74 results on '"Zheng, Jiaqi"'
Search Results
2. Amendments affect the community assembly and co-occurrence network of microorganisms in Cd and Pb tailings of the Eucalyptus camaldulensis rhizosphere
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Yang, Jiaqi, Ouyang, Linnan, Chen, Shaoxiong, Zhang, Cheng, Zheng, Jiaqi, and He, Shae
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- 2024
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3. The development history, current state, challenges, and future directions of the BASIC-OHCA registry in China: A narrative review
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Zheng, Wen, Zheng, Jiaqi, Wang, Chunyi, Pan, Chang, Zhang, Jianbo, Liu, Rugang, Bian, Yuan, Ma, Jingjing, Cheng, Kai, Xu, Feng, and Chen, Yuguo
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- 2024
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4. An optimized non-T cell transfection system based on HEK293FT cells for CD3ζ phosphorylation and ubiquitination
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Zheng, Jiaqi, Zhang, Yuchuan, Cai, Yiting, Han, Wei, and Chen, Wei
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- 2024
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5. Uric acid levels and heart failure: A mendelian randomization study
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Zheng, Jiaqi, Cen, Kaiwen, Zhang, Jiajun, Zhang, Huan, Zhao, Mingguang, and Hou, Xiaowen
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- 2024
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6. Wormwood-infused porous-CaCO3 for synthesizing antibacterial natural rubber latex
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Chen, Xi, Zheng, JiaQi, You, LinXin, Qiu, Tian, Christoforo, Tyler, and Wei, Yen
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- 2024
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7. Rapid fabrication of porous metakaolin-based geopolymer via microwave foaming
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Zheng, Jiaqi, Li, Xinyu, Bai, Chengying, Zheng, Kankan, Wang, Xiaodong, Sun, Gaohui, Zheng, Ting, Zhang, Xiaohong, and Colombo, Paolo
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- 2024
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8. Coupling Ru single-atom and oxygen vacancy in Ru/SnO2−x for efficient nitrogen reduction to ammonia via electronic synergistic effect
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Zheng, Jiaqi, Yu, Kaiqiang, Yuan, Shisheng, Xiang, Lijuan, Wang, Kaiwen, Jing, Shubo, and Li, Nan
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- 2023
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9. Fine and coarse particulate air pollution and out-of-hospital cardiac arrest onset: a nationwide case-crossover study in China
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Pan, Chang, Xu, Chang, Zheng, Jiaqi, Song, Ruixue, Lv, Chuanzhu, Zhang, Guoqiang, Tan, Huiqiong, Ma, Yu, Zhu, Yimin, Han, Xiaotong, Li, Chaoqian, Yan, Shengtao, Zheng, Wen, Wang, Chunyi, Zhang, Jianbo, Bian, Yuan, Ma, Jingjing, Cheng, Kai, Liu, Rugang, Hou, Yaping, Chen, Qiran, Zhao, Xiangkai, McNally, Bryan, Chen, Renjie, Kan, Haidong, Meng, Xia, Chen, Yuguo, and Xu, Feng
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- 2023
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10. Ultrasound-driven electrical stimulation based on 3D hierarchical porous piezoelectric nanofiber-aerogel scaffold promotes bone defect repair
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Chen, Zhengrong, Zheng, Jiaqi, Pei, Xiaomin, Sun, Shuang, Cai, Jinhong, Liu, Yang, Wang, Yunming, Zheng, Li, and Zhou, Huamin
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- 2023
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11. Synergizing lattice strain and electron transfer in TMSs@ 1 T-MoS2 in-plane heterostructures for efficient hydrogen evolution reaction
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Wang, Kaiwen, Yu, Kaifeng, Xu, Shaonan, Yuan, Shisheng, Xiang, Lijuan, Pang, Bingxue, Zheng, Jiaqi, and Li, Nan
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- 2023
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12. Optimizing incremental SDN upgrades for load balancing in ISP networks
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Cheng, Yunlong, Zhou, Hao, Gao, Xiaofeng, Zheng, Jiaqi, and Chen, Guihai
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- 2023
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13. High-strength and recyclable pure chitosan films manufactured by an ionic liquid assisted roll-forming method
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Sun, Shuang, Zheng, Jiaqi, Liu, Zijie, Huang, Siluo, Cheng, Qikuan, Fu, Yue, Cai, Weihao, Chen, Dan, Wang, Dong, Zhou, Huamin, and Wang, Yunming
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- 2023
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14. Ultrasound improves the thermal stability and binding capacity of ovomucin by promoting the dissociation of insoluble ovomucin aggregates
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Zheng, Jiaqi, Cheng, Yujia, Bao, Miaomiao, Li, Zhirong, Lü, Xin, and Shan, Yuanyuan
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- 2023
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15. Activating molybdenum carbide via a surface sulfur modification to enhance hydrogen evolution activity
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Yuan, Shisheng, Liu, Yuhua, Zheng, Jiaqi, Cui, Mengyang, Wang, Kaiwen, and Li, Nan
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- 2023
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16. Packet-in request redirection: A load-balancing mechanism for minimizing control plane response time in SDNs
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Xia, Rui, Dai, Haipeng, Zheng, Jiaqi, Xu, Hong, Li, Meng, and Chen, Guihai
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- 2022
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17. BaTiO3/PVDF-TrFE skeleton separators with superior ion conductivity and mechanical property integrated for flexible seconds self-charging supercapacitors
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Zheng, Jiaqi, Wang, Yunming, Liu, Guang, Yu, Zhaohan, Sun, Shuang, Fu, Yue, Chen, Dan, Cai, Weihao, Cui, Jingqiang, Wang, Guosheng, and Zhou, Huamin
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- 2022
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18. Particle erosion under multiphase bubble flow in horizontal-vertical-upward elbows
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Chen, Ping, Cui, Bochao, Li, Jianchao, Zheng, Jiaqi, and Zhao, Yuanqi
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- 2022
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19. Prevalence and risk factors associated with circadian syndrome in community-dwelling middle-aged to older adults: Based on health ecology model.
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Liang, Haixu, Zheng, Jiaqi, and Sun, Yongkang
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MIDDLE-aged persons , *ENVIRONMENTAL health , *OLDER people , *BASIC income , *SOCIAL isolation - Abstract
To explore the prevalence and risk factors associated with circadian syndrome (CricS) in community-dwelling middle-aged to older adults. We performed a cross-sectional analysis of 13,516 participants from the China Health and Retirement Longitudinal Study (CHARLS). We used logistic regression to compute the odds ratios (OR) and 95 % confidence intervals (Cls), using covariates derived through the health ecology model. The overall prevalence of CricS was 31.5 % (25.0 % males and 37.1 % females). With controlling all covariates, social isolation (OR 1.164, 95%CI 1.033–1.310), irritable mood (OR 1.689, 95%CI 1.488–1.917), fear responses (OR 1.546, 95%CI 1.262–1.894), chronic disease (OR 1.577, 95%CI 1.392–1.788), and financial debt (OR 0.806, 95%CI 0.657–0.990) were significantly correlated with increased CricS risk in males, whereas CricS syndrome was significantly associated with age (OR 1.285, 95%CI 1.214–1.361), married (OR 1.258, 95%CI 1.089–1.452), current drinkers (OR 0.835, 95%CI 0.716–0.974), social isolation (OR 1.175, 95%CI 1.065–1.296), irritable mood (OR 1.346, 95%CI 1.210–1.497), fear responses (OR 1.202, 95%CI 1.047–1.378), chronic disease (OR 1.363, 95%CI 1.225–1.517), chronic pain (OR 1.177, 95%CI 1.058–1.309), and universal basic income (OR 0.742, 95%CI 0.611–0.900) in females. CricS is common in middle-aged to older adults, and health behavior factors have an important impact on CricS. The potential predictors identified for CricS should be further studied to prevent the occurrence of adverse health events in the presenium stage. • Circadian syndrome is a major health problem around the world. • The prevalence of circadian syndrome in the present study was 31.5 %. • Circadian syndrome risk factors are multi-level, multi-dimensiona. [ABSTRACT FROM AUTHOR]
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- 2024
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20. How stakeholders influence MaaS implementation? An analysis based on evolutionary game theory.
