Yu Zhang

© 2016 Macmillan Publishers Limited.Layered transition metal dichalcogenides are ideal systems for exploring the effects of dimensionality on correlated electronic phases such as charge density wave order and superconductivity. In bulk NbSe 2 a CDW sets in at T CDW = 33 K and superconductivity sets in at T c = 7.2 K. Below T c these electronic states coexist but their microscopic formation mechanisms remain controversial. Here we present an electronic characterization study of a single two-dimensional layer of NbSe 2 by means of low-temperature scanning tunnelling microscopy/spectroscopy, angle-resolved photoemission spectroscopy, and electrical transport measurements. We demonstrate that 3 × 3 CDW order in NbSe 2 remains intact in two dimensions. Superconductivity also still remains in the 2D limit, but its onset temperature is depressed to 1.9 K. Our STS measurements at 5 K reveal a CDW gap of= 4 meV at the Fermi energy, which is accessible by means of STS owing to the removal of bands crossing the Fermi level for a single layer. Our observations are consistent with the simplified electronic structure of single-layer NbSe 2, thus providing insight into CDW formation and superconductivity in this model strongly correlated system.

© 2015 American Physical Society.The level of electronic correlation has been one of the key questions in understanding the nature of superconductivity. Among the iron-based superconductors, the iron chalcogenide family exhibits the strongest electron correlations. To gauge the correlation strength, we performed a systematic angle-resolved photoemission spectroscopy study on the iron chalcogenide series Fe1+ySexTe1-x, a model system with the simplest structure. Our measurement reveals an incoherent-to-coherent crossover in the electronic structure as the selenium ratio increases and the system evolves from a weakly localized to a more itinerant state. Furthermore, we found that the effective mass of bands dominated by the dxy orbital character significantly decreases with increasing selenium ratio, as compared to the dxz/dyz orbital-dominated bands. The orbital-dependent change in the correlation level agrees with theoretical calculations on the band structure renormalization, and may help to understand the onset of superconductivity in Fe1+ySexTe1-x.

© 2015 American Institute of Chemical Engineers.Current lithium-ion batteries are predicted to be unable to provide the specific energy required to meet the ever-increasing demands of rapidly emerging technologies. Due to a high theoretical specific capacity of 1675 mAh/g, sulfur has gained much attention as a promising positive electrode material for high specific energy rechargeable batteries. Although the lithium/sulfur cell has been studied for many years and continues to receive much attention today as an alternative power source for zero-emission vehicles and advanced electronic devices, the realization of this novel cell's promise as a commercial product has yet to be successful. The major problems with sulfur electrodes involve: the dissolution of sulfur and the resulting diffusion of dissolved polysulfides and the deposition of insulating products on both the negative and the positive electrodes. These solid deposits can physically block the electrode reaction sites, thus passivating the electrode surfaces. Another important problem is the large volume change that occurs with the conversion of S to Li 2 S. It is important to understand that the performance of Li/S cells is hampered by linked chemical and mechanical degradations and both degradation mechanisms must be correctly alleviated in order to markedly improve current-technology Li/S cells. In this study, improved cycling performance via the reactive functional groups on graphene oxide to successfully immobilize sulfur and lithium polysulfides during operation has been demonstrated. The use of a new electrolyte and binder leads to improved cell performance in terms of high-rate capability and good reversibility, yielding at least 800 cycles have also been demonstrated.

