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Volumetric data modeling and analysis based on seven-directional box spline

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Science China(Information Sciences) 2014年第6期57卷 260-273页

作者： FANG MeiE lu jia PENG QunSheng School of Computer Science and technology Hangzhou Dianzi University State Key Lab of CAD&CG Zhejiang University

The existing methods for visualizing volumetric data are mostly based on piecewise linear *** all kinds of analysis based on them have to be substituted by coarse *** both accuracy and reliability of the traditional framework for visualization and analysis of volumetric data are far from our needs of digging information implied in volumetric data *** this paper,we propose a novel framework based on a C2-continuous seven-directional box spline,under which reconstruction is of high accuracy and differential computations relative to analysis based on the reconstruction model are *** introduce a polynomial differential operator to improve the reconstruction *** order to settle the difficulty of evaluating upon the seven-directional box spline,we convert it into B′ezier form and propose effective theories and algorithms of extracting iso-surfaces,critical points and *** of examples are also given in this paper to illustrate that the novel framework is suitable for analysis,the improved reconstruction method has high accuracy,and our algorithms are fast and stable.

关键词： volumetric data visualization and analysis seven-directional box spline iso-surface critical points curvature

Expression of cyclin-dependent kinase 9 is positively correlated with the autophagy level in colon cancer

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World Journal of Gastrointestinal Oncology 2024年第2期16卷 314-330页

作者： Lei Zheng jia lu Da-lu Kong Department of Colorectal Cancer Surgery National Clinical Research Center for CancerKey Laboratory of Cancer Immunology and Biotherapy of TianjinTianjin Key Laboratory of Digestive CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjin 300060China Department of Infection Management National Clinical Research Center for CancerKey Laboratory of Cancer Immunology and Biotherapy of TianjinTianjin Key Laboratory of Digestive CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjin 300060China

BACKGROUND Cyclin-dependent kinase 9(CDK9)expression and autophagy in colorectal cancer(CRC)tissues has not been widely ***9,a key regulator of transcription,may influence the occurrence and progression of *** expression of auto-phagy-related genes BECN1 and drug resistance factor ABCG2 may also play a role in *** normal physiological conditions,autophagy can inhibit tumorigenesis,but once a tumor forms,autophagy may promote tumor ***,understanding the relationship between autophagy and cancer,partic-ularly how autophagy promotes tumor growth after its formation,is a key motivation for this *** To investigate the relationship between CDK9 expression and autophagy in CRC,assess differences in autophagy between left and right colon cancer,and analyze the associations of autophagy-related genes with clinical features and *** We collected tumor tissues and paracarcinoma tissues from colon cancer patients with liver metastasis to observe the level of autophagy in tissues with high levels of CDK9 and low levels of *** also collected primary tissue from left and right colon cancer patients with liver metastasis to compare the autophagy levels and the expression of BECN1 and ABCG2 in the tumor and paracarcinoma *** The incidence of autophagy and the expression of BECN1 and ABCG2 were different in left and right colon cancer,and autophagy might be involved in the occurrence of chemotherapy *** analysis of the rela-tionship between the expression of autophagy-related genes CDK9,ABCG2,and BECN1 and the clinical features and prognosis of colorectal cancer showed that the high expression of CDK9 indicated a poor prognosis in colorectal *** This study laid the foundation for further research on the combination of CDK9 inhibitors and autophagy inhibitors in the treatment of patients with CRC.

关键词： Autophagy Tumorigenesis Tumor tissue Paracarcinoma tissue Expression Left/right colon cancer

Numerical Simulation and Experimental Research on Microstructural Evolution During Compact Hot Extrusion of Heavy Caliber Thick-Wall Pipe

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Chinese Journal of Mechanical Engineering 2019年第1期32卷 113-126页

作者： lu jia Yongtang Li Tianjing Hui Yang Zhang Department of Mechanical Engineering Taiyuan Institute of Technology Shanxi Key Laboratory of Metallic Materials Forming Theory and Technology Taiyuan University of Science and Technology School of Materials Science and Engineering Taiyuan University of Science and Technology Hebei Hongrun Nuclear Equipment Technology Industry Co. Ltd

