检索结果-内蒙古大学图书馆

constructing sandwich structure of Nb-substituted Na3V2(PO4)3/c nanoparticles enwrapped on three-dimensional graphene with superior sodium storage property

引用

cERAMIcS INTERNATIONAL 2022年第22期48卷 33957-33966页

作者： chen, Bifen Peng, Zhenbo Yuan, Zhengyong Ningbo Polytech Chem Engn Coll Ningbo 315800 Peoples R China

Poor intrinsic conductivity has been a principal limiting factor for Na3V2(PO4)3 (NVP) cathode material. Herein, a synergistic strategy of Nb5+ substitution and constructing with three-dimensional rGO lamella is proposed for the first time to optimize the characteristics of NVP. The introduction of Nb5+ generates beneficial carriers and vacancies that optimize the electronic structure of NVP system. Meanwhile, rGO substrate can construct an effective conductive network for the facilitated electronic transportation and form a stabilized SEI layer after cycling to protect the active particles from being collapsed. This double treatment significantly improves the kinetic characteristics of NVP. Moreover, theoretical calculations indicate that beneficial Nb5+ doping can effectively reduce the band gap between conductive and valence bands, as well as decline the energy barrier of migration for Na+. Notably, the modified Nb0.15-NVP/c@rGO exhibits impressive electrochemical performance. It delivers a capacity of 107.9 mAh g-1 and keeps a value of 102.6 mAh g-1 after 500 cycles at 2c with a high retention of 95.35%. It submits a capacity value of 97.2 mAh g-1 at 20c, 82.92% reversible capacity (80.6 mAh g-1) could be retained after 2000 cycles. Even at 120 and 300c, this material still performs high values of 84.9 and 71.3 mAh g-1, indicating the superior rate capability.

关键词： Sandwich structure Nb-doped c Graphene Sodium storage property

来源：评论

学校读者我要写书评

暂无评论

c# and the .NET Framework: Ready for real time

引用

IEEE SOFTWARE 2003年第1期20卷 74-+页

作者： Lutz, MH Laplante, PA Siemens Hlth Serv Malvern PA 19355 USA Penn State Univ Great Valley Sch Grad Profess Studies Malvern PA 19355 USA

Microsoft's next-generation platform, the NET Framework, offers a new language, c#, which aims to offer the power of c++ with the ease of Visual Basic. In this article, the authors consider the application of c# and the NET Framework to real-time systems. Their performance tests show that c and c# performance is comparable in some cases. However, they show that c# is not currently suitable for hard real-time applications and should be used for firm and soft real-time applications only with care.

关键词： c language programming environments real-time systems c Microsoft NET Visual integrated development environment overflow-sensitive arithmetic thread synchronization type unsafe features SLc6A2 gene NET Framework IDE ELK3 gene Online resources Microsoft programming environments real-time systems c language

来源：评论

学校读者我要写书评

暂无评论

c,N-chelated organotin(IV) compounds as catalysts for transesterification and derivatization of dialkyl carbonates

引用

APPLIED ORGANOMETALLIc cHEMISTRY 2012年第6期26卷 293-300页

作者： Weidlich, Tomas Dusek, Libor Vystrcilova, Barbora Eisner, Ales Svec, Petr Ruzicka, Ales Univ Pardubice Dept Gen & Inorgan Chem Fac Chem Technol CZ-53210 Pardubice Czech Republic Univ Pardubice Inst Environm & Chem Engn Fac Chem Technol CZ-53210 Pardubice Czech Republic Univ Pardubice Dept Analyt Chem Fac Chem Technol CZ-53210 Pardubice Czech Republic

The potential catalytic activity of selected c,N-chelated organotin(IV) compounds (e.g. halides and trifluoroacetates) for derivatization of both dimethyl carbonate (DMc) and diethyl carbonate (DEc) was investigated. Some tri-, di- and monoorganotin(IV) species (LcN(n-Bu)2Sncl (1), LcN(n-Bu)*** (1a), LcN(n-Bu)2SnI (2), LcNPh2Sncl (3), LcNPh2SnI (4), LcN(n-Bu)Sncl2 (5), LcNSnBr3 (6) and [LcNSn(Oc(O)cF3)]2(mu-O)(mu-Oc(O)cF3)2 (7)) bearing the LcN moiety (LcN?=?2-(N,N-dimethylaminomethyl)phenyl-) were assessed as catalysts for reactions of both DMc and DEc with various substituted anilines. The catalytic activities of 4 and 7 for derivatization of DMc with p-substituted phenols were studied for comparison with the standard base K2cO3/Silcarbon K835 catalyst (catalyst 8). The composition of resulting reaction mixtures was monitored by multinuclear NMR spectroscopy, Gc and Gc-MS techniques. In general, catalysts 1, 3 and 7 exhibited the highest catalytic activity for all reactions studied, while some of them yielded selectively carbonates, carbamates, lactam or substituted urea. copyright (c) 2012 John Wiley & Sons, Ltd.

