Customizing Multifunctional Sulfur Host Materials Via a General Anion-Exchange Process with Metal–Organic Solid

Fe/Co/Ni-based discrete nanoparticles are often explored to chemically adsorb and catalytically convert polysulfides for high-performance Li–S batteries. Herein, by manipulating the anion-exchange process between Ni–Co acetate microcrystals and various organic anions, porous single- or multi-layered hierarchically functionalized carbon nanoshells are customized. Among them, the shell-in-shell composite, namely C–NiCoPi@C–Ni₂Co, which has an external Ni₂Co-decorated carbon nanoshell and an internal Ni₃P-anchored carbon nanoshell encapsulated within a 3D-structured continuous NiCo-phosphate (NiCoPi) layer, displays collective merits as a sulfur host. Particularly, compared with discrete nanoparticles, the network-like NiCoPi layer is structurally and inherently advantageous in chemical adsorption and catalytic conversion of polysulfides, as also supported by Density Functional Theory calculations, while the metallic Ni₂Co nanoparticles enable high local conductivity. Such S@C–NiCoPi@C–Ni₂Co displays an initial specific capacity of 1237 mAhg^–1 at 0.1 C and maintains 1010 mAhg^–1 after 100 cycles; at 0.5 C, its discharge specific capacity in the 1st cycle is as high as 1038 mAhg^–1 and maintains capacity retention as high as 86% after 500 cycles. This study provides a straightforward strategy in customizing multifunctional sulfur hosts for high-performance Li–S batteries.     

基于USB的多通道虚拟频谱分析仪

介绍一种基于USB技术的多通道虚拟频谱分析仪的设计.系统以FPGA为主控芯片,采用多通道A/D转换器进行数据采集,USB接口高速传输,LabVIEW编程来实现频谱分析功能.与传统频谱分析仪相比,具有性能稳定、开发成本低、便于重构等优点.系统支持多通道信号同步采样,可完成三相电压监测,功率谱分析等功能.     

Experimental study on seismic behavior of RC frames strengthened with CFRP sheets

The purpose of this study was to investigate experimentally the seismic performance and hysteretic energy capacity of strengthened reinforced concrete (RC) frames using carbon fiber reinforced polymer (CFRP) sheets under low-cyclic lateral loading. Two test specimens were constructed and tested under low-cyclic lateral loading. Two 1/3 scaled one-bay and one-storey RC frames specimens were constructed to simulate a two-storey industrial workshop. One specimen was reinforced by CFRP at the ends of beams, columns and at the joints; the other specimen was not reinforced and was used for comparison. This experimental study mainly investigated the effects of CFRP sheets on specimen seismic behavior. The information about the crack development, the damage characteristics, the hysteretic curves of the steel bar and CFRP sheets and the skeleton curves of frame were presented. In addition, the maximum crack width and the ultimate bearing capacity were measured. Test results indicate that the CFRP sheets reinforced frame shows a good hysteretic energy capacity and a higher ductility, which indicates that the CFRP sheets reinforced frame has a better seismic behavior. The results provide an important insight of the role of CFRP sheets in improving the earthquake resistance of frame buildings.     

15N稳定同位素标记集胞藻的生物合成研究

目的建立实验室生物合成15N稳定同位素标记集胞藻的最优培养条件,并驯化得到高丰度15N集胞藻藻种。方法对培养温度、光照及p H值等条件进行优化,优选出最佳培养工艺。将培养基中的14N氮源替换为15N氮源,优化配方,使用同位素比质谱仪测量藻体中15N、14N同位素组成。结果实验室培养条件选定为培养温度25℃、光照强度2000 lux、初始p H值为7时,集胞藻生长良好。将配方中硝酸钠浓度设定为1.5 g/L时,产品丰度最大。驯化得到高丰度15N-集胞藻藻种。结论本试验优化的培养工艺和配方,适宜15N稳定同位素标记集胞藻生长。得到的藻种产品丰度高,生产成本低。     

面向高比例新能源电网的重大耗能企业需求响应调度

随着国家“双碳”重大战略的提出, 高比例新能源并网将成为我国电力能源转型的重要态势. 针对火电机组、配电网和需求侧关联的系列运行约束制约了电网对高比例新能源的有效消纳这一问题, 本文提出重大耗能企业这一主要电力负荷参与网需求响应(Demand response, DR)的研究思路, 通过重大耗能企业与电网协调调度促进新能源消纳, 并获得经济补偿以减少运行成本. 研究首先基于混合需求侧响应机制, 提出以重大耗能企业、新能源、火电机组为核心的协调调度方法, 并根据新能源预测值−预测误差的信息依存顺序提出了两步调度策略. 在此基础上, 进行生产过程行为建模以实现重大耗能企业需求侧响应决策描述, 并建立高比例新能源并网的重大耗能企业需求响应与电网协调调度优化模型. 最后, 基于烟台电网实际系统进行算例分析, 验证了重大耗能企业通过需求响应参与电网协调调度以及两步调度策略的有效性.     