Compact hot extrusion(CHE) process of heavy caliber thick-wall pipe is a new material-saving production process. In order to reveal the optimum hot extrusion parameters in CHE process, the e ects of the extrusion parameters on the microstructural evolution are investigated systematically. The metadynamic recrystallization(MDRX) kinetic models and grain size models of as-cast P91 steel are established for the first time according to the hot compression tests performed on the Gleeble-3500 thermal-simulation machine. Then a thermal-mechanical and micro-macro coupled hot extrusion finite element(FE) model is established and further developed in DEFORM software. The results indicated that the grain size of the extruded pipe increases with the increasing of initial temperature and extrusion speed, decreases when extrusion ratio increases. Moreover, the grain size is more sensitive to the initial temperature and the extrusion ratio. The optimum hot extrusion parameters are including that, the initial extrusion temperature of 1250 °C, the extrusion ratio of 9 and the extrusion speed of 50 mm/s. Furthermore, in order to verify the simulation precisions, hot extrusion experiment verification on the heavy caliber thick-wall pipe is carried out on the 500 MN vertical hot extrusion equipment. The load–displacement curve of the extrusion process and the grain sizes of the middle part extruded pipe are in good accuracy with the simulation results, which confirms that the hot extrusion FE models of as-cast P91 steel could estimate the hot extrusion behaviors. The proposed hot extrusion FE model can be used to guide the industrial production research of CHE process.

关键词： Heavy caliber thick-wall pipe Compact hot extrusion process Microstructural evolution Numerical simulation Average grain size

Crack defect of tailor rolled blank in deep drawing process

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Journal of Iron and Steel Research International 2018年第12期25卷 1237-1243页

作者： Hua-wei Zhang jia-lu Wu Xin-gang Wang School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819LiaoningChina

The deformation process of tailor rolled blank (TRB)is different from that of a monolithic blank as a result of the variable thickness in the rolling direction,and thus,the mechanism of the crack phenomenon needs to be further *** crack defect of TRB square box was studied by numerical simulation and stamping *** stress state of TRB square box was *** this basis,the forming characteristics of TRB square box were *** effects of blank size and blank holder force (BHF)on the thickness thinning of TRB were ***,the *** the crack defect for TRB square box was *** indicate that non-uniformity is the most prominent characteristic during forming of TRB square *** larger the blank size and BHF on the thinner side are,the more inclined TRB is to crack. Excessive BHF or insufficient BHF on the thicker side can also lead to the occurrence of the crack *** on the thinner side slightly greater than that on the thicker side (40 kN on the thinner side and 20 kN on the thicker side)is advantageous to restrict the excessive thickness thinning of TRB and acquire a better *** location inclined to crack for TRB square box is the round comer of the wall on the thinner side.

关键词： Tailor rolled blank Square box Crack Blank size Blank holder force

Effect of the Curved Spacetime on the Electrostatic Potential Energy Distribution of Strange Stars

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Chinese Physics Letters 2001年第1期18卷 145-147页

作者： CHEN Ci-Xing ZHANG jia-lu Center for Astrophysics University of Science and Technology of ChinaHefei 230026 National Astronomical Observatories Chinese Academy of SciencesBeijing 100012

The effect of the strong gravitational field of the strange core of a strange star on its surface electrostatic potential energy distribution is *** present the general-relativistic hydrodynamics equations of fluids in the presence of the electric fields and investigate the surface electrostatic potential distribution of the strange core of a strange star in hydrostatic equilibrium to correct Alcock and coworker's result[Astrophys.J.310(1986)261].Also,we discuss the temperature distribution of the bare strange star surface and give the related formulae,which may be useful if we are concerned further about the physical processes near the quark matter surfaces of strange stars.

关键词： electrostatic concerned quark

Treatment of Wet FGD Wastewater by a Modified Chemical Precipitation Method Using a Solid Powder Reagent

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Transactions of Tianjin University 2017年第2期23卷 110-121页

作者： Yong Kang jia lu Jing Guo School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China

This research focused on developing a modified chemical precipitation (MCP) method for treating wet flue gas desulfurization (FGD) waste water by adding a solid powder reagent directly. Simulated wet FGD wastewater was treated by MCP method in simulation experiments. Optimization experiments were carried out with the help of response surface methodology (RSM) and central composite design (CCD) to evaluate the effects and the interactions of experimental variables, including reagent dosage, temperature and pH value. The optimal reagent dosage, temperature and pH value were 3018.0 mg/L, 40.5 °C and 5.7, respectively. The RSM was demonstrated as an appropriate approach for the optimization of wet FGD wastewater treatment with the MCP method. A comparative study between the MCP method and the traditional chemical precipitation (TCP) method on raw wet FGD wastewater treatment was conducted. Results indicate that the MCP had less reagent dosage and variety than the TCP method had. Thus, the MCP method had a lower cost. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

