Search

To explore the inhibitory effects of a novel, smartphone-controlled, and wearable tibial nerve stimulation device on nonnociceptive and nociceptive bladder reflexes in anesthetized cats and to compare the stimulus results of two current waveforms outputted by this new stimulator.A novel, intelligent tibial nerve stimulator was put on the ankles of 14 cats and controlled by a mobile application. Cystometrograms (CMGs) were performed repeatedly by infusing 0.9% normal saline (NS) and 0.5% acetic acid (AA) through a urethral catheter. Inhibitory effects were explored by measuring the bladder capacity (BC) in two areas: (1) on nonnociceptive bladder reflex (infused with NS) and on nociceptive bladder reflex (filled with AA to induce overactive bladder [OAB] model); and (2) under the stimulation of two different current waveforms (waveforms A and B).In Group 1, the BC of AA-induced OAB (41.48 ± 8.40%) was significantly different compared with the capacity of a NS-infused bladder (104.89 ± 1.32%, p 0.05). Both NS-filled (151.35 ± 5.71%, p 0.05) and AA-instilled (71.41 ± 9.34%, p 0.05) bladder volumes significantly increased after tibial nerve stimulation (TNS). In Group 2, the BC increased to 166.18 ± 15.17% (p = 0.026) and 127.64 ± 13.00% (p = 0.239), respectively, after TNS with waveforms A and B current.Results revealed that this novel, smartphone-based, wearable, and wireless tibial nerve stimulation system could inhibit the micturition reflex on physiological condition, serving as a potential option for OAB treatment. In addition, the waveforms of stimulation current had an important influence on the effects of TNS.

In this paper, the refined plate theory (RPT), Hamilton’s principle, and isogeometric analysis (IGA) are applied to investigate the static bending, free vibration and buckling behaviors of functionally graded graphene-platelet-reinforced piezoelectric (FG-GRP) plates resting on a Winkler elastic foundation. The graphene platelets (GPLs) are distributed in polyvinylidene fluoride (PVDF) as a power function along the plate thickness direction to generate functionally gradient materials (FGMs). The modified Halpin–Tsai parallel model predicts the effective Young’s modulus of each graphene-reinforced piezoelectric composite plate layer, and the rule of the mixture can be used to calculate the effective Poisson’s ratio, mass density, and piezoelectric properties. Under different graphene distribution patterns and boundary conditions, the effects of a plate’s geometric dimensions, GPLs’ physical properties, GPLs’ geometric properties and the elastic coefficient of the Winkler elastic foundation on deflections, frequencies and bucking loads of the FG-GRP plates are investigated in depth. The convergence and computational efficiency of the present IGA are confirmed versus other studies. Furthermore, the results illustrate that a small amount of GPL reinforcements can improve the FG-GRP plates’ mechanical properties, i.e., GPLs can improve the system’s vibration and stability characteristics. The more GPL reinforcements spread into the surface layers, the more effective it is at enhancing the system’s stiffness.

Deployment of clean energy technologies will require a considerable amount of materials. The surge in demand for metals related to emerging energy technologies may hinder the energy transition. In this study we provide a comprehensive overview and analysis of existing work in this field, a solid quantitative baseline for material requirements of different energy technologies and quantitative information that can be used to generate learning curves for the material requirements of different energy technologies. We conducted a quantitative review of the material requirements of low-carbon energy technologies in 132 scientific publications, and provided a comparative analysis of detailed data including material intensity and lifetime data. Besides providing a large amount of structured quantitative data, the results of our work indicate that: (1) research on the demand for low carbon technology related metals has received much attention since the 2010s; (2) around 80% of the publications focus on the global level while national level studies are underrepresented; (3) science-based future scenarios are the main means of estimating total future material requirements; (4) most studies foresee material constraints of large-scale implementation of low-carbon technologies and the secure and responsible supply of these materials is still the subject of discussion; (5) changes in metal intensity caused by technological development and material requirements for non-critical components are important though often overlooked.

In order to find low-toxic light-absorbing materials for perovskite solar cells, the electronic structures and optical absorption spectra of doped perovskites CsPb₁–ₓMₓI₂Br (M = Ge, Sn, Sr, and Cu) have been investigated with the first-principles method. Ge- and Sn-doped perovskites display monotonously decreased band gaps with increasing x, opposite to Sr- and Cu-doped ones. Different from group IV Ge and Sn elements, Sr and Cu dopants show distinct electronic characteristics, that is, weak interaction with halogens because of the d orbitals splitting in octahedral complexes and unique density of states and band-decomposed charge densities. Meanwhile, Ge, Sn, and Cu dopants prefer substituting Pb sites in the CsI-terminated surfaces based on thermodynamic consideration, and the dopants accumulating on surfaces will deteriorate the optical absorption of perovskites based on the comparison of the absorption spectra of various doped structures. Therefore, this study provides a theoretical insight into the declined absorption spectra with the increasing concentration of dopants in experimental observations.

