检索结果-南通市图书馆

Journal of Materials Science & Tech.ology 1996年第4期12卷 318-320页

作者： Lung, CW Jiang, JA Zhang, ch International Centre for Materials Physics Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of factorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals.

关键词： Fracture

Electronic Absorption Spectroscopy of H2X （X=O, Te, Po）： Theoretical Treatment of Spin-Orbit Effects

在线全文

学校读者我要写书评

暂无评论

ch.nese Journal of ch.mical Physics 2009年第2期22卷 171-177页

作者： ch.rif A. A. Ndoye ch.ntal Daniel Laboratoire de ch.mie Quantique Institut de Chimie UMR 7177 CNRS-Université de Strasbourg 4 Rue Blaise Pascal 67000 Strasbourg France

The electronic spectroscopy of H2X （X=O, Te, Po） was investigated by means of spinorbit configuration interaction （EPCISO） and restricted active space state interaction （SORASSI）. The transition energies to the low-lying singlet and triplet states of H2O, in which.the SO interaction is zero, compare rather well with the experimental data as well as to other theoretical values. The theoretical electronic absorption spectrum is ch.racterized by three allowed transitions A^1B1 （2px（O）→σ^＊g/3s（O））, B^1A1（σg→σ^＊g/3s（O）） and A^1S2（σg→σ^＊u） calculated at 7.68, 9.94, and 11.72 eV, respectively. The theoretical absorption spectra of H2X （X=Te, Po） are shifted to the red with the A^1B1 （npx（X）→σ^＊g） states calculated at 5.06 eV （H2Te） and 4.40 eV （H2Po） and the A^1B2 （σg→σ^＊u） states calculated at 7.89 eV （H2Te） and 7.77 eV （H2Po）. The largest SO splitting amounts to 0.34 eV and is found for the lowest a^3A1 of H2Po. In H2Te the SO effects are still negligible with a maximum splitting of 0.04 eV for the lowest a^3B2. The two methods lead to comparable results but the EPCISO approach.depends strongly on the reference wavefunction.

关键词： Spin-orbit Excited state Group Ⅵ dihydride

Ship Hull Slamming Analysis with Nonlinear Boundary Element Method

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

ch.na Ocean Engineering 1997年第4期12卷 411-418页

作者： Lu, ch.He, YS Shanghai Jiao Tong Univ Dept Mech Engn Shanghai 200030 Peoples R China

A boundary element method is developed for calculating the flare ship hull slamming problem. The nonlinear free surface elevation and the linear element assumption are employed. The method has been verified by comparisons with results for the water entry of wedges with various deadrise angles. Numerical results show that the pressure distribution varies greatly with the ship hull with different curvilinear equations, and the slamming features are also different; From the numerical simulation, the authors found that the structural damage of the flare hull might be caused by the increasing hydrodynamic pressure over an extensive area on the flare when the upper part of the flare comes into contact with water.

关键词： slamming boundary element method ship full slamming analysis

Irrigation Demand VS Supply-Remote Sensing and GIS Approach

在线全文

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2016年第1期4卷 43-49页

作者： ch. Ramesh Naidu M. V. S. S. Giridhar GVP College of Engineering (Autonomous) Visakhapatnam India Jawaharlal Nehru Tech.ological University Hyderabad India

To determine the irrigation requirements of rice crop on different soils, an integrated approach.is used using Remote Sensing and GIS tech.iques. Depending on the type of soil, climate and the crop acreage, the water requirement for paddy fields is derived. This study is focused on estimating the water demand for rice crop in Rabi season. Crop evapo-transpiration and soil percolation losses account more in rice fields especially in hot climate like Rabi season. In addition to evapo-transpiration and percolation losses, the conveyance losses are also accountable in the case of unlined canals. Satellite data is used to estimate the rice and fallow lands. In conjunction to satellite interpreted data, climate and soil data are also integrated in GIS platform. CROPWAT model is used to determine the crop evapo-transpiration (ETc). There are 11 Water User’s Associations (WUA) in the command area and under which.13 canal blocks are delineated. These blocks are again delineated in to 212 sub blocks. This study indicates that there exists a 5% to 20% of water deficiency in some WUAs and also water surplus in some WUAs varying from 15% to 40%.

关键词： GIS Water Users Association Evapo-Transpiration Remote Sensing Irrigation

Influence of Density on Sound Absorption Coefficient of Fibre Board

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

Open Journal of Acoustics 2017年第1期7卷 1-9页

作者： Anand Nandanwar M. C. Kiran K. ch. Varadarajulu Indian Plywood Industries Research.and Training Institute IPIRTI Bangalore India

For acoustic applications such.as theaters, cinema halls, auditoriums the data on acoustic properties i.e. sound absorption coefficient and sound transmission loss are required to evaluate the acoustic behavior of panel products and to facilitate the necessary design computations. Fibre boards are widely used in private and commercial buildings, but not much.data are available on acoustic efficiency of fibre boards. The study was carried using acoustic pulse tester based on standing wave method for evaluating sound absorption coefficient. Wood fibre boards of different densities ranging from 200 to 800 kg/m3 were taken and their sound absorption coefficients at frequencies ranging from 125 Hz to 4000 Hz were evaluated in third octave band. Noise reduction coefficient of the samples was also computed. From the study, it is observed that low density fibre board possess high sound absorption coefficient and noise reduction coefficient when compared with high density fibre boards. It was seen that sound absorption coefficient increases with decrease in density and vice versa.

