First demonstration of a self-aligned p-channel GaN back gate injection transistor

In this study,we present the development of self-aligned p-channel Ga N back gate injection transistors(SA-BGITs)that exhibit a high ON-state current.This achievement is primarily attributed to the conductivity modulation effect of the 2-D electron gas(2DEG,the back gate)beneath the 2-D hole gas(2DHG)channel.SA-BGITs with a gate length of 1μm have achieved an impressive peak drain current(I_(D,MAX))of 9.9 m A/mm.The fabricated SA-BGITs also possess a threshold voltage of 0.15 V,an exceptionally minimal threshold hysteresis of 0.2 V,a high switching ratio of 10~7,and a reduced ON-resistance(RON)of 548Ω·mm.Additionally,the SA-BGITs exhibit a steep sub-threshold swing(SS)of 173 mV/dec,further highlighting their suitability for integration into Ga N logic circuits.

A method for Improving the Efficiency of Pear Tree Crossbreeding

In view of the short blooming period of pear tree crossbreeding and the complexity of pollination process, a method that can improve the efficiency of crossbreeding of pear trees was provided. Meanwhile, this method can also be applied to the study of pollen xenia effect, pollination tree selection and pure pollen collection in pear tree cultivation.

Study of Effects of Plant Growth Regulators on Fruit Quality of Table Grape

The effects of different treatments on the seedlessness and fruit quality of‘Miguang’table grape was studied by using plant growth regulators,gibberellin acid(GA 3)and forchlorfenuron(CPPU),under different concentrations and application time.The results showed that the effects of different treatments on the seedlessness and fruit quality were different.Seedless rate,cluster weight,berry weight,berry shape index,soluble solid content,total acid content,soluble solids to acidity ratio,pulling resistance,turgor pressure and flesh firmness without skin were comprehensively evaluated,as a result of which,the optimum treatment on‘Miguang’table grape was to apply with GA 320 mg/L+SM 200 mg/L at one week before bloom and GA 325 mg/L+CPPU 3 mg/L at two weeks after bloom.

Thrombin increases the expression of cholesterol 25-hydroxylase in rat astrocytes after spinal cord injury

Astrocytes are important cellular centers of cholesterol synthesis and metabolism that help maintain normal physiological function at the organism level.Spinal cord injury results in aberrant cholesterol metabolism by astrocytes and excessive production of oxysterols,which have profound effects on neuropathology.25-Hydroxycholesterol(25-HC),the main product of the membrane-associated enzyme cholesterol-25-hydroxylase(CH25H),plays important roles in mediating neuroinflammation.However,whether the abnormal astrocyte cholesterol metabolism induced by spinal cord injury contributes to the production of 25-HC,as well as the resulting pathological effects,remain unclear.In the present study,spinal cord injury-induced activation of thrombin was found to increase astrocyte CH25H expression.A protease-activated receptor 1 inhibitor was able to attenuate this effect in vitro and in vivo.In cultured primary astrocytes,thrombin interacted with protease-activated receptor 1,mainly through activation of the mitogen-activated protein kinase/nuclear factor-kappa B signaling pathway.Conditioned culture medium from astrocytes in which ch25h expression had been knocked down by siRNA reduced macrophage migration.Finally,injection of the protease activated receptor 1 inhibitor SCH79797 into rat neural sheaths following spinal cord injury reduced migration of microglia/macrophages to the injured site and largely restored motor function.Our results demonstrate a novel regulatory mechanism for thrombin-regulated cholesterol metabolism in astrocytes that could be used to develop anti-inflammatory drugs to treat patients with spinal cord injury.

High-performance enhancement-mode GaN-based p-FETs fabricated with O_(3)-Al_(2)O_(3)/HfO_(2)-stacked gate dielectric

In this letter,an enhancement-mode(E-mode)GaN p-channel field-effect transistor(p-FET)with a high current den-sity of−4.9 mA/mm based on a O_(3)-Al_(2)O_(3)/HfO_(2)(5/15 nm)stacked gate dielectric was demonstrated on a p++-GaN/p-GaN/AlN/AlGaN/AlN/GaN/Si heterostructure.Attributed to the p++-GaN capping layer,a good linear ohmic I−V characteristic fea-turing a low-contact resistivity(ρc)of 1.34×10^(−4)Ω·cm^(2) was obtained.High gate leakage associated with the HfO_(2)high-k gate dielectric was effectively blocked by the 5-nm O_(3)-Al_(2)O_(3)insertion layer grown by atomic layer deposition,contributing to a high ION/IOFF ratio of 6×10^(6)and a remarkably reduced subthreshold swing(SS)in the fabricated p-FETs.The proposed structure is compelling for energy-efficient GaN complementary logic(CL)circuits.

