Research on self-supporting T-shaped gate structure of GaN-based HEMT devices

A self-supporting T-shaped gate(SST-gate) GaN device and process method using electron beam lithography are proposed.An AlGaN/GaN high-electron-mobility transistor(HEMT) device with a gate length of 100 nm is fabricated by this method.The current gain cutoff frequency(f_(T)) is 60 GHz,and the maximum oscillation frequency(f_(max)) is 104 GHz.The current collapse has improved by 13% at static bias of(V_(GSQ),V_(DSQ))=(-8 V,10 V),and gate manufacturing yield has improved by 17% compared with the traditional floating T-shaped gate(FT-gate) device.

Recent progress of self-supported air electrodes for flexible Zn-air batteries

Smart wearable devices are regarded to be the next prevailing technology product after smartphones and smart homes,and thus there has recently been rapid development in flexible electronic energy storage devices.Among them,flexible solid-state zinc-air batteries have received widespread attention because of their high energy density,good safety,and stability.Efficient bifunctional oxygen electrocatalysts are the primary consideration in the development of flexible solid-state zinc-air batteries,and self-supported air cathodes are strong candidates because of their advantages including simplified fabrication process,reduced interfacial resistance,accelerated electron transfer,and good flexibility.This review outlines the research progress in the design and construction of nanoarray bifunctional oxygen electrocatalysts.Starting from the configuration and basic principles of zinc-air batteries and the strategies for the design of bifunctional oxygen electrocatalysts,a detailed discussion of self-supported air cathodes on carbon and metal substrates and their uses in flexible zinc-air batteries will follow.Finally,the challenges and opportunities in the development of flexible zinc-air batteries will be discussed.

Recent advances of carbon fiber-based self-supported electrocatalysts in oxygen electrocatalysis

Oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are the key reactions in numerous renewable energy devices. Unlike conventional powdered catalysts, self-supported catalysts are extensively employed in oxygen electrocatalysis because of the enhanced electron-transfer rate, high specific surface area, and superior mechanical flexibility. Among the self-supported conductive substrates, carbon fiber usually exhibits several distinctive advantages, such as a straightforward preparation process, relatively low cost, good stability, and excellent conductivity. Against this background,carbon fiber-based self-supported electrocatalysts have been widely applied and studied in oxygen electrocatalysis, indicating a promising development direction in oxygen electrocatalyst research.Thus, it is essential to offer an overall summary of the research progress in this field to facilitate its subsequent development. Taking the regulatory mechanisms and modification methods as a starting point, this review comprehensively summarizes recent research on carbon fiber-based self-supported electrocatalysts in recent years. Firstly, a brief overview of the synthesis methods and regulatory mechanisms of carbon fiber-based self-supported electrocatalysts is given. Furthermore, the view also highlights the modification methods and research progress of self-supported electrocatalysts synthesized on carbon fiber-based substrates in recent years in terms of different dopant atoms. Finally, the prospects for the application of self-supported electrocatalysts based on carbon fiber in oxygen electrocatalysis and the possible future directions of their development are presented. This review summarizes recent developments and applications of self-supported bi-functional electrocatalysts with carbon fiber-based materials as the conducting substrate in oxygen electrocatalysis. It also lays a robust scientific foundation for the subsequent reasonable design of highly effective carbon fiber-based self-supported electrocatalysts.

基于Realms的主存R树索引的实现

为了充分发挥主存数据库技术的优越性,提高系统性能,需要使用空间索引,并将索引也放在主存中。R树类是目前空间数据索引的研究热点,具有动态性及构造和维护的简单性,在基本R树索引的基础上便于作各种算法改进,文中开发的基于Realms的空间分析数据库管理系统SADBS中实现了主存R树索引的创建及插入、删除、更新、查询等操作。

Carbon-based flexible self-supporting cathode for lithium-sulfur batteries:Progress and perspective

