检索结果-南通市图书馆

Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

在线全文

学校读者我要写书评

暂无评论

原子与分子物理学报 2025年第4期42卷 27-32页

作者： XU Jian-Qiang MA zhao-Peng cheng Si LIU Zhi-Cong ZHU Guang-Lai Department of Physics School of Physics and Electronic InformationAnhui Normal UniversityWuhu 241002China

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this *** following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution *** results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient ***,the excess molar volume initially decreases,reaches a minimum,and then *** rules of radial distribution functions(RDFs)of characteristic atoms are *** increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then *** indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

关键词： Pyridinium ionic liquids Thermodynamic properties Molecular dynamics simulation Radial distribution functions

基于钢结构BIM模型的结构分析数据转换和软件开发

在线全文

学校读者我要写书评

暂无评论

哈尔滨工业大学学报 2025年第1期57卷 161-169页

作者：赵诗华刘栋余香林石永久清华大学土木工程系北京100084

为解决当前在钢结构建筑信息模型(building information modeling,BIM)与结构分析模型之间进行数据转换时存在的关键技术问题,本文在分析工业基础类(industry foundation classes,IFC)标准表达方法的基础上,以ABAQUS为结构分析平台,开... 详细信息

为解决当前在钢结构建筑信息模型(building information modeling,BIM)与结构分析模型之间进行数据转换时存在的关键技术问题,本文在分析工业基础类(industry foundation classes,IFC)标准表达方法的基础上,以ABAQUS为结构分析平台,开发了钢结构BIM模型数据转换算法,运用C#语言和Xbim工具包,实现了结构构件信息提取、构件空间位置调整和分析数据自动添加,并形成了相应的转换软件;通过钢框架结构实例分析验证了该软件的可靠性和准确性,并将其应用于安阳市游客集散中心的BIM模型转换和结构分析。结果表明,所开发的算法和软件解决了生成的结构分析模型节点不连接和人工添加分析数据工作量大等问题,实现了BIM中的钢结构设计模型或深化设计模型向ABAQUS结构分析模型数据的准确转换。与传统的在ABAQUS中直接建立结构分析模型相比,本文提出的方法能大大提高复杂钢结构的结构分析建模速度和效率。

关键词：钢结构建筑信息模型(BIM) IFC标准模型转换结构分析

Photoinduced C--C Bond Cleavage and Oxidation of CycloketoximeEsters

同方期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2018年第11期36卷 995-999页

作者： Binlin zhao Hui Tan cheng Chen Ning Jiao Zhuangzhi shi State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210093 China State Key Laboratory of Natural and Biomimetic Drugs School of Phar-maceutical Sciences Peking University Xue Yuan Road 38 Beijing100191 China

A novel structural reorganization of cycloketoxime esters beyond the traditional Beckmann rearrangement process has been established to build cyano‐containing ketones in the presence of photocatalyst. This novel transformation is remarkable with selective C—C bond cleavage and an oxidation process enabled by DMSO used as the solvent, oxidant, and oxygen source avoiding acid, base and toxic cyanide salts as the cyano source. Further applications in late‐stage modification of complex and chiral molecules have also been reported.

关键词： C—C activation radical cycloketoxime oxygenation photocatalysis DMSO

Highly ordered Ag-TiO2 nanocomposited arrays with high visible-light photocatalytic activity

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2017年第3期11卷 241-249页

作者： Cong zhao Da-chuan ZHU Xiao-yao cheng shi-xiu CAO Research Institute for New Materials Technology Chongqing University of Arts and Sciences Chongqing 402160 China College of Materials Science and Engineering Sichuan University Chengdu 610065 China

TiO2 is active only in the ultraviolet region. To enhance the active ability, a combined method consisting of the anodic oxidation method and the hydrothermal method was developed to prepare highly ordered Ag-TiO2 nanocomposited arrays. The anodic oxidation was used to synthesize amorphous nanotubes with high chemical activity that subsequently served as highly ordered templates in preparing the final sample. The amorphous nanotubes got converted to highly ordered Ag-TiO2 （anatase） arrays in the silver nitrate ＆ glucose aqueous solution via hydrothermal treatment. SEM and TEM results show that the Ag-TiO2 nanocomposite was composed of a large number of Ag nanoparticles and anatase TiO2 nanoparticles, and the morphology of those at the top of the arrays was found different from that of its trunk. The morphology evolution mechanism of the obtained sample was discussed. It is also revealed that the Ag-TiO2 nanocomposite has high visible-light photocatalytic activity.

关键词： TiO2 nanoparticles silver heterojunction

Functions and Application of the AP2/ERF Transcription Factor Family in Crop Improvement

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2011年第7期53卷 570-585页

作者： zhao-shi Xu Ming Chen Lian-cheng Li You-Zhi Ma National Key Facility of Crop Gene Resources and Genetic Improvement (NFCRI) Key Laboratory of Crop Genetics and Breeding Ministry of Agriculture Institute of Crop Science Chinese Academy of Agriculture Sciences (CAAS) Beijing 100081 China

Plants have acquired sophisticated stress response systems to adapt to changing environments. It is important to understand plants＇ stress response mechanisms in the effort to improve crop productivity under stressful conditions. The AP2/ERF transcription factors are known to regulate diverse processes of plant development and stress responses. In this study, the molecular characteristics and biological functions of AP2/ERFs in a variety of plant species were analyzed. AP2/ERFs, especially those in DREB and ERF subfamilies, are ideal candidates for crop improvement because their overexpression enhances tolerances to drought, salt, freezing, as well as resistances to multiple diseases in the transgenic plants. The comprehensive analysis of physiological functions is useful in elucidating the biological roles of AP2/ERF family genes in gene interaction, pathway regulation, and defense response under stress environments, which should provide new opportunities for the crop tolerance engineering.

