The Non-Singular Fast Terminal Sliding Mode Control of Interior Permanent Magnet Synchronous Motor Based on Deep Flux Weakening Switching Point Tracking

This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.

Fluorescent polymer-modified gold nanobipyramids for temperature sensing during photothermal therapy in living cells

The temperature monitoring of treated cancer cells is critical in photothermal therapy.Current methods of detecting intracellular temperatures have low accuracy and poor spatial resolution,which limits their application to photothermal therapy.Herein,a strategy for targeted recognition and selective capture of MCF-7 breast cancer cells based on fluorescent polymer poly(N-isopropylacrylamide-benzoxadiazole-2-vinyl-4,4-dimethyl azlactone,PNMV)and modified gold nanobipyramids(Au NBPs-PNMV)was developed for temperature sensing during photothermal therapy.A mucin-1 protein aptamer(Apt)was applied to selectively target mucin-1 protein overexpressed on the surfaces of the MCF-7 cells,which can reduce interference by affinity interaction between the Apt and proteins.During photothermal therapy,the significant Au NBPs photothermal effect increases the fluorescence intensity of PNMV with temperature.Irradiation of MCF-7 cells cultured with Au NBPs-PNMV@Apt by an 808 nm laser increases the temperature of the system,while the cells can be inactivated because of the remarkable Au NBPs-PNMV@Apt photothermal effect.The results indicate that variation in the fluorescence of Au NBPs-PNMV@Apt can be applied as thermometers to monitor the intracellular effect of photothermal therapy.

Aquafeed fermentation improves dietary nutritional quality and benefits feeding behavior,meat flavor,and intestinal microbiota of Chinese mitten crab(Eriocheir sinensis)

Normally,proper fermentation can be an efficient and widely used method to improve feed quality in animal rearing;however,the studies on crustaceans,especially Eriocheir sinensis,remain limited.This study aimed to investigate whether feed fermentation could meliorate dietary nutritional value and benefit E.sinensis rearing.First,non-fermented feed(NFD)and fermented feed(FD)were produced and assessed,respectively.Then,the“Y”maze feed choice behavior test(180 times;30 times,6 rounds)was conducted to assess the attractiveness of these 2 feeds for crabs.Finally,a total of 80 crabs(44.10±0.80 g)were randomly assigned into 2 groups with 4 replicates,and fed the experimental diets for 8 weeks to evaluate the effects of each feed on growth,antioxidant capacity,meat flavor,and intestinal microbiota.In this study,FD showed higher levels of crude protein(P<0.01),soluble protein(P<0.01),amino acids(P<0.05),lactic acid(P<0.001),and lower levels of crude fiber(P<0.05)and antinutritional factors(agglutinin,trypsin inhibitor,glycinin,andβ-conglycinin)(P<0.001)than NFD.Additionally,FD was more attractive to crabs than NFD(P<0.01)and it stimulated the appetite of crabs more than NFD(P<0.05).The growth performance,feed efficiency,and digestive enzyme activity of FDfed crabs were significantly higher than those of NFD-fed crabs(P<0.05).The electronic sensory measurements and free amino acid profiles revealed that the FD diet had positive impacts on the meat flavor of crabs,particularly in“sweet”and“umami”tastes.Moreover,the antioxidant capacity of FD-fed crabs was significantly higher than that of NFD-fed crabs(P<0.05).Fermented feed also affected the diversity and composition of intestinal microflora.The functional prediction of microbial communities showed that crabs fed FD had a better microecological environment in the intestine.In conclusion,the fermentation of aquafeed could be an effective approach to enhance feed quality and therefore benefit E.sinensis rearing.

A critical literature review of bioretention research for stormwater management in cold climate and future research recommendations

Bioretention is a popular best management practice of low impact development that el/ecUvely restores urban hydrologic characteristics to those ofpredevelopment and improves water quality prior to conveyance to surface waters. This is achieved by utilizing an engineered system containing a surface layer of mulch, a thick soil media often amended with a variety of materials to improve water oualitv, a variety of vegetation, and underdrains, depending on the surrounding soil characteristics.Bioretention systems have been studied quite extensively for warm climate applications, but ctata strongly supporting their long-tema efficacy and application in cold climates is sparse. Although it is apparent that biorelention is an effective stormwater management system, its design in cold climate needs further research. Existing cold climate research has shown that coarser media is required to prevent concrete frost from forming. For spring, summer and fall seasons, if sufficient permeability exists to drain the system prior to freezing, peak flow and volume reduction can be maintained. Additionally. contaminants that are removed via filtration are also not impacted by cold climates. In contrary, dissolved contaminants, nutrients, and organics are significantly more variable in their ability to be removed or degraded via bioretention in colder temperatures. Winter road maintenance salts have been shown to negatively impact the removal of some contaminants and positively impact others, while their effects on properly selected vegetation or bacteria health are also not well understood. Research in these water quality aspects has been inconsistent and therefore requires further study.

