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Numerical solution of potential flow equations with a predictor-corrector finite difference method

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第5期13卷 393-402页

作者： zhi-qiang LUO Department of System Science and Applied Mathematics School of ScienceKunming University of Science and TechnologyKunming 650083China

We develop a numerical solution algorithm of the nonlinear potential flow equations with the nonlinear free surface boundary condition.A finite difference method with a predictor-corrector method is applied to solve the nonlinear potential flow equations in a two-dimensional (2D) *** irregular tank is mapped onto a fixed square domain with rectangular cells through a proper mapping function.A staggered mesh system is adopted in a 2D tank to capture the wave elevation of the transient *** finite difference method with a predictor-corrector scheme is applied to discretize the nonlinear dynamic boundary condition and nonlinear kinematic boundary *** present the numerical results of wave elevations from small to large amplitude waves with free oscillation motion,and the numerical solutions of wave elevation with horizontal excited *** beating period and the nonlinear phenomenon are very *** numerical solutions agree well with the analytical solutions and previously published results.

关键词： Predictor-corrector method Nonlinear potential flow equations Finite difference method Staggered grid Nested iterative method

Mathematical Basis of Idea That Harmonious Marriage Can Lengthen Life-span

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Acta Mathematicae Applicatae Sinica 2009年第2期25卷 321-326页

作者： zhi-qiang Zhang School of Mathematical Science Xiamen University Xiamen 361005 China

It is a very important issue for us to explore the effects of the marriage to life. In recent years, many scholars have proved that the marriage can lengthen life-span from different angles. With the development of theory of dependence random variables, we discuss the effects of the marriage to life and provide a mathematical basis of the idea that the harmonious marriage can lengthen life-span in this paper. Meanwhile, we analyze the impact of the marriage on life on the basis of the net single premium.

关键词： Marriage joint-life status last survivor status comonotonicity copula

Exosomal miRNA in early-stage hepatocellular carcinoma

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World Journal of Clinical Cases 2023年第3期11卷 528-533页

作者： zhi-qiang Wu Yi-Xin Zhu Yun Jin yin-Chu Zhan Department of Surgery The Second People's Hosptal of QuzhouQuzhou 324000Zhejiang ProvinceChina Department of Surgery The Second Affiliated HospitalZhejiang UniversitySchool of MedicineHangzhou 310009Zhejiang ProvinceChina

The incidence and mortality of hepatic carcinoma(HCC)remain high,and early diagnosis of HCC is seen as a key approach in improving clinical ***,the sensitivity and specificity of current early screening methods for HCC are not *** recent years,research around exosomal miRNA has gradually increased,and these molecules have emerged as attractive candidates for early diagnosis and treatment of *** review summarizes the feasibility of using miRNAs in peripheral blood exosomes as early diagnostic tools for HCC.

关键词： Hepatic carcinoma Early diagnosis Exosomal miRNA Biomarker

Dynamics of luffing motion of a hydraulically driven shell manipulator with revolute clearance joints

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Defence Technology（防务技术） 2022年第4期18卷 689-708页

作者： Chen zhi-qun Qian Lin-fang Chen Guang-song Nie Shou-cheng yin qiang Yue Cai-cheng School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China Northwest Institute of Mechanical and Electrical Engineering Xianyang712099ShaanxiChina China North Industry Corporation Beijing100053China

In this study,a modeling method for investigating the dynamic characteristics of a hydraulically driven shell manipulator with revolute clearance joints is *** model accounts for the effect of the clearance,the flexibility of the rotating beam,and the coupled dynamic characteristics of the hydraulic cylinder.A modified contact force model was developed to simulate the physical properties of realistic revolute joints with small clearances,heavy loads,and variable contact stiffnesses and damping coefficients with variations of the *** the strong coupling relationship between the hydraulic cylinder and the flexible beam,a system equation of motion combining the state variables of the hydraulic cylinder and mechanical system was *** complex nonlinear friction force of the hydraulic cylinder motion was constructed using a modified Lu Gre model,and the parameters of the friction model were identified using intelligent identification ***,a test system for the shell manipulator was established to achieve experimental ***,the effects of the clearance size and the stiffness of the cylinder support on the dynamic response were investigated.