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Ye, Jianhong and Zheng, Jiaqi
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GAME theory , *BUSINESS models , *SUBSIDIES , *EVOLUTIONARY models - Abstract
Mobility as a service (MaaS) is an emerging mobility service that has received high expectations from the transportation sector in recent years. MaaS integrates multiple transportation services into a single platform, enhancing the accessibility of various transportation resources. However, the complex integration involved in MaaS leads to uncertainty in stakeholder interaction and system implementation. For the successful deployment and development of MaaS, this study aims to identify stakeholder enablers and barriers as well as to solve the uncertainty in MaaS implementation. We construct a tripartite evolutionary game model among government, transportation service providers (TSPs) and travelers. By synthesizing the evolutionary stability of each participant through simulation, we explored the impact of factors on stakeholder strategy choices and further analyzed the stability of equilibrium points in the system. The results show that: 1) Government subsidies and penalties, TSPs' costs and revenues, travelers' utility and expenses all impact the strategy choices of stakeholders. 2) The costs of government policy-making and TSPs will influence the evolution of MaaS system into two different development modes: free-market model and policy-supported model. 3) Travelers' utilities play a crucial role in promoting the stability of travelers' adoption of MaaS. This study provides new insights into identifying stakeholder demands. The findings contribute to formulating specific policy recommendations and incentive measurements to help in the strengthen and forward movement of MaaS development in the future. • Employed tripartite evolutionary game theory to explore MaaS stakeholder interactions. • Identified the key factors influencing stakeholders' decisions. • Integrated analysis of model outcomes with business models for comprehensive evaluation. • Simulation analysis was conducted to verify the validity of the results. [ABSTRACT FROM AUTHOR]
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- 2024
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21. DC-ECN: A machine-learning based dynamic threshold control scheme for ECN marking in DCN
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Majidi, Akbar, Jahanbakhsh, Nazila, Gao, Xiaofeng, Zheng, Jiaqi, and Chen, Guihai
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- 2020
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22. Ultrasonic-assisted citrus pectin modification in the bicarbonate-activated hydrogen peroxide system: Chemical and microstructural analysis
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Hu, Weiwei, Chen, Shiguo, Wu, Dongmei, Zheng, Jiaqi, and Ye, Xingqian
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- 2019
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23. Rapid fabrication of coal gangue-based alkali activated foams and application as pH regulators
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Li, Xinyu, Zheng, Jiaqi, Zheng, Kankan, Su, Feiyan, Zhao, Zhenquan, Bai, Chengying, Zheng, Ting, Wang, Xiaodong, Qiao, Yingjie, and Colombo, Paolo
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- 2023
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24. What drives the change of nitrogen and phosphorus loads in the Yellow River Basin during 2006-2017?
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Zheng, Jiaqi, Cao, Xianghui, Ma, Chunzi, Weng, Nanyan, and Huo, Shouliang
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WATERSHEDS , *SPATIO-temporal variation , *ENVIRONMENTAL security , *NITROGEN , *PHOSPHORUS , *PHOSPHORUS in water - Abstract
• RSPARROW was optimized by combing climatic factors and various emission sources. • Spatio-temporal trends of TN and TP loads were analyzed in the YRB on a long-time scale. • Precipitation and point source are key drivers of trends in inter-annual TN load. • Point source is the driving forces in inter-annual variation of TP load in the whole basin. The Yellow River Basin (YRB) plays a very important role in China's economic and social development and ecological security. In particular, the ecosystem of the YRB is sensitive to climate change. However, the change of nutrient fluxes in this region during the past years and its main driving forces remain unclear. In this study, a hydrologic model R System for Spatially Referenced Regressions on Watershed Attributes (RSPARROW) was employed to simulate the spatio-temporal variations in the fluxes of total nitrogen (TN) and total phosphorus (TP) during the period of 2006-2017. The results suggested that the TN and TP loads increased by 138% and 38% during 2006-2014, respectively, and decreased by 66% and 71% from 2015 to 2017, respectively. During the period of 2006-2017, the annual mean fluxes of TN and TP in the YRB were in the range of 3.9 to 591.6 kg/km2/year and 1.7 to 12.0 kg/km2/year, respectively. TN flux was low in the upstream area of the Yellow River, and presented a high level in the middle and lower reaches. However, the flux of TP in Gansu and Ningxia section was slightly higher than that in the lower reaches of the Yellow River. Precipitation and point source are the key drivers for the inter-annual changes of TN loads in most regions of the YRB. While the inter-annual variations of TP loads in the whole basin are mainly driven by the point source. This study demonstrates the important impacts of climate change on nutrient loads in the YRB. Moreover, management measures should be taken to reduce pollution sources and thus provide solid basis for control of nitrogen and phosphorus in the YRB. [Display omitted]. [ABSTRACT FROM AUTHOR]
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- 2023
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25. Prevalence and related factors of do-not-resuscitate orders among in-hospital cardiac arrest patients.
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Jiang, Tangxing, Ma, Yanyan, Zheng, Jiaqi, Wang, Chunyi, Cheng, Kai, Li, Chuanbao, Xu, Feng, and Chen, Yuguo
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• In mainland China, the DNR rate among IHCA patients is low. • Female, older age, being a local resident, pulmonary infection, respiratory insufficiency, state of shock, acute stroke, neurological dysfunction and cancer were independently associated with a higher DNR rate. • Patients with new-onset coronary artery disease were less likely to create DNR orders. Studies concerning do-not-resuscitate (DNR) orders in mainland China are rather scarce. We explored the prevalence and related factors of DNR orders among in-hospital cardiac arrest (IHCA) patients at a general tertiary hospital in mainland China. We identified all IHCA patients hospital-wide between July 2019 and September 2020. Data regarding DNR status were collected from medical records. We investigated the frequency of DNR orders and explored the determinant factors of DNR establishment using logistic regression. A total of 1154 IHCA patients were included, 535 (46.4%) of whom established DNR orders. The following variables were independently associated with a higher DNR rate: female (OR 1.491; 95% CI 1.130–1.965), older age (OR 1.016; 95% CI 1.008–1.024), being a local resident (OR 1.790; 95% CI 1.344–2.383), pulmonary infection (OR 1.398; 95% CI 1052–1.859), respiratory insufficiency (OR 1.356; 95% CI 1.009–1.823), shock (OR 1.735; 95% CI 1.301–2.313), acute stroke (OR 1.821; 95% CI 1.235–2.686),neurological dysfunction (OR 1.527; 95% CI 1.149–2.028) and cancer (OR 3.316; 95% CI 2.461–4.468). Counterintuitively, patients with new-onset coronary artery disease (OR 0.592; 95% CI 0.419–0.837) were less likely to create DNR orders. In mainland China, the DNR order signing rate is low, and the establishment of a DNR order is associated with demographics and comorbidity characteristics. [ABSTRACT FROM AUTHOR]
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- 2022
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26. Review: Phytate modification serves as a novel adsorption strategy for the removal of heavy metal pollution in aqueous environments.