The flexible self-supporting electrode can maintain good mechanical and electrical properties while retaining high specific capacity,which meets the requirements of flexible batteries.Lithium-sulfur batteries(LSBs),as a new generation of energy storage system,hold much higher theoretical energy density than traditional batteries,and they have attracted extensive attention from both the academic and industrial communities.Selection of a proper substrate material is important for the flexible self-supporting electrode.Carbon materials,with the advantages of light weight,high conductivity,strong structural plasticity,and low cost,provide the electrode with a large loading space for the active material and a conductive network.This makes the carbon materials meet the mechanical and electrochemical requirements of flexible electrodes.In this paper,the commonly used fabrication methods and recent research progresses of the flexible self-supporting cathode with a carbon material as the substrate are introduced.Various sulfur loading methods are summarized,which provides useful information for the structural design of the cathode.As the first review article of the carbon-based flexible self-supporting LSB cathodes,it provides valuable guidance for the researchers working in the field of LSB.

Self-supporting and hierarchically porous Ni_(x)Fe-S/NiFe_(2)O_(4) heterostructure as a bifunctional electrocatalyst for fluctuating overall water splitting

Stable non-noble metal bifunctional electrocatalysts are one of the challenges to the fluctuating overall water splitting driven by re-newable energy.Herein,a novel self-supporting hierarchically porous Ni_(x)Fe-S/NiFe_(2)O_(4) heterostructure as bifunctional electrocatalyst was constructed based on porous Ni-Fe electrodeposition on three-dimensional(3D)carbon fiber cloth,in situ oxidation,and chemical sulfuration.Results showed that the Ni_(x)Fe-S/NiFe_(2)O_(4) heterostructure with a large specific surface area exhibits good bifunctional activity and stability for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)because of the abundance of active sites,synergistic effect of the heterostructure,superhydrophilic surface,and stable,self-supporting structure.The results further confirmed that the Ni_(x)Fe-S phase in the heterostructure is transformed into metal oxides/hydroxides and Ni_(3)S_(2) during OER.Compared with the commercial 20wt%Pt/C||IrO_(2)-Ta_(2)O_(5) electrolyzer,the self-supporting Ni1/5Fe-S/NiFe_(2)O_(4)||Ni1/2Fe-S/NiFe_(2)O_(4) electrolyzer exhibits better stability and lower cell voltage in the fluctu-ating current density range of 10-500 mA/cm^(2).Particularly,the cell voltage of Ni1/5Fe-S/NiFe_(2)O_(4)||Ni1/2Fe-S/NiFe_(2)O_(4) is only approximately 3.91 V at an industrial current density of 500 mA/cm^(2),which is lower than that of the 20wt%Pt/C||IrO_(2)-Ta_(2)O_(5) electrolyzer(i.e.,approximately 4.79 V).This work provides a promising strategy to develop excellent bifunctional electrocatalysts for fluctuating overall water splitting.

Self-supporting NiFe LDH-MoS_(x) integrated electrode for highly efficient water splitting at the industrial electrolysis conditions

Developing effective and practical electrocatalyst under industrial electrolysis conditions is critical for renewable hydrogen production.Herein,we report the self-supporting NiFe LDH-MoS_(x) integrated electrode for water oxidation under normal alkaline test condition(1 M KOH at 25℃)and simulated industrial electrolysis conditions(5 M KOH at 65℃).Such optimized electrode exhibits excellent oxygen evolution reaction(OER)performance with overpotential of 195 and 290 mV at current density of 100 and 400 mA·cm^(-2) under normal alkaline test condition.Notably,only over-potential of 156 and 201 mV were required to achieve the current density of 100 and 400mA·cm^(-2) under simulated industrial electrolysis conditions.No significant degradations were observed after long-term durability tests for both conditions.When using in two-electrode system,the operational voltages of 1.44 and 1.72 V were required to achieve a current density of 10 and 100 mA·cm^(-2) for the overall water splitting test(NiFe LDH-MoS_(x)/INF||20%Pt/C).Additionally,the operational voltage of employing NiFe LDH-MoS_(x)/INF as both cathode and anode merely require 1.52 V at 50mA·cm^(-2) at simulated industrial electrolysis conditions.Notably,a membrane electrode assembly(MEA)for anion exchange membrane water electrolysis(AEMWEs)using NiFe LDH-MoS_(x)/INF as an anode catalyst exhibited an energy conversion efficiency of 71.8%at current density of 400 mA·cm^(-2)in 1 M KOH at 60℃.Further experimental results reveal that sulfurized substrate not only improved the conductivity of NiFe LDH,but also regulated its electronic configurations and atomic composition,leading to the excellent activity.The easy-obtained and cost-effective integrated electrodes are expected to meet the large-scale application of industrial water electrolysis.

