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Study on the morphology, crystalline structure and thermal properties of yam starch acetates with different degrees of substitution

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Science China Chemistry 2008年第9期51卷 859-865页

作者： WANG Xu GAO WenYuan ZHANG LiMing XIAO PeiGen YAO LiPing LIU Yi LI KeFeng xie weiguang School of Pharmaceutical Science and Technology Tianjin UniversityTianjin 300072China College of Bioengineering Tianjin University of Science and TechnologyTianjin 300457China Institute of Medicine Plant Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100094China College of Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjin 300193China

This study was carried out to understand and establish the changes in physicochemical properties of starch extracted from Chinese yam (Dioscorea opposita Thunb.) after acetylation. Yam starch acetates with different degrees of substitution (DS) were prepared by the reaction of yam starch with glacial acetic acid/acetic anhydride using sulfuric acid as the catalyst. Their formation was confirmed by the presence of the carbonyl signal around 1750 cm?1 in the Fourier transform infrared (FT-IR) spectra. The thermal behavior of the native starch and starch acetate were investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results reveal that the starch acetates are more thermally stable than the native starch. The starch esters showed 50% weight loss at temperatures from 328°C to 372°C, while the native starch underwent 50% weight loss at 325°C. The glass transition temperature (T g) of the starch decreased from 273°C to 226°c. The X-ray diffraction (XRD) patterns could be classified as typical of the C-type for yam starch. X-ray diffraction also showed the loss of the ordered C-type starch crystalline structure and the degree of crystallinity of starch decreased from 36.10% to 10.96% with the increasing DS. The scanning electron microscopy (SEM) suggested that the most of the starch granules disintegrated with many visible fragments with the increasing DS.

关键词： yam starch acetate physicochemical characterization

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Dynamic Polling MAC Scheme Considering Emergency Access in WSNs Based on Priorities

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China Communications 2012年第4期9卷 45-54页

作者： Pei Qingqi Chen Chen xie weiguang The State Key Laboratory of Integrated Services Networks Xidian UniversityXi'an 710071 P. R. China Institute of China Electronic System Engineering Corporation Beijing P. R. China

In Wireless Sensor Networks(WSNs),polling can obviously improve the throughput and decrease average access delay by allocating bandwidth efficiently and *** this paper,a Dynamic Polling Media Access Control (DPMAC) scheme designed according to WSNs' features is *** is a priority based access control protocol with the characteristics that its polling table is dynamically refreshed depending on whether the sensor node is active and that the bandwidth is dynamically allocated according to the traffic *** access priorities are determined by the emergency levels of events and the scheduler proposed in our MAC is preemptive based on the deadline of the *** results show that DPMAC can efficiently utilize bandwidth and decrease average access delay and response time for emergency events with different access priorities in WSNs.

关键词： WSNs polling throughput MAC

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2019年东莞市儿童家长疫苗犹豫及其影响因素调查

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中国疫苗和免疫 2024年第1期30卷 49-53页

作者：彭淋陈文静谢伟光董晓梅别智敏蔡碧兰张婷刘思渊王莹陈绍丽东莞市疾病预防控制中心广东东莞523000 暨南大学基础医学院公共卫生与预防医学系广东广州510632

目的了解东莞市儿童家长疫苗犹豫现状及其影响因素。方法制定儿童家长疫苗犹豫量表,采用分层抽样方法在东莞市8家社区卫生服务中心预防接种门诊选择儿童家长开展调查,分析疫苗犹豫得分及其影响因素。结果在750例调查对象中,疫苗犹豫得分... 详细信息

目的了解东莞市儿童家长疫苗犹豫现状及其影响因素。方法制定儿童家长疫苗犹豫量表,采用分层抽样方法在东莞市8家社区卫生服务中心预防接种门诊选择儿童家长开展调查,分析疫苗犹豫得分及其影响因素。结果在750例调查对象中,疫苗犹豫得分在0-70分之间,平均得分为30.09±13.03分,得分≥50分比例为6.67%。Logistic回归分析显示,乙肝和乙肝疫苗相关知识得分高的调查对象疫苗犹豫得分≥50分比例低(OR=0.43,95%CI:0.24-0.77)。结论调查地区儿童家长的疫苗犹豫较低;需加强儿童家长疫苗相关知识宣传以进一步降低疫苗犹豫。