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Xue, Xiaoliang, Han, Yuzhu, Wu, Xinming, Wang, Hongji, Wang, Shuang, Zheng, Jiaqi, Ran, Rong, and Zhang, Chaowen
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HEAVY metal toxicology ,PHYTIC acid ,HEAVY metals removal (Sewage purification) ,PROCESS capability ,ADSORPTION (Chemistry) ,BIOCHAR - Abstract
With the intensification of industrial and agricultural wastewater pollution, biotoxin heavy metals remain in the natural hydrosphere, posing a great threat to the ecological environment. In the ten methods for heavy metal removal in aqueous environments discussed in this paper, the adsorption method demonstrates greater flexibility and superior cost and environmental benefits. Phytate, with its abundant phosphate groups and good conductivity, is widely used in the modification process of various adsorbents. The report in this study shows that phytate-modified adsorbents generally improve the adsorption of heavy metals, such as the adsorption rate of cadmium and copper on nanofiltration membranes reaching nearly 100%, the adsorption capacity of magnetic particles increasing by 11.480 times, and even up to 17.233 times for biochar. In addition, a large number of adsorbents modified with phytate can maintain good adsorption performance after 2–5 cycles and are easy to regenerate. In this paper, we compare a wide range of remediation techniques for heavy metal pollution and the advantages and disadvantages of adsorbents, and analyze the structure and adsorption mechanism of phytate. The synthetic process and adsorption capability of the composite products regarding the application of phytate modification are highlighted. This paper focuses on several effective adsorbents for phytate modification, reflecting the benefits and potentials of phytate as a modifier, with the goal of enhancing the adsorption performance of raw materials and remediating heavy metal pollution in water environments. [Display omitted] • Comparison of performance between phytate and commonly used adsorbents. • Elaboration on the adsorption mechanism and influencing factors of phytate. • The adsorption performance of typical phytate modified composite agents was compared. • Existing problems and development directions of phytate modification are analyzed. • Phytate modification has the feasibility of controlling heavy metal pollution in water environments. [ABSTRACT FROM AUTHOR]
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- 2023
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27. A Study on the Evaluation of a Risk Score of Osteonecrosis of the Femoral Head Based on Survival Analysis.
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Zheng, Jiaqi, Wang, Huan, Gao, Youshui, and Ai, Zisheng
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Background: This study aimed at developing a risk score predicting the probability of developing an osteonecrosis of the femoral head (ONFH) in patients with femoral neck fracture within 3 years after closed reduction internal fixation and evaluating its performance, clinical utility, and internal validity.Methods: A retrospective follow-up study of 378 newly injured femoral neck fracture patients treated with 3 partially threaded parallel cannulated screws in 3 hospitals in Shanghai from March 2013 to January 2017 was performed. The patients were divided into development (n = 284) and validation (n = 94) cohorts. The risk score was constructed by Cox regression analysis in a form of nomogram. The performance and clinical utility were illustrated by box plots, calibration plots, and decision curve analysis.Results: Eighty-three of 378 patients had developed ONFH within 3 years. Garden alignment index, time to surgery, preoperative displace, impaction, and postoperative malposition were used as predictors to construct the risk score in a form of nomogram. In the development and validation cohort, the concordance index was 0.96 and 0.94, respectively; the discrimination slope was 0.51 and 0.47, respectively. In both cohorts, the calibration slopes and intercepts were 1 and 0, respectively. The risk score was clinically useful between the risk threshold of 0% and 88%. The performance and utility in the validation data illustrated good repeatability.Conclusion: The risk score had satisfactory discrimination and calibration performance and demonstrated clinical utility with good internal validity. It managed to distinguish high-risk groups for post-traumatic ONFH. [ABSTRACT FROM AUTHOR]- Published
- 2021
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28. A shape-adaptable and highly resilient aerogel assembled by poly(vinylidene fluoride) nanofibers for self-powered sensing.
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Sun, Shuang, Cheng, Qikuan, Chen, Zhengrong, Zheng, Jiaqi, Liu, Rong, Liu, Zijie, Wang, Yunming, and Zheng, Li
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Flexible piezoelectric nanogenerators with high power output and superior mechanical stability that can respond to tiny human movements are essential for the development of portable power sources and smart sensors. Herein, a poly(vinylidene fluoride) (PVDF) nanofiber aerogel with a bionic cytoplasmic matrix structure and controllable super-elasticity is constructed by wet electrospinning for self-powered sensing. The PVDF-based aerogel exhibits remarkable elastic resilience with a high compressive stress of 2 MPa at 50% strain. The three-dimensional porous structure and high specific surface area endow the aerogel excellent electrical properties. The corresponding PVPU-NG device has an optimum output of 156 V and 34.9 μA with a power density of 5.5 W m
−2 , which can illuminate 50 light-emitting diodes. In addition, this PVPU-NG can respond to tiny human movements and convert mechanical energy into electrical energy to power miniature electronics. Specifically, the PVPU-NG can generate peak-to-peak voltages of approximately 1.8 V and 31 V during elbow bending and walking, respectively. As a result, the PVDF-based nanofiber aerogel, which exhibits high compressive strength and improved pressure sensitivity, demonstrates broad application prospects in wearable electronics and portable power sources. [Display omitted] • The three-dimensional nanofiber structure is achieved by the wet-electrospinning. • The aerogel shows controllable elastic resilience with a strength of 2 MPa. • The optimal electrical output is 156 V, 34.9 μA and a power density of 5.5 W m-2 . • The PTNG can respond to tiny human movements. [ABSTRACT FROM AUTHOR]- Published
- 2023
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29. Fabrication of rhamnogalacturonan-I enriched pectin-based emulsion gels for protection and sustained release of curcumin.
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Zhang, Laiming, Zheng, Jiaqi, Wang, Yi, Ye, Xingqian, Chen, Shiguo, Pan, Haibo, and Chen, Jianle
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CURCUMIN , *EMULSIONS , *PECTINS , *SYNERESIS , *GELATION , *EDIBLE fats & oils , *BIOAVAILABILITY - Abstract
Rhamnogalacturonan-I (RG-I) was considered to be incompatible with gel formation. Due to its important health benefits, our previous study reported synergistic gelation of RG-I enriched pectin from citrus membranes with sequential acidic and alkaline treatment. In the present study, we further fabricated RG-I enriched pectin-based emulsion gels with the synergistic gelation for hydrophobic bioactive encapsulation. The effect of oil fraction and interfacial compositions including pectin itself and Tween 20 on the physical properties and delivery characteristics of emulsion gels was investigated. As to interfacial compositions, pectin reduced syneresis and swelling ratio and increased water holding capacity. Oil fraction had no marked influence on syneresis and swelling ratio, but significantly increased water holding capacity. Particularly, all the emulsion gels showed an elastic behavior and a full structure recovery after shearing. Increase in pectin instead of Tween 20 onto the surface of oil droplets and oil fraction markedly improved their gel strength. Curcumin was encapsulated within the oil phase of emulsion gels. Improvement in gel strength provided enhanced protection of curcumin against heat-induced degradation. In vitro digestion revealed that interfacial compositions decelerated curcumin release by increasing the proportion of pectin onto the surface, but didn't change its bioaccessibility eventually. Increase in oil fraction accelerated curcumin release, but reduced its bioaccessibility. Overall, fabrication of RG-I enriched pectin-based emulsion gel with pectin itself as interfacial composition and low oil fraction would contribute to improving curcumin bioavailability for its sustained release, which should be further validated in vivo. [Display omitted] • Rhamnogalacturonan-I enriched pectin-based emulsion gels were fabricated. • Interfacial compositions influenced strength of the emulsion gels. • Increase in oil fraction improved strength of the emulsion gels. • Curcumin was encapsulated within oil phase of the emulsion gels. • Protection and sustained release of curcumin were achieved. [ABSTRACT FROM AUTHOR]
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- 2022
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30. Integrated piezo-tribo hybrid acoustic-driven nanogenerator based on porous MWCNTs/PVDF-TrFE aerogel bulk with embedded PDMS tympanum structure for broadband sound energy harvesting.