关键词： Parameter identification Shell manipulator Hydraulic cylinder Revolute clearance joint

Synergistic effect of RhBMP-2 and bFGF on ectopic osteogenesis in mice

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Asian Pacific Journal of Tropical Medicine 2015年第1期8卷 53-59页

作者： Shu-Yuan Ma zhi-qiang Feng Ren-Fa Lai zhi-ying Zhou Zhong-Da yin First Affiliated Hospital of Ji'nan University

Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor(bFGF).Methods:24 KM male mice were randomly divided into 6 groups with 4 mice in each group,namely,Group A(control group),Group B(only treated with collagen),Group C(treated with2 ng bFGF+collagen).Group D(treated with 4μg rhBMP-2+collagen),Group E(treated with 4 μg rhBMP-2+2 ng bFGF+collagen) and Group F(treated with 4 μg rhBMP-2+4 ng bFGF+*** composites were implanted into the intermuscular septum of hind legs mice:whereas in control group,intermuscular septum of mice was separated and no implantation was *** observation,detection of concentration of calcium content,micro computed tomography(Micro-CT).three-dimensional reconstruction *** of bone mineral density(BMD).bone volume fraction(BVF) and trabecular thickness(***).as well as histological observation with HE staining and ALP and CD34 immumohistochemical staining were ***:Ectopic osteogenesis was found in Groups D.F and F *** difference in concentration of calcium contents was statistically significant between Groups D and E(P0.05).Micro-CT and three-dimensional reconstruction revealed continuous newborn bone substance in external surface of ectopic bone formation,and the center of bone formation did not show obvious substantial filling by bone *** differences in BMD,BVF and *** were statistically significant between Groups D and E or F(P<0.01 or <0.05).HE staining showed that in Groups D.E and *** bone substance was mainly located at the edge of ectopic bone formation,and the bone formation in Groups E and F was better than that in Group *** and CD34 immumohistochemical staining revealed the positive expression mainly at the edge of ectopic bone formation,and area of positive expression in Groups E and

关键词： BMP-2 bFCF Ectopic osteogenesis Micro-CT

Continuous regional arterial infusion and laparotomic decompression for severe acute pancreatitis with abdominal compartment syndrome

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World Journal of Gastroenterology 2011年第44期17卷 4911-4916页

作者： zhi-Gang Deng Jian-yin Zhou Zhen-Yu yin You-Yuan Peng Fu-qiang Wang Xiao-Min Wang Department of Hepatobiliary Surgery Xiamen University Zhongshan Hospital Xiamen 361004 Fujian Province China

AIM:To evaluate the therapeutic effects of abdominal decompression plus continuous regional arterial infusion(CRAI) via a drug delivery system(DDS) in severe acute pancreatitis(SAP) patients with abdominal compartment syndrome(ACS).METHODS:We presented our recent experience in 8 patients with *** patients developed clinical ACS,which required abdominal *** the operation,a DDS was inserted into the peripancreatic artery(the catheter was inserted from the right gastroepiploic artery until it reached the junction between the pancreaticoduodenal and gastroduodenal artery).Through this DDS,a protease inhibitor,antibiotics and octreotide were infused *** duration of the regional artery infusion ranged from 8 to 41 *** outcomes and the changes in the APACHE Ⅱ score,computed tomography(CT) severity index and intraabdominal pressure(IAP) of the patients were retrospectively ***:Eight patients with an initial APACHE Ⅱ score of 18.9(range,13-27) and a Balthazar CT severity index of 9.1(range,7-10) developed severe local and systemic *** patients underwent subsequent surgical decompression and CRAI therapy because of intra-abdominal hypertension(IAH).After a mean interval of 131.9 ± 72.3 d hospitalization,7 patients recovered with decreased APACHE Ⅱ scores,CT severity indexes and *** mean APACHE Ⅱ score was 5.4(range,4-8),the CT severity index was 2.3(range,1-3),and IAP decreased to 7.7 mmHg(range,6-11 mmHg) 60 d after *** patient died of multiple organ failure 1 wk after ***:CRAI and laparotomic decompression might be a therapeutic option for SAP patients with ACS.

关键词： Severe acute pancreatitis Arterial infusion Laparotomy Abdominal compartment syndrome

Review:Advances in research of stress-assisted corrosion fatigue problem

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第2期8卷 221-227页

作者： TANG zhi-bo LI qiang Division of Engineering Zhejiang Ocean University Zhoushan 316004 China

Ceramic materials are notable for their rigidity, insulation and resistance to hostile environment, Nevertheless, if a stressed ceramic component is exposed to chemical attack, it may suffer from a form of delayed fracture known as static fatigue. From the point of view of a designer, it is clearly desirable to determine the behavior of sub-critical crack growth; the crack path and crack growth rate, as a function of material properties and loading conditions are of particular interest. This paper presents a review of advances in stress assisted corrosion problem in history and its corresponding numerical approaches in the last decades, and finally, comes uo with consideration and crucial suggestions for future work.