A series of Ca15(PO4)2(SiO4)6:xCe3+,yTb3+ phosphors have been prepared by a high-temperature solid-state reaction. Under the excitation of near-UV with 371 nm wavelength, Ca15(PO4)2(SiO4)6:xCe3+ phosphors exhibit strong blue emission with a broad peak at 432 nm. Based on the photoluminescence of Ca15(PO4)2(SiO4)6:xCe3+ phosphors, the coordination environment around Ce3+ ions and the concentration quenching mechanism are inferred. With the doping of Tb3+ ions into Ca15(PO4)2(SiO4)6:1.33%Ce3+, the luminescence color from blue to cyan can be well tuned. By measuring the luminescence intensity and lifetime of the as-prepared phosphors, it can be judged that there exists an energy transfer from Ce3+ to Tb3+. To achieve white light, the optimal Ca15(PO4)2(SiO4)6:1.33%Ce3+, 9%Tb3+ phosphors are mixed with commercial SrAlSiN3:Eu2+ powders and finally warm white light emission could be obtained. The results show that Ca15(PO4)2(SiO4)6:xCe3+,yTb3+ phosphors have potential applications in warm white light-emitting diodes.

The rapid growth in the scale of the intelligent connected vehicles (ICVs) brings about the need for novel random access schemes that realize collision avoidance and reliable communication. The coded random access (CRA) scheme utilizes successive interference cancellation (SIC) across slots to enable the extraction of multiple users' packets from the collision slots and proves to be an efficient solution to collision resolution. In this paper, we propose a random backoff-based CRA scheme to achieve a tradeoff between the access success probability and access delay for CRA. Specifically, we partition the traditional CRA frame into subframes, so that the user access delay is reduced to the same scale of the subframe length. In addition, the backoff operation among subframes is introduced so that access failures originated from the subframe length limit can be reduced with the retransmission in subsequent subframes. In particular, we consider practical Nakagami-m fading channel in the CRA performance analysis and take into account the capture effect in the iterative interference cancellation process. Simulation results show that backoff-based CRA can significantly reduce the average access delay without severe negative effect on the access success probability for moderate system load compared with traditional CRA. Comparisons with the state-of-the-art non-orthogonal random access (NORA) scheme proposed for 5G indicates that backoff-based CRA provides a feasible solution for random access of large-scale ICVs.

Various methods exist for locating lung nodules, each with its own advantages and disadvantages. Aiming to find a more accurate, safe, effective, economical and practical method for locating lung nodules, this study evaluated the safety and feasibility of a precise three-dimensional (3D) method for positioning small pulmonary nodules based on anatomical landmarks.From June 2019 to December 2021, 120 patients with 131 pulmonary nodules who underwent video-assisted thoracoscopic surgery at the University of Hong Kong-Shenzhen Hospital were included in the study. Surgical data such as the positioning time, accuracy rate, pathological result, localization-related complication rate and length of postoperative hospital stay were retrospectively reviewed and analyzed. During surgery, pulmonary nodules were accurately located by the 3D positioning method based on anatomical landmarks and then removed to determine the pathology.A total of 120 patients, including 35 males and 85 females, were included, and the median age was 53 years [interquartile range (IQR), 41-63 years]. No mortality or major morbidity occurred within 30 days. The median localization time was 11 minutes (IQR, 8-14 minutes). The accuracy of localization was 98.5%. The median diameter of the pulmonary nodules was 8 mm (IQR, 7-13 mm), and the median distance from the visceral pleura was 6 mm (IQR, 2-10 mm). No location-related complications occurred. The median length of postoperative hospital stay was 5 days (IQR, 3-7 days).The proposed positioning method is accurate, safe and feasible for selected patients with pulmonary nodules. Compared with other preoperative and intraoperative positioning methods, it can significantly reduce localization-related complications.

Low fertility willingness has become a major practical reality in China. From the perspective of family gender equality, this paper analyzes the impact of division of housework on women’s fertility willingness by using the data of China Family Panel Studies (CFPS). The results of propensity score matching method and instrumental variable method show that husbands’ participation in housework can effectively improve wives’ fertility willingness. Mechanism analysis shows that husbands’ active participation in housework can effectively reduce wives’ work–family conflict, increase wives’ satisfaction with husbands’ housework contribution, and help improve wives’ happiness and fertility willingness. Further discussion on whether families have had children or not shows that women who have had children are more sensitive to their husbands’ participation in housework. This study provides empirical evidence for the applicability of family gender equality theory in China and the factors affecting women’s fertility willingness.