Oxidative stress has been implicated in cardiac arrhythmia, although a causal relationship remains undefined. We have recently demonstrated a marked up-regulation of NADPH oxidase isoform 4 in patients with atrial fibrillation, which is accompanied by overproduction of reactive oxygen species. In this study, we investigated the impact on the cardiac phenotype of NOX4 overexpression in zebrafish. One-cell stage embryos were injected with NOX4 RNA prior to video recording of a GFP-labeled beating heart in real time at 24-31 h post-fertilization. Intriguingly, NOX4 embryos developed cardiac arrhythmia that is characterized by irregular heartbeats. When quantitatively analyzed by an established LQ-1 program, the NOX4 embryos displayed much more variable beat-to-beat intervals. Both the phenotype and the increased ROS in NOX4 embryos were attenuated by NOX4 morpholino co-injection, treatments of the embryos with polyethylene glycol-conjugated superoxide dismutase, or NOX4 inhibitors fulvene-5, 6-dimethylaminofulvene, and proton sponge blue. Injection of NOX4-P437H mutant RNA had no effect on the cardiac phenotype or ROS production. In addition, phosphorylation of calcium/cal-modulin-dependent protein kinase II was increased in NOX4 embryos but diminished by polyethylene glycol-conjugated superoxide dismutase, whereas its inhibitor KN93 or AIP abolished the arrhythmic phenotype. Taken together, our data for the first time uncover a novel pathway that underlies the development of cardiac arrhythmia, namely NOX4 activation, subsequent NOX4-specific NADPH-driven ROS production, and redox-sensitive CaMKII activation. These findings may ultimately lead to novel therapeutics targeting cardiac arrhythmia. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Lithium/sulfur cells are receiving significant attention as an alternative power source for zero-emission vehicles and advanced electronic devices due to the very high theoretical specific capacity of the sulfur cathode. However, the poor cycle life and rate capability have remained a grand challenge, preventing the practical application of this attractive technology. Here, we report that a Li/S cell employing a cetyltrimethyl ammonium bromide -modified sulfur-graphene oxide nanocomposite cathode can be discharged at rates as high as 6C and charged at rates as high as 3C while still maintaining high specific capacity, with a long cycle life exceeding 1500 cycles and an extremely low decay rate, perhaps the best performance demonstrated so far for a Li/S cell. The initial estimated cell-level specific energy of our cell was ∼500 W·h/kg, which is much higher than that of current Li-ion cells. Even after 1500 cycles, we demonstrate a very high specific capacity, which corresponds to ∼414 mA·h/g of electrode: still higher than state-of-the-art Li-ion cells. Moreover, these Li/S cells with lithium metal electrodes can be cycled with an excellent Coulombic efficiency of 96.3% after 1500 cycles, which was enabled by our new formulation of the ionic liquid-based electrolyte. The performance we demonstrate herein suggests that Li/S cells may already be suitable for high-power applications such as power tools. Li/S cells may now provide a substantial opportunity for the development of zero-emission vehicles with a driving range similar to that of gasoline vehicles. © 2013 American Chemical Society.

Previous research has consistently demonstrated the importance of parents' expectations and adolescents' expectations on adolescents' academic achievement. Less is known, however, about the reciprocal relationships among these constructs. To address this issue, we analyzed two waves of data from the National Education Longitudinal Study of 1988 using longitudinal cross-lagged path models. The sample consisted of 14,376 students. Results indicated that there was a reciprocal relationship between parents' expectations and adolescents' expectations. Moreover, there was a reciprocal relationship between expectations and adolescents' academic achievement. Multiple-group analyses of gender and ethnicity revealed that the effects of parents' expectations on students' expectations were stronger among males than among females. With respect to ethnic differences, the effects of adolescents' expectations were weakest on parents' expectations among African Americans as compared to the other ethnic groups. Implications of these findings are discussed. © 2010 The Author.

Some scholars concluded that mind-body theories had come to an impasse. Trying to include mental phenomenon addressed in Buddhism and other value-seeking philosophies in eastern cultures, this thesis provides a solution based on a recognition of a wider range of the mental phenomena and the differences of their qualities. Through a “census” of most types and constitutes of mental phenomena and their qualities, we claim that there are at least four kinds of mind-body relation: the relation between the mind and the body as a whole, between the mind as a whole and constitutive parts of the body, between types of mental phenomena and constitutive parts of the body, and between types of mental phenomena and the body as a whole.

Most scholars believe that western philosophy of mind is endowed with the truth-seeking goal in its investigation of the nature of the mind, whereas Chinese philosophy of mind aims at the value-seeking objective through its endeavors to the interpretation of the mind’s function to human being’s becoming saints. However, we insist that, besides the value-seeking tendency, the Chinese philosophy of mind also demonstrates its truth-seeking objective. This thesis reveals and reconstructs the focus questions, content and features of the truth-seeking Chinese philosophy of mind by means of looking into the soul concept, mind-body theory, psychological phenomenology and psychosemantics in Chinese philosophy.