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Yu, Zhaohan, Zhang, Yongkang, Wang, Yunming, Zheng, Jiaqi, Fu, Yue, Chen, Dan, Wang, Guosheng, Cui, Jingqiang, Yu, Shengrui, Zheng, Li, Zhou, Huamin, and Li, Dequn
- Abstract
In this work, a novel type of acoustic-driven nanogenerator (ANG) that integrates piezoelectric and triboelectric effects is reported for broadband sound energy harvesting. With an internal structure combining beam-like porous multi-walled carbon nanotubes/polyvinylidene fluoride-trifluoroethylene (MWCNTs/PVDF-TrFE) aerogel and polydimethylsiloxane (PDMS) tympanum, the integrated MWCNTs/PVDF-TrFE/PDMS (MCPP) ANG achieves efficient collection of acoustic energy through the enhanced vibration and friction generated internally. Besides, by eliminating the need for a contact separation structure or an external resonator cavity, this design greatly simplifies the structure and contributes to the flexibility and durability of the device. The MCPP ANG, with 20 wt% sodium carboxymethyl cellulose (SCMC), 2 wt% MWCNTs and 5% w/v PDMS, reaches an optimal output of 34.4 V and 1.74 μA under 150 Hz and 115 dB sound stimulation, corresponding to an areal power density of 11.62 mW/m
2 . It possesses a broad working bandwidth from 110 Hz to 400 Hz, and can directly illuminate 7 light-emitting diodes (LEDs) in series. Employing a novel, simple and effective structural design, the ANG proposed here achieves flexible and stable acoustic collection, offering a promising path toward sound spectrum analysis, noise detection and power supply for various low-power sensors. A novel type of piezo-tribo hybrid acoustic-driven nanogenerator (ANG), with an internal structure combining beam-like porous MWCNTs/PVDF-TrFE aerogel and PDMS tympanum, is proposed for broadband sound energy harvesting. The ANG possesses a broad working bandwidth from 110 Hz to 400 Hz, and can directly illuminate 7 LEDs in series. [Display omitted] • A piezo-tribo MCPP ANG based on porous aerogel bulk is proposed for sound capture. • PDMS valve simplifies the structure and contributes to flexibility and durability. • An appropriate amount of MWCNTs is doped to improve the charge transfer efficiency. • The MCPP ANG possesses a broad working bandwidth from 110 Hz to 400 Hz. • A self-powered acoustic sensor with music recognition capabilities is demonstrated. [ABSTRACT FROM AUTHOR]- Published
- 2022
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31. Flexible self-charging lithium battery for storing low-frequency mechanical energy.
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Yu, Shengrui, Ling, Yan, Sun, Shuang, Wang, Yunming, Yu, Zhaohan, Zheng, Jiaqi, Liu, Guang, Chen, Dan, Fu, Yue, Liu, Yang, and Zhou, Huamin
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Flexible self-charging power source, with admirable capability to harvest/store the energy generated by human motion, is considered as the most suitable power supply for next generation of wearable electronic devices. Herein, we demonstrated a flexible self-charging lithium battery for storing low-frequency tiny motion energy. The electrospinning polyvinylidene fluoride-trifluoro ethylene (P(VDF-TrFE)) porous membranes was adopted as a piezoelectric separator and a supporting layer of the electrode to fabricate a novel flexible self-charging power cell (SCPC). The flexible SCPC could be effectively charged by directly collecting movement energy through mechanical deformation. The SCPC sealed in flexible case could be charged via periodic tapping (6 N, 1 Hz), indicating a storage capacity of 0.092 μA h in 330 s. Compared with traditional self-charging batteries, the flexible SCPC can work effectively at lower frequency and pressure, and collect the tiny motion energy of human body to power wearable electronic devices. This work may provide an innovative way to develop new self-charging wearable electronic devices. A flexible self-charging lithium battery for storing low-frequency tiny movement energy has been realized basing on electrospinning P(VDF-TrFE) nanofiber film. And the self-charging battery can work effectively at lower frequencies and pressures (6 N 1 Hz), showing a storage capacity of 0.092 μA h within 330 s [Display omitted] • The flexibility is attributed to the integrated structure of electrode and separator. • Unique hierarchical porous structure facilitates to collect tiny movement energy. • The storage capacity reached 0.092 μA h within 330 s by compression deformation. [ABSTRACT FROM AUTHOR]
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- 2022
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32. Metallothionein-1 gene from Exopalaemon carinicauda and its response to heavy metal ions challenge.
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Liu, Yujie, Wu, Zixuan, Guo, Kun, Zhou, Yongzhao, Xing, Kefan, Zheng, Jiaqi, Sun, Yuying, and Zhang, Jiquan
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HEAVY metals ,METAL ions ,AMINO acid sequence ,GENES ,AMINO acids - Abstract
Metallothioneins (MTs) belong to a conserved low-molecular-weight protein family that participates in heavy metal binding and detoxification. EcMT-1 was amplified by PCR from genomic DNA of Exopalaenon carinicauda. It contained a 180 bp open reading frame and encoded 59 amino acids. A total of 18 cysteine (Cys) residues were found in the deduced amino acid sequence, which was consistent with the Cys-rich characteristics of MTs. EcMT-1 was mainly expressed in hepatopancreas, followed by stomach and gill. The expression profiles of EcMT-1 indicated that EcMT-1 was significantly increased at 24, 48 h and 12, 24, and 48 h under the treatment of 2.5 μmol/L CdCl 2 and 50 μmol/L CuSO 4. The expression of EcMT-1 at gastrula stage was very low; it was detectable until nauplius stage, and the highest expression level appeared in the postlarvae stage. [Display omitted] • EcMT-1 gene was obtained from E. carinicauda. • EcMT-1 was predominantly expressed in hepatopancreas of E. carinicauda. • EcMT-1 was up-regulated after challenge with CdCl 2 or CuSO 4. • EcMT-1 was detectable at nauplius stage. [ABSTRACT FROM AUTHOR]
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- 2022
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33. Seasonal variability in multimedia transport and fate of benzo[a]pyrene (BaP) affected by climatic factors.
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Cao, Xianghui, Huo, Shouliang, Zhang, Hanxiao, Ma, Chunzi, Zheng, Jiaqi, Wu, Fengchang, and Song, Shuai
- Subjects
SEASONS ,CLIMATE change ,PYRENE ,WIND speed ,LOW temperatures - Abstract
The impact of meteorological factors on the transport behavior and distribution of volatile and semi-volatile organic pollutants has become an area of increasing concern. Here, we analyzed seasonal variation in climatic variables including wind, temperature, and precipitation to quantitatively assess the impact of these factors on the multimedia transport and fate of BaP in the continental region of China using a Berkeley-Trent (BETR) model. The advective rates of air exhibited an increasing trend of autumn (1.830 mol/h) < summer (1.975 mol/h) < winter (2.053 mol/h) < spring (2.405 mol/h) in association with increasing wind speed, indicating that lower atmospheric BaP concentrations are present in regions with high wind speeds and advective rates. The air-soil transport rates (0.08–45.55 mol/h) in winter were higher than in summer (0.07–32.41 mol/h), while low winter temperatures accelerate BaP accumulation in terrestrial ecosystems due to cold deposition. Cold deposition effects were more evident in northern regions than in southern regions. Further, increasing precipitation enhanced air-soil and soil-freshwater transport rates with the correlation coefficients of r = 0.445 and r = 0.598 respectively, while decreasing the air-vegetation transport rates (r = 0.475), thereby contributing to the accumulation of BaP in soils and freshwaters. In the light of the potential dispersion of BaP pollution at regional and global scales affected by these key climatic factors, this indirectly indicated the impact of future climate change on the BaP transport. Thus, flexible policy interventions should be enacted to slow future climate change. [Display omitted] • Wind drives the dispersion of BaP to adjacent regions. • Low temperatures accelerate BaP accumulation in terrestrial ecosystems. • The cold deposition effects were more obvious in the north than in the south of China. • Increasing precipitation contributes to the accumulation of BaP in soils and freshwaters. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Fixed-time sliding mode tracking control for autonomous underwater vehicles.
