination Polymers Zhi-Tao Wang • Valentin Valtchev • Qian-Rong Fang • Xiu-Mei Li • Ya-Ru Pan Two new complexes [Zn 2 (pzdc)(L) 2 (H 2 O)] 2n •2nH 2 O (1) and [Mn(µ 2-O)(H 2 O) 2-(HL)] 2n •2nNIPH (2) (H 2 pzdc = pyrazine-2,3-dicarboxylic acid, HL = 3-(2-Pyridyl) pyrazole, H 2 NIPH = 5-nitroisophthalic acid) have been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, UV spectrum, TG, fluorescence spectrum and single-crystal X-ray diffraction. Complex 1 shows two-dimensional (2D) network, which was stabilized by O-H•••O, C-H•••O hydrogen bonding and π-π interactions and extended into 3D supramolecular architecture. Complex 2 is zero-dimensional structure, which was further extended into 3D supramolecular framework through N-H•••O, O-H•••O, C-H•••O hydrogen bonds and π-π interactions.
- Published
- 2019
38. [Case-control studies on modified anterolateral approach with modified postmedial approach for the treatment of trimalleolar fractures]
- Author
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Zhi-Tao, Wang, Jun-Feng, Zhan, Nan, Zhu, and You-Jia, Xu
- Subjects
Adult ,Fracture Healing ,Male ,Adolescent ,Middle Aged ,Ankle Fractures ,Supination ,Fracture Fixation, Internal ,Young Adult ,Treatment Outcome ,Case-Control Studies ,Humans ,Female ,Aged - Abstract
To compare clinical effect of modified anterolateral approach combined with modified posteromedial approach and conventional posterolateral approach combined with medial-aided in treating trimalleolar fractures.From January 2015 to August 2017, 108 patients with trimalleolar fractures were enrolled and randomly divided into modified approaches (experimental group) and conventional approaches(control group). There were 53 patients in experimental group including 31 males and 22 females aged from 18 to 67 years old with an average of(40.2±16.4) years old; 19 patients on the left side and 34 patients on the right side; 39 patients were supination external rotation and 14 patients were pronation-external rotation; preoperative waiting time ranged from 6 to 14 d with an average of(9.6±3.1) d; performed operation through modified anterolateral approach combined with modified posteromedial approach. There were 55 patients in control group, including 34 males and 21 females aged from 19 to 69 years old with an average of (42.1±15.3) years old; 18 patients on the left side and 37 patients on the right side; 42 patients were supination external rotation and 13 patients were pronation-external rotation; preoperative waiting time ranged from 7 to 16 d with an average of (10.3±3.4) d; performed operation through conventional posterolateral approach combined with medial-aided. Operation time, intraoperative blood loss, postoperative drainage volume, cases of incision complications and excellent-good reduction, fracture healing time, cases of nerve injury and muscular flexor contracture, cases of incision complications between two groups were compared; AOFAS score were used to evaluate clinical efficacy at 1 year after operation.All patients were followed up from 12 to 24 months with an average of (16.4 ±7.5) months. Operation time, intraoperative blood loss, postoperative drainage volume and incision complication in experimental group were (95.3±22.6) min, (114.7±68.7) ml, (127.5±87.8) ml and 1 case, respectively; while in control group were (112.5±53.8) min, (155.2±79.6) ml, (178.4±73.8) ml and 3 cases respectively; the data in experimental group were better than that of control group. In experimental group, 36 cases got excellent results, 14 good and 3 poor on the quality of reduction, while 30 patients got excellent results, 15 good and 10 poor in control group; the experimental group was better than control group. Fracture healing time in experimental group were(5.5±1.6) months, 2 patients occurred incision complications, while(6.7±2.1) months, 12 patients in control group; the experiment group were better than control group. Postoperative AOFAS score at 12 months in experimental group was 92.9±18.4, and better than control group 80.3±38.3; 32 patients got excellent results, 17 good, 3 moderate and 1 poor in experimental group; 25 patients got excellent results, 18 good, 8 moderate and 4 poor in control group; there was statistical difference between two groups.Both of modified anterolateral approach combined with modified posteromedial approach and conventional posterolateral approach combined with medial-aided in treating trimalleolar fractures could receive good clinical effect. While compared with conventional posterolateral approach combined with medial-aided, modified anterolateral approach combined with modified posteromedial approach is more fit for blood supply of local soft tissue, and has advantages of less trauma, safety operation and clearly exposure.
