检索结果-南通市图书馆

Synthesis and Crystal Structure of [Cp_2Ln(OC(SEt)NPh )]_2

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2006年第2期25卷 131-134页

作者： ZHANG Chun-mei LIU Rui-ting ZHOU Xi-Geng Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan University Shanghai 200433 China Department of Chemistry East China University of Science and Technology Shanghai 200237 China

Treatment of Cp3Y with EtSH, followed by reaction with an equivalent of PhNCO, yielded the dinuclear complex [Cp2Y（μ-η^1：η^3-OC（SEt）NPh）]2. The structure was characterized by elemental analysis, IR, MS and single-crystal X-ray diffraction analysis. The title compound crystallizes in triclinic, space group P1^- with a = 8.643（3）, b = 10.752（4）, c = 11.161（4）A°, α= 117.840（5）, β = 94.086（5）, γ= 101.008（5）°, V = 884.8（6） A°^3, Z = 1, Mr = 798.66 （C38H40N2O2S2Y2）, λ（MoKα） = 0.710730 .A°, ,μ= 3.417 mm^-1, Dc = 1.499 g/cm^3, F（000） = 408, the final R = 0.0453 and wR = 0.1007 for 3067 unique reflections （Rint = 0.0317） with 2357 observed ones （I 〉 2σ（I））. X-ray analysis reveals an unusual bonding mode of the OC（SEt）NPh ligand and the OCN fragment acts as a both bridging and side-on chelating ligand. Each yttrium atom is coordinated by two η^5-cyclopentadienyl groups, one chelating η^3-OC（SEt）NPh ligand and one bridging O atom from another η^3-OC（SEt）NPh ligand.

关键词： organolanthanide isocyanate insertion structure cyclopentadienyl

Investigation of the oxidation of hydroquinone at the liquid/liquid interface

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第2期21卷 225-228页

作者： Lu, Xiao Quan Dong, De Fang Liu, Xiu Hui Yao, Dong Na Wang, wen ting Xu, Yu mei NW Normal Univ Coll Chem & Chem Engn Lanzhou 730070 Peoples R China

The oxidation of hydroquinone(QH_2) was investigated for the first time at liquid/liquid(L/L) interface by scanning electrochemical microscopy(SECM).In this study,electron transfer(ET) from QH_2 in aqueous to ferrocene(Fc) in nitrobenzene (NB) was *** apparent heterogeneous rate constants for ET reactions were obtained by fitting the experimental approach curves to the theoretical *** results showed that the rate constants for oxidation reaction of QH_2 were sensitive to the changes of the dri...

关键词： SECM Electron transfer Liquid/liquid interface Hydroquinone

Optimal Credibility Estimation of Random Parameters in Hierarchical Random Effect Linear Model

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2015年第5期28卷 1058-1069页

作者： wen Limin FANG Jing mei Guoping WU Xianyi School of Mathematics and Information Science Jiangxi Normal University School of Information Management Jiangxi University of Finance and Economics Department of Statistics and Actuarial Science East China Normal University

In the hierarchical random effect linear model, the Bayes estimator of random parameter are not only dependent on specific prior distribution but also it is difficult to calculate in most *** paper derives the distributed-free optimal linear estimator of random parameters in the model by means of the credibility theory method. The estimators the authors derive can be applied in more extensive practical scenarios since they are only dependent on the first two moments of prior parameter rather than on specific prior distribution. Finally, the results are compared with some classical models and a numerical example is given to show the effectiveness of the estimators.

关键词： Bayes theory credibility estimator hierarchical linear model random effect

Effect of BaO and MgO on structure and properties of aluminate slag with various CaO/Al_(2)0_(3)ratios

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第1期31卷 204-214页

作者： Yu-qi Kong ting Wu wen-zhi Xia wen Yang Hai-chuan Wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resource Recycling(Ministry of Education) Anhui University of TechnologyMa’anshan243002AnhuiChina