- Author
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Zheng, Jiaqi, Song, Lei, Liu, Lingya, Yu, Wenbin, Wang, Yiyin, and Chen, Cailian
- Subjects
- *
SLIDING mode control , *AUTONOMOUS underwater vehicles , *TRACKING control systems - Abstract
In this paper, a fixed-time sliding mode controller (FSMC) with disturbance observer (DO) is proposed to solve the trajectory tracking control problem for autonomous underwater vehicles (AUVs) under time-varying external disturbances. Firstly, by using the sliding mode control method, an FSMC is proposed for reducing the tracking errors. Secondly, considering the estimation problem of time-varying disturbances, a fixed-time DO is designed to reconstruct the information of the AUV. Finally, The DO can compensate time-varying disturbances and the FSMC can reduce the tracking errors incorporating the information from the DO. Thus, the FSMC-DO for AUV is derived. Compared with the conventional FSMC and the finite time controller, the proposed FSMC-DO not only offers a faster convergence rate but also a higher tracking accuracy and robustness for the trajectory tracking control of AUVs. Simulation results are provided to show the superior performance of the proposed FSMC-DO. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
35. Synergistic gelling mechanism of RG-I rich citrus pectic polysaccharide at different esterification degree in calcium-induced gelation.
- Author
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Chen, Shiguo, Zheng, Jiaqi, Zhang, Laiming, Cheng, Huan, Orfila, Caroline, Ye, Xingqian, and Chen, Jianle
- Subjects
- *
GELATION , *HYDROCOLLOIDS , *ESTERIFICATION , *CITRUS , *HYDROGEN bonding , *PECTINS - Abstract
• RG-I rich pectic polysaccharide were abundant in fruits and vegetables. • RG-I rich pectic polysaccharide were extracted by sequential mild treatment. • Blend gels showed improved gel properties in calcium-induced gelation. • Ca-bridges promoted the three-dimensional structure of blend gels. RG-I rich pectic polysaccharide is common in fruit and vegetable and possesses health benefits. However, it is removed during commercial pectin production because of poor gelling properties. Synergistic gelation can improve rheological properties of RG-I pectic polysaccharide and expand its application in functional food hydrocolloids. In the study, RG-I rich pectic polysaccharides at different degree of esterification was extracted from citrus membrane by sequential mild acidic (0.4% HCl, 28 °C) and alkaline (0.6% NaOH, 32 °C) treatment. The pectic polysaccharide from acid water (PA) composes of 41% RG-I and 44% HG with DM of 45%, while the pectic polysaccharide from basic water (PB) composed of 63% RG-I and 19% HG with DM of 15%. PA/PB blend gel under CaCO 3 -glucono-δ-lactone system showed improved rheological properties compared with pure gels. Ca-bridges connected pectin aggregates and promoted the three-dimensional structure of PA/PB blend gels, while neutral sugar side-chains prompted hydrogen bonds and strengthened gel network. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
36. PANI/PVDF-TrFE porous aerogel bulk piezoelectric and triboelectric hybrid nanogenerator based on in-situ doping and liquid nitrogen quenching.
- Author
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Yu, Shengrui, Zhang, Yongkang, Yu, Zhaohan, Zheng, Jiaqi, Wang, Yunming, and Zhou, Huamin
- Abstract
Limited by the inherent properties of being difficult to be polarized due to its high resistance, PVDF bulk material with high β-phase content is hard to obtain by conventional methods which are suitable for membrane material. Herein, a novel strategy is proposed for the mass production of high-performance β-PVDF-based piezoelectric and triboelectric hybrid nanogenerator (PTNG) employing large-scale PVDF films or bulks by using liquid nitrogen to induce a phase transition and in-situ doped conductive polyaniline (PANI). Polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) with high piezoelectric coefficient, filled with PANI as a conductive material and sodium carboxymethyl cellulose (SCMC) for increasing porosity, is hot pressed to obtain a composite piezoelectric polymer for PTNG. The subsequent "quenching" process of the piezoelectric polymer allows its high content of β-phase, which in turn makes the PTNG exhibit excellent piezoelectric properties. The optimal output of the PTNG, with a β-phase content of up to 71%, reaches 246 V and 122 μA at the frequency of 30 Hz and pressure of 0.31 MPa, and the power density is calculated to be 6.69 W/m
2 . Moreover, the PTNG can directly light up 119 blue light-emitting diodes (LEDs) with a size of 3 mm in series. The excellent performance verifies the reliability and accuracy of the method, that is, the β-phase transformation of disordered amorphous PVDF occurs at low temperature and high-rate quenching, and PANI opens the channel for carriers to move charge in the bulk material. This innovative method presented here is a simple and efficient approach for preparation of bulks with high β-phase and low internal resistance, which undoubtedly provides a feasible direction for the industrialization of high-performance PENGs. A novel PANI/PVDF-TrFE porous aerogel bulk piezoelectric/triboelectric nanogenerator (PTNG) is prepared based on in-situ doping and liquid nitrogen quenching. The rapidly fabricated PTNG exhibits satisfactory performance (U = 246 V, I = 122 μA, Q = 6.69 W/m2 ) and can light up 119 blue light-emitting diodes in series with a size of 3 mm. The PVDF-based piezoelectric bulk eliminating the need of polarization treatment exhibits excellent electrical properties and will undoubtedly show encouraging potential in the industrialization of high-performance PTNG devices. ga1 • High-rate quenching of liquid nitrogen achieves β-phase transformation of the bulk. • Polyaniline can enhance the charge transfer efficiency and improve the output performance of bulk nanogenerators. • The decomposition of SCMC realizes the preparation of thermoformed porous bulk, thereby improving the output performance of PTNG. • The prepared PANI/PVDF-TrFE PTNG exhibits excellent performance (U = 246 V, I = 122 μA, Q = 6.67 W/m2 ). • The PTNG can directly illuminate 119 blue light-emitting diodes (LEDs) with a size of 3 mm in series. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
37. Structure-activity relationship of Citrus segment membrane RG-I pectin against Galectin-3: The galactan is not the only important factor.