- Published
- 2019
39. Characterisation of thickness changes in the peripapillary retinal nerve fibre layer in patients with Leber's hereditary optic neuropathy.
- Author
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Dan Wang, Hong-Li Liu, Yang-Yang Du, Jiajia Yuan, Xin Li, Zhen Tian, Haiqiang Zhou, Shuang Wang, Lin Song, Jian Sun, Xiao Xiao, Zhi-Tao Wang, and Bin Li
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- 2021
- Full Text
- View/download PDF
40. Preparation, Structure, and Surface Chemistry of Ni–Au Single Atom Alloys
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Mostafa El-Soda, E. Charles H. Sykes, Andrew J. Therrien, Michail Stamatakis, Angelos Michaelides, Matthew T. Darby, and Zhi-Tao Wang
- Subjects
Alloy ,Nanotechnology ,02 engineering and technology ,Substrate (electronics) ,engineering.material ,010402 general chemistry ,01 natural sciences ,Catalysis ,law.invention ,Steam reforming ,law ,Physical and Theoretical Chemistry ,Deposition (law) ,Chemistry ,technology, industry, and agriculture ,equipment and supplies ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,Chemical engineering ,Physical vapor deposition ,engineering ,Density functional theory ,Scanning tunneling microscope ,0210 nano-technology - Abstract
Ni/Au is an alloy combination that while, immiscible in the bulk, exhibits a rich array of surface geometries that may offer improved catalytic properties. It has been demonstrated that the addition of small amounts of Au to Ni tempers its reactivity and reduces coking during the steam reforming of methane. Herein, we report the first successful preparation of dilute Ni–Au alloys (up to 0.04 ML) in which small amounts of Ni are deposited on, and alloyed into, Au(111) using physical vapor deposition. We find that the surface structure can be tuned during deposition via control of the substrate temperature. By adjusting the surface temperature in the 300–650 K range, we are able to produce first Ni islands, then mixtures of Ni islands and Ni–Au surface alloys, and finally, when above 550 K, predominantly island-free Ni–Au single atom alloys (SAAs). Low-temperature scanning tunneling microscopy (STM) combined with density functional theory calculations confirm that the Ni–Au SAAs formed at high temperature c...
- Published
- 2016
41. Cloaking the Static Magnetic Fields by Alternate Superconductor–Ferromagnet Heterostructure
- Author
-
Pengbo Zhou, Guangtong Ma, Tianyong Gong, Zhi-Tao Wang, Chang-Qing Ye, and Zhang Han
- Subjects
Physics ,Superconductivity ,Condensed matter physics ,Magnetic energy ,Magnetic domain ,Cloaking ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Magnetostatics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Paramagnetism ,0103 physical sciences ,Diamagnetism ,Electrical and Electronic Engineering ,010306 general physics ,0210 nano-technology - Published
- 2016
42. Transportation of Quasistatic Magnetic Fields by Superconductor-Ferromagnet Heterostructures
- Author
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Pengbo Zhou, Zhi-Tao Wang, Chen Yang, and Guangtong Ma
- Subjects
Materials science ,Electromagnet ,business.industry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Inductor ,01 natural sciences ,Current transformer ,Electronic, Optical and Magnetic Materials ,law.invention ,Magnetic circuit ,Nuclear magnetic resonance ,Magnetic core ,law ,Electromagnetic coil ,0103 physical sciences ,Optoelectronics ,010306 general physics ,0210 nano-technology ,business ,Transformer ,Magnetic reactance - Abstract
We have devised a magnetic circuit for improved transport of quasistatic magnetic fields from a transmitter to a receiver in order to increase the transfer efficiency of electromagnetic devices such as transformers. This novel structure is made by coating a superconductor-ferromagnet heterostructure on a traditionally used magnetic core. We tested the transfer efficiency of the proposed magnetic circuit in transporting ac current from the primary to the secondary coils, which could be regarded as a proof-of-principle demonstration of the current transformer. The measured and calculated results clearly show that the proposed current transformer could transport current to the secondary coil with much higher efficiency than a conventional naked magnetic core. Characterization of the current transformer shows a dependence of transfer efficiency on the amplitude and frequency of the primary current. The results could also be applied to enhance the efficiency of voltage transformers, which rely on the same principle as the current transformer.
