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

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chinese Journal of chemistry 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

Asymptotic periodic solutions of some generalized Burgers equations

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Applied Mathematics(A Journal of chinese 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

chemical pattern recognition applied to materials optimal design and industry optimization

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chinese Science Bulletin 1997年第10期42卷 793-799页

作者： chen, 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 chemical kinetics of complicated chemical 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 searching. An integrated system named KDPAG has been built for materials optimal design or industrial optimization. Appli-cation to chemical, petrochemical and metallurgical industries and materials optimal design gives good results.

关键词： chemical pattern recognition materials design industrial optimization.

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

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Science china Mathematics 2018年第12期61卷 2139-2156页

作者： Arnaud chéritat 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 Schwarzian derivative and area inequalities à la Graczyk-(S′)wia tek.

关键词： Siegel disks quasicircles quasiconformal surgery Schwarzian derivative

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

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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 chance of post-hepatectomy liver failure in patients with borderline or insufficient future liver remnant. ALPPS is still in an early developmental stage and its techniques have not been standardized. This study aimed to review the technical modifications of the conventional ALPPS procedure. DATA SOURCES: Studies were identified by searching 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

Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production

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chinese Journal of chemical Engineering 2019年第11期27卷 2835-2843页

作者： ch.chingakham Asha David V.Sajith School of Nano Science and Technology National Institute of Technology CalicutIndia Malabar christian College CalicutIndia

Biodiesel is a green fuel which can replace diesel while addressing various issues such as scarcity of hydrocarbon fuels and environmental pollution to an extent. The high production cost of biodiesel and the recovery of the catalyst after the transesterification process are the major challenges to be addressed in biodiesel production. In the present work, a cheap and promising solid base oxide catalyst was synthesized from chicken eggshell by calcination at 900 ℃ forming catalyst eggshells(CES) and was impregnated with the nanomagnetic material(Fe3O4) to obtain Fe3O4 loaded catalytic eggshell(CES–Fe3O4). Fe3O4 nanomaterials were synthesized by co-precipitation method and were loaded in catalytic eggshell by sonication, for better recovery of the catalyst after transesterification process. CES–Fe3O4 material was characterized by Thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, a vibrating-sample magnetometer, Brunauer-Emmett-Teller, Dynamic light scattering, and Scanning electron microscopy. Biodiesel was synthesized by transesterification of Pongamia pinnata raw oil with 1:12 oil to methanol molar ratio and 2 wt% catalyst loading for 2 h at a temperature of 65 ℃ and yields were compared. The reusability of the catalyst was studied by the transesterification of the raw oil and its catalytic activity was found to be retained up to 7 cycles with a yield of 98%.

关键词： Catalyst Biodiesel Nanoparticles Fe3O4 Impregnation Transesterification

SEQUENTIAL CONVEX PROGRAMMING METHODS FOR SOLVING LARGE TOPOLOGY OPTIMIZATION PROBLEMS： IMPLEMENTATION AND COMPUTATIONAL RESULTS

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Journal of Computational Mathematics 2005年第5期23卷 491-502页

作者： Qin Ni ch.Zillober K.Schittkowski Nanjing University of Aeronautics and Astronautics 210016 Nanjing China Department of Computer Science University of BayreuthD-95440 BayreuthGermany

In this paper, we describe a method to solve large-scale structural optimization problems by sequential convex programming （SCP）. A predictor-corrector interior point method is applied to solve the strictly convex subproblems. The SCP algorithm and the topology optimization approach are introduced. Especially, different strategies to solve certain linear systems of equations are analyzed. Numerical results are presented to show the efficiency of the proposed method for solving topology optimization problems and to compare different variants.

关键词： Large scale optimization Topology optimization Sequential convex programming method Predictor-corrector interior point method Method of moving asymptotes

Estimating rock properties using sound signal dominant frequencies during diamond core drilling operations

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 850-859页

作者： ch.Vijaya Kumar Harsha Vardhan ch.S.N.Murthy N.C.Karmakar Department of Mining Engineering National Institute of Technology KarnatakaSurathkalIndia Indian Institute of Technology (BHU) VaranasiIndia

In many engineering applications such as mining,geotechnical and petroleum industries,drilling operation is widely *** drilling operation produces sound by-product,which could be helpful for preliminary estimation of the rock ***,determination of rock properties is very difficult by the conventional methods in terms of high accuracy,and thus it is expensive and *** this context,a new technique was developed based on the estimation of rock properties using dominant frequencies from sound pressure level generated during diamond core drilling ***,sound pressure level was recorded and sound signals of these sound frequencies were analyzed using fast Fourier transform (FFT).Rock drilling experiments were performed on five different types of rock samples using computer numerical control (CNC) drilling machine BMV 45 *** simple linear regression analysis,mathematical equations were developed for various rock properties,*** compressive strength,Brazilian tensile strength,density,and dominant frequencies of sound pressure *** developed models can be utilized at early stage of design to predict rock properties.

关键词： Rock properties Sound pressure level Fast Fourier transform (FFT) Sound signal Core drilling Dominant frequencies

ENHANCEMENT　OF　INTRAMOLECULAR　EXCIMER　FORMATION　AND　PHOTODIMERIZATION　OF　POLYETHERS　BEARING　NAPHTHALENE　chROMOPHORES　VIA　COMPLEXATION　WITH　CATIONS

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chinese chemical Letters 1995年第2期6卷 113-116页

作者： Tung, ch Wu, LZ Acad Sinica Inst Photog Chem Beijing 100101 Peoples R China

The fluorescence spectra and photodimerization of naphthalene end-laballed poly(ethylene glycol) oligomers (N-Pn-N) in methanol in the prescence of alkali cations have been investigated. The ion enhances or inhibits intramolecular excimer formation and photodimerization of N-Pn-N, depending on the size of the ion and the length of the polyether chain. This observation suggests that the polyether chain binds the ion, thus adopts a crown ether-like conformation.

关键词： VIA chROMOPHORES COMPLEXATION WITH NAPHTHALENE AND BEARING