关键词： Stress corrosion Finite element method (FEM) Fracture Static fatigue Meshless local Petrov-Galerkin (MLPG)

西北绿洲灌区玉米叶片衰老特征对不同地膜覆盖利用方式的响应

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作物学报 2025年第1期51卷 233-246页

作者：王丽萍李盼赵连豪樊志龙胡发龙范虹何蔚柴强殷文甘肃农业大学农学院/省部共建干旱生境作物学国家重点实验室甘肃兰州730070

西北绿洲灌区玉米传统生产模式中大量使用地膜伴随着生态环境污染严重,且在极端高温下玉米出现叶片早衰。针对该现象,通过免耕一膜2年覆盖利用技术探讨延缓玉米叶片衰老并增加玉米产量的可行性,以期为构建西北绿洲灌区地膜减量玉米高效... 详细信息

西北绿洲灌区玉米传统生产模式中大量使用地膜伴随着生态环境污染严重,且在极端高温下玉米出现叶片早衰。针对该现象,通过免耕一膜2年覆盖利用技术探讨延缓玉米叶片衰老并增加玉米产量的可行性,以期为构建西北绿洲灌区地膜减量玉米高效生产技术提供理论支撑。2013年在西北绿洲灌区设置免耕一膜2年覆盖利用(NTP)、秋免耕春覆膜(RTP)和传统每年覆新膜(对照, CTP) 3种处理(本文采用2021-2023数据),探究玉米叶片光合源、持绿特性、细胞抗氧化酶活性和渗透调节物质含量对不同地膜覆盖利用方式的响应。结果表明,NTP和RTP可有效调节玉米生育期内光合源和叶片持绿性能的动态关系,维持生育后期较大的叶面积指数(LAI)、光合势(LAD)、叶片持绿性(SG)和叶绿素相对含量(SPAD),有利于延缓叶片衰老。与CTP相比, NTP玉米出苗后75~120 d的LAI、LAD、SG和SPAD分别提高15.1%~16.1%、14.8%~15.5%、7.2%~9.2%和11.3%~11.7%,RTP分别提高12.4%~13.0%、11.5%~12.4%、10.0%~17.6%和6.0%~6.7%。同时,通过单株绿色叶面积的拟合,发现NTP和RTP较CTP叶片衰老时间平均推迟了5.8~7.0d和6.2~7.7d,这可能是由于NTP和RTP有助于增强玉米大喇叭口期-灌浆期叶片的抗氧化能力和细胞渗透调节作用。玉米出苗后60~105 d, NTP较CTP叶片抗氧化酶(SOD、POD、CAT和APX)活性分别提高17.6%~20.0%、28.4%~34.4%、6.7%~8.4%和8.3%~10.9%, RTP较CTP分别提高11.3%~11.7%、16.9%~18.2%、4.4%~6.1%和5.8%~7.7%。此外,与CTP相比,NTP与RTP可溶性蛋白和脯氨酸含量分别提高35.9%~43.9%和29.5%~31.8%,20.7%~31.7%和17.4%~20.4%,丙二醛含量分别降低26.0%~27.8%和17.5%~25.9%。NTP对抗氧化酶和渗透调节物质的影响更大,NTP较CTP增产5.2%~6.0%。免耕一膜2年覆盖利用技术是西北灌区在实现资源减投条件下,有效延缓玉米叶片衰老且增加产量的适宜措施。

关键词：地膜覆盖光合源抗氧化酶活性细胞渗透调节能力籽粒产量

Onboard real time modeling of aircraft engines with Hammerstein-Wiener representation

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航空动力学报 2014年第10期29卷 2499-2506页

作者： WANG Ji-qiang YE zhi-feng HU Zhong-zhi Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and Astronautics

An identification-based approach for aircraft engine modeling using the nonlinear HammersteinWiener representation was ***-Wiener modeling for both limited flight envelope and extended flight envelope was *** shows that the resulting model can be valid over 10%variation of rotational speed of the engine,compared with those linear models that are only valid over 3%—5%change of rotational *** is further demonstrated that the proposed method can be utilized over large envelope up to 20% variation of rotational speed of the *** fundamental idea is to use nonlinear models to extend the feasible/valid region rather than those linear *** may consequently simplify the switching logic in the onboard digital control *** is often overlooked in aircraft engine control community,but has been emphasized in the research.

关键词： aircraft engines engine modeling onboard real time modeling system identification Hammerstein-Wiener representation