检索结果-南通市图书馆

Quantification of flupirtine maleate polymorphs using X-ray powder diffraction

Chinese Chemical Letters 2016年第11期27卷 1666-1672页

作者： Yu-Mei Zhao Zhi-bing zheng Song Li Laboratory of Computer-Aided Drug Design & Discovery Beijing Institute of Pharmacology and Toxicology Laboratory of Structure Identification Beijing Institute of Pharmacology and Toxicology State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology

Flupirtine maleate, a pharmaceutical compound for treating psychotic disease in clinics, has seven polymorphs. Form A, with better crystal stability and bioavailability, has been widely used as the pharmaceutical crystal form. Unfortunately, it is usually found in a polymorphic mixture with form B. In this study, pure crystal forms of A and B were prepared and characterized by X-ray powder diffraction （XRPD）, Fourier transform infrared spectroscopy （FT-IR） and thermal analysis. An XRPD-based method for the quantitative determination of the amount of the flupirtine maleate polymorphs form A and form B was also established through a systematic optimization of instrumental parameters. The results of the analytical methodology validation showed that the XPRD method had a broad quantitative range of 0- 100% （w/w）, good linear relationship, with R2= 0.999, excellent repeatability and precision and low limits of detection （LoD） of 0.15% （w/w） and quantification （LoQ） of 0.5% （w/w）. The results also showed that the single-peak method was not as good as the whole pattern in reducing the influence of the preferred orientation, but this can be compensated for by a systematic optimization of instrumental parameters and validating the analytical methodology to reduce errors and obtain a good, repeatable, sensitive, and accurate method. This XRPD method can be used to analyze mixtures of flupirtine maleate polymorphs （forms A and B） quantitatively and control the quality of the bulk drug.

关键词： Flupirtine maleate X-ray powder diffraction Quantitative analysis of polymorphs Preferred orientation Transmission

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The influence of main ecological and environmental factors on the energy budget of Schlegel＇ s black rockfish Sebastes schlegeli

引用

Acta Oceanologica Sinica 2007年第3期26卷 90-100页

作者： SUN Yao zheng bing ZHANG Bo TANG Qisheng Key Laboratory for Sustainable Utilization of Marine Fisheries Resources of Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fisheries Sciences Qingdao 266071 China

In the Maidao Ecological Laboratory of the Huanghai Sea Fisheries Research Institute in 1998 ~ 2000, the continuous flow-through method was adopted to determine the energy budget components and models of Schlegel＇ s black rockfish under different ecological and environmental factors, such as temperature, food species, body mass and feeding level, etc. The body mass of test fish ranged from 21.2 to 224.5 g. The specific growth rate tended to invert ＂U＂ change with temperature increase. The ecological conversion efficiency showed the same trend as temperature and feeding level rise. Only the specific growth rate tended to decelerate the increment with the rise of feeding level. From the above quantitative relationships, the maximum and optimal growth temper- atures could be obtained as 17.5 and 16.2 ℃, and the maintenance feeding rate and optimum feeding rate as 0.8% and 4. 1% of the body mass. The specific growth rate and ecological conversion coefficient showed a decelerating decrease trend with body mass increment. The small-sized fish food was more advantageous to the feeding level increase in comparison with the small-sized shrimp food, which led to the increase of growth, metabolism and excretion, but had no significant influence on the ecological conversion coefficient. All of temperature, feeding level, body mass and food species can obviously change the energy budget models. The assigning rate of growth energy tended to change along the invert ＂U＂ curve with the increase of temperature and feeding level, and decrease with the body mass increase, but the assigning rates of metabolism energy and excretion energy were quite reverse. These relationships could be quantitatively described as quadratic or power function curve. If the above relationships proved true to other marine fish, the establishment of energy budget model of the same fish under different conditions can be largely simplified.

关键词： influence ecological and environmental factors energy budget Sebastes schlegeli

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structures, Stabilities and Work Functions of Alkali-metal-adsorbed Boron α1-Sheets

引用

Chemical Research in Chinese Universities 2017年第4期33卷 631-637页

作者： YI Tingting zheng bing YU Haitao XIE Ying Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials Science Heilongfiang University Harbin 150080 P. R. China

In this study, we employed the density functional theory method to simulate Li-, Na- and K-adsorbed boron α1-sheets（al-BSTs）. After optimizing possible structures, we investigated their thermodynamic stabilities, barriers for metal atom diffusion on the substrate, and work functions. The computed results indicate that the work function of α1-BST decreases significantly after the adsorption of Li, Na and K. Furthermore, under high hole coverage, these alkali-metal-adsorbed α1-BSTs have lower work functions than the two-dimensional materials of greatest concern and the commonly used electrode materials Ca and Mg. Therefore, the Li-, Na- and K-adsorbed α1-BSTs are potential low-work-function nanomaterials.