关键词： organotin(IV) compounds c N-chelating ligand dialkyl carbonates catalysis

来源：评论

学校读者我要写书评

暂无评论

Integrated Analysis of MRNA and MiRNA Expression Profiles in dys-1 Mutants of c. Elegans After Spaceflight and Simulated Microgravity

引用

MIcROGRAVITY ScIENcE AND TEcHNOLOGY 2023年第3期35卷 31页

作者： Jiang, Jiahong Zhao, Lei Guo, Lin Xing, Yanfang Sun, Yeqing Xu, Dan Dalian Maritime Univ Inst Environm Syst Biol Coll Environm Sci & Engn Linghai Rd 1 Dalian 116026 Peoples R China

Dystrophin-like dys-1 gene is expressed and required in muscle tissue, playing a vital role in gravisensing in caenorhabditis elegans (c. elegans). To date, microRNA (miRNA)-mediated epigenetic mechanism in microgravity-induced muscular atrophy remains to be elucidated. In the present study, we first analyzed mRNA and miRNA expression profiles in space-flown dys-1(cx18) mutants and wild type worms (wt) of c. elegans. The results showed that spaceflight and microgravity have fewer effects on mRNA and miRNA expression in dys-1 mutant than in wt worms. mRNA and miRNA expression patterns of dys-1 mutants were changed by microgravity. Hierarchical clustering analysis showed that the alterations of genes function on neuromuscular system under space environment. Seven miRNAs (cel-miR-52, 56, 81, 82, 84, 124 and 230) have 18 significant anti-correlated target genes under space environment. RT-qPcR analysis confirmed that miR-52 and cdh-3, miR-84 and lin-14, miR-124 and mgl-3 in dys-1 mutants reversely altered under microgravity environment and in simulated microgravity experiment. Locomotion ability was only reduced in F0 wt worms but not in dys-1 mutants as well as their F1 offspring after simulated microgravity. We observed expression alterations of 7 neuromuscular genes (unc-27, nlp-22, flp-1, egl-5, flp-4, mgl-3, unc-94) in F0 wt worms, which might be involved in the regulation of locomotion ability of c. elegans. This study provides important insights to reveal the mechanism in the pathogenesis of muscular atrophy induced by microgravity.

关键词： c elegans Dys-1 mutants miRNAs Microgravity neuromuscular system

来源：评论

学校读者我要写书评

暂无评论

Effect of synthesis temperature on the structure and electrochemical performances of LiFePO4/c

引用

IONIcS 2019年第12期25卷 5697-5707页

作者： Lin, Yan Wu, Jianbo Huang, Xiaohua cao, Yiqi Guo, Renqing Taizhou Univ Sch Pharmaceut & Mat Engn Taizhou 318000 Peoples R China Zhejiang Univ State Key Lab Silicon Mat Hangzhou 310027 Peoples R China

A LiFePO4/c material with different amounts of iron phosphides was synthesized by a sol-gel method with different calcination temperatures. XRD, HRTEM, SEM, FTIR, BET, Raman, and magnetic measurements were carried out to characterize the physical properties of the LiFePO4/c, while EIS, cV, and charge-discharge tests were carried out to characterize the electrochemical performance. It is obtained that the crystallinity, the particle size of the LiFePO4, and the amount of iron phosphides in the sample are the factors that affect the electrochemical performance of the material, where the key factor determining the electrochemical performance varies in different situations. The samples possessing well-crystallized LiFePO4 particles and similar particle size demonstrated improved rate performance with the increasing amount of iron phosphides when the calcination temperature increased from 650 to 750 degrees c. The results showed that the rate performance could be improved by harmonious improvement of the ionic conductivity of Li+ and the electronic conductivity.