Public value facilitates the democratization of public policy making, it should be the common-sense and bottom-line for policymakers. However, it has not been paid enough attention by the practical and theoretical circles. How to realize the transformation from individual value to public value and make public policies be in line with citizens’ preferences, is vital for the democratic politics. How individual value becomes public value in the agenda-setting stage during the policy-making process? What are the key influencing factors? Using the case of Yangzhou Chemical Co. Youjia Program and interview data, this paper studies the mechanisms that could make individual value be transformed to public value through deeply observing and measuring individuals’ attitudes, demands, motivations, beliefs, and preferences. We argue that (1) public value is an essential foundation for agenda setting and guidance to policy making, whereas individual value cannot naturally substitute value orientation in the public sphere. (2) Transferring individual value to public value can reduce divergence appearing in the subsequent stage in policy activities. (3) Factors that can influence this transformation are policy subjects, relations, rule and expression channels with various determinants and conditions. (4) Public value can terminate irrational and unreasonable policies or drag the policy issues back into the agenda-setting stage. This paper provides unique insights into why individual citizens enter the public sphere to take public actions so that the Chinese government can recognize additional public opinions, which makes cooperative governance be realized.

This paper uses agent-based modelling to study the frequent booms and busts in Chinese agricultural markets. First, an artificial agricultural commodity market consisting of heterogeneous agents, such as producers, consumers, and speculators, is built. A numerical simulation suggests that speculation can cause large price fluctuations via nonlinear price dynamics. Then, parameters are estimated by the simulated method of moments using garlic and ginger price data in China from 2006Q2 to 2018Q3. The estimation yields a statistically significant speculative behavior parameter, supporting speculators’ existence. Based on the well-estimated model, a low-cost policy experiment aiming at market stabilization is carried out. The essence of this policy is to release the theoretical steady state of the estimated model as the government-guided price to producers. The guided price, even partially followed by producers, can reduce simulated price variances and weaken speculators’ negative impact on market stability. Robustness tests show that the effect of policy experiment is robust under a 20% change in any parameter value or a 5% change in the guided price.

Considering the importance of China’s digital economy, industrial Internet, and high-quality development, this study analyzed China’s urban network from the perspective of the communications technology service industry. Three sub-networks and a comprehensive network were constructed. The density, centrality, and cohesive subgroups of the above network were identified. The results show that: cohesion of urban networks in China is weak and resource sharing is low. From west to east, the urban network forms a multilevel diamond structure in the periphery, a parallelogram structure in the semiperiphery, and a triangle structure in the center. The spatial distribution of cohesive subgroups is scattered, disobeying the first law of geography. By constructing sub-networks and a comprehensive network, the subnetworks that dominate China’s urban networks were identified and their typical characteristics described. This study clarifies the technical support pattern behind China’s digital economy development and industrial internet construction and provides a basis for policy-makers to optimize the country’s high-quality development in the future.

Technology licensing as a vital part of business behavior in many industries has drawn a fair amount of attention in industrial organization literature. Most existing literature on licensing decisions assumes that all firms engage in Cournot or Bertrand competition, while the type of mixed competition may affect the choice of the licensor. In this context, what decision will the licensor make faced with different mixed competitions? This paper studies the optimal technology licensing contract of a licensor firm engaging in different mixed competitions with a potential licensee in a differentiated duopoly market considering one upstream firm that provides key inputs. We find that if either the royalty or fixed-fee licensing is applied, the licensor favors royalty licensing under Bertrand-Cournot competition when the degree of substitution is small and prefers the fixed-fee licensing no matter under what kind of mixed competition as the degree of substitution increases. In the case of fixed-fee licensing, the result shows that the profits of licensors are the same under different types of mixed competition. Besides, fixed-fee licensing is not always the optimal choice for consumers, and they would prefer royalty licensing when the degree of substitution is very small.

The psychological impact of the COVID-19 epidemic on college students is an important topic. With the entry of the post-epidemic era, how universities can better improve students’ psychological resilience in teaching is the research topic of this article. In the form of a questionnaire survey, some entrepreneurial college students investigated the loneliness and psychological resilience of college students after the outbreak of the epidemic and explored the role of self-efficacy in it. The data is collected online through cooperation with an entrepreneurial event, and the participating students are asked for background information such as colleges, grade, and majors. After collecting this information, they answered a series of simplified scale questions about loneliness, self-efficacy, and psychological resilience. In the end, a total of 200 questionnaires from different universities were collected, and the structural equation model was used to explore the role of self-efficacy. The results show that: loneliness has a significant negative effect on Self-efficacy, β = -0.292, p < 0.001; Self-efficacy has a significant positive effect on psychological resilience, β = 0.556, p < 0.0 01; loneliness has a significant negative effect on psychological resilience, β = -0.244, p < 0.01. Self-Efficacy has a significant intermediate effect in loneliness and psychological resilience, with an effective value of -0.111 and p < 0.01. The results show that this exploratory survey finds it important to provide targeted personal self-efficacy improvement activities for college students with a strong sense of loneliness and to combine school and family education organically to help college students form a healthy and upward mentality to better cope with the unknown and troubles caused by the epidemic, which will help improve the psychological resilience of college students in the epidemic.