Topology Optimization of Self-Supporting Structures for Additive Manufacturing with Adaptive Explicit Continuous Constraint

The integration of topology optimization(TO)and additive manufacturing(AM)technologies can create significant synergy benefits,while the lack of AM-friendly TO algorithms is a serious bottleneck for the application of TO in AM.In this paper,a TO method is proposed to design self-supporting structures with an explicit continuous self-supporting constraint,which can be adaptively activated and tightened during the optimization procedure.The TO procedure is suitable for various critical overhang angles(COA),which is integrated with build direction assignment to reduce performance loss.Besides,a triangular directional self-supporting constraint sensitivity filter is devised to promote the downward evolution of structures and maintain stability.Two numerical examples are presented;all the test cases have successfully converged and the optimized solutions demonstrate good manufacturability.In the meanwhile,a fully self-supporting design can be obtained with a slight cost in performance through combination with build direction assignment.

基于Realms的空间数据库系统实现技术

Realms是将所有空间元素定义在分辨率确定的网格上的数学模型,它提出所有空间对象共享一个空间元素集合及空间元素的排序规则。Realms可以对空间数据进行离散化和约束,使二维空间线性化为一维有序元素集,基于Realms的空间数据组织能有效地支持平面扫描算法,通过对空间对象的平面扫描高效简单地实现多数空间分析算法。文中阐述了Realms的概念,给出了基于Realms的空间数据库对空间对象的建模,并用扫描线技术实现空间分析算法。

Self-supported metal(Fe, Co, Ni)-embedded nitrogen-doping carbon nanorod framework as trifunctional electrode for flexible Zn-air batteries and switchable water electrolysis

To meet the practical demand of wearable/portable electronics, developing high-efficiency and durable multifunctional catalyst and in-situ assembling catalysts into electrodes with flexible features are urgently needed but challenging. Herein, we report a simple route to fabricate bendable multifunctional electrodes by in-situ carbonization of metal ion absorbed polyaniline precursor. Alloy nanoparticles encapsulated in graphite layer are uniformly distributed in the N-doping carbon nanorod skeleton. Profiting from the favorable free-standing structure and the cooperative effect of metallic nanoparticles, graphitic layer and N doped-carbon architecture, the trifunctional electrodes exhibit prominent activities and stability toward HER, OER and ORR. Notably, due to the protection of carbon layer, the electrocatalysts show the reversible catalytic HER/OER properties. The overall water splitting device can continuously work for 12 h under frequent exchanges of cathode and anode. Importantly, the bendable metal air batteries fabricated by self-supported electrode not only displays the outstanding battery performance,achieving a decent peak power density(125 mW cm^(-2)) and exhibiting favorable charge-discharge durability of 22 h, but also holds superb flexible stability. Specially, a lightweight self-driven water splitting unit is demonstrated with stable hydrogen production.