关键词： LiFePO4 c calcination temperature Electrochemical performance Iron phosphides Particle size

来源：评论

学校读者我要写书评

暂无评论

Effect of well-designed graphene heat conductive channel on the thermal conductivity of c/Sic composites

引用

cERAMIcS INTERNATIONAL 2021年第13期47卷 19115-19122页

作者： Zhang, Yunhai Liu, Yongsheng cao, Yejie cao, Liyang Zheng, Xutong Wang, Jing Pan, Yu Wang, Ning Northwestern Polytech Univ Sci & Technol Thermostruct Composite Mat Lab Xian 710072 Shaanxi Peoples R China Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Scramjet Lab Changsha 410073 Hunan Peoples R China

Poor thermal conductivity, especially in thickness direction, is a major obstacle to extend the service lifetime of c/Sic composite. However, there are few papers focusing on finely designing heat conductive channel but a simply introduction of various modifiers to improve c/Sic thermal conductivity, which leads to less success. Herein, multi-layer graphene sheets were utilized to improve the thermal conductivity of c/Sic composites via an effective method to design graphene heat conductive channels. To determine the role of graphene sheets in improving thermal conductivity, the effect of the different loading fractions of graphene and microstructure of as-prepared composites were systemically investigated. Results revealed that the thermal conductivity of composites increased by 204% with well-designed graphene heat conductive channels. Besides, compared with the porosity, the orderly aligned heat conductive pathways played a more important role in thermal conductivity. This work provides a new and effective method for preparing well-designed heat conductive channels to enhance thermal conductivity of c/Sic.

关键词： c Sic composites Graphene Thermal conductivity Laser machining Well-designed heat conductive channel

来源：评论

学校读者我要写书评

暂无评论

Modeling and experimental study on electrical impedance response to damage accumulation in 2D c/Sic composites

引用

JOURNAL OF THE EUROPEAN cERAMIc SOcIETY 2022年第10期42卷 4144-4153页

作者： Huo, Yanyan Yang, Qiang chen, Sian Meng, Songhe Zhao, Jingyu Jiang, Jieyu Harbin Inst Technol Natl Key Lab Sci & Technol Natl Def Adv Composites Harbin 150001 Peoples R China Harbin Inst Technol Postdoctoral Res Ctr Mat Sci & Technol Harbin 150001 Peoples R China Natl Univ Def Technol Sci & Technol Adv Ceram Fibers & Composites Lab Changsha 410073 Peoples R China

The electrical properties of c/Sic composites could be used for online and in-situ damage monitoring. To investigate alternating current (Ac) impedance response to damage in the c/Sic composites, monotonic and incremental cyclic tensile tests were performed. Both Ac impedance and acoustic emission (AE) techniques were applied to clarify the damage evolution during the tests. The relationship between damage and electrical impedance response was investigated and validated via macroscopic equivalent circuit models. The effects of longitudinal deformation and damage on Ac impedance characteristics, including impedance magnitude and phase angle, were obtained from the models. Results showed that the longitudinal deformation increases the impedance magnitude and the phase angle, and the damage causes the impedance magnitude to increase and the phase angle to decrease. The phase angle is significantly sensitive to fiber breakage, which makes the Ac-based method more suitable for online damage monitoring and final failure warning.

关键词： c Sic composites Electrical impedance Damage monitoring Macroscopic equivalent circuit model

来源：评论

学校读者我要写书评

暂无评论

Influence of c-O-H Volatiles on Ni, co, and P Partition between Silicate Melt and Liquid Metal Fe Alloy at 4 GPa, 1550°c

引用

GEOcHEMISTRY INTERNATIONAL 2020年第6期58卷 670-686页

作者： Lukanin, O. A. Tsekhonya, T. I. Koltashev, V. V. Kononkova, N. N. Russian Acad Sci Vernadsky Inst Geochem & Analyt Chem GEOKhI Moscow 119991 Russia Russian Acad Sci Fiber Opt Res Ctr Moscow 119333 Russia

