[(n-C_4H_9)_3SnO_2C(CH_2)_2CO_2Sn(C_4H_9-n)_3]: A Novel Three-dimensional Framework Structure of Organotin Complex

The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3) Angstrom, V = 7446(2) Angstrom(3), Z = 8, D-c = 1.242 g/cm(3), mu = 1.365 mm(-1), F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms.

A New Heteropolyoxotungstate with a Three-dimensional All-inorganic Framework [(C_2H_4N_2)_4(P_4Co_3W_4O_(28)H_6)(H_2C_2O_4)]_n

A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1006（17）,b = 17.1006（7）,c = 10.7525（5）,V = 3144.2（2）3,Z = 4,Dc = 3.795 g·cm-3,F（000） = 3300,MoKα（λ = 0.71073 ）,μ = 16.460 mm-1,the final R = 0.0335 and wR = 0.0776.In the heteropolyoxotungstate,tungsten-oxygen octahedra are linked by sharing two cis-vertexes into an infinite helical chain extending along the c axis.Cobalt atoms in the octahedral geometry act as the linkers of these chains,forming a three-dimensional framework.The cobalt and phosphorus atoms in the tetrahedral geometry play a role in stabilizing the three-dimensional framework.Ethylenediamine molecules are polymerized into organic chains which locate in the interspaces of the framework in the way of interwinding with the W-O chains.

Exploring the Three-dimensional Framework of Knowledge Service in the field of Library and Information Science(LIS)

The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However at present, academic research on knowledge service is falling short and its definition is far from clear and complete. As such,this article proposes the Three-dimensional Framework Knowledge Service(TdFKS) for libraries and information institutions based on the knowledge value chain model. By making reliability analysis and mean value analysis of a questionnaire survey result, the article clarifies the structure of the three-dimensional framework and verifies the rationality of the TdFKS.

Analysis on Discourse Construction of HK Riots between HK Protesters and China's Mainland Media Based on Fairclough’s Three-dimensional Framework of Critical Discourse Analysis

The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structure,and overall organization of texts as well as to provide a critical dimension in its theoretical and descriptive accounts of texts.Since June last year,HK protests or HK violence have been frequently reported by worldwide media.In this paper,the author aims to find out how the HK protesters and the Mainland media describe the same event based on the three-dimensional framework of CDA.At last,the author concludes that the mainland media generally describe the event as violence and riot while the HK protesters define themselves as warriors striving for more freedom,justice and democracy.Besides,on this event,the Mainland media mainly accuses some western countries of interference into HK affairs,which is undoubtedly of China’s internal affairs,and the media give full support to the HK police in safeguarding the peace and stability of Hong Kong.But from the perspective of HK protesters,they firmly believe that they are using their actions to protect all the people of HK,and they are defending their values such as freedom,democracy and justice.These are two totally different systems of language,and the author also gives its potential reasons in the paper so as to offer some viewpoints in this aspect in combination with the CDA theory.

基于MultiLayer水平集的脑MRI图像分割框架

提出了一种新的自动初始化水平集的方法和基于MultiLayer水平集的活动轮廓模型。该模型同时进行偏移场去除和图像分割,因此可以有效地克服灰度不均匀性的影响。最后利用了大脑皮层的距离信息,在框架中增加了厚度约束项。实验结果显示,相比著名的LBF模型,该框架不但可以获得更高的分割精度,而且分割时间也大大减少。

A Novel Three-dimensional Ni Coordination Polymer Based on Flexible Di-carboxylate Ligand and 4,4′-Pyridine: Synthesis, Characterization and Topological Analysis

A novel Ni（II） coordination polymer [Ni（dtba）（4,4′-bpy）] （1, H2dtba = 2,2′-dithio- bisbenzoic acid, 4,4′-bpy = 4,4′-bipyridine） has been synthesized by H2dtba and Ni（CH3COO）2·4H2O with exo-bidentate rigid ligand 4,4′-bpy by using hydrothermal method, and its structure was determined by single-crystal X-ray diffraction. X-ray crystal structure analysis reveals that complex 1 crystallizes in monoclinic, space group Cc with a = 11.7624（9）, b = 18.7933（19）, c = 10.3071（11）, β = 97.6510（10）°, V = 2258.2（4）3, Z = 4, C24H16N2NiO4S2, Mr = 519.22, Dc = 1.527 g/cm3, μ = 1.079 mm-1 and F（000） = 1064. The structure was solved by direct methods and refined to R = 0.0434 and wR = 0.1000 for 3281 observed reflections （I 〉 2σ（I））. The coordination environment of Ni（II） is a distorted octahedron, and a three-dimensional structure was formed with the coordination effect of dtba2- and 4,4′-bpy ligands. The topological analysis reveals that the whole framework of 1 is a 2-nodal net of （52.6）（53.64.72.8） topology. The thermal stability and XRD pattern of 1 were also investigated