To provide theoretical guidance for performance stability control of low-reactive mold fluxes,the effects of BaO and MgO on the structure and properties of aluminate slag with various CaO/Al_(2)0_(3)(C/A)ratios were investigated using the Fourier transform infrared spectrometer,Raman spectroscope,hemispherical melting point instrument,rotational viscometer and X-ray *** results indicated that with BaO and MgO addition,the structure polymerization was first weakened and then enhanced at C/A of 1.1,and the transition contents corresponded to 8 wt.%BaO and 2 wt.%MgO,respectively,while the structure polymerization decreased continuously at C/A of *** the viscosity change was well consistent with the structure evolution,the polymerization degree played a more prominent role in the slag viscosity than superheat degree when the melting temperature difference was within 40℃.The break temperature decreased initially and then increased with augment of BaO and MgO at C/A of 1.1,while it manifested a decrease trend with BaO addition,and it decreased obviously but then turned to increase with MgO increment at C/A of *** crystallization phase and crystallization ratio kept stable with BaO increment,while the crystallization ratio rose greatly with MgO promoting LiAlO_(2)precipitation at C/A of *** crystal types of all experimental slags were mainly Ca_(12)Al_(14)O_(33)and CaF_(2)at C/A of 1.3,and the precipitation of crystalline phase BaAl2O4 demonstrated a rising trend,while that of Ca_(12)Al_(14)O_(33)gradually declined with BaO augment.

关键词： Aluminate slag Structure MgO BaO Viscosity Property

Synthesis of Small-sized Coesite Under Lower Pressure

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

Chemical Research in Chinese Universities 2010年第3期26卷 352-354页

作者： WANG De-jun LIU Xiao-mei ZHU Cheng-jun YAN Duan-ting LIU Fu-lin SU wen-hui State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun 130021 P R. China Adult Education College of Changchun University Changchun 130022 P. R. China Center of the Condensed Matter Science and Technology Harbin Institute of Technology Harbin 150001 P R. China International Centre for Materials Physics Chinese Academy of Sciences Shenyang 110016 P. R. China

With the help of high-energy mechanical milling and a-SiO2 as the initial material, we investigated the synthesis of coesite at a high temperature and high pressure under the condition of adding a certain amount of hard Fe filling. The synthetic samples were measured by XRD and Raman spectroscopy. The results show that a small amount of small-sized coesite can be obtained under 2.5 GPa and 973 K.

关键词： Coesite High temperature and high pressure High-pressure micro-area a-SiO2

In Situ Elimination of Pores During Laser Powder Bed Fusion of Ti–6.5Al–3.5Mo–l.5Zr–0.3Si Titanium Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 439-452页

作者： Ling Zhang wen-He Liao ting-ting Liu Hui-Liang Wei Chang-Chun Zhang School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094.China

The printing quality of components manufactured using laser powder bed fusion(LPBF)generally depends on the presence of various defects such as massive ***,the efficient elimination of pores is an important factor in the production of a sound LPBF *** this study,the efficacy of two in situ laser remelting approaches to eliminating pores during the LPBF of a titanium alloy Ti–6.5 Al–3.5 Mo–l.5 Zr–0.3 Si(TC11)was assessed both experimentally and *** two remelting methods are surface remelting and layer-by-layer printing and remelting.A multi-track multi-layer phenomenological model was established to analyze the variation of pores with the temperature and velocity *** results showed that surface remelting with a high laser power,such as 180 W,can eff ectively eliminate pores within three deposited ***,such remelting could not reach defects in deeper ***-by-layer remelting with a 180 W laser could eff ectively eliminate the pores formed in the previous layer in real *** results obtained in this study can provide useful guidance for the in situ control of printing defects supported by real-time monitoring,feedback,and operating systems of an intelligent LPBF equipment.

关键词： Laser powder bed fusion Ti–6.5Al–3.5Mo–l.5Zr–0.3Si Pores Laser remelting

Scalar field in massive BTZ black hole and entanglement entropy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2020年第1期44卷 129-135页

作者： Yu-ting Zhou Xiao-mei Kuang College of Mathematics and Science Yangzhou UniversityYangzhou 225009China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

In this paper,we investigate the quantum scalar fields in a massive BTZ black hole *** study the entropy of the system by evaluating the entanglement entropy using a discretized ***,we fit the results with a log-modified formula of the black hole entropy,which is introduced by quantum *** coefficients of leading and sub-leading terms affected by the mass of graviton are numerically analyzed.