Multifunctional anti-wax coatings for paraffin control in oil pipelines

Paraffin deposition is a severe global problem during crude oil production and transportation. To inhibit the formation of paraffin deposits, the commonly used methods are mechanical cleaning, coating the pipe to provide a smooth surface and reduce paraffin adhesion, electric heating, ultrasonic and microbial treatments, the use of paraffin inhibitors, etc. Pipeline coatings not only have the advantages of simple preparation and broad applications, but also maintain a long-term efficient and stable effect. In recent years, important progress has been made in research on pipe coatings for mitigating and preventing paraffin deposition. Several novel superhydrophilic organogel coatings with low surface energy were successfully prepared by bionic design. This paper reviews different types of coatings for inhibiting wax deposition in the petroleum industry. The research prospects and directions of this rapidly developing field are also briefly discussed.     

Synthesis,Antifungal Activities and Qualitative Structure Activity Relationship of Carabrone Hydrazone Derivatives as Potential Antifungal Agents

Aimed at developing novel fungicides for relieving the ever-increasing pressure of agricultural production caused by phytopathogenic fungi, 28 new hydrazone derivatives of carabrone, a natural bioactive sesquisterpene, in three types were designed, synthesized and their antifungal activities against Botrytis cinerea and Colletotrichum lagenarium were evaluated. The result revealed that all the derivatives synthesized exhibited considerable antifungal activities in vitro and in vivo, which led to the improved activities for carabrone and its analogues and further confirmed their potential as antifungal agents.     

面向具体任务的最小裕度系统建模与仿真

在以往的导弹武器信息处理设备的先期系统方案设计过程中通常无法对信息处理算法、软件调度、运算时间经常无法做出特别准确的估计, 为保证系统性能而盲目选择高配置的硬件就可能造成资源上不必要的浪费. 针对该问题, 首先通过工具软件进行仿真建模, 面向明确的任务对信息处理器运算能力、软件处理流程、数据接口、数据包结构模拟, 接下来结合具体需求对仿真结果进行分析, 判断从指标和功能上是否满足系统方案的设计, 最后提出, 利用仿真建模技术以最小裕度完成系统的设计, 在满足功能性能和技术指标的要求的同时, 合理降低硬件资源配置, 可以有效节约成本.     

In situ microscope FTIR studies of methanol adsorption and oxidation on an individually addressable array of nanostructured Pt microelectrodes

An individually addressable array of nanostructured Pt microelectrodes was designed and prepared according to the concept of combinatorial electrochemistry. Different nanostructures on the array were obtained systematically by electrochemical deposition under cyclic voltammetric conditions. The surface structure and electrochemical behavior of the array were investigated, respectively using scanning tunneling microscopy (STM) and cyclic voltammetry (CV), and electrocatalytic properties of the array towards methanol oxidation were studied by CV and in situ microscope Fourier transform infrared reflection spectroscopy (MFTIRS). The results revealed the higher electrocatalytic activity of nanostructured Pt surfaces, and demonstrated that the combination of an individually addressable array with in situ MFTIRS is an efficient combinatorial approach in studies of electrocatalytic reaction processes at molecular level.     

An Algorithm for Simultaneous Backbone Threading and Side-Chain Packing

To fully utilize all available information in protein structure prediction, including both backbone and side-chain structures, we present a novel algorithm for solving a generalized threading problem. In this problem, we consider simultaneously backbone threading and side-chain packing during the process of a protein structure prediction. For a given query protein sequence and a template structure, our goal is to find a threading alignment between the query sequence and the template structure, along with a rotamer assignment for each side-chain of the query protein, which optimizes an energy function that combines a backbone threading energy and a side-chain packing energy. This highly computationally challenging problem is solved through first formulating this problem as a graph-based optimization problem. Various graph-theoretic techniques are employed to achieve the computational efficiency to make our algorithm practically useful, which takes advantage of a number of special properties of the graph representing this generalized threading problem. The overall framework of our algorithm is a dynamic programming algorithm implemented on an optimal tree decomposition of the graph representation of our problem. By using various additional heuristic techniques such as the dead-end elimination, we have demonstrated that our algorithm can solve a generalized threading problem within practically acceptable amount of time and space, the first of its kind.