基于证据理论的多层超网络影响力节点识别方法

针对多层超网络研究多集中于拓扑结构,且影响力节点识别方法中涉及指标较为单一,无法全面准确识别影响力节点的情况,提出一种基于证据理论的多层超网络影响力节点识别方法。首先,在多层超网络拓扑结构基础上,根据聚合网络思想构建多层聚合超网络;其次,基于证据理论定义问题的辨识框架;最后,利用D-S(Dempster-Shafer)证据组合方法,融合网络的局部、位置和全局指标以识别网络影响力节点。将该方法应用于arXiv数据集构建的物理−计算机科学双层科研合作超网络(MAH),在基于RP(Reactive Process)和CP(Contact Process)策略的易感−感染−易感(SIS)超网络传播模型中,与超度中心性、K-shell、接近中心性方法等相比,传播速度最快,且最先达到稳态;隔离影响力排名前6%节点后,网络平均超度、聚类系数以及网络效率均减小;随着隔离影响力节点比例的增大,网络子图数量增速与接近中心性方法相近;通过单调性指标值度量识别结果粗粒度,达到0.9998,识别结果具有较高区分度。综合多个实验结果,表明该多层超网络影响力节点识别方法准确有效。

Construction of three-dimensional carbon framework-loaded silicon nanoparticles anchored by carbon film for highperformance lithium-ion battery anode materials

Si materials are widely considered to be the next-generation anode to replace the current commercial graphite-based anode due to its high energy density.However,the large volume variation of silicon during(de)lithiation process leads to rapid capacity decay,hindering its commercial application.Although the various hollow structure designs of Si nanomaterials have improved their cycling stability in the laboratory,the high-pressure calendering process in the current industrial electrode preparation process might collapse the hollow structure and weaken the structural advantages of hollow silicon anode materials.In this work,a silicon carbon composite material(Si@3DC)in which Si nanoparticles were anchored on a three-dimensional carbon framework through carbon films was prepared by a simple proton exchange method.The three-dimensional carbon framework with multiple hierarchical pores of Si@3DC was compatible with the high-pressure calendering process,but also could provide expansion space for Si nanoparticles during the lithiation process,and ensure good electronic and ionic conductivity.The carbon film on the surface of Si nanoparticles promoted the formation of stable solid electrolyte interphase(SEI)films,ensuring the good cycle stability of Si@3DC.

Three-dimensional Covalent Organic Frameworks as Host Materials for Lithium-Sulfur Batteries

Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulfur batteries.Owing to possessing excellent porosities as well as abundant hydroxyl groups in the pore walls,COF-301 can not only trap lithium polysulfides(PSs)via physical adsorption inside the pores,but also capture PSs by chemical interactions to relieve the shuttle effect.Interestingly,it is the first time that 3D-COFs were utilized as host materials for lithium-sulfur batteries as well as hydroxyl groups were introduced into COFs for improving the battery performance.As a result,COF-301@S as cathode material could reserve the capacity of 411.6 mA·h·g^-1 after 500 cycles with only 0.081%fading per cycle at 0.5 C,exhibiting better battery performance compared with COF-300@S.This study not only expands the applications of 3D-COFs but also provides a new route for designing lithium-sulfur batteries.