Fluid simulation of the effect of a dielectric window with high temperature on plasma parameters in inductively coupled plasma

To maintain the high-density plasma source in inductively coupled plasma(ICP),very high radiofrequency power is often delivered to the antenna,which can heat the dielectric windows near the antenna to high temperature.This high temperature can modulate the plasma characteristics to a large degree.We thus study the effect of dielectric window temperature on plasma parameters in two different ICP structures based on COMSOL software.The distributions of various plasma species are examined at different dielectric window temperatures.The concentration of neutral gas is found to be largely modulated at high dielectric window temperature,which further affects the electron collision probability with neutrals and the electron temperature.However,the electron density profiles are barely affected by the dielectric window temperature,which is mainly concentrated at the center of the reactor due to the fixed power input and pressure.

3D fluid model analysis on the generation of negative hydrogen ions for negative ion source of NBI

A radio-frequency(RF) inductively coupled negative hydrogen ion source(NHIS) has been adopted in the China Fusion Engineering Test Reactor(CFETR) to generate negative hydrogen ions.By incorporating the level-lumping method into a three-dimensional fluid model,the volume production and transportation of H^(-) in the NHIS,which consists of a cylindrical driver region and a rectangular expansion chamber,are investigated self-consistently at a large input power(40 k W) and different pressures(0.3–2.0 Pa).The results indicate that with the increase of pressure,the H^(-) density at the bottom of the expansion region first increases and then decreases.In addition,the effect of the magnetic filter is examined.It is noteworthy that a significant increase in the H^(-) density is observed when the magnetic filter is introduced.As the permanent magnets move towards the driver region,the H^(-) density decreases monotonically and the asymmetry is enhanced.This study contributes to the understanding of H-distribution under various conditions and facilitates the optimization of volume production of negative hydrogen ions in the NHIS.

Optimization of Electricity Purchase and Sales Strategies of Electricity Retailers under the Condition of Limited Clean Energy Consumption

In the process of my country’s energy transition,the clean energy of hydropower,wind power and photovoltaic power generation has ushered in great development,but due to the randomness and volatility of its output,it has caused a certain waste of clean energy power generation resources.Regarding the purchase and sale of electricity by electricity retailers under the condition of limited clean energy consumption,this paper establishes a quantitative model of clean energy restricted electricity fromthe perspective of power system supply and demand balance.Then it analyzes the source-charge dual uncertain factors in the electricity retailer purchasing and selling scenarios in the mid-to long-term electricity market and the day-ahead market.Through the multi-scenario analysis method,the uncertain clean energy consumption and the user’s power demand are combined to form the electricity retailer’s electricity purchase and sales scene,and the typical scene is obtained by using the hierarchical clustering algorithm.This paper establishes a electricity retailer’s risk decisionmodel for purchasing and selling electricity in themid-and long-term market and reduce-abandonment market,and takes the maximum profit expectation of the electricity retailer frompurchasing and selling electricity as the objective function.At the same time,in themediumand longterm electricity market and the day-ahead market,the electricity retailer’s purchase cost,electricity sales income,deviation assessment cost and electricity purchase and sale risk are considered.The molecular results show that electricity retailers can obtain considerable profits in the reduce-abandonment market by optimizing their own electricity purchase and sales strategies,on the premise of balancing profits and risks.

母亲教养行为在幼儿气质对执行功能影响中的调节作用

儿童执行功能的发展不仅受到气质等自身因素的影响,而且也受到家长教养行为等外部因素的作用.本研究以139名幼儿为研究对象,考察小班时幼儿气质对中班时幼儿执行功能的影响,并探究母亲自主支持和体罚行为的调节作用.结果发现,幼儿外倾性显著负向预测抑制控制,消极情绪显著负向预测调节能力和工作记忆,努力控制显著正向预测调节能力和工作记忆.母亲的自主支持可以缓解消极情绪对调节能力的消极作用,而母亲体罚行为可以抑制努力控制对调节能力和工作记忆的积极作用.母亲应尊重幼儿气质特点,采取自主支持行为,避免体罚,努力为幼儿执行功能的发展营造和谐、安全的家庭环境.