关键词：疫苗犹豫影响因素儿童家长

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Self-assembled monolayer modulated Plateau-Rayleigh instability and enhanced chemical stability of silver nanowire for invisibly patterned,stable transparent electrodes

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Nano Research 2022年第5期15卷 4552-4562页

作者： Gui-Shi Liu Huajian Zheng Zijie Zeng Yexiong Wang Weidong Guo Ting Wang Heng Chen Yunsen Chen Shiqi Hu Lei Chen Yaofei Chen weiguang xie Bo-Ru Yang Yunhan Luo Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Key Laboratory of Visible Light Communications of GuangzhouKey Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education InstitutesDepartment of Optoelectronic EngineeringJinan UniversityGuangzhou 510632China Siyuan Laboratory Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy MaterialsDepartment of PhysicsJinan UniversityGuangzhou 510632China State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510006China

Patterned silver nanowire(AgNW)networks have been widely used as transparent electrodes in many optoelectrical ***,obvious patterning visibility and poor thermostability of AgNW are still limiting its practical ***,we report self-assembled monolayer(SAM)modulated Plateau-Rayleigh instability(PRI)of AgNW,which allows invisible patterning and superior stability of the AgNW *** opposite effects of different SAMs on the PRI are identified:the alkanethiol SAMs activate surface atom diffusion while the mercaptobenzoheterocyclic(MBH)SAMs suppress the *** degradation temperature of the AgNWs can be therefore,for the first time,tuned in the range of 193-381℃,so that the AgNW network can be patterned via PRI with a tiny optical difference between the insulative and conductive regions,i.e.,patterning ***,the MBH SAMs provide AgNW with excellent durability under thermal annealing and oxidation,which enhances the maximum heating temperature of the AgNW transparent heater by over 120℃.Beyond the micro-patterning,we consider that the developed SAM strategy can be extended to other metal nanowires for stability improvement and has huge potential in nanoengineering of one-dimensional metal materials.

关键词： Plateau-Rayleigh instability self-assembled monolayer invisible patterning thermal stability

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高校思政课对话式教学法的生成逻辑、价值意蕴和实践路径

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教育科学 2022年第4期38卷 52-58页

作者：谢伟光王慎十鲁迅美术学院思政部辽宁大连116650

高校思想政治理论课对话式教学法具有深刻的生成逻辑和丰富的价值意蕴,对讲好思政课具有重大意义。其生成逻辑表现为:在课程逻辑上,马克思主义的人民性决定其必然性;在教法逻辑上,独白式教学的单一性决定其必要性;在学情逻辑上,对象与... 详细信息

高校思想政治理论课对话式教学法具有深刻的生成逻辑和丰富的价值意蕴,对讲好思政课具有重大意义。其生成逻辑表现为:在课程逻辑上,马克思主义的人民性决定其必然性;在教法逻辑上,独白式教学的单一性决定其必要性;在学情逻辑上,对象与学科的统一性决定其可能性。价值意蕴在于:实现建设性与批判性的统一,筑牢信仰之基;实现理论性与实践性的统一,锻造时代新人;实现主导性与主体性的统一,促进教学相长;实现灌输性与启发性的统一,于无声处化人。实施对话式教学法的主要路径是:教——预设理论框架,加强引导总结;中介——设置良好话题,激发学生兴趣;学——积极发言倾听,协同共建共享。

关键词：思政课对话主体性

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Mass extinctions, their causes and consequences: an interview with Douglas *** and Shuzhong Shen

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National Science Review 2024年第1期11卷 66-70页

作者： Shucheng xie State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences at Wuhan

‘Mass extinctions’ have been a hot topic for several decades. What triggers a mass extinction? How does a mass extinction impact the evolution of life? How does our ecosystem recover after a mass extinction? These questions attracted the interest of both scientists and the public *** spoke to two renowned researchers in the field of mass extinctions: Prof. Douglas H. Erwin from the National Museum of Natural History of the USA, and Prof. Shuzhong Shen from Nanjing University, China.