关键词： Boron α1-sheet Binding energy Migration barrier Alkali metal adsorption, Work function

来源：

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

Influence of carbon addition on mechanical properties of Fe-Mn-C twinning-induced plasticity steels

引用

Journal of Iron and Steel Research International 2022年第9期29卷 1446-1454页

作者： Peng Fu Zhi-bing zheng Wei-ping Yang Hao-kun Yang School of Engineering Jiangxi Agricultural UniversityNanchang 330045JiangxiChina Institute of New Materials GuangdongAcademy of SciencesGuangdong Provincial iron Matrix Composite Engineering Research CenterGuangzhou 510650GuangdongChina Smart Manufacturing Division Hong Kong Productivity CouncilHong Kong 999077.China

Mechanical properties and microstructural evolution of Fe-22Mn-0.6C and Fe-22Mn-1.0C(wt.%)twinning-induced plasticity(TwIP)steels were investigated by monotonic,stress-relaxation and unloading-reloading tensile *** dynamic strain aging(DSA)effect,resulting from pinning of dislocations,effectively improved the dislocation activation volume of the two TWIP *** the meanwhile,DSA-facilitated twinning nucleation mechanism kept similar twinning capabilities of the two TWIP *** strain increasing,the formation of high-density deformation twins restricted the dislocation motion and reduced the activation volume with increasing ***,C addition simultaneously improved the ultimate tensile strength and uniform elongation,and significantly enhanced the friction stress,rather than back *** stronger short-range order effect,brought by friction stress,promotes the planar dislocation slipping,thus improving the work-hardening *** a result,the additional work-hardening capacity can be achieved in Fe-Mn-C with higher C addition.

关键词： Twinning induced plasticity steel Work-hardening rate Dynamic strain aging Short-range order Deformation twin

来源：

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

Corrosion Behaviors of Pure Titanium and Its Weldment in Simulated Desulfurized Flue Gas Condensates in Thermal Power Plant Chimney

引用

Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 477-486页

作者： zheng-bing Wang Hong-Xiang Hu Chun-Bo Liu Huai-Ning Chen Yu-Gui zheng Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences Center for Wear and Corrosion Resistant Materials Huadian Zhengzhou Mechanical Design Institute Co.Ltd. Laboratory of Properties and Reliable Joining of Welded Joints Institute of Metal ResearchChinese Academy of Sciences

The corrosion behaviors of pure titanium and its weldment welded by tungsten inert gas （TIG） welding in simulated desulfurized flue gas condensates in thermal power plant chimney were investigated using potentiodynamic polarization, electrochemical impedance spectroscopy （EIS） and immersion tests. The effects of heat input and shielding gases on the corrosion behavior of the welded titanium were also studied. Grain coarsening and Widmanst^itten structure were found in both the fusion zone and the heat-affected zone. The welded titanium exhibited active-passive behavior in the simulated condensates. Both the polarization curves and EIS measurements confirmed that TIG welding process with different parameters had few effects on the corrosion behavior. It was proved that the microstructure changes were not the key material factors affecting the corrosion behavior of pure titanium under the test conditions, while the oxide film had remarkable effect on improving the corrosion resistance.

关键词： Pure titanium Tungsten inert gas welding Simulated desulfurized flue gas condensates Corrosion behavior Microstructure Oxide film

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on Diffusion Behavior of 72LX Blooms in the Decarburization Process

引用

Journal of Wuhan University of Technology(Materials Science) 2022年第4期37卷 716-721页

作者： XU Dong zheng bing PANG Hongxuan WANG Xuexi ZOU Zhipeng Technology Innovation Center for High Quality Cold Heading Steel of Hebei Province Hebei University of EngineeringHandan 056038China Technology Center Zhongyuan Special Steel Equipment Manufacturing Co.LtdAnshan 114051China School of Materials and Metallurgy University of Science and Technology LiaoningJiyuan 459008China Engineering Research Center for High Toughness Wind Tower Steel of Hebei Province Hebei Puyang Iron and Steel Co.LtdHandan 056305China

To elucidate the diffusion behavior of carbon atoms within the austenite region,the decarbonization of 72LX steel bloom was *** studies were performed to obtain the depth profiles of the decarburized layers within the temperature range of 950-1250℃.The findings show that,within a temperature range of 950-1200℃,both the depth of the decarburization layer of the grain interior(h_(in))and the depth of the decarbonization effect zone of the grain boundary(h_(b))increase concurrently with increasing holding temperatures and times and an inflection point is observed at 1200℃.By measuring the change in the sample diameter before and after the experiment,the change in the radius reduction of h_(Fe) causes by oxidation is *** changes are observed in h_(Fe) when the temperature is below 1050℃.As the temperature increases to 1100℃,a sudden change in h_(Fe) is observed,which corresponds to a rapid increase in *** temperatures above 1100℃,a more gradual change is *** the experimental results,a two-dimensional decarburization mathematical model is established and the carbon diffusion coefficients at different temperatures are obtained by simulation and regression *** simulation values obtain from the carbon diffusion model matched well with the experimental values,thereby confirming the accuracy of the simulation process.