家长视角下的幼儿园教师家园合作能力

家园合作需要教师与家长双方的参与和配合,家长对教师的角色需求对家园合作效果至关重要。本研究采用行为事件访谈法,对60名3~6岁幼儿的家长进行半结构式访谈,以探讨家长视角下的幼儿园教师家园合作能力结构。结果发现家长认为幼儿园教师应具备支持儿童发展的能力、支持父母的能力及相应的个人品质才有可能做好家园合作工作。支持儿童发展的能力具体包括专业知识、关心能力、观察了解能力、个性化教育能力和问题解决能力。支持父母的能力具体包括课程可视化能力、教养支持能力、信息沟通能力、解读家长类型的能力和计划与组织家长活动的能力。应具备的个人品质具体包括换位思考能力、自我情绪控制、反思与自我发展。幼儿园教师职前培养和职后培训都应关注幼儿园教师家园合作能力的发展,注意让教师对家园合作中教师与家长都特别关注或者容易出现问题的环节进行针对性的学习。

In-plane dynamics of a fluid-conveying corrugated pipe supported at both ends

The dynamics and stability of fluid-conveying corrugated pipes are investigated. The flow velocity is assumed to harmonically vary along the pipe rather than with time. The dimensionless equation is discretized with the differential quadrature method (DQM). Subsequently, the effects of the mean flow velocity and two key parameters of the corrugated pipe, i.e., the amplitude of the corrugations and the total number of the corrugations, are studied. The results show that the corrugated pipe will lose stability by flutter even if it has been supported at both ends. When the total number of the corrugations is sufficient, this flutter instability occurs at a micro flow velocity. These phenomena are verified via the Runge-Kutta method. The critical flow velocity of divergence is analyzed in detail. Compared with uniform pipes, the critical velocity will be reduced due to the corrugations, thus accelerating the divergence instability. Specifically, the critical flow velocity decreases if the amplitude of the corrugations increases. However, the critical flow velocity cannot be monotonously reduced with the increase in the total number of the corrugations. An extreme point appears, which can be used to realize the parameter optimization of corrugated pipes in practical applications.

A Privacy-Preserving Mechanism Based on Local Differential Privacy in Edge Computing

With the development of Internet of Things(IoT),the delay caused by network transmission has led to low data processing efficiency.At the same time,the limited computing power and available energy consumption of IoT terminal devices are also the important bottlenecks that would restrict the application of blockchain,but edge computing could solve this problem.The emergence of edge computing can effectively reduce the delay of data transmission and improve data processing capacity.However,user data in edge computing is usually stored and processed in some honest-but-curious authorized entities,which leads to the leakage of users’privacy information.In order to solve these problems,this paper proposes a location data collection method that satisfies the local differential privacy to protect users’privacy.In this paper,a Voronoi diagram constructed by the Delaunay method is used to divide the road network space and determine the Voronoi grid region where the edge nodes are located.A random disturbance mechanism that satisfies the local differential privacy is utilized to disturb the original location data in each Voronoi grid.In addition,the effectiveness of the proposed privacy-preserving mechanism is verified through comparison experiments.Compared with the existing privacy-preserving methods,the proposed privacy-preserving mechanism can not only better meet users’privacy needs,but also have higher data availability.

Overexpression of IbPAL1 promotes chlorogenic acid biosynthesis in sweetpotato

Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities,is distributed in all edible parts of sweetpotato.However,little is known about the specific metabolism of CGA in sweetpotato.In this study,IbPAL1,which encodes an endoplasmic reticulum-localized phenylalanine ammonia lyase(PAL),was isolated and characterized in sweetpotato.CGA accumulation was positively associated with the expression pattern of IbPAL1 in a tissue-specific manner,as further demonstrated by overexpression of IbPAL1.Overexpression of IbPAL1 promoted CGA accumulation and biosynthetic pathway genes expression in leaves,stimulated secondary xylem cell expansion in stems,and inhibited storage root formation.Our results support a potential role for IbPAL1 in sweetpotato CGA biosynthesis and establish a theoretical foundation for detailed mechanism research and nutrient improvement in sweetpotato breeding programs.