Self-supporting and dual-active 3D Co-S nanosheets constructed by ligand replacement reaction from MOF for rechargeable Al battery

Metal sulfides with high theoretical capacities are expected as promising cathode materials of Al batteries(AIBs). However, powdery active materials are mainly synthesized and loaded on current collector by insulating binder without capacity. Meanwhile, S as inert element in metal sulfides can not usually provide capacity. So, powdery metal sulfides only exhibit limiting practical capacity and poor cycling stability due to weak conductivity and low mass utilization. Herein, the novel self-supporting and dual-active Co-S nanosheets on carbon cloth (i.e. Co-S/CC) with hierarchically porous structure are constructed as cathode of AIBs. Co-S nanosheets are derived from ZIF-67 nanosheets on CC by a facile ligand replacement reaction. As a result, the binder-free Co-S/CC cathode with good conductivity delivers excellent initial discharge capacity of 383.4 m Ah g^(-1)(0.211 m Ah cm^(-2)) at current density of 200 m A g^(-1)and maintain reversible capacity of 156.9 m Ah g^(-1)(0.086 m Ah cm^(-2)) with Coulombic efficiency of 95.8% after 500 cycles,which are much higher than those of the traditional slurry-coating cathodes. Both Co and S as active elements in Co-S/CC contribute to capacity, which leads to a high mass utilization. This work provides a significant strategy for the construction of self-supporting metallic cathode for advanced high-energy density Al battery.

Synthesis of Zeolite LTN-(SOD) Self-Supporting Membranes from SiO2-Rich Industrial Waste

Synthesis of zeolite LTN (“Linde Type N”) was investigated under insertion of a SiO2-rich filtration residue (FR) from waste water cleaning of the silane production. A new synthesis procedure was therefore developed applying a flotation mechanism with the aim to grow LTN in form of thin membrane like sheets. Preparation starts with preactivation of FR by slurrying first in alkaline solution, followed by an addition of aluminate solution and citric acid. The latter was added as suitable chelating agent for the initiation of the flotation process. In the course of these experiments, we succeeded in synthesizing zeo-lite LTN with more or less zeolite SOD as byproduct in the form of a stable compact membrane-like layer at low temperature of 60℃. The crystallization was performed under isotherm static conditions in an open reaction system without addition of organic templates as structure directing agents (OSDA’s). FR was utilized as a total substitute of sodium silicate in all experiments and an expansive pre-treatment procedure like calcinations was not needed. Furthermore, membrane formation with LTN of usual synthesis needs chemically functionalized supports. In contrast self-supporting membranous LTN layers were grown for the first time in the present study.

Study on the Self-supporting Logistics Mode based on B2C E-commerce Enterprises

Taking B2C E-commerce enterprises as the center, it can be divided into a set of logistics activities upstream supply chain logistics producer to B2C e-commerce enterprises, and the B2C e-commerce enterprise logistics to client consumer, and the paper focuses on the study of self-supporting logistics for the E-commerce enterprise. According to the development status of current B2C electronic commerce enterprise in our country and logistics, the paper study B2C electric business enterprise how to correctly choose the logistics mode and how to promote the business logistics operation level.

New Realms and New Highlights in the Legal Protection of Human Rights——Theoretical and Practical Innovations in the Legal Protection of Human Rights Since the 18th CPC National Congress

Since the 18th National Congress of the Communist Party of China （CPC）, the system for the legal protection of human rignts under socialism with Chinese characteristics has experienced innowtive development. In particular, the Decision on Certain Key Issues on Comprehensively Deepening Reform, which was adopted by the Third Plenary Session of the 18th CPC Central Committee, has made major reform arrangements related to the system and mechanisms for the legal protection of human rights under socialism with Chinese characteristics. Taking the theoretical and practical innovations since the 18th CPC National Congress in the protection of human rights as its perspective, this, article discusses new realms and new highlights in the legal protection of human rights.

中华优秀传统文化道德人格境界论及其对大学生人格修养的启示

中华优秀传统文化道德人格境界论以天人合一的天道观为基础,以道德修养的层次和境界为依据,将人格分为君子人格和小人人格,并以君子、贤人、圣人为理想的人格境界,主张培育人的道德主体性,树立居仁求义、自强不息、厚德载物、胸怀天下的人格境界和担当精神。分析中华优秀传统文化道德人格境界论对新时代大学生人格意识的激发、健全人格的养成、道德自信和担当精神的确立、人格修养的提升以及和谐人际关系的建立均具有重要的理论价值和现实意义。