At present, people mainly focus on health education for adolescents. The health education of adolescents is related to future of adolescents. In youth, their emotions are easily influenced. Therefore, this manuscript constructs an interactive health education model for adolescents through affective computing. Researchers in various countries have done a lot of research on human–computer interaction, and affective computing is one of the research hotspots. This manuscript aims to study the use of affective computing to construct an interactive health education model for adolescents. It proposed an interactive emotional algorithm based on emotional computing and focuses on the ICABoost algorithm. The experimental results of this paper show that the surveyed junior high school students are divided into three grades: the first, second, and third grades. Among them, 11, 11, and 13 were mentally healthy, with a total percentage of only 18.5%; 16, 14, and 16 were moderately severe in health education, accounting for 24.3%. The percentage of severe cases was 29.6%. It can be seen that, through the investigation of this manuscript, it can be seen that today’s youth health education should be paid attention to. Only by constructing a corresponding interactive health education model for young people can we promote the comprehensive and healthy development of young people.

Congenital nystagmus in infants and young children can lead to early blindness. Previous neuroimaging studies have demonstrated that EB is accompanied by alterations in brain structure and function. However, the effects of visual impairment and critical developmental periods on brain functional connectivity at rest have been unclear. Here, we used the voxel-wise degree centrality method to explore the underlying functional network brain activity in adolescents with EB. Twenty-one patients with EBs and 21 sighted controls underwent magnetic resonance imaging. Differences between the two groups were assessed using the DC method. Moreover, the support vector machine method was used to differentiate patients with EB patients from the SCs according to DC values. Compared with the SCs, the patients with EB had increased DC values in the bilateral cerebellum_6, cerebellum vermis_4_5, bilateral supplementary motor areas, and left fusiform gyrus; the patients with EB had decreased DC values in the bilateral rectal gyrus and left medial orbital frontal gyrus. The SVM classification of the DC values achieved an overall accuracy of 70.45% and an area under the curve of 0.86 in distinguishing between the patients with EB and the SCs. Our study may reveal the neuromechanism of neuroplasticity in EB; the findings provide an imaging basis for future development of restorative visual therapies and sensory substitution devices, and future assessments of visual rehabilitation efficacy.

In service marketing, AI assistants and self-service technology have become popular. As a result, it is critical to enrich the understanding of whether consumers react differently in the artificial intelligence service context in comparison with the human service context. This study examines the effect of assistant type on consumers’ decision-making. Through three experiments, this research finds that variety seeking will be higher when consumers are making decision in AI service environment. Furthermore, we tested uncertainty as the underlying mechanism. Moreover, we demonstrated that this pattern is moderated by situational involvement. Specifically, in consumption contexts of high involvement, the consumers are less likely to seek variety, and in consumption contexts of low involvement, they prefer more variety. This research offers service providers new insights by revealing how, why, and when the interaction of AI technology influences consumers’ decision-making in service marketing.

Currently, advancements in information and communication technology and an increased interest in using the Internet for educational purposes have led educators to work in new virtual settings. However, using technology in teaching requires the understanding and information of English educators. Technological Pedagogical Content Knowledge is an educator's knowledge concept regarding integrating technology into education. Also, how educators integrate technology effectively into their classes is a significant issue, as learning environments are influenced by rapid advances in instructional technology. Consistent with this issue, it is critical for teacher development to integrate ICT into educational tasks in the design, application, and assessment of practices in a virtual setting. To this end, the objective of the present review is to consider the role of practice in the virtual platform in developing EFL teachers' TPACK. Ultimately, some implications are presented for the EFL educational stakeholders.