Multi-Objective Task Assignment for Maximizing Social Welfare in Spatio-Temporal Crowdsourcing

With the development of the Internet of Things(IoT),spatio-temporal crowdsourcing(mobile crowdsourcing)has become an emerging paradigm for addressing location-based sensing tasks.However,the delay caused by network transmission has led to low data processing efficiency.Fortunately,edge computing can solve this problem,effectively reduce the delay of data transmission,and improve data processing capacity,so that the crowdsourcing platform can make better decisions faster.Therefore,this paper combines spatio-temporal crowdsourcing and edge computing to study the Multi-Objective Optimization Task Assignment(MOO-TA)problem in the edge computing environment.The proposed online incentive mechanism considers the task difficulty attribute to motivate crowd workers to perform sensing tasks in the unpopular area.In this paper,the Weighted and Multi-Objective Particle Swarm Combination(WAMOPSC)algorithm is proposed to maximize both platform’s and crowd workers’utility,so as to maximize social welfare.The algorithm combines the traditional Linear Weighted Summation(LWS)algorithm and Multi-Objective Particle Swarm Optimization(MOPSO)algorithm to find pareto optimal solutions of multi-objective optimization task assignment problem as much as possible for crowdsourcing platform to choose.Through comparison experiments on real data sets,the effectiveness and feasibility of the proposed method are evaluated.

Bioinspired soft actuators with highly ordered skeletal muscle structures

Mammals such as humans develop skeletal muscles composed of muscle fibers and connective tissue,which have mechanical properties that enable power output with three-dimensional motion when activated.Artificial muscle-like actuators developed to date,such as the McKibben artificial muscle,often focus sole contractile elements and have rarely addressed the contribution of flexible connective tissue that forms an integral part of the structure and morphology of biological muscle.Herein,we present a class of pneumatic muscle-like actuators,termed highly mimetic skeletal muscle(HimiSK)actuator,that consist of parallelly arranged contractile units in a flexible matrix inspired by ultrasonic measurements on skeletal muscle.The contractile units act as a muscle fiber to produce active shortening force,and the flexible matrix functions as connective tissue to generate passive deformation.The application of positive pressure to the contractile units can produce a linear contraction and force.In this actuator,we assign different flexible materials as contractile units and a flexible matrix,thus forming five mold actuators.These actuators feature three-dimensional motion on activation and present both intrinsic force-velocity and force-length characteristics that closely resebmle those of a biological muscle.High output and tetanic force produced by harder contractile units improve the maximum output force by up to about 41.3%and the tetanic force by up to about 168%.Moreover,high displacement and velocity can be generated by a softer flexible matrix,with the improvement of maximum displacement up to about 33.3%and velocity up to about 73%.The results demonstrate that contractile units play a crucial role in force generation,while the flexible matrix has a significant impact on force transmission and deformation;the final force,velocity,displacement,and three-dimensional motion results from the interplay of contractile units,fluid and flexible matrix.Our approach introduces a model of the presented HimiSK actuators to better understand the mechanical behaviors,force generation,and transmission in bioinspired soft actuators,and highlights the importance of using flexible connective tissue to form a structure and configuration similar to that of skeletal muscle,which has potential usefulness in the design of effective artificial muscle.

Multi-stage online task assignment driven by offline data under spatio-temporal crowdsourcing

In the era of the Internet of Things(IoT),the crowdsourcing process is driven by data collected by devices that interact with each other and with the physical world.As a part of the IoT ecosystem,task assignment has become an important goal of the research community.Existing task assignment algorithms can be categorized as offline(performs better with datasets but struggles to achieve good real-life results)or online(works well with real-life input but is difficult to optimize regarding in-depth assignments).This paper proposes a Cross-regional Online Task(CROT)assignment problem based on the online assignment model.Given the CROT problem,an Online Task Assignment across Regions based on Prediction(OTARP)algorithm is proposed.OTARP is a two-stage graphics-driven bilateral assignment strategy that uses edge cloud and graph embedding to complete task assignments.The first stage uses historical data to make offline predictions,with a graph-driven method for offline bipartite graph matching.The second stage uses a bipartite graph to complete the online task assignment process.This paper proposes accelerating the task assignment process through multiple assignment rounds and optimizing the process by combining offline guidance and online assignment strategies.To encourage crowd workers to complete crowd tasks across regions,an incentive strategy is designed to encourage crowd workers’movement.To avoid the idle problem in the process of crowd worker movement,a drop-by-rider problem is used to help crowd workers accept more crowd tasks,optimize the number of assignments,and increase utility.Finally,through comparison experiments on real datasets,the performance of the proposed algorithm on crowd worker utility value and the matching number is evaluated.