- Published
- 2016
43. Origin of Coverage Dependence in Photoreactivity of Carboxylate on TiO2(110): Hindering by Charged Coadsorbed Hydroxyls
- Author
-
Igor Lyubinetsky, Michael A. Henderson, and Zhi-Tao Wang
- Subjects
Intermolecular force ,General Chemistry ,Electron ,Photochemistry ,Dissociative adsorption ,Catalysis ,Dissociation (chemistry) ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Carboxylate ,Scanning tunneling microscope ,Ultraviolet photoelectron spectroscopy - Abstract
The influence of reactant coverage on photochemical activity was explored using scanning tunneling microscopy (STM) and ultraviolet photoelectron spectroscopy (UPS). We observed diminished reactivity of carboxylate species (trimethyl acetate, TMA) on TiO2(110) as a function of increasing coverage. This effect was not linked to intermolecular interactions of TMA but to the accumulation of the coadsorbed bridging hydroxyls (HOb) deposited during (thermal) dissociative adsorption of the parent, trimethylacetic acid (TMAA). Confirmation of the hindering influence of HOb groups was obtained by the observation that HOb species originated from H2O dissociation at O-vacancy sites have a similar hindering effect on TMA photochemistry. Though HOb’s are photoinactive on TiO2(110) under ultrahigh vacuum conditions, UPS results show that these sites trap photoexcited electrons, which in turn likely (electrostatically) attract and neutralize photoexcited holes, thus suppressing the hole-mediated photoreactivity of TMA....
- Published
- 2015
44. Hysterosalpingo-contrast-sonography vs. magnetic resonance-hysterosalpingography for diagnosing fallopian tubal patency: A systematic review and meta-analysis
- Author
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Ling-Shan Chen, Xu-Yu Hu, Mei-Mei Zhang, Zheng-Qiu Zhu, Ye Qiang, Jing Li, Zhi-Tao Wang, and Zhongqiu Wang
- Subjects
Adult ,Cochrane Library ,Multimodal Imaging ,Sensitivity and Specificity ,Fallopian Tube Patency Tests ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Hysterosalpingography ,Laparoscopy ,Fallopian Tubes ,Ultrasonography ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,Ultrasound ,Reproducibility of Results ,General Medicine ,Magnetic Resonance Imaging ,Confidence interval ,ROC Curve ,030220 oncology & carcinogenesis ,Meta-analysis ,Diagnostic odds ratio ,Female ,business ,Nuclear medicine - Abstract
Purpose To compare hysterosalpingo-contrast-sonography (HyCoSy) and magnetic resonance-hysterosalpingography (MR-HSG) in the diagnosis of fallopian tubal patency. Materials and methods The databases of PubMed, Embase, and the Cochrane Library were searched for records up to November 30, 2019. Studies involved in the diagnostic detection of HyCoSy or MR-HSG for fallopian tubal patency using conventional HSG or laparoscopy as the reference test were included. Data was analyzed by meta-analysis. We compared sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (sROC) plots of both HyCoSy and MR-HSG. Quality was assessed using the QUADAS-2 tool. Results The analysis included 24 articles involving 1340 patients. HyCoSy was studied in 17 studies, and MR-HSG was studied in seven studies. For HyCoSy in diagnosis of fallopian tubal patency, pooled sensitivity was 89 % (95 % confidence interval [CI], 87 %–91 %), and specificity was 93 % (95 % CI, 91 %–94 %). For MR-HSG in diagnosis of fallopian tubal patency, pooled sensitivity was 100 % (95 % CI, 98 %–100 %), and specificity was 82 % (95 % CI, 74 %–89 %). The sROC showed similar diagnostic accuracy for MR-HSG and HyCoSy. 3D/4D HyCoSy with ultrasound microbubbles had equal sensitivity (95 % vs. 100 %, P = 0.186) and significantly higher specificity (94 % vs. 82 %, P = 0.005) compared with MR-HSG. Conclusions HyCoSy and MR-HSG showed similar overall diagnostic performance for diagnosing fallopian tubal patency. 3D/4D HyCoSy with ultrasound microbubbles could significantly improve the diagnostic specificity of HyCoSy.