The automated valuation of benchmark land price plays an essential role in regulating land demand in Chinese real-estate market as the big data are currently accumulated rapidly. However, this problem becomes highly challenging due to the multidimension, large volume, and nonlinearity of the land price-influencing factors. In this paper, an effective data-driven automated valuation framework is proposed for valuing real estate assets by combining a GIS and neural network technologies. This framework can automatically obtain the values of spatial factors affecting land price from GIS and generate training set data for training the neural network to identify the complex relationship between all kinds of factors and benchmark land prices. The effectiveness and universality of the framework is verified via the data of benchmark land prices in Wuhan. The framework can be applied for automated benchmark land price valuation in other cities.

© 2016 IOP Publishing Ltd.Few-layer thick MoSe2 and WSe2 possess non-trivial spin textures with sizable spin splitting due to the inversion symmetry breaking embedded in the crystal structure and strong spin-orbit coupling. We report a spin-resolved photoemission study of MoSe2 and WSe2 thin film samples epitaxially grown on a bilayer graphene substrate. We only found spin polarization in the single-and trilayer samples-not in the bilayer sample-mostly along the out-of-plane direction of the sample surface. The measured spin polarization is found to be strongly dependent on the light polarization as well as the measurement geometry, which reveals intricate coupling between the spin and orbital degrees of freedom in this class of material.

© 2015 American Chemical Society.Near-infrared dye-sensitized upconversion nanoparticles can broaden the absorption range and boost upconversion efficiency of UCNPs. Here, we achieved significantly enhanced upconversion luminescence in dye-sensitized core/active shell UCNPs via the doping of ytterbium ions in the UCNP shell, which bridged the energy transfer from the dye to the UCNP core. As a result, we synergized the two most practical upconversion booster effectors to amplify upconversion efficiency. We demonstrated two biomedical applications using these UCNPs. By using dye-sensitized core/active shell UCNP embedded poly polymer implantable systems, we successfully shifted the optogenetic neuron excitation window to a biocompatible and deep tissue penetrable 800 nm wavelength. Furthermore, UCNPs were water-solubilized with Pluronic F127 with high upconversion efficiency and can be imaged in a mouse model.

Resistance to anoikis, or apoptosis triggered by detachment from the extracellular matrix, lengthens the survival of malignant cells, facilitating reattachment and colonization of secondary sites. To examine the molecular mechanisms underlying resistance to anoikis in human oral squamous cell carcinoma cells, we cultured human squamous carcinoma cells in suspension on plates coated with poly-2-hydroxyethyl methacrylate, which blocks access to the ECM. Cells in suspension that formed multicellular aggregates had significantly lower levels of apoptosis than single cells. Aggregates, but not single cells, had high levels of fibronectin. Preincubation with a cyclic arginine-glycine-aspartic acid peptide or fibronectin-blocking antibody significantly increased anoikis. Single cells had markedly lower expression of the integrin αv receptor than aggregates. Blocking αv function with a blocking antibody or by transfection with an antisense oligonucleotide increased apoptosis and inhibited aggregation. In single cells but not aggregates, phosphorylation of the integrin-associated focal adhesion kinase at tyrosine 397 was reduced, and p53 levels were increased. Apoptosis was increased by blocking FAK with an antisense oligonucleotide and reduced by blocking p53. These findings show that SCC cells escape suspension-induced anoikis by forming multicellular aggregates that avail themselves of fibronectin survival signals mediated by integrin αv. Single cells in suspension that do not form aggregates undergo anoikis because of decreased FAK phosphorylation and increased p53 levels. Thus, SCC cells appear to use neighboring cells and the ECM molecule FN to promote the metastatic phenotype.

Ultra-high isotropic resolution imaging of retinal structures was made possible with an adaptive optics system using dual deformable mirrors and a Fourier-domain optical coherence tomography system with correction for longitudinal chromatic aberration. This system was used to image microscopic retinal structures of healthy as well as diseased retinas in vivo. The improved resolution and contrast enhanced visualization of morphological structures in the retina can be clearly seen. The benefits of this instrument are apparent from comparison of new images with those acquired using a previous generation AO-OCT instrument. Big change in the appearance of speckle field can be observed as well. Additionally, further improvements in volumetric data acquisition and image representation will be discussed. This includes creation of large Field of View AO-OCT volume from multiple sub-volumes and its visualization. Also techniques and results of reducing speckle contrast by averaging multiple B-scans will be presented.