- Author
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Wu, Dongmei, Zheng, Jiaqi, Hu, Weiwei, Zheng, Xiaoliang, He, Qiaojun, Linhardt, Robert J., Ye, Xingqian, and Chen, Shiguo
- Subjects
- *
PECTINS , *GALECTINS , *STRUCTURE-activity relationships , *CITRUS , *SUGAR , *FUNCTIONAL foods - Abstract
Rhamnogalacturonan I (RG-I) pectin are regarded as strong galectin-3 (Gal-3) antagonist because of galactan sidechains. The present study focused on discussing the effects of more structural regions in pectin on the anti-Gal-3 activity. The water-soluble pectin (WSP) recovered from citrus canning processing water was categorized as RG-I pectin. The controlled enzymatic hydrolysis was employed to sequentially remove the α-1,5-arabinan, homogalaturonan and β-1,4-galactan in WSP. The Gal-3-binding affinity KD (kd/ka) of WSP and debranched pectins were calculated to be 0.32 μM, 0.48 μM, 0.56 μM and 1.93 μM. Moreover, based on the more sensitive cell line (MCF-7) model, the IC 30 value of WSP was lower than these of modified pectins, indicating decreased anti-Gal-3 activity. Our results suggested that the total amount of neutral sugar sidechains, the length of arabinan and cooperation between HG and RG-I played important roles in the anti-Gal-3 activity of WSP, not the Gal/Ara ratio or RG-I/HG ratio. These results provided a new insight into structure-activity relationship of citrus segment membrane RG-I as a galectin-3 antagonist and a new functional food. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
38. A study on users' willingness to accept mobility as a service based on UTAUT model.
- Author
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Ye, Jianhong, Zheng, Jiaqi, and Yi, Fabin
- Subjects
WILLINGNESS to pay ,METHODOLOGY ,TRANSPORTATION ,QUESTIONNAIRES ,ECONOMIC policy - Abstract
• Identifying the key variables that affect user acceptance and user's requirements. • Methodologies used: Questionnaire and Unified Theory of Acceptance and Use Technology model (UTAUT). • The relationship found between influencing factor and willingness to acceptance MaaS. • Five important strategies are proposed to promote and apply MaaS. MaaS has received highly anticipated from the field of transportation theory and practice in recent years. Many Chinese cities have also proposed plans to build MaaS systems and have begun to implement them. As a new type of travel service paradigm, user recognition, acceptance, and continued use are prerequisites for the survival and development of MaaS. Therefore, accurately identifying the key variables that affect user acceptance and grasping the user's requirements are important support to ensure the MaaS has been applying successfully. Based on the Unified Theory of Acceptance and Use Technology model (UTAUT), this study establishes an analysis framework of MaaS acceptance and intention. A small town with a very common use of cars in the suburbs of Shanghai was selected as the survey object, and the potential uses and requirements of MaaS for 314 households and 600 residents were collected. This study proposes five important strategies for the promotion and application of MaaS: 1. Strengthen publicity and promote the MaaS concept to be more easily understood and accepted. 2. Improve convenience in the manual and avoid cumbersome operations; 3. Grasp the users' curiosity and the early adopters, and cultivate the approved user base. 4. Focus on improving user experience, maintaining MaaS reputation, rewarding users for sharing register invitations. 5. Strengthening the protection of user information and service stability of MaaS guarantee to eliminate user concerns. At the same time, different services can be launched for different groups. Such as providing customized MaaS travel packages for middle-aged, elderly people and minors; making more detailed tutorials for people without membership experience, inviting free experiences, etc. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
39. Gelling mechanism of RG-I enriched citrus pectin: Role of arabinose side-chains in cation- and acid-induced gelation.
- Author
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Zheng, Jiaqi, Chen, Jianle, Zhang, Hua, Wu, Dongmei, Ye, Xingqian, Linardt, Robert J., and Chen, Shiguo
- Subjects
- *
PECTINS , *GELATION , *HYDROGEN bonding interactions , *CITRUS - Abstract
RG-I enriched pectin is present in fruit and vegetable containing products. However, it is removed by the hot acid treatment during commercial pectin production to improve gelling properties and to afford a more uniform pectin quality. Recently, an awareness of the health benefits of RG-I enriched pectin has caused technologists to rethink its utilization by the food industry, especially as a novel healthy gelling agent. Unique RG-I enriched pectin with abundant arabinan side-chains was extracted from citrus membrane by sequential mild acidic and alkaline treatment. Arabinose was then removed by enzymatic treatment to investigate the impact of arabinose side-chains on gelation. The properties of RG-I enriched pectin gels, prepared using cations or acid, showed it could form gels under conditions required for both low and high methoxyl pectin as a result of its highly branched structure. In cation-induced gelation, the HG region forms egg-box junction zones with divalent cations and the side-chains of the RG-I region stabilizes the network structure through entanglements. In acid-induced gelation, low pH promotes formation of hydrogen bonding and hydrophobic interactions within the HG region and the side-chains create a tighter conformation, eventually allowing for stronger interactions between the pectin chains. Image 1 • RG-I enriched pectin extracted from citrus membrane by sequential mild treatment contains abundant arabinan side-chains. • RG-I enriched pectin forms gel under both cation and acid conditions and its side-chains improve network formation. • Arabinan side-chains stabilize junction zones in cation-induced gel through entanglements. • Arabinan side-chains form dense network in acid-induced gel through hydrogen bonds. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
40. Integrated nanospheres occupancy-removal and thermoforming into bulk piezoelectric and triboelectric hybrid nanogenerators with inverse opal nanostructure.
- Author
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Zheng, Jiaqi, Wang, Yunming, Yu, Zhaohan, Fu, Yue, Chen, Dan, Zhao, Peng, and Zhou, Huamin
- Abstract
Traditional processing methods (such as thermoforming and injection moulding) limit the fabrication of nanostructure and make it hard to be directly applied to the assembly of piezoelectric nanogenerators or triboelectric nanogenerators, whose electrical conversion properties have a strong reliance on nanostructure and porosity. Here we report an innovative strategy combining both traditional processing and nanofabrication to develop poly (vinylidene fluoride) (PVDF)–based piezoelectric and triboelectric hybrid nanogenerators (PTNGs), demonstrating promising potential in developing low-cost and scalable PTNGs with a wide material applicability and convenient operation. We showed that periodically ordered and interconnected nanoporous PVDF bulks, as hearts of PTNGs converted mechanical energy into electric energy, were quickly and simply constructed by thermoforming and template removal using monodisperse silicon dioxide (SiO 2) nanospheres as placeholder, whereas the pore shape, aperture and porosity of materials could be effectively controlled. Under the simulated periodic vibration, the optimal PVDF bulk with inverse opal structure exhibited a high output voltage of 242 V, which can be applied to light a processed LED bulb (220 V, 3 W) directly. This innovative method opens a new route for the rapid and simple fabrication of nanoporous structure which can be used as various functional devices and directly promote the industrialization, such as optical and electrochemical sensors, wireless charging equipment and capacitors. In this paper, we demonstrated an original, rapid and simple approach to fabricate large-area bulk piezoelectric and triboelectric hybrid nanogenerators with inverse opal structure using the method integrating nanospheres occupancy-removal and thermoforming. The optimal PVDF bulk with inverse opal structure exhibited a high output voltage of 242 V, which can be applied to light a processed LED bulb (220 V, 3 W) directly. This work will undoubtedly promote fundamental scientific research in PTNGs and the industrialization towards electrochemical sensors, wireless charging equipment and capacitors in the near future. Image 1 • The strategy of thermoforming and nanospheres occupancy-removal successfully fabricated large-area bulk inverse opal structural materials with controllable porosity and pore diameters. • Introducing orderly and uniformed pores significantly improved output performance of PTNGs. • The output voltage, power density and charge density of the device reached 242 V, 155.12 W/m
3 and 130.67 mC/m2 • This PTNG lit a processed LED bulb (220 V, 3 W) directly. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