关键词： massive BTZ black hole entanglement entropy scalar field

Changes in the esophagogastric junction outflow obstruction manometric feature based on the Chicago Classification updates

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2022年第30期28卷 4163-4173页

作者： Yue-Yuan Li wen-ting Lu Jian-Xiang Liu Li-Hong Wu Meng Chen Hong-mei Jiao Department of Geriatrics Peking University First HospitalBeijing 100034China Department of Gastroenterology and Hepatology Peking University First HospitalBeijing 100034China

BACKGROUND The critical diagnostic criteria for esophagogastric junction outflow obstruction(EGJOO)were published in the latest Chicago Classification version 4.0(CCv4.0).In addition to the previous criterion[elevated integrated relaxation pressure(IRP)in supine position],manometric diagnosis of EGJOO requires meeting the criteria of elevated median-IRP during upright wet swallows and elevated intrabolus ***,with the diagnostic criteria modification,the change in manometric features of EGJOO remained *** To evaluate the esophageal motility characteristics of patients with EGJOO and select valuable parameters for confirming the diagnosis of *** We performed a retrospective analysis of 370 patients who underwent highresolution manometry with 5 mL water swallows×10 in supine,×5 in upright position and the rapid drink challenge(RDC)with 200 mL water from November 2016 to November 2021 at Peking University First ***-one patients with elevated integrated supine IRP and evidence of peristalsis were enrolled,with 24 patients meeting the updated manometric EGJOO diagnosis(CCv4.0)as the EGJOO group and 27 patients not meeting the updated EGJOO criteria as the isolated supine IRP elevated group(either normal median IRP in upright position or less than 20%of supine swallows with elevated IBP).Forty-six patients with normal manometric features were collected as the normal high-resolution manometry(HRM)*** esophageal sphincter(UES),esophageal body,and lower esophageal sphincter(LES)parameters were compared between *** Compared with the normal HRM group,patients with EGJOO(CCv4.0)had significantly lower proximal esophageal contractile integral(PECI)and proximal esophageal length(PEL),with elevated IRP on RDC(P<0.05 for each comparison),while isolated supine IRP elevated patients had no such *** with EGJOO also had more significant abnormalities in the esophagogastric junction than isolated supine IRP elevate

关键词： Esophagogastric junction outflow obstruction High-resolution manometry Esophageal motility disorders Upper esophageal sphincter Proximal esophagus

Improved performances of lithium disilicate glass-ceramics by seed induced crystallization

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 Advanced Ceramics 2021年第3期10卷 614-626页

作者： ting ZHAO mei-mei LIAN Yi QIN Jian-Feng ZHU Xin-Gang KONG Jian-Feng YANG School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

Self-reinforced lithium disilicate(Li_(2)Si_(2)O_(5),LD)glass-ceramics were hot pressing sintered by introducing 5 wt%Li_(2)Si_(2)O_(5)crystal seeds into two different glass compositions of SiO_(2)-Li_(2)O-P2O_(5)-ZrO_(2)-Al_(2)O_(3)-K_(2)O-La_(2)O_(3)(7C LD)and SiO_(2)-Li_(2)O-K_(2)O-La_(2)O_(3)(4C LD).The results show that the seeds play an important role in the crystallization inducement,and microstructural and property improvement of the glass,especially for the glass powder without the nucleating agent of P_(2)O_(5).The microstructure features a wider bimodal grain size distribution with large rod-like crystals epitaxially grown along the seeds and small crystals nucleated from the glass powder itself,contributing to the improvement of the performance especially the fracture *** specimen of 4C LD glass with the addition of 5 wt%Li_(2)Si_(2)O_(5) seeds exhibited the best comprehensive properties with a good flexural strength(396±7 MPa),improved fracture toughness(3.31±0.19 MPa·m^(1/2)),and comparable translucency as IPS *** research provides a new idea and method for the improvement of the fracture toughness of lithium disilicate glass-ceramics without affecting its aesthetic appearance,and lays the foundation for its clinical applications.

关键词： lithium disilicate(LD) seeds mechanical properties translucency