- Published
- 2020
45. A Novel Partial Melting Process for YBa2Cu3O7−z Superconducting Films by Fluorine-Free Polymer-Assisted Metal Organic Deposition Approach
- Author
-
M.H. Pu, Zhi-Tao Wang, Yue Zhao, Wang Mingnian, Xu Zhang, Ming Lei, and W. T. Wang
- Subjects
chemistry.chemical_classification ,Materials science ,Partial melting ,Substrate (electronics) ,Polymer ,engineering.material ,Condensed Matter Physics ,Epitaxy ,Microstructure ,Electronic, Optical and Magnetic Materials ,Coating ,Chemical engineering ,chemistry ,engineering ,Texture (crystalline) ,Thin film - Abstract
High-performance YBa2Cu3O7−z (YBCO) super conducting films have been prepared on single-crystal substrate by fluorine-free polymer-assisted metal organic deposition (PA-MOD) method. The introduction of polymers into the precursor solution can make the coating solution more homogeneous and stable. And, the novel high temperature partial melting process can enhance the epitaxial growth of the precursor films. The influence of partial melting time on the texture, microstructure, and properties was thoroughly investigated. The results indicate YBCO film melting for 5 min has biaxial texture, smooth and dense microstructures, as well as high critical current density (77 K, 0 T) over 3 MA/cm2.
- Published
- 2015
46. Influence of metal cation concentration on structure and performance of SmBa2Cu3O7−z superconducting films by non-fluorine CSD method
- Author
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Ming Lei, Xu Zhang, Zhi-Tao Wang, Wang Mingnian, W. T. Wang, and Yue Zhao
- Subjects
Superconductivity ,Materials science ,Mechanical Engineering ,Analytical chemistry ,chemistry.chemical_element ,Nanotechnology ,Substrate (electronics) ,Condensed Matter Physics ,Microstructure ,Magnetic field ,Metal ,chemistry ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,Fluorine ,General Materials Science ,Texture (crystalline) ,Thin film - Abstract
SmBa2Cu3O7−z (SmBCO) films with different metal cation concentrations (MCCs) were prepared on (00l) LaAlO3 substrate by self-developed non-fluorine chemical solution deposition (CSD) method. The influence of MCC on structure and performance of SmBCO films was investigated. The film with MCC of 1.0 mol/L shows better c-axis texture and smoother as well as denser surface microstructure than other films. With increasing the MCC, the superconducting transition temperature (Tc) of the films has a peak value of 91.2 K at MCC of 1.0 mol/L. And the films with MCC of 0.8 mol/L and 1.0 mol/L show higher current carrying capabilities in the magnetic fields according to the Jc−H behaviors.
- Published
- 2015
47. Low-Temperature Reductive Coupling of Formaldehyde on Rutile TiO2(110)
- Author
-
Igor Lyubinetsky, Ke Zhu, Zhenrong Zhang, Kenneth Park, Yaobiao Xia, Miru Tang, Zdenek Dohnálek, Zhi-Tao Wang, and Qingfeng Ge
- Subjects
Ethylene ,Formaldehyde ,Photochemistry ,Coupling reaction ,Dissociation (chemistry) ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,General Energy ,chemistry ,law ,Desorption ,Molecule ,Physical and Theoretical Chemistry ,Scanning tunneling microscope ,Methylene - Abstract
The formation and coupling of methylene upon dissociation of formaldehyde on reduced TiO2(110) are studied using variable temperature scanning tunneling microscopy (STM). In agreement with prior studies, formaldehyde preferably adsorbs on the bridging-bonded oxygen vacancy (VO) defect site. VO-bound formaldehyde couples with Ti-bound formaldehyde forming a diolate species, which appears as the majority species on the surface at 300 K. Here, STM images directly visualize a low-temperature coupling reaction channel. Two VO-bound formaldehyde molecules can couple and form Ti-bound species, which desorbs above ∼215 K. This coupling reaction heals both VO sites indicating the formation and the desorption of ethylene. We also directly observed the diffusion of methylene groups to nearby empty VO sites upon dissociation of the C–O bond in VO-bound formaldehyde, which suggests that the ethylene formation occurs via coupling of the methylene groups. Statistical analysis shows that the sum of visible reaction produ...