关键词： Stratigraphy

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Turbulence Statistics of Thermo-Buoyancy Supercritical Fuel Flow in a Regenerative Cooling Channel

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Journal of Thermal Science 2024年第1期33卷 126-137页

作者： SUN Feng xie Gongnan School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Department of Thermal Engineering Tsinghua UniversityBeijing 100084China

Active regenerative cooling with supercritical hydrocarbon fuel is considered as the most promising thermal protection *** existence of buoyancy force would lead to strongly anisotropic flow and thermal transport *** is closely related to the cooling performance of the *** elucidate the mechanisms of turbulent transport,the large eddy simulation(LES) was performed to assess turbulence statistics within different turbulence *** results indicated that the buoyancy and inertial force together dominated the change of turbulent ***,the spatial thermal buoyancy effect significantly suppressed the vertical velocity *** is due to the laminar motion caused by the buoyancy force,thereby weakening the thermal *** the statistics of velocity fluctuation,it was found that the buoyancy force and inertial force greatly weaken the vertical and streamwise velocity fluctuation,*** the statistics of thermal transport,the results pointed out that the near-wall heat transport characteristics need to be paid more *** thickness of the temperature mixing boundary layer led to the attenuation of vertical heat flux,which inhibited vertical temperature diffusion and predisposed to extreme conditions of heat transfer *** results can enhance the academic understanding of the heat transfer mechanism of supercritical fluids,and give guidance for further applications of thermal protection.

关键词： active regenerative cooling large eddy simulation(LES) buoyancy force turbulence statistics

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Output feedback stabilization of stochastic high-order planar nonlinear systems with stochastic inverse dynamics and output-constraint

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Science China(Information Sciences) 2024年第3期67卷 182-196页

作者： Ruiming xie Shengyuan XU Nanjing University of Science and Technology School of Automation

In this paper, we solve the output feedback control problem of stochastic high-order planar nonlinear systems with output constraint and stochastic integral input-to-state stability(SiISS) inverse dynamics. By employing a key coordinate transformation, a stochastic nonlinear system with output constraint and SiISS inverse dynamics is converted into an unconstrained system. By skillfully constructing an observer and adopting SiISS small-gain conditions, we develop a new output feedback control design and analysis method, and prove that all the closed-system signals are bounded almost surely, the output constraint is not violated almost surely, and the equilibrium point of the closed-loop system is stochastically asymptotically stable.

关键词： stochastic high-order planar nonlinear system output constraint stochastic inverse dynamics output feedback stabilization stochastic integral input-to-state stability (SiISS)

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Fixed-time stabilization of output-constrained stochastic high-order nonlinear systems

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Science China(Information Sciences) 2024年第4期67卷 5-20页

作者： Ruiming xie Shengyuan XU Nanjing University of Science and Technology School of Automation

In this study, the fixed-time stabilization problem of stochastic high-order nonlinear systems with output constraint and high-order and low-order nonlinearities is addressed. A new coordinate transformation is employed to directly convert output-constrained stochastic systems into an equivalent unconstrained *** fully extracting the characteristics of system nonlinearities and using the stochastic fixed-time stability theorem, a new design and analysis method is constructed to guarantee that the trivial solution of the closed-loop system is stochastically fixed-time stable while fulfilling the output constraint.

关键词： stochastic high-order nonlinear system output constraint high-order and low-order nonlinearity fixed-time stabilization finite-time stabilization

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本科院校旅游管理专业旅游规划课程体系优化设计

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河北旅游职业学院学报 2011年第1期16卷 69-72页

作者：谢维光佳木斯大学旅游管理学院黑龙江佳木斯154007

我国大多数开设旅游管理专业的本科院校在旅游规划类课程体系设置不够科学,学生实践能力培养方法欠缺。针对课程体系不完善的现状,通过建立甘特图对旅游规划类课程体系进行统筹定位,期望为高校完善旅游规划课程体系、培养本科生实践应... 详细信息

我国大多数开设旅游管理专业的本科院校在旅游规划类课程体系设置不够科学,学生实践能力培养方法欠缺。针对课程体系不完善的现状,通过建立甘特图对旅游规划类课程体系进行统筹定位,期望为高校完善旅游规划课程体系、培养本科生实践应用能力提供参考。

关键词：旅游规划类课程课程体系优化设计

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