关键词： Sound Absorption Coefficient Sound Transmission Loss Acoustic Efficiency Panel Products

Asymptotic periodic solutions of some generalized Burgers equations

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

Applied Mathematics(A Journal of ch.nese Universities) 2018年第4期33卷 390-408页

作者： Smriti Nath ch.Srinivasa Rao Department of Mathematics Indian Institute of Technology Madras

In this paper, we construct asymptotic periodic solutions of some generalized Burgers equations using a perturbative approach. These large time asymptotics(constructed) are compared with relevant numerical solutions o... 详细信息

关键词： periodic solution large time asymptotics generalized Burgers equations

ch.mical pattern recognition applied to materials optimal design and industry optimization

在线全文

学校读者我要写书评

暂无评论

ch.nese Science Bulletin 1997年第10期42卷 793-799页

作者： ch.n, NY Li, ch.Qin, P Shanghai Institute of Metallurgy Chinese Academy of Sciences Shanghai China

The multi-dimensional spaces, spanned by the dimensionless numbers describing the equilibrium states or the macroscopic ch.mical kinetics of complicated ch.mical reaction systems, have been used for the data processing of the process-es in materials preparation or industrial production. It has been found that there are four common topological types of the rela-tions between the optimization zone and the operation zone in the multi-dimensional spaces. Various computation methods us-ing pattern recognition, artificial neural network and genetic algorithm are used for model-building and optimization strategy search.ng. An integrated system named KDPAG has been built for materials optimal design or industrial optimization. Appli-cation to ch.mical, petroch.mical and metallurgical industries and materials optimal design gives good results.

关键词： ch.mical pattern recognition materials design industrial optimization.

Isomeric structures, isomerization and decomposition of silylenoids H2SiMX(MX=KF,KCl LiBr,NaBr and KBr)

在线全文

学校读者我要写书评

暂无评论

ch.nese Journal of ch.mistry 1995年第6期13卷 481-486页

作者： Feng, DC Feng, SY Deng, ch SHANDONG UNIV INST THEORET CHEMSHANDONG 250100PEOPLES R CHINA

The isomeric structures, isomerization and decomposition of silylenoids H(2)SiMX (MX=KF, KCl, LiBr, NaBr and KBr) have been investigated by ab initio molecular orbital theory. These silylenoids have four kinds of very similar equilibrium structures. The three-membered ring and p-complex structures should be stable and experimentally detectable. The lifetime of sigma-complex and tetrahedral structures would be very short and experimentally undetectable.

关键词： silylenoids H(2)SiMX isomeric structures isomerization decomposition

Bounded type Siegel disks of finite type maps with few singular values Dedicated to the Memory of Professor Lei Tan

在线全文

学校读者我要写书评

暂无评论

Science ch.na Mathematics 2018年第12期61卷 2139-2156页

作者： Arnaud ch.ritat Adam Lawrence Epstein CNRS Institut de Mathematiques de ToulouseUniversite Paul SabatierToulouse F-31062France Mathematics Institute University of WarwickCoventry CV47ALUK

Let U be an open subset of the Riemann sphere C. We give sufficient conditions for which.a finite type map f : U →C with at most three singular values has a Siegel disk compactly contained in U and whose boundary is a quasicircle containing a unique critical point. The main tool is quasiconformal surgery à la Douady-Ghys-Herman-(S′)wia tek. We also give sufficient conditions for which. instead, ? has not compact closure in U. The main tool is the Sch.arzian derivative and area inequalities à la Graczyk-(S′)wia tek.

关键词： Siegel disks quasicircles quasiconformal surgery Sch.arzian derivative

Modifications of ALPPS–from complex to more complex or from complex to less complex operations

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2017年第4期16卷 346-352页

作者： Wan Yee Lau Eric ch.Lai Faculty of Medicine The Chinese University of Hong KongShatinNew TerritoriesHong Kong SARChina Department of Surgery Pamela Youde Nethersole Eastern HospitalHong Kong SARChina

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has recently been developed to induce rapid liver hypertrophy to reduce the ch.nce of post-hepatectomy liver failure in patients with borderline or insufficient future liver remnant. ALPPS is still in an early developmental stage and its tech.iques have not been standardized. This study aimed to review the tech.ical modifications of the conventional ALPPS procedure. DATA SOURCES: Studies were identified by search.ng MEDLINE and PubMed for articles published from January 2007 to December 2016 using the keywords 'associating liver partition and portal vein ligation for staged hepatectomy' and 'ALPPS'. Additional articles were identified by a manual search.of references from key articles. RESULTS: There have been a lot of modifications of the conventional ALPPS. These are classified as: (1) modifications aiming to improve surgical results; (2) modifications aiming to expand surgical indications; (3) salvage ALPPS; (4) ALPPS using the minimally invasive approach. Some of these modifications have made the conventional ALPPS procedure to become even more complex, although there have also been other attempts to make the procedure less complex. The results of most of these modifications have been reported in small case series or case reports. We need better well-designed studies to establish the true roles of these modifications. However, it is interesting to see how this conventional ALPPS procedure has evolved since its introduction. CONCLUSIONS: There is a trend for the use of minimally invasive procedure in the phase 1 or 2 of the conventional ALPPS procedure. Some of these modifications have expanded the use of ALPPS in patients who have been considered to have unresectable liver tumors. The long-term oncological outcomes of these modifications are still unknown.

关键词： associating liver partition and portal vein ligation for stage hepatectomy hepatocellular carcinoma hepatectomy liver metastasis portal vein embolization