V-MOF-derived V_(2)O_(5) nanoparticles-modified carbon fiber cloth-based dendrite-free anode for high-performance lithium metal batteries

At present,commercial Li-ion batteries are hardly to satisfy the growing demand for high energy density,for this purpose,lithium metal batteries have attracted worldwide attention in recent years.However,its practical applications are hindered by the formation of Li dendrites and volume effect during Li plating/stripping process,which leads to a lot of safety hazards.Herein,we first employed MOF-derived V_(2)O_(5) nanoparticles to decorate the carbon fiber cloth(CFC)backbone to acquire a lithiophilic 3D porous conductive framework(CFC@V_(2)O_(5)).Subsequently,the CFC@V_(2)O_(5) skeleton was permeated with molten Li to prepare CFC@V_(2)O_(5)@Li composite anode.The CFC@V_(2)O_(5)@Li composite anode can be stably cycled for more than 1650 h at high current density(5 mA·cm^(-2))and areal capacity(5 mA·h·cm^(–2)).The prepared full cell can initially maintain a high capacity of about 143 mA·h·g^(-1) even at a high current density of 5 C,and can still maintain 114 mA·h·g^(-1) after 1000 cycles.

面向数智化异构学习环境的学习者交互多层网络分析——基于Traces分析框架的应用与展望

在数智时代,学习逐渐呈现出学习空间开放多元、学习过程复杂非线性的特点,学习的社会化、智能化、情境化、网络化特征愈发显著,学习发生的情境是一个复杂系统。连续的学习行为数据以不同粒度分散在多个异构学习环境中,关联这些环境中的数据是对复杂学习行为形成连续认识、系统深入把握数智化学习规律的关键,而如何对粒度不一且分散的交互数据进行关联和分析是学习分析研究中必须解决的问题。为此,研究指出基于多层网络分析法——Traces分析框架是应对这一问题的解决方案,并系统梳理了Traces分析框架的特征、核心概念、各个层级的分析过程及支持方法,进而通过案例展示了该方法既可以整体应用于识别交互会话及关键参与者、识别学习者群组(社区)、分析参与者之间的关系以及参与情况随时间的演变态势,又可以局部应用于微观层面的数据分析。研究表明,Traces分析框架能跨越多个数智化异构学习环境,从多个层次有效融合线程分析法、社会网络分析等多种方法,突破单一维度和还原论分析法的局限,关注行动者之间的复杂关系并扩展了分析对象,有助于研究者形成对复杂学习行为的连续性认识,堪称人类迈向“数据海洋”的数智时代教育研究新范式。该方法为全面地理解数智化异构学习环境中的交互规律,从整体和系统层面深度把握数智时代学习的复杂规律提供了新思路。

A three-dimensional polycyclic aromatic hydrocarbon based covalent organic framework doped with iodine for electrical conduction

Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectronic. Iodine doping is an effective way to enhance the electrical conductivity of COFs. Here, a novel 3D imine COF with lvt topology is synthesized from two different pentacene derivatives with the same core in the form of structural complementarity. DDHP-COF is a highly crystalline material featuring high surface area of 1679 m^(2)/g and excellent thermal stability up to 490 ℃. Upon doping with iodine, the electrical conductivity can reach as high as 1.5×10^(-2)S/m which is significantly enhanced over 6 orders of magnitude compared with the pristine COF.

Hydrothermal Synthesis and Properties of Open-Framework Mixed-valence Iron Phosphates IIIII21.543FeFe(PO) with Three-dimensional Structure

The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized in the triclinic, space group P1with a=0.64724(4) nm, b=0.79651(6) nm, c=0.94229(5) nm, =104.447(2)? =108.919(4)? =101.741(4)? V=0.42302(5) nm3, Z=1 and R1 (wR2)=0.0307 (0.0793). Crystal data were collected on a Rigaku R-AXIS RAPID IP diffractometer with Mo K?(=0.071073 nm) at 293(2) K in the range of 2.43埃迹?7.46? The structure of 1 consists of 19 non-hydrogen atoms including three and a half crystallographically in-dependent Fe and three P atoms. Fe(1) connects its symmetrical Fe(1A) through bridging oxygen forming a dimer and the dimers are connected by Fe(4) forming an infinite staircase-like chain. Fe(2) and Fe(3) connect the infinite chains into a layer with bridging oxygen. Layers are interconnected via Fe(4) forming the six-membered and eight-membered channel systems.

