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Multi-scale calculation of settling speed of coarse particles by accelerated Stokesian dynamics without adjustable parameter

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Acta Mechanica Sinica 2009年第3期25卷 303-310页

作者： Long Wang Jiachun li jifu Zhou Institute of Mechanics, CAS, 100190 Beijing, China Institute of Mechanics CAS Beijing China

The calculation of settling speed of coarse particles is firstly addressed, with accelerated Stokesian dynamics without adjustable parameters, in which far field force acting on the particle instead of particle velocity is chosen as dependent variables to consider inter-particle hydrodynamic interactions. The sedimentation of a simple cubic array of spherical particles is simulated and compared to the results available to verify and validate the numerical code and computational scheme. The improved method keeps the same computational cost of the order O（NlogN） as usual accelerated Stokesian dynamics does. Then, more realistic random suspension sedimentation is investigated with the help of Mont Carlo method. The computational results agree well with experimental fitting. Finally, the sedimentation of finer cohesive particle, which is often observed in estuary environment, is presented as a further application in coastal engineering.

关键词： Sedimentation Stokesian dynamics Many-body interactions Multi-scale

An optimization approach to the similarity criteria of flows and its application

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Progress in Natural Science:Materials International 2006年第3期16卷 241-247页

作者： ZHOU jifu and li Jiachun (Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

In the present paper, we propose an optimization approach to investigate the similarity criteria of complex flows. With this approach, we may identify the dominant dimensionless variables governing complex flows by numerical sensitivity analysis. Firstly, we define the sensitivity factor and examine its dependence on the dimensionless variables. Then, we apply this approach to study the similarity criteria of porous media flow in a presumed oil reservoir. The similarity principle obtained from the numerical sensitivity analysis is in agreement with the theoretical law, thus demonstrating the feasibility of the proposed optimization approach. Further explanation is given by analyzing the deviation of pressure distribution in a model from its prototype. In addition, we examine the effects of flow parameter variation on the sensitivity factors and find that the dominant dimensionless variables may change from different sets of parameters.

关键词： similarity optimization sensitivity analysis complex flows model.

Effects of flavonoids derived from Taxus yunnanensis on p-glycoprotein and cytochrome P450 3A4

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Asian Journal of Pharmaceutical Sciences 2013年第3期8卷 168-173页

作者： jifu li Dake Cai Huichang Bi Jing Jin Min Huang Institute of Clinical Pharmacology School of Pharmaceutical ScienceSun Yat-sen UniversityNo.132Waihuan Dong RoadUniversity CityGuangzhou 510006China

The intestinal uptake of paclitaxel is hampered by trans-membrane efflux transporters such as P-glycoprotein(P-gp),and paclitaxel is mainly metabolized by cytochrome P4503A4(CYP3A4)presented in the *** previous results demonstrated that flavonoids extracted from Taxus yunnanensis could improve the oral absorption of *** current study was purposed to investigate the effects of the flavonoid extracts on P-gp and CYP3A4 in *** expression and activity of P-gp were detected by western blotting and intracellular rhodamine 123 accumulation assay in Caco-2 cells treated with the flavonoids *** expression of CYP3A4 was investigated by western blotting in mouse primary hepatocytes and the activity of CYP3A4 was detected by LC-MS/MS method using rat liver *** results showed that the flavonoid extracts from *** could inhibit P-gp activity and concurrently decrease the expression and activity of *** conclusion,activity of P-gp and CYP3A4 could be inhibited by flavonoids extracted from *** which might be potential candidates for development of oral formulation of paclitaxel.

关键词： Taxus yunnanensis Flavonoid P-glycoprotein CYP3A4 Pregnane X receptor

Fluid Inclusion Geochemistry of Metallic Ore Deposits in the South- Central Sector of theDa Hinggan Mountains in China

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Acta Geologica Sinica(English Edition) 1995年第3期69卷 289-302页

作者： Sheng jifu, Zhang Dequan and li YanInstitute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing Jiang M inxi Institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing

Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to the minerogenetic series of deposits.

关键词： south-central sector of the Da Hinggan Mountains metallic ore deposit fluid inclusion geochemistry

Plasma biomarkers and plaque strain predict long-term cardiovascular events in patients with acute coronary syndrome

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Science China(life Sciences) 2020年第2期63卷 269-278页

作者： Mingjun Xu Xiaobo Hu lin Wang Wei Zhang lindi Wu jifu li Yuguo Chen Pengfei Zhang Haijun Su Yaling Han Cheng Zhang Mei Zhang Yun Zhang The Key Laboratory of Cardiovascular Remodeling and Function Research Chinese Ministry of EducationChinese National Health Commission and Chinese Academy of Medical SciencesThe State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineDepartment of CardiologyQilu Hospital of Shandong UniversityJinan 250012China Department of Intensive Care Unit Shandong Provincial Hospital affiliated to Shandong UniversityJinan 250012China School of Mathematics Shandong UniversityJinan 250012China Department of Cardiology Shenyang Military Region General HospitalShenyang 110016China