In this paper, we propose an analytical model of neighbor election-based distributed slot access by considering the relationship between the age of information (AoI) and the slot access process of nodes in wireless ad hoc networks. A node first maintains the information updates from its neighbors by relaying and receiving messages and determines message transmission slots by holding elections with its relevant competing neighbors. We first find out and analyze the interaction relationship between the transmission probability of nodes, the competing probability of neighbor nodes, and the violation probability that AoI exceeds the timeliness threshold of the neighbor election. Next, we obtain the approximated expression of the competing probability and the age violation probability based on the comprehensive analysis of the neighbor election process. Numerical and simulation results show that our approximation is tighter than the one in the literature and also provides insights into enhancing the design of network-aware distributed multiple access schemes.

The cloud intelligent classroom, supported by modern technologies, is the main trend of curriculum design in the future. The purpose of this study is to explore the promotion and integration between digital technology and the curriculum design of mental health education in colleges and universities and realize their real value. First, the overall idea and practical value of the study are clarified after the relevant literature is reviewed. Second, the setting, the teaching methods, and the ideas of the cloud classrooms based on digital technology are elaborated in detail. Then, the final effect of mental health education in cloud intelligent classrooms is demonstrated and summarized after the teaching practice, a questionnaire survey, and the expert assessment. Finally, the research conclusions are drawn and the suggestions for constructing the cloud intelligent classrooms of mental health education are proposed based on the practice and surveys. The research is based on the reality of mental health education in colleges and universities, rational thinking, and action. While updating the means and methods of the curriculum design of the mental health education in the high school, it expands the connotation of cloud intelligent classroom and pursues the unity of “form” and “content.” The cloud intelligent classroom helps to improve the teaching quality of mental health education for the music majors in colleges and universities in the short term. Cloud intelligent classrooms can also help to achieve the curriculum design and teaching objectives.

This paper develops an analytical framework for multi-cell uplink NOMA systems based on stochastic geometry. We propose two scenarios for the clustering of NOMA UEs and derive the Laplace transform of the inter-cell interference taking into account uplink power control. We utilize two different ordering techniques, namely mean signal power- (MSP-) and instantaneous signal-to-intercell-interference-and-noise-ratio- (ISĨNR-) based, for the successive interference cancellation process at the BSs. For each technique, we present a signal-to-interference-and-noise-ratio (SINR) analysis and derive the transmission success probabilities for the NOMA UEs. We show that uplink power control, which generally reduces the signal power disparity between UEs, does not necessarily degrade the NOMA performance. We discuss how UE clustering and the power control exponent impact this finding. ISĨNR-based ordering, which jointly considers path loss, fading, inter-cell interference, and noise, is generally superior to MSP-based ordering. Moreover, we show that the advantage of NOMA vanishes when the target SINR exceeds a certain threshold. A comparison of the two UE clustering scenarios indicates that excluding the UEs which are relatively far from the serving BS may improve the NOMA performance.

Based on the first-principles calculations, the influence of different geometry models on the theoretical results about the electronic properties of LaAlO3/SrTiO3 perovskite heterostructures has been studied. The results show that the superlattice model can indicate n-type conductivity of interfaces, but it is limited to describe the insulator-metal transition of heterostructures. The sandwich and thin film models with the vacuum layer can take into account the surface termination effect on the electronic properties of the interface. The AlO2 or LaO atomic layer as the outmost surface termination is selected during constructing the model, leading to the distinct electronic properties of the heterostructures. The build-in electric filed appears in the AlO2-terminated structure, whereas it does not exist in LaO-terminated structure. Therefore, the AlO2-terminated structure can give a clear description about the insulator-metal transition of heterostructure and the charge transfer mechanism. The build-in electric filed, the atomic rumpling and surface termination effect of perovskite materials codetermine the conductivity of interfaces. The results would be helpful to construct theoretical model and understand the novel electronic properties during investigating other perovskite heterostructures.

(CF3C6H4)2SnO, (CH3C6H4)2SnO and Ph2SnO were successfully synthesized for the transesterification of DMC with BPA. The products of mono-methylcarbonate-ended-BPA (MmC(1)) and two-methylcarbonate-ended-BPA (DmC(1)) were selectively synthesized over them. The catalysts were characterized by FT-IR, TG and XPS. When Ph2SnO was used as the catalyst at 170 °C, the BPA conversion reached to 28.60% and the transesterification selectivity reached to 98.35%. As for (CF3C6H4)2SnO, BPA conversion and transesterification selectivity declined to 12.48% and 64.74%, respectively. The BPA conversion increased to 42.83%, but the transesterification selectivity declined to 44.55% over (CF3C6H4)2SnO. Notability, the higher transesterification selectivity of Ph2SnO was due to its lowest electron binding energy of Sn4+. More importantly, the DMC adsorption, activation and decomposition process over (CF3C6H4)2SnO, (CH3C6H4)2SnO and Ph2SnO were characterized by TG–MS and in situ DRIFT techniques, which provided more information about the mechanism of transesterification and methylation.