An Analysis of Policy Ecology of Scientific Data under the Dual Three-dimensional Framework

The analysis of the current big data policy for scientific research can promote the ecological optimization of big data policy,and is a positive response to the national big data strategy.This paper constructs a“dual three-dimensional framework”to analyze the central and local science data policies from 2013 to 2022.With the dissemination and popularization of the concept of scientific data sharing,policies and regulations related to scientific data management have been issued,which promotes the emergence of scientific data policy ecology.The scientific data policy ecology is a complex and multicollaborative dynamic system composed of policy text,policy environment and related personnel,the core of which lies in the policy itself,aiming to ensure the security of scientific data and promote the development of science.There are the following problems in the scientific data policy ecology:In terms of policy text,the policy effectiveness is low and the use of policy tools is uneven.In terms of relevant personnel,the cooperation network density among various subjects is low and there is a lack of highquality talents.In terms of policy environment,there is an imbalance of regional funding support.It also puts forward some optimization strategies,such as strengthening the systematization of policy texts,improving the degree of coordination of policy subjects to form a long-term cooperation network,and improving the degree of compatibility between environment,personnel and policies.

水面舰艇大型训练模拟系统关键技术实现研究

针对水面舰艇大型训练模拟系统网络通信拥堵、软件开发复杂、口令评估和训练组织困难的问题,提出了基于多层次分布式服务的分布仿真支撑环境、面向agent的操控台软件开发框架、指挥口令自动识别和响应构件3项关键技术的实现方法,有效保证了水面舰艇大型训练模拟系统可靠稳定通信、软件快速开发,实现了指挥员口令的评估和训练战位无人值守自动响应操纵。这些关键技术已经应用于水面舰艇大型训练模拟系统,并投入训练使用。

引航管理信息化系统技术框架探讨

在分析了船舶引航信息化管理的特点和需求基础上,探讨了基于J2EE的分布式多层体系架构实现引航管理信息化系统的框架结构,对各个组成部分做了描述。结合实际开发的系统总结了实现系统的网络拓扑结构和系统的较完整的6个功能组成部分,各个部分功能相互独立,又相互联系,交换信息。并对系统的实现细节和技术特点进行了说明。将计算机技术、网络技术和通讯技术结合,实现静态信息与动态信息的融合,是船舶引航管理工作的发展方向,是实施科学引航的有效技术手段。

基于Web Services的企业培训管理系统多层架构设计

介绍Web Services的体系结构及其关键技术。在.NET平台上,采用多层架构思想设计实现基于Web Services的企业培训管理系统。此系统具有跨平台、分布式、易维护等特点,可为企业培训管理系统的开发提供一种新的开发模式。

基于图割框架的改进多层图彩色图像分割方法

彩色图像中所含有的颜色信息和纹理信息量很大且非常复杂,伴随着多个目标区域的出现,当前图像分割法很难整合纹理特征与颜色特征,图像分割效果不佳,因此,提出一种基于图割框架的改进多层图彩色图像分割方法,将多层图彩色图像分割问题看作是计算机视觉中的二元标识问题,转换成能量函数最小化问题,给出多标签MRF马尔科夫随机场能量函数,将颜色信息与纹理信息进行融合,通过建立多层图割模型对多类彩色图像能量函数的最小化问题进行求解。为了得到多类分割结果,采用一种自适应迭代收敛准则进行修改,在图割框架下进行多次迭代分割。实验结果表明,所提方法不仅分割效果良好,而且性能优越。

长焦距航空遥感器多框架复合热控设计

长焦距航空遥感器对温度变化极为敏感,为了保证极端条件下航空遥感器内部的温度水平和均匀性,实现对地面景物信息的有效采集,对某型长焦距航空遥感器的热控系统进行了设计.首先,分析了温度变化及温度梯度对光学系统折射率、面型、焦平面位置及像差的影响.然后,阐述了传统的热控设计的局限性,并对设备进行了多框架复合热控设计.最后,通过计算给出了系统的热控性能指标,通过仿真分析和实验对三种设计方式进行了比较.实验结果表明:多框架复合热控设计可以将设备内部的温度稳定在19℃±1℃范围内,基本消除了光学系统的温度变化和温度梯度,与常温环境成像分辨率60 lp/mm对比,图像分辨率无下降解决了该设备在低温环境下无法成像的技术难题.

多层次命令行解析框架研究与设计

针对大型网络服务器中命令行程序缺乏统一、不支持多层命令解析等问题,在集成Commons CLI的基础上,提出命令管理器的概念,利用命令调用器从命令类中分离出命令处理策略,简化了命令实现逻辑,提出了一种多层次命令行解析框架,并介绍了框架的主要组成和操作。最后对框架的兼容性、扩展性和灵活性等方面进行了分析。