41. High temperature ablation behavior of pressureless sintered Ta0.8Hf0.2C-based ultra-high temperature ceramics.
- Author
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Zhang, Buhao, Yin, Jie, Zheng, Jiaqi, Liu, Xuejian, Huang, Zhengren, Dusza, Ján, and Jiang, Dongliang
- Subjects
- *
HIGH temperatures , *CERAMICS , *SCANNING electron microscopy , *ELECTRON diffraction , *X-ray diffraction - Abstract
Ablation behavior of Ta 0.8 Hf 0.2 C and Ta 0.8 Hf 0.2 C-10 vol%SiC ceramics was investigated by plasma flame ablation test in air. Linear ablation rate was used for the characterization of ablation resistance and grazing-incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD) were used for characterization. Ta 0.8 Hf 0.2 C-10 vol%SiC exhibited significantly higher ablation resistance, with ablation rate of 0.7 μm/sec in comparison to the monolithic system with 3.5 μm/sec. An unstable single oxide layer of monolithic Ta 0.8 Hf 0.2 C with thickness approximately 20 μm was observed after ablation. Oxidation reactions happened individually as TaC and HfC while 'self-sacrificial' volatilization was mainly controlled by active oxidation of TaC. Hf 6 Ta 2 O 17 was generated by the combination of HfO 2 and TaO. A more stable double reaction-layer was observed after ablation of Ta 0.8 Hf 0.2 C-10 vol%SiC ceramic. Passive oxidation of TaC was dominant. Textured Ta 2 O 5 skeleton, filled with Hf-containing TaO 6 , stopped consumption of SiC and hampered oxygen further diffusion. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
42. A novel thermally matched conductive phase of silicon nitride ceramics.
- Author
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Wang, Lujie, Qi, Qian, Zheng, Jiaqi, Huang, Hao, Li, Tongyang, Qiao, Zhuhui, Tang, Huaguo, Liu, Xuejian, and Huang, Zhengren
- Subjects
- *
SILICON nitride , *CERAMICS , *THERMAL expansion , *ELECTRIC conductivity , *THERMAL conductivity , *TUNGSTEN - Abstract
Tungsten was first proposed as a conductive phase that better matches the thermal expansion of silicon nitride ceramics. Silicon nitride ceramics containing 20 vol% tungsten particles were fully densified via gas pressure sintering under a following nitrogen atmosphere. After introducing the tungsten particles, the thermal conductivity is increased two-fold and thermal expansion coefficient (CTE) almost remains as low as the monolithic silicon nitride ceramics. Most importantly, the composite ceramics achieve good electrical conductivity and a small and complex shape was machined via wire-electrode cutting to confirm its good wire-electrical discharge machinability. Tungsten particles have been proven to be a new ideal conductive phase for silicon nitride ceramics, and a new wire-electrical discharge machinable silicon nitride-based ceramic was prepared. • A new conductive Si 3 N 4 -based ceramic was prepared by gas pressure sintering. • Tungsten has been proved to be a new conductive phase matches the CTE of the Si 3 N 4. • The W/Si 3 N 4 ceramics shows excellent electrical discharge machinability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Source emissions and climate change impacts on the multimedia transport and fate of persistent organic pollutants, Chaohu watershed, eastern China.
- Author
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Cao, Xianghui, Huo, Shouliang, Zhang, Hanxiao, Zheng, Jiaqi, He, Zhuoshi, Ma, Chunzi, and Song, Shuai
- Subjects
- *
CLIMATE change , *WATERSHEDS , *ENVIRONMENTAL engineering , *PERSISTENT pollutants , *POLYCHLORINATED biphenyls - Abstract
Emission intensity and climate change control the transport flux and fate of persistent organic pollutants (POPs) in multiple environmental compartments. This study applied a multimedia model (BETR model) to explore alternations in the spatio-temporal trends of concentrations and transport flux of benzopyrene (BaP), phenanthrene (Phe), perfluorooctane sulfonates (PFOS) and polychlorinated biphenyls (PCBs) in the Chaohu watershed, located in the lower reaches of the Yangtze River, China in response to changes in source emissions and climate. The potential historic and future risks of these pollutants also were assessed. The results suggest that current trends in concentrations and transport were similar to that of their emissions between 2005 and 2018. During the next 100 years, temporal trends and spatial patterns were not predicted to change significantly, which is consistent with climate change. Based on sensitivity and correlation analyses, climate change had significant effects on multi-media concentrations and transport fluxes of BaP, Phe, PFOS and PCBs, and rainfall intensity was the predominant controlling factor. Risk quotients (RQs) of BaP and Phe-in soil increased from 0.42 to 0.95 and 0.06 to 0.35, respectively, from 2005 to 2090, indicating potential risks. The RQs of the other examined contaminants exhibited little potential risk in soil, water, or sediment. Based on spatial patterns, it was inferred that the ecosystem around Lake Chaohu is the most at risk. The study provides insights needed for local pollution control of POPs in the Chaohu watershed. In addition, the developed approach can be applied to other watersheds world-wide. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Fabrication of SiC ceramics with invariable value resistivity in the range of 20–400 ℃ using MAX phase- Ti3AlC2 additives.
- Author
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Chen, Wenhui, Chen, Jian, Zhu, Ming, Zheng, Jiaqi, Ma, Ning-ning, Liu, Xuejian, Chen, Zhongming, and Huang, Zhengren
- Subjects
- *
CERAMICS , *SPECIFIC gravity , *ELECTRICAL resistivity , *MECHANICAL properties of condensed matter , *LOW temperatures , *TITANIUM carbide - Abstract
• Ti 3 AlC 2 was effective in promoting densification of SiC ceramics. During the sintering process, Al produced by the decomposition of Ti 3 AlC 2 would be dissolved into SiC lattice to promote the densification. With the increase of Ti 3 AlC 2 content, the relative density of samples increased and SiC ceramics could be densified at a low temperature of 1850 ℃ with 20 wt% Ti 3 AlC 2. • The enhancement of Ti 3 AlC 2 content changed the voltage-current characteristics of the sample from nonlinear to linear, since the increase of TiC generated by the decomposition of Ti 3 AlC 2 led to the formation of a conductive network in the sample. Electrical percolation was obtained when the Ti 3 AlC 2 content was 15 wt%, and the electrical resistivity of the corresponding sample is 52 Ω cm. • The addition of Ti 3 AlC 2 could reduce the temperature sensitivity of the electrical properties of the sample. The resistivity with 15 wt% Ti 3 AlC 2 addition remained almost invariable throughout the temperature range (20–400 ℃), which can provide an insight into applications of constant-resistivity SiC resistors. SiC ceramics were fabricated by SPS sintering at 1850 ℃ with different amounts of Ti 3 AlC 2. The effects of Ti 3 AlC 2 content on the microstructure and electrical properties of the material were discussed. The densification and electrical properties of SiC ceramics have been improved by adding MAX phase Ti 3 AlC 2. Ti 3 AlC 2 decomposes to produce TiC and Al in the sintering process. The conductivity of SiC ceramics is elevated by TiC serving as a conductive second phase, and Al is dissolved into SiC lattice to promote the densification of SiC ceramics. With the addition of 15 wt% Ti 3 AlC 2 , the voltage-current curve of the sample changes from nonlinear to linear electrical characteristics with the resistivity dropping to 52 Ω cm. Moreover, the introduction of Ti 3 AlC 2 reduces the temperature sensitivity of SiC ceramics. When the Ti 3 AlC 2 content reaches 15 wt%, the resistivity of SiC ceramics remains relatively constant within the range of 20–400 ℃. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. The new steady state voltage stability analysis methods with computation loads separation technique in DC power systems.
- Author
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Wang, Yuqi, Xu, Qingshan, and Zheng, Jiaqi
- Subjects
- *
ELECTRIC potential , *STEADY state conduction , *SECURITY systems - Abstract
• Explore the relationship among injected current, bus voltage, line current and voltage. • Different types of the computation loads can be separated. • A correctness method for CPF problem is proposed. • The physical essence of voltage collapse is explained. The steady state voltage stability analysis is extremely important to the security of power systems. The continuation power flow (CPF) is one of the important tools for the steady state voltage stability analysis. However, its computation load is very large. To improve the analysis performance in DC power systems, a basic technique is used to explore the exact relationships between injected currents, buses voltages, lines currents and lines voltages. Based on the basic technique, the computation loads can be separated and some repeated computation can be avoided. In this paper, two new methods to calculate critical point are proposed. One is by combining the basic technique and a correctness method for CPF. The method improves the calculation speed by avoiding the repeated computation of same topology and buses types analysis. Another method is a direct method. The direct method is based on the novel view to understand power systems and the physical (and mathematical) essence of critical point and voltage collapse. Most CPF is discussed in AC system. The corresponding CPF in DC system will be studied to get standard results for comparison. Compared with CPF in DC systems, the numerical verification shows that the proposed methods can reduce most computation loads of CPF method in DC systems. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
46. Microstructure and properties of C/C–SiC composites prepared by reactive melt infiltration at low temperature in vacuum.