关键词： 72LX steel diffusion behavior diffusion coefficient decarburized layer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Heavy metal pollution in tidal zones of Bohai Bay using the dated sediment cores

引用

Journal of Environmental Sciences 2006年第3期18卷 610-615页

作者： QIN Yan-wen MENG Wei zheng bing-hui SU Yi-bin River and Coastal Environment Research Center Chinese Research Academy of Environmental Sciences Beijing 100012 China

Three sediment cores were collected in November 2003 from Dagu estuary to Qikou estuary. The main polluted heavy metals in the sediment of tidal zones for the Bohai Bay have been found by analyzing the relationship among the contents of heavy metals, the contents of geochemical elements （Fe, AI and Mn） and the size of grain. The dominating contaminative elements in tidal sediments of Bohai Bay are Pb, Zn and Cd. Their contents are higher than the corresponding upper limit of environmental background values and they have very faint correlation with the corresponding contents of geochemical elements and the size of grain, indicating the anthropogenic enrichment. Especially, the preliminary study on the pollution sources and the history of heavy metals in the Dagu estuary has been done using the dated results. The contamination by Zn and Cd also started in the middle 1950s, while the contamination by Pb appeared in the early 1940s. The pollution by Zn and Cd mainly originate from sewage discharge, while the pollution by Pb has many sources, like atmosphere deposition and industrial discharRe.

关键词： Bohai Bay tidal zone the dated sediment core heavy metal pollution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Treatment of tannery wastewater by electrocoagulation

引用

Journal of Environmental Sciences 2007年第12期19卷 1409-1415页

作者： FENG Jing-wei SUN Ya-bing zheng zheng ZHANG Ji-biao LI Shu TIAN Yuan-chun State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China

Treatment of tannery wastewater by electrocoagulation with low cell current （≤ 1A） and soluble electrodes （mild steel electrodes and aluminum electrodes） was studied. Compared with aluminum electrodes, mild steel electrodes were more effective for the removal of sulfide, with a removal efficiency of over 90%. But during the treatment process, black color precipitate typical to iron（Ⅱ） sulfides was produced. While aluminum electrodes were effective to eliminate the colority of the effluent, the removal efficiency of sulfide was lower than 12%. The mechanisms of the removal of chemical oxygen demand, ammonia, total organic carbon, sulfide and colority with the two soluble electrodes （mild steel and aluminum electrodes） were discussed in detail. In order to exert the predominance of diffenent types of electrodes, the tannery wastewater was treated using mild steel electrodes first followed by the filter and finally by the aluminum electrodes, the elimination rates of chemical oxygen demand, ammonia, total organic carbon, sulfide and colority were 68.0%, 43.1%, 55.1%, 96.7% and 84.3%, respectively, with the initial concentrations 2413.1 mg/L, 223.4 mg/L, 1000.4 mg/L, 112.3 mg/L and 256 dilution times, respectively. The absorbance spectra and energy consumption during electrocoagulation process were also discussed.

关键词： tannery wastewater electrocoagulation mild steel electrodes aluminum electrodes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Emerging porous nanosheets:From fundamental synthesis to promising applications

引用

Nano Research 2021年第1期14卷 1-28页

作者： Yun Fan Jia Zhang Yu Shen bing zheng Weina Zhang Fengwei Huo Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Nanjing Tech University(NattjingTech)Nanjing 211816China

Metal-organic framework(MOF)nanosheets and covalent organic framework(COF)nanosheets as emerging porous materials nanosheets have captured increasing attention owing to their attractive properties originating from the advantages of large lateral size,ultrathin thickness,tailorable physiochemical environment,flexibility and highly accessible active sites on surface,and the applications of them have been explored in a wide range of *** MOF and COF nanosheets own many similar properties,their applications in various fields show significant differences,probably due to their different compositions and bonding ***,we summarize the recent progress of MOF and COF nanosheets by comparative analysis on their advantages and limitations in synthesis and applications,providing a more profound and full-scale perspective for researchers or beginners to understand this ***,the categories of preparation methods of MOF and COF nanosheets are firstly discussed,including top-down and bottom-up ***,the applications of MOF and COF nanosheets for separation,catalysis,sensing and energy storage are ***,based on current achievements,we put forward our personal insights into the challenges and outlooks on the synthesis,characterizations,and promising applications for future research of MOF and COF nanosheets.

关键词： metal-organic framework(MOF)nanosheets covalent organic framework(COF)nanosh eets top-down methods bottom-up methods two-dimensional(2D)nanomaterials

来源：

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

Commentary on “Transurethral seminal vesiculoscopy for recurrent hemospermia: experience from 419 cases”

引用

Asian Journal of Andrology 2020年第2期22卷 227-228页

作者： Kun Pang bing-zheng Dong Cong-Hui Han Department of Urology Xuzhou Central HospitalXuzhou Clinical College Affiliated to Xuzhou Medical UniversityXuzhou 221009China

Dear Editor,We have read the article by Chen et al.1 with great *** reported the effect of transurethral seminal vesiculoscopy(TSV)for the treatment of recurrent hemospermia,and they concluded that TSV was an effective and safe procedure in the management of seminal tract disorders.1 TSV is an endoscopic technique that has developed rapidly in recent *** it is a relatively simple procedure and does not change the normal anatomical structures of seminal vesicles,this technique is becoming an alternative for the diagnosis and treatment of seminal vesicle and seminal tract diseases.

关键词： TSV treatment recurrent

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：