关键词： Charge coupled devices pH Transmission control protocol Wastewater treatment

The Nonlinear Lopsided HSS-Like Modulus-Based Matrix Splitting Iteration Method for Linear Complementarity Problems with Positive-Definite Matrices

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Communications on Applied Mathematics and Computation 2021年第1期3卷 109-122页

作者： lu jia Xiang Wang Xiao-Yong Xiao Department of Mathematics Nanchang UniversityNanchang 330031China Numerical Simulation and High-Performance Computing Laboratory Nanchang UniversityNanchang 330031China

In this paper,by means of constructing the linear complementarity problems into the corresponding absolute value equation,we raise an iteration method,called as the nonlinear lopsided HSS-like modulus-based matrix splitting iteration method,for solving the linear complementarity problems whose coefficient matrix in R^(n×n)is large sparse and positive *** the convergence analysis,it is appreciable to see that the proposed method will converge to its accurate solution under appropriate *** examples demonstrate that the presented method precede to other methods in practical implementation.

关键词： Linear complementarity problem Modulus-based matrix splitting Lopsided HSS

Bifurcation\instability forms of high speed railway vehicles

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Science China(Technological Sciences) 2013年第7期56卷 1685-1696页

作者： DONG Hao ZENG Jing XIE jianHua jia lu State Key Laboratory of Traction Power Southwest Jiaotong University Department of Mechanical Engineering Southwest Jiaotong University Emei Campus of Southwest jiaotong University

The China high speed railway vehicles of type CRH2 and type CRH3, modeled on Japanese high speed Electric Multiple Units (EMU) E2 series and Euro high speed EMU ICE3 series possess different stability behaviors due to the different matching re-lations between bogie parameters and wheel profiles. It is known from the field tests and roller rig tests that, the former has a higher critical speed while large limit cycle oscillation appears if instability occurs, and the latter has lower critical speed while small limit cycle appears if instability occurs. The dynamic model of the vehicle system including a semi-carbody and a bogie is established in this paper. The bifurcation diagrams of the two types of high speed vehicles are extensively studied. By using the method of normal form of Hopf bifurcation, it is found that the subcritical and supercritical bifurcations exist in the two types of vehicle systems. The influence of parameter variation on the exported function Rec1(0) in Hopf normal form is studied and numerical shooting method is also used for mutual verification. Furthermore, the bifurcation situation, subcritical or supercritical, is also discussed. The study shows that the sign of Re(λ) determinates the stability of linear system, and the sign of Rec1(0) determines the property of Hopf bifurcation with Rec1(0)>0 for supercritical and Rec1(0)<0 for subcritical.

关键词： high speed vehicle bifurcation critical speed limit cycle normal form

Relationship between light and heavy fractions of organic matter for several agricultural soils in China

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Journal of Environmental Sciences 2005年第6期17卷 917-920页

作者： YIN Yun-feng CAI Zu-cong lu jia-long State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China College of Geographical Sciences Fujian Normal University Fuzhou 350007 China College of Resourcesand Environment Northwest Sci-Tech University of Agriculture and Forestry Yangling 712100 China

Although numerous studies about the nature and turnover of soil organic matter（SOM） in light and heavy fractions（ LFOM and HFQM, respectively） have been made, little information is available in relation to the relationship between LFQM and HFOM, and no attempts have been made to quantify a general relationship between LFQM and HFQM for agricultural soils under field condition. Qur hypothesis is there may be an inherent relationship between LFQM and HFQM for agricultural soils under certain unaltered management practices for a long period, to this end, we therefore studied typically soils taken from different parts in China by using a simple density fractionation procedure. The results indicated that LFQM was positively correlated with LFOM/HFOM ratio for three typical soils. This information will be of particular use not only in deepening our understanding of the dynamics of SQM fractions but also in evaluating the potential of agricultural soils to sequestrate C under different management practices in a long term.

关键词： soil organic matter light fraction heavy fraction agricultural soils