A set of experiments was carried out in the system NaAlSi3O8-FeO-NiO-coO-Sic-NaH(2)PO(4)at 1550 degrees c, 4 GPa, and oxygen fugacity (fO(2)) 0.5-2.9 log. units below the iron-wustite (IW) buffer to estimate how c-O-H components can affect Ni, co, and P partition between silicate melt and a liquid metallic phase at redox conditions under which the metallic phase is segregated into melting products of the early reduced mantles of the Earth and other planetary bodies. It has been established that the Ni, co, and P partition coefficientsD(\M)(met/sil)between silicate melts saturated with carbon and containing dissolved c-O-H volatiles (mainly in the form of OH groups, H(2)and cH4) at relatively oxidized conditions (fO(2)> IW - 1.5) correspond toD(\M)(met/sil)values expected of metal-silicate melt equilibrium in volatile-free systems at analogousP,T,f(O2), andnbo/tparameters. Under more reduced conditions (fO(2)<= IW - 2), the presence of c-O-H volatiles leads to a decrease inD(\M)(met/sil)for Ni and P compared to that in "dry" melts. This difference increases with decreasingfO(2)and reaches similar to 0.5 and more than one order of magnitude for Ni and P, respectively, atfO(2)= IW - 2.9. The effect of volatiles onD(co)(met/sil)is much weaker, and hence, a decrease infO(2)leads to thatD(Ni)(met/sil)andD(co)(met/sil)converge. The Raman spectra of the experimental glasses and their SIMS analyses for hydrogen show that water content (OH + H2O) in the melts decreases with decreasingfO(2), whereas the contents of cH(4)and complexes with c-H bonds significantly increases. The likely reasons for the decrease inD(\M)(met/sil)under strongly reduced conditions may be changes in the structure of the silicate melts and the origin of complex compounds of siderophile elements with volatiles in these melts.

关键词： experiment oxygen fugacity c Ni co P silicate melt siderophile elements silicate-metal partition

来源：评论

学校读者我要写书评

暂无评论

Highly diastereoselective cycloaddition of diarylnitrilimines to the c=S bond of (1R)-thiocamphor as a source of chiral spiro-1,3,4-thiadiazoles

引用

JOURNAL OF SULFUR cHEMISTRY 2013年第3期34卷 250-258页

作者： Itto, My Youssef Ait Feddouli, Amal Boutalib, Abderrahim Riahi, Abdelkhalek Daran, Jean-claude Univ Cadi Ayyad Fac Sci Semlalia Dept Chim Marrakech Morocco UFR Sci CNRS UMR 7312 Inst Chim Mol Reims F-51687 Reims 2 France CNRS Chim Coordinat Lab UPR8241 F-31077 Toulouse France

Highly diastereoselective 1,3-dipolar cycloaddition of in situ generated c,N-diaryl nitrilimines to (1R)-thiocamphor leads to chiral spiro-1,3,4-thiadiazolocamphane derivatives in good yields. The structures and stereochemistries of the new cycloadducts were fully established by spectroscopic methods including X-ray diffraction data. The diastereoselectivity observed in this reaction was explained by means of a brief theoretical study.

关键词： c N-diaryl nitrilimines (1R)-thiocamphor spiro-1 3 4-thiadiazoles diastereoselectivity X-ray analysis DFT calculations

来源：评论

学校读者我要写书评

暂无评论

Low residual stress c/c composite-titanium alloy joints brazed by foam interlayer

引用

cERAMIcS INTERNATIONAL 2022年第4期48卷 5260-5266页

作者： Guo, Wei Li, Kui Zhang, Hongqiang Zhu, Ying Shen, Xiaoyu Zhang, Lei Sun, Huawei Zhong, Sujuan Long, Weimin Beihang Univ Sch Mech Engn & Automat Beijing 100191 Peoples R China AECC Hunan Aviat Powerplant Res Inst Zhuzhou 412002 Peoples R China China Acad Space Technol Beijing 100081 Peoples R China Zhengzhou Res Inst Mech Engn State Key Lab Adv Brazing Filler Met & Technol Zhengzhou 450001 Peoples R China China Innovat Acad Intelligent Equipment Ningbo C Ningbo 315700 Peoples R China

Metallic foam was introduced as an interlayer to improve the performance of the brazed c/c composite-titanium alloy joint, and the interfacial microstructure and residual stress of the brazed joint were investigated. compared with the brazed joint without foam, introducing foam interlayer could achieve the uniform bonding interface, and Ag-based solid solution (Ag(s,s)) became more dispersed and smaller in the center of the brazing seam. The thickness of reaction layer close to c/c composite side was less than 1 mu m. Some cu-based solid solution (cu(s,s)) was detected, indicating that cu foam still existed after brazing. The residual stress and its distribution calculated by finite element method (FEM), and the residual stress of the brazed joint decreased from 293 MPa to 228 MPa. The introduction of the foam interlayer could obtain homogeneous microstructure, change stress distribution, and improve mechanical properties of the brazed joints.

关键词： Brazing Residual stress Foam interlayer c c composite Titanium alloy

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：