智能革命对人性的深度拷问

当科学技术发展到影响人类行为的所有领域时,合乎伦理的技术发展和基于技术发展的伦理学研究就成为时代之需。因为智能机器的自主性、适应性和交互性带来了人类劳动或工作形态的大变革,突破了传统的制度安排和伦理规范的限度,提出了如何重新理解“自由”“劳动”“成功”等关乎人性的概念问题;基因编辑、脑机接口等技术的发展促进了人的身体技术化趋势,互联网、大数据、元宇宙、可穿戴设备等技术的发展导致了人的精神技术化趋势,提出了如何认知人的身体边界、精神愉悦、自我尊严、自我实现乃至生命意义等关乎人性的实践问题。对这些问题的回答,建立在对人性的深度拷问之基础上。这开启了“人,成之为人”的第二个过程,提出了必须平衡科技发展与人类价值保护,平衡技术的应用价值与社会责任的要求。这种情况表明,人类社会在从工业文明转向智能文明的过程,迫切需要重塑或营造有利于人的身心成长和生命意义提升的人文环境。

“中和”与书法艺术辩证法

从先秦“中”“和”观念发展而来的“中和”思想规约了中国艺术的理想境界与价值鹄的,其中包含着深刻的艺术辩证法。在书法中,“中和”体现在“情感”的中节合度、“法则”的对立统一、“风格”的众体兼备等方面,是各种风格元素交融互渗之后的典范形态。当代书法界应抑制过度追求标新立异的冲动,回归中和的审美心态,书家要实现笔墨与情感的共舞;创作上力避纯视觉化的倾向,依照“中和”的美学圭臬,对作品形式要素之间的矛盾统一关系加以探究与验证;同时应注重书法生态的整体平衡,兼蓄并包,和而不同,以臻至“中和”之艺术胜境。

成都市花境色彩配置模式研究

本文系统阐述了花境色彩配置的主要原则,包括色相、饱和度、明度占比及其比例变化的精细调控,以及其他色彩构成因子的合理搭配,将其共同构成花境色彩设计的基础框架。针对成都市独特的地域文化与景观特色,提出了花境色彩配置模式的优化路径:强调色彩与环境的和谐共生,注重色彩间的相互作用与视觉平衡,通过植物色彩随季节更迭展现自然之美,融入文化元素,使花境设计富含地域文化韵味,持续监测与评估。通过成都市多年生草本花卉植物花境色彩配置的案例设计,展示了色彩配置的景区自然衔接技巧,指出应当考虑季节性色彩变换的合理搭配。

论精神与人格的关系

心理、人格和精神的关系是一种升华或超越的关系,人只有具有精神,才会成为真正的人。人格是人性的现实化,具有动力、能力、品质和精神四个层次结构,其中精神是最高的层次,主导观念、最高理想和基本信念是其核心结构。精神是人格的灵魂,在人格中居于统率地位,对人格中其他三个层次的要素起规导作用。人格及其各要素的形成都自觉不自觉地以主导观念为依据,并受其规导;最高理想决定着人格理想的一致性、人格运行的方向乃至人格层次;基本信念则可以调动人格的各种因素、凝聚人格的各种力量去追求最高理想的实现。就个人而言,精神有不同的境界,精神境界与人格境界、人生境界既相互联系又有区别,精神境界是提升人格境界的结果,人生境界则是人格境界的体现。

高平开化寺大殿东壁卢舍那法界人中图像的来源及意涵

山西高平开化寺的大殿四壁绘有北宋元祐七年至绍圣三年的佛教壁画。其中,东壁所绘华严经变之南端,有卢舍那法界人中图像一铺。从该图像入手,通过将其与相关材料进行比对分析,基本可以获知其来源为流行华严与密教的辽国。辽代佛教的盛行,极大刺激了雕版印刷的发展,并带动了跨地域的图像传播。开化寺卢舍那法界人中图像的出现,一方面体现了10至11世纪弥漫于辽宋社会的末法观念,另一方面也意在强调华严的救度思想。