Optimal Implementation Strategy of Carbon Emission Reduction Policy Instruments in Consideration of Cost Efficiency

In this paper, regulatory and optimum programming model has been adopted. Considering the costs of emission reduction, supervision and penalty, we went all out to analyze the optimal decision of cost efficiency of regulators when implementing these three policy instruments: carbon emission standards, carbon emission trading permissions, and carbon taxes as well. Its result has indicated: In strict accordance with control target of total carbon emissions, regulators are willing to render social and economic cost able to achieve the goal of optimal cost efficiency by regulating carbon emission standards and supervising marginal cost caused by variations in the probability; fortunately, under the conditions of low supervisory cost and certain criteria which is met, the implementation of carbon emission trading permissions could provide social and economic cost with opportunities to realize that objective; through comparative analysis, carbon emission trading permissions have the advantages of higher efficiency than carbon emission standards on the premise of incomplete information. During the implementation of carbon taxes strategy, when there exists uncertainty information in the enterprises reduction behaviors, the condition which enterprises can fully comply with is the tax rate level is not higher than marginal penalty function; the tax rate level of enterprises perfect compliance ought not to be lower than the division of marginal penalty cost and marginal supervisory cost. The optimal strategy of enterprises imperfect compliance is that regulators varying the marginal cost of emission standards is equal to varying that of supervisory probability.

Policy spillover and regional linkage characteristics of the real estate market in China's urban agglomerations

The main purpose of this study is to determine the spillover effect of real estate regulatory policies released by core cities on the surrounding cities in major urban agglomerations based on regional linkage characteristics of China's real estate market.In this study,real estate transaction data of 157 cities were selected from 11 major urban agglomerations.Agglomeration's housing transaction volatility and spillover effect caused by the core city's regulatory policies were simulated by integrating spatial and temporal analysis model,event analysis,and symbolic time series analysis.The findings showed that(1)the regional linkage of the real estate market in the Harbin-Changchun and Middle-South Liaoning,Middle Reaches of the Yangtze River,Yangtze River Delta,Pearl River Delta,and West Side of the Straits agglomerations were remarkably tight and the core cities'policy spillover effect was significant,of which the house purchase limitation and credit limitation policies had the widest influence;(2)the regional linkage of the real estate market in the Beijing-Tianjin-Hebei agglomeration,Shandong Peninsula,Guanzhong Plain,and Chengdu-Chongqing agglomerations was relatively weaker,but the core cities'policies of mar-ket regulation and taxation had certain spillover effect;(3)there were significant differ-ences in the spillover effects of different types of policies in different urban agglomerations;(4)generally,the core cities'policy spillover often reduced the changing characteristics of the real estate market and made it more ordered with more certainty in the whole agglomeration,with the exception of the Beijing-Tianjin-Hebei,West Side of the Straits,and Chengdu-Chongqing agglomerations.

Localized or Regional? Urban Housing Policy Spillover in China’s Urban Agglomerations 2010–2018

Spatio-temporal model and event analysis were integrated in this paper, with 156 prefecture level cities’ housing transaction data and 167 items policies proposed by 10 central cities between January, 2010 and December, 2018 as samples. This paper studied the regional and cross-regional spillover effects of central cities’ urban housing regulation policies to the peripheral cities in the scope of urban agglomerations, as well as the policy-driven interactions of different regional real estate markets. The results indicated that: China’s regional housing market has obvious characteristics of policy orientation, of which the regulation measures on some central cities can affect the residential market and produce certain spillover interference on the market fluctuations of peripheral cities in time and space dimension. When geographical factor was considered, the 10 central cities had different degree of policy spillover effects caused by distinct policy types in their respective urban agglomerations. When ignoring spatial factors, restrictive policies in Beijing, Shanghai, Zhengzhou, Xi’an, Wuhan and Shenzhen had significant cross-regional spillover effects and drove the surrounding housing markets to have geared interactions, which to a certain extent revealed the flowing way of population and wealth in China’s regional economy during the past dozen years.