关键词： AP2/ERF gene regulation signal pathway stress tolerance transgenic plant

Exactly solving some typical Riemann-Liouville fractional models by a general method of separation of variables

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2020年第5期72卷 46-51页

作者： cheng-shi Liu Department of Mathematics Northeast Petroleum UniversityDaqing 163318China

Finding exact solutions for Riemann–Liouville(RL)fractional equations is very *** propose a general method of separation of variables to study the *** obtain several general results and,as applications,we give nontrivial exact solutions for some typical RL fractional equations such as the fractional Kadomtsev–Petviashvili equation and the fractional Langmuir chain *** particular,we obtain non-power functions solutions for a kind of RL time-fractional reaction–diffusion *** addition,we find that the separation of variables method is more suited to deal with high-dimensional nonlinear RL fractional equations because we have more freedom to choose undetermined functions.

关键词： Riemann–Liouville derivative exact solution fractional differential equation separation of variables method

QuEChERS结合HPLC检测辣椒及其制品中天然辣椒素、二氢辣椒素和合成辣椒素

在线全文

学校读者我要写书评

暂无评论

食品科学 2025年第2期46卷 240-247页

作者：成璐瑶温雅君石文婷周子莹马丽艳中国农业大学食品科学与营养工程学院北京100083 北京市农产品质量安全中心北京100029 农业农村部农产品质量检验测试中心(北京) 北京100083

建立一种QuEChERS结合高效液相色谱快速检测辣椒及其制品中的天然辣椒素、二氢辣椒素和合成辣椒素的方法。样品用乙腈提取,无水硫酸镁、十八烷基硅烷(C18)、乙二胺-N-丙基硅烷化硅胶、石墨化炭黑复合吸附剂净化。采用Agilent Eclipse Pl... 详细信息

建立一种QuEChERS结合高效液相色谱快速检测辣椒及其制品中的天然辣椒素、二氢辣椒素和合成辣椒素的方法。样品用乙腈提取,无水硫酸镁、十八烷基硅烷(C18)、乙二胺-N-丙基硅烷化硅胶、石墨化炭黑复合吸附剂净化。采用Agilent Eclipse Plus C18(150 mm×4.6 mm,5μm)分离,以0.4%磷酸水溶液和90%乙腈溶液为流动相进行梯度洗脱,荧光检测器进行检测。结果表明:天然辣椒素、二氢辣椒素和合成辣椒素在0.20~100 mg/L范围内线性关系良好,决定系数(R2)均大于0.999。天然辣椒素的方法检出限为0.014~0.069 mg/kg,定量限为0.046~0.23 mg/kg;二氢辣椒素的方法检出限为0.023~0.12 mg/kg,定量限为0.077~0.39 mg/kg;合成辣椒素的方法检出限为0.018~0.088 mg/kg,定量限为0.059~0.30 mg/kg。在干辣椒、鲜辣椒、香菇酱、辣椒油4种基质中,3个不同添加水平下的加标回收率为91.6%~117.2%,相对标准偏差为0.2%~6.1%。该方法简便、准确,不仅适用于干、鲜辣椒,而且适用于高油、高蛋白等辣椒制品中天然辣椒素、二氢辣椒素和合成辣椒素含量的检测。

关键词： QuEChERS 高效液相色谱辣椒辣椒素合成辣椒素

Cyclic oligourea synthesized from CO_(2):Purification,characterization and properties

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2022年第3期7卷 477-484页

作者： Ruhui shi Haiyang cheng Hongxiang Li Peixuan Wu Chao Zhang Masahiko Arai Fengyu zhao State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesNo.5625 Renmin Rd.Changchun130022China University of Science and Technology of China No.96 Jinzhai Rd.Hefei230026China Jilin Province Key Laboratory of Green Chemistry and Process Changchun Institute of Applied ChemistryChinese Academy of SciencesNo.5625 Renmin Rd.Changchun130022China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesNo.5625 Renmin Rd.Changchun130022China

Carbon dioxide(CO_(2)) as a sustainable resource instead of toxic reagents has attracted considerable attention in synthesis of chemicals and polymeric ***,a kind of cyclic oligourea was synthesized via polycondensation of CO_(2) with 4,7,10-trioxa-1,13-tridecanediamine(TTD)followed by effective separation and purification *** developed an efficient separation strategy in which the linear oligourea molecules were selectively transformed to macromolecular polyurea molecules by a reaction of the–NH_(2) end group with 4,4’-diphenylmethane diisocyanate(MDI),followed by separation from cyclic oligourea using selected *** structure and physicochemical properties were confirmed by MALDI-TOF mass spectra,NMR,Cryo-EM,thermal analysis and solubility *** well-defined cyclic oligourea was produced with a high purity(99.4%)and the average-number molecular weight(Mn)of 1040 *** is semi-crystalline in structure with a melting point of 106℃and glass transition point of-10℃.The cyclic oligourea presented characteristically difference to its linear *** work provides a new member to cyclic polymer family.

关键词： materials separation purity

FM interference suppression for PRC-CW radar based on adaptive STFT and time-varying filtering

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2010年第2期21卷 219-223页

作者： zhao zhao Xiangquan shi School of Electronic Engineering and Optoelectric Technology Nanjing University of Science and Technology Nanjing 210094 E R. China

The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform （STFT） and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM （LFM） and sinusoidal FM （SFM）, under different signal-to-jamming ratio （S JR） are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection.

关键词： interference suppression frequency modulation in- terference adaptive short-time Fourier transform (STFT) time- varying filtering pseudo random code continuous wave (PRC-CW) radar.