Influence of magnetic filter field on the radio-frequency negative hydrogen ion source of neutral beam injector for China Fusion Engineering Test Reactor

In the design of negative hydrogen ion sources,a magnetic filter field of tens of Gauss at the expansion region is essential to reduce the electron temperature,which usually results in a magnetic field of around 10 Gauss in the driver region,destabilizing the discharge.The magnetic shield technique is proposed in this work to reduce the magnetic field in the driver region and improve the discharge characteristics.In this paper,a three-dimensional fluid model is developed within COMSOL to study the influence of the magnetic shield on the generation and transport of plasmas in the negative hydrogen ion source.It is found that when the magnetic shield material is applied at the interface of the expansion region and the driver region,the electron density can be effectively increased.For instance,the maximum of the electron density is 6.7×10^(17)m^(-3)in the case without the magnetic shield,and the value increases to 9.4×10^(17)m^(-3)when the magnetic shield is introduced.

A Lightweight MVC Framework Based on Code Decoupling Principle

This paper analyzed the problems in the existing framework, and achieved a reasonable framework based on reflection and aspect-oriented programming combined with annotations to map the request parameters, and inversion of the control of the various components. The proposed framework reduced the volume of the application context, and achieved the purpose that dependencies between the various components are controlled by the framework. Based on the problems existing in the known framework, the lightweight MVC framework was implemented and the proposed framework was tested by JMeter test tool. The test results showed that the framework proposed in this paper can respond to requests faster, improve access throughput and enhance application performance and user experience. The framework proposed in this paper combined the functions of MVC and IOC to minimize the volume of external dependencies in the development and greatly improved the efficiency of Web applications development.

Thoughts on the Professional Training of Scientific and Technological Management Team of High-level Talents in Provincial Agricultural Research Institutes

From two aspects:the composition of scientific research management institutions and the tasks undertaken by scientific research management departments,the present situation of scientific and technological management team in agricultural research institutes is expounded.Some problems existed in the scientific and technological management team of provincial agricultural research institutes are analyzed,such as uneven knowledge structure of scientific research management personnel,low degree of specialization,poor stability,lack of professional and systematic job training,etc.Professional development countermeasures are proposed,such as optimizing the structure of scientific research management team,establishing a professional management system with the characteristics of agricultural scientific research institutions,formulating corresponding evaluation mechanism for scientific research management personnel,and strengthening the training of agricultural scientific research management personnel.

Mapping QTLs for Salt Tolerance at Seeding Stage of Landrace Rice (Oryza sativa L.)

[Objectives] The identification of salt tolerant genetic loci in rice can provide a research basis for the molecular mechanism of salt tolerance and gene resources for improving salt tolerant cultivars. [Methods] Recombinant inbred lines(RILs) derived from Zhaxima, an indica landrace variety from Yunnan Province and Nanjing 46, an elite japonica variety with superior grain quality from Jiangsu Province were used. The salt tolerance at seeding stage in the RIL population was investigated as the phenotypic value. [Results] Combined with the linkage map, a total of 4 QTLs were detected: qSST-1, qSST-3, qSST-5 and qSST-11, located in rice chromosomes 1, 3, 5 and 11, respectively. All positive alleles were from the parent Nanjing 46. Three QTLs among them were not included in chromosome intervals the same as cloned rice salt tolerance genes, and thus were described as new candidate gene loci associated with seeding-stage salt tolerance. [Conclusions] This study provides important information for further exploration and utilization of new salt tolerant QTLs in rice. It is of great significance for improving the utilization of saline land in China and ensuring the stable rice production.