基于低轨卫星网络的遥感卫星任务计算卸载策略

在低轨卫星上部署边缘服务器,可以将遥感卫星产生的遥感卫星任务在靠近边缘端进行处理,减少了任务传输时延的同时,极大的缓解了遥感卫星的计算压力。然而,由于低轨卫星自身能源有限,过度使用能源可能会缩短其寿命。此外,当大量遥感卫星任务产生时,计算资源遭遇短缺,从而增加了任务处理的延迟。因此,针对上述问题,提出了一种基于Dueling DQN的遥感卫星任务计算卸载策略,该策略可以充分利用低轨卫星的计算资源,并最大程度上减少任务处理能源消耗。最后,大量仿真结果表明,与其他卸载方法相比,所提策略能有效降低系统任务处理的平均能耗。

Dynamics design of a non-natural transcription factor responding to androst-4-ene-3,17-dione

The production of androst-4-ene-3,17-dione(AD)by the steroidal microbial cell factory requires transcription factors(TFs)to participate in metabolic regulation.However,microbial cell factory lacks effective TFs that can respond to AD in its metabolic pathway.Additionally,finding and obtaining natural TFs that specifically respond to AD is a complex and onerous task.In this study,we devised an artificial TF that responds to AD,termed AdT,based on structure-guided molecular dynamics(MD)simulation.According to MD analysis of the conformational changes of AdT after binding to AD,an LBD in which the N-and C-termini exhibited convergence tendencies was used as a microswitch to guide the assembly of a DNA-binding domain lexA,a linker(GGGGS)2,and a transcription activation domain B42 into an artificial TF.As a proof of design,a AD biosensor was designed and constructed in yeast on the basis of the ligand-binding domain(LBD)of hormone receptor.In addition,the transcription factor activity of AdT was increased by 1.44-fold for its variant F320Y.Overall,we created non-natural TF elements for AD microbial cell factory,and expected that the design TF strategy will be applied to running in parallel to the signaling machinery of the host cell.

Intrinsic effects of precursor functional groups on the Na storage performance in carbon anodes

The oxygen-containing functional groups in disordered carbon anodes have been widely reported to influence the Na storage performance.However,the effect of original oxygen-containing groups in the precursors on the final structures and electrochemical performance is rarely studied.Herein,we used the anthraquinone derivatives with different oxygen-containing functional groups as precursors to make the disordered carbon anodes for Na-ion batteries(NIBs).Through comprehensive structural and electrochemical analyses,we found that the different types of functional groups in carbon precursors directly affect the cross-linking process during carbonization.The original precursors containing enough inter-chain oxygen or oxygen-containing functional groups with unsaturated bonds unattached to the ring are beneficial for the oxygen atoms to remain or cross-link in structure to result in more C–O–C group,forming nanovoids and disordered structure,which then determine the high performance of the carbon anodes in NIBs.This work highlights the importance of the type/content of functional groups in precursor and provides guidance for the future design of carbon anodes in NIBs from the perspective of precursor selection.

The Role of Social Media in Providing Crisis Information in China:A Critical Evaluation of the Tianjin Fire Incident

This paper focusses on the information asymmetry in crisis news after a serious incident in Tianjin, China, in 2015. The incident caused enormous damage and resulted in societal unrest because of the lack of reliable information from the formal media channels. Social media — micro blogs —played a major role in reporting on crisis situations. We divided netizens(i.e., the citizens of the net)into high and low types according to their information-critical level to the crisis news. The data shows information deterioration on the crisis news, related to the netizens’ information-critical level. For the traditional media there is the opportunity to use information quality distortion to make more marginal profits. This is possible only if the citizens’ information stays under a certain quality level. The result is overprovision of low quality news and high quality news driven out of the market, whereupon adverse selection(i.e., a lack of symmetric information) appears. However, by adopting a process view, we found self-correcting mechanism(i.e., dying out of rumors) of the social media communities in China.We provided a agent-base model and simulation to show that the more media exist in the market, the faster speed of the information deterioration, but also the capacity to ‘discuss’ rumors.

Simulation Study on Emergency Evacuation Behavior of College Students in Considering the Influence of Dormitory Interpersonal Relationship

As one of the most common social relationships among college students,the dormitory interpersonal relationship has important effects on students'psychology and behavior.For quantitative analysis of the dormitory interpersonal influence on college students'emergency evacuation behavior,an evacuation simulation experiment of college students carried out and coupling questionnaire survey,measurement and social force model of society to visualize the normal dormitory interpersonal relationship and emergency evacuation following relationship of college students,then simulation experiment is used to explore the impact of different types of dormitory relationship structure on emergency evacuation.The results show that dormitory interpersonal relationship is an important component of college students'interpersonal network and has an important impact on emergency evacuation behavior.The close and united dormitory relationship has a good promotion effect on the emergency evacuation efficiency.When the emergency occurs,the dormitory interpersonal relationship of college students will partly transform into the leader-following behavior relationship,and the evacuation efficiency will decrease.The influence of dormitory interpersonal relationship on evacuation behavior is related to gender and grade which is higher for female students than male students,and is higher for junior students than senior students.