Lithium doped TiO2 were prepared by simple impregnation, which was used as heterogeneous catalysts for the transesterification of DMC with BPA. The characterized results of FTIR, XRD, XPS, SEM, TEM and temperature programmed desorption of CO2 (CO2-TPD) showed that the structure and performance of the catalysts were obviously influenced by the doping amount of Li+ and calcining temperature. The optimum catalytic activity was obtained when the molar ratio of Ti/Li reached 6 and the calcination temperature came up to 400 ℃, which was due to Li+ reaction with TiO2 to form surface Ti-O-Li at 400 ℃ (Ti/Li-6-400). When the transesterification of DMC with BPA was carried out at 160–180 ℃ over Ti/Li-6-400, BPA conversion reached 46.67%, and the yields of one-methylcarbonate-ended-BPA (MmC(1)) and two-methylcarbonate-ended-BPA (DmC(1)) achieved 36.36% and 5.97%, respectively, and only 9.3% methylation selectivity was detected. In addition, the possible transesterification mechanism was provided.

Cascade reservoirs were designed for Yalong River Basin, which ranks the 3rd largest hydropower base in China. Reservoir impoundment has certain impacts on local climate, but few researches focus on this field. This paper integrates the spatiotemporal analysis techniques and geostatistical methods to identify the reservoir projected meteorological indices (MIs) variations as well as the impact scope under different circumstances. Results show: The reservoir projected variations of moisture indexes were much more significant than temperatures. Anthropogenic disturbance has led to dramatic decrease of relative humidity in the past decade, far beyond its periodic amplitude range. Moreover, dry valley faced more serious drought risk but reservoir impoundment of this region alleviated the local drought risk. The daily minimum temperature, relative to the maximum temperature, was more sensitive to catchment changes with an earlier appearance of temperature zone variation. Since impounding, the MIs internal relationships in non-dry valley varied significantly more than that in dry valley, with the positive correlation of 0.7 between the relative humidity and precipitation weakened greatly. The severe warming hotspots distributed in the upper reach and had the probability of 0.95- 1 to exceed 1.5℃ IPCC control target. This study provides references for the disturbance of reservoir impoundment to local climate at multiple temporal-spatial scales under different circumstances and contributes to the MIs variation pattern identification and quantitative risk assessment.

Clarifying specific water resources distribution and quantifying water security are vital for sustainable management. There is still unexplored gap regarding security indicators as the linkage between water footprint and availability. This study proposed a dynamic water security assessment framework considering the boundary consistency between green water footprint and provision at multi spatio-temporal scales and applied it to Yalong River Basin (YLRB) of southwest China. Results show: 1) The temporal variation of blue water was stronger than green water. Green water flow exhibited more homogeneous spatial distribution than blue water and green water storage. 2) The hotspots of green water crisis were observed in the middle reach with the higher scarcity/vulnerability. 3) Under anthropogenic disturbance, pastureland exhibited lower green water sustainability with scarcity >1 than forest. 4) Lower green water scarcity denoted the potential for rain-fed agriculture in the southeastern YLRB and higher blue water security indicated the water supply prospect for socioeconomic utilization. This work contributes to ensure water resources sustainable management in eco-socioeconomic nexus.

Aluminum (Al) toxicity in acidic soils severely reduces crop production worldwide. Sorghum (Sorghum bicolor L.) is an important agricultural crop widely grown in tropical and subtropical regions, where Al toxicity is prevalent. ATP-binding cassette (ABC) transporters play key roles in the development of plants and include the member sensitive to aluminum rhizotoxicity 1 (STAR1), which is reported to be associated with Al tolerance in a few plant species. However, a STAR1 homolog has not been characterized in sorghum with respect to Al tolerance. Here, we identified and characterized a SbSTAR1 gene in sweet sorghum encoding the nucleotide-binding domain of a bacterial-type ABC transporter. The transcriptional expression of SbSTAR1 is induced by Al in a time- and dosage-dependent manner in root, especially in root tip, which is the key site of Al toxicity in plants. The typical Al-associated transcription factor SbSTOP1 showed transcriptional regulation of SbSTAR1. SbSTAR1 was present at both the cytoplasm and nuclei. Overexpression of SbSTAR1 significantly enhanced the Al tolerance of transgenic plants, which possibly via regulating the hemicellulose content in root cell wall. This study provides the first ABC protein in sorghum implicated in Al tolerance, suggesting the existence of a SbSTAR1-mediated Al tolerance mechanism in sorghum.