- Published
- 2015
48. Tracking Site-Specific C–C Coupling of Formaldehyde Molecules on Rutile TiO2(110)
- Author
-
Igor Lyubinetsky, Qingfeng Ge, Ke Zhu, Kenneth Park, Bryan Jan, Zdenek Dohnálek, Yaobiao Xia, Zhi-Tao Wang, Zhenrong Zhang, and Miru Tang
- Subjects
Ethylene ,Chemistry ,Inorganic chemistry ,Formaldehyde ,chemistry.chemical_element ,Reaction intermediate ,Photochemistry ,Oxygen ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,General Energy ,law ,Rutile ,Vacancy defect ,Molecule ,Physical and Theoretical Chemistry ,Scanning tunneling microscope - Abstract
Direct imaging of site-specific reactions of individual molecules as a function of temperature has been a long-sought goal in molecular science. Here, we report the direct visualization of molecular coupling of formaldehyde on reduced rutile TiO2(110) surfaces as we track the same set of molecules using scanning tunneling microscopy (STM) when the temperature is increased from 75 to 170 K. Our previous study showed that formaldehyde preferably adsorbs at bridging-bonded oxygen (Ob) vacancy (VO) defect site. Herein, images from the same area as the temperature is increased show that VO-bound formaldehyde couples with Ti-bound formaldehyde forming a diolate intermediate. Consequently, exposure of formaldehyde at room temperature leads to diolate as the majority species on the surface, and no VO-bound formaldehyde is observed. The diolate species are the key reaction intermediates in the formation of ethylene reported in previous ensemble-averaged studies.
- Published
- 2015
49. Imaging of Formaldehyde Adsorption and Diffusion on TiO2(110)
- Author
-
Zhu Ke, Yaobiao Xia, Miru Tang, Kenneth Park, Qingfeng Ge, Zdenek Dohnálek, Zhenrong Zhang, Zhi-Tao Wang, and Igor Lyubinetsky
- Subjects
Chemistry ,Diffusion ,Analytical chemistry ,Formaldehyde ,Charge density ,General Chemistry ,Catalysis ,law.invention ,chemistry.chemical_compound ,Adsorption ,law ,Vacancy defect ,Molecule ,Density functional theory ,Scanning tunneling microscope - Abstract
Surface reactions of formaldehyde with reduced TiO2(110) surfaces have been studied using variable-temperature scanning tunneling microscopy (STM) and density functional theory (DFT). STM images taken from a same area at various temperatures clearly show that formaldehyde preferentially adsorbs on the bridge-bonded oxygen (Ob) vacancy (VO) defect sites. Bias-dependent STM images show that the STM features corresponding to both the Ti-bound CH2O and the VO-bound CH2O are positioned between the Ob row and the Ti row. While the VO-bound formaldehyde rotates at 95 K, the Ti-bound CH2O does not. The VO-bound CH2O starts to diffuse along the Ob row as –CH2– at ~170 K and starts to diffuse along the Ti row as an intact molecule at ~215 K. However, the stabilities and the configurations of the Ti-bound and VO-bound formaldehyde calculated using DFT are not in line with the experimental results. The discrepancy between the experiment and theory indicates the presence of a complex charge distribution related to the surface defects.
- Published
- 2014
50. Compressor Performance Curve Extrapolation Method Based on the Similarity Theory
- Author
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Zhi Tao Wang, Shu Ying Li, Meng Qi Wang, Bing Bai, and Qing Cai Yang
- Subjects
Gas turbines ,Low speed ,Simple (abstract algebra) ,Compressibility ,Extrapolation ,Process (computing) ,Applied mathematics ,General Medicine ,Gas compressor ,Algorithm ,Similarity theory ,Mathematics - Abstract
Due to the fact that the low speed pump similarity theory is only applicable to incompressible fluid, this theory cannot be used for extrapolation of compressor performance curve. Considering the compressibility of working medium; therefore, this paper has modified the similarity theory and put forward a new index relationship equation. The two low speed performance lines which are already known were used to get the similar working points and extrapolate the performance lines through the optimization method. Compared with the existing performance lines, the results show that the method is simple, convenient and qualified with practicability and accuracy. This method plays an important role on studying startup process of a gas turbine and improving the accuracy of the simulation of startup process.
- Published
- 2014
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