- Author
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Liu, Lei, Zhang, Leilei, Feng, Wei, Li, Jianping, Bai, Yaping, Tao, Dong, Su, Xiaoqin, Cao, Yi, Bao, Tong, and Zheng, Jiaqi
- Subjects
- *
MELT infiltration , *LOW temperatures , *VACUUM , *THERMAL expansion , *MICROSTRUCTURE - Abstract
Dense C/C–SiC composites were prepared by reactive melt infiltration at 1100–1200 °C in vacuum through addition of 20–40 wt% Al into Si powder. XRD and EDS analysis showed that the composites were composed of carbon, SiC, Al and residual Si. The composite with 20% wt.% Al had the maximum compressive strength and modulus, while the composite with 30 wt% Al possessed the highest density and thermal expansion coefficient. The micro-cracks in composites were responsible for the compressive behavior, and caused decrease of thermal expansion of the composites from 30 to 40 wt% Al. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. PAN: Pipeline assisted neural networks model for data-to-text generation in social internet of things.
- Author
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Jiang, Nan, Chen, Jing, Zhou, Ri-Gui, Wu, Changxing, Chen, Honglong, Zheng, Jiaqi, and Wan, Tao
- Subjects
- *
ARTIFICIAL neural networks , *INTERNET of things , *AGE groups , *PIPELINES , *NATURAL languages , *SOCIAL contact - Abstract
• We conduct the first attempt to the data-to-text generation in Social Internet of Things (SIoT). • We propose a novel model to automatically generate the natural language sequence description from the nonlinguistic input data in SIoT. • The proposed model integrates the traditional pipeline modules with the end-to-end neural network model. • The experimental results demonstrate that our model outperforms several other existing solutions. Social Internet of Things (SIoT) is an emerging paradigm connecting the Internet of things and social networks, enabling the social functions expanded into human-to-thing or inter-thing. There is an urgent issue of how to realize the social contact for communications between human and things or between things. This requires the natural language generation (NLG), focusing on generating text in human languages from non-linguistic data, which is of vital importance to achieve the interaction without barriers between human and other smart objects in SIoT. However, the existing solutions for data-to-text transformation rely on the specific template and standard neural networks models, which are not flexible when applying to the cross-domain data with diverse meaning. In this paper, we propose a novel model, called pipeline assisted neural networks (PAN), which integrates the traditional pipeline modules and neural generation systems, to conduct data-to-text generation tasks in SIoT. Our new PAN model makes use of attention module and gate mechanism to complete content selection, by analyzing records correlation and filtering redundant records. Then, a dedicated neural network is developed for salient span selection, pointing and transition to achieve content planning. In the end, we conduct experiments on the ROTOWIRE dataset to evaluate the performance of PAN. The results demonstrate that our proposed PAN model outperforms the existing solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. Toward optimal participant decisions with voting-based incentive model for crowd sensing.
- Author
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Jiang, Nan, Xu, Dong, Zhou, Jie, Yan, Hongyang, Wan, Tao, and Zheng, Jiaqi
- Subjects
- *
CROWDS , *TRUTHFULNESS & falsehood , *TASKS , *REINFORCEMENT learning , *AUCTIONS - Abstract
With the rapid development of crowd sensing in sensing applications, excellent incentive mechanisms are playing an increasingly important role. However, most existing solutions do not fully consider the ability of participants to perform tasks, the degree to which they complete tasks, or the credibility of the task sensing results. In this paper, we aim to develop an incentive model based on voting mechanism for crowd sensing(abbreviated as CIBV), which includes three algorithms. The first is a participant decision algorithm (PDA) that adopts a reverse auction model and comprehensively considers candidate execution capability; the second is the budget balance and extra reward algorithm (BBER); the third is the evaluate algorithm (EA) to be applied at the end of sensing tasks. Compared with previous work, the experimental results show that in our proposed CIBV model, each task is performed by multiple participants, and each participant can perform multiple tasks, our model can greatly improve the participants' execution ability value and provide the platform with the ability to control the process of selecting participants. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. A novel system operation mode with flexible bus type selection method in DC power systems.
- Author
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Wang, Yuqi, Xu, Qingshan, Liu, Mengjia, and Zheng, Jiaqi
- Subjects
- *
DIRECT current power transmission , *POWER electronics , *RENEWABLE energy sources , *ELECTRIC power distribution , *MULTIVARIABLE control systems - Abstract
With the development of power electronics technology, the DC power system shows great advantages to improve the power system performance. However, the research on DC power system is far from enough, and there is great demand for the improvement of system flexibility and renewable energy integration ability. Thus, the new flexible system operation mode which can satisfy the requirements is of interest. This paper carefully analyzes and discusses the power flow problem of DC power systems first. Then, some new bus types are proposed to construct new system operation modes which can improve the system flexibility (includes friendly renewable energy sources integration ability and flexible power flow ability). The proposed power flow calculation method can solve the power flow problem with the new operation modes and new bus types. However, the feasibility of system operation may be broken by arbitrary selection of new bus types. Thus, the flexible bus type selection method is further proposed to select proper bus types. As a result, the system flexibility can be improved and the feasibility of system can be assured. At last, the numerical experiments results are presented to verify the effectiveness of proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
50. Effects of Lactobacillus plantarum and its fermentation products on growth performance, immune function, intestinal pH, and cecal microorganisms of Lingnan yellow chicken.
- Author
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Wang, Jingyi, Yao, Lan, Su, Jun, Fan, Runran, Zheng, Jiaqi, and Han, Yuzhu
- Subjects
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FEATHERS , *FERMENTATION , *YEAST culture , *INTESTINES , *GASTROINTESTINAL system , *DIETARY supplements , *MICROORGANISMS , *CHICKENS , *LACTOBACILLUS plantarum - Abstract
The present research was conducted to investigate the effects of dietary supplementation of Lactobacillus plantarum and its fermentation products on growth performance, specific immune function, intestinal pH, and cecal microorganisms in yellow-feather broilers. A total of 1,200 yellow-feather broilers of similar weight and good health condition at 1 d of age were selected and randomly divided into 5 groups. The CK group was fed the basal diet, and the experimental group (I, II, III, IV) were supplemented with 0.1, 0.15% L. plantarum and 3, 4% L. plantarum fermentation products. The results showed that each treatment could improve the growth performance (P < 0.05) and feed conversion rate of yellow-feather broilers. Besides, the pH value of the gastrointestinal tract of yellow-feather broilers (P < 0.05) was significantly reduced through the use of L. plantarum and its fermentation products as additives, which also facilitated the animals to regulate the balance of cecal microorganisms. The immune function assay showed that the bursal index (P < 0.05), spleen index (P < 0.05), and the content of serum immunoglobulins IgA and IgG (P < 0.05) were significantly increased in yellow-finned broilers aged 1 to 21 d by supplementing the diet with L. plantarum. In conclusion, adding L. plantarum or its fermentation products to the diet can improve the growth performance of yellow-feather broilers, and the direct addition of L. plantarum is better than adding fermentation products. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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