To test whether circulating and intracoronary biomarkers and coronary plaque strain have additive values to Global Registry of Acute Coronary Events(GRACE) score for predicting long-term cardiovascular events in ACS patients. One hundred ACS patients were enrolled and the GRACE score and plasma levels and intracoronary gradients of a number of biomarkers were measured. Coronary plaque burden and morphology in non-critical stenotic plaques were determined by intravascular ultrasound(IVUS) technique, and the maximal shear strain(SSmax) and maximal area strain(ASmax) were determined by intravascular ultrasound elastography(IVUSE) technique. Patients were followed for cardiovascular events and the predictive values of clinical characteristics, plasma biomarkers and plaque parameters were compared with GRACE score, and the incremental values of these measurements to the GRACE score were assessed. GRACE score, plasma biomarkers and plaque strain were independent predictors of cardiovascular events. Combination of GRACE score, plasma biomarkers and plaque strains significantly improved the predictive value of the GRACE score alone with the receiver-operating characteristic area increased from0.457 to 0.667(P=0.014). The combination of circulating and intracoronary biomarkers, plaque strain and GRACE score provides a better predictive tool than GRACE score alone in patients with ACS.

关键词： plasma biomarker plaque strain GRACE score cardiovascular events acute coronary syndrome

Effects of Mechanical Harvesting of Main Crop on Soil Rolling and Yield of Ratooned Rice

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Asian Agricultural Research 2022年第10期14卷 37-41页

作者： Ruyu YAN Ximei ZHAO jifu li College of Agriculture Yangtze UniversityJingzhou 434025China

[Objectives]To study the effect of mechanical harvesting of main crop on soil rolling and yield of ratooned rice.[Methods]In this study,the harvesting method was optimized and improved through field research and theoretical research.[Results]Compared with farmers'habits,the mechanical harvesting method could significantly increase the working area per unit time and reduce the rolling area in the field,but it would increase the rolling rate of the land or transfer *** the same time,the optimization method could reduce the soil bulk density in the primary rolling area,but it had no significant impact on soil compactness.[Conclusions]Compared with the farmer's customary method,the optimization method could reduce the crushing and damage of rice piles in the field,increase the seedling rate and panicle extraction rate,thus increasing the yield of rice in the ratooning season.

关键词： Ratooned rice Mechanical harvesting Rice pile crushing Production Optimization method

Efficient computation of the compositional model for gas condensate reservoirs

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Communications in Nonlinear Science and Numerical Simulation 2000年第4期5卷 141-146页

作者： jifu ZHOU, Jiachun li and Jigen YE (Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China The Research Institute of Petroleum Exploration and Development, Beijing 100083, China) (Received December 2, 2000) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Res. Inst. Petrol. Explor./Devmt. Beijing 100083 China

In this paper, a direct method, unsymmetric-pattern multifrontal factorization, for a large sparse system of linear equations is applied in the compositional reservoir model. The good performances of this approach are shown by solving the Poisson equation. And then the numerical module is embedded in the compositional model for simulating X15(3) gas condensate reservoir in KeKeYa gas field, Northwest China. The results of oil/gas reserves, variations of stratum pressure and oil/gas production, etc. are compared with the observation Good agreement comparable to COMP4 model is achieved, suggesting that the present model is both efficient and powerful in compositional reservoir simulations.

关键词： gas condensate reservoir compositional model sparse matrix

Characteristics of Central Heating Cinder and Its Influence on Soil Properties

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Meteorological and Environmental Research 2022年第2期13卷 78-82,97页

作者： Guoyu GAN Chao li Xu ZHANG li YANG Yunfeng CHEN Bo liU Yanli li jifu li College of Agriculture/Analytical&Testing Center of Agricultural Resources and Environment Yangtze UniversityJingzhou 434025China Jingzhou District Agricultural Science and Technology Service Center Jingzhou 434025China Key Laboratory of Fertilization Utilization of Waste Ministry of Agriculture and Rural AreasWuhan 430070China

[Objective]The research was designed to explore the effect of long-term stacking of solid waste produced in the coal-burning process of central heating enterprises on physical and chemical properties of soil.[Method]This study took the heating enterprises in Shenyang City as the research *** morphological structure and element composition of coal cinder were determined by continuously collecting coal and cinder samples in different *** the same time,the original soil and cinder soil of the stacking site were collected to determine the changes of soil morphological structure,element composition and physical and chemical properties,so as to provide reference for the resource utilization of local cinder waste and the potential pollution risk of the stacking site.[Result]The contents of C,H,O,N,and S non-metallic elements in coal cinder decreased by 69.5%,71.2%,76.0%,74.5%,and 34.6%,respectively when compared with raw coal;while the content of Si increased significantly by 95.7%.The contents of Al,K,and Fe in cinder decreased by 4.3%,60.2%,and 33.3%,respectively,while the contents of Mg and Na increased by 36.1%and 130.9%,*** with the original soil,the contents of C,H,and O in shallow cinder soil and deep cinder soil increased by 126.5%,67.9%,80.93%,and 21.3%,25.0%and 42.3%,*** residual carbon existed in the form of activated *** contents of Mg,Al,K,Na,Ca,and Fe in shallow cinder soil and deep cinder soil increased by 61.6%,5.4%,46.1%,35.8%,32.5%,6.3%and 22.3%,12.3%,12.2%,15.6%,5.8%and 2.8%,respectively compared with the original *** content of heavy metal elements in coal cinder did not reach the detection *** the scanning electron microscope,the raw coal is mainly block structure,while the cinder is honeycombed and porous and dust.[Conclusion]Cinder stacking can significantly improve the content of organic matter and available K in shallow cinder soil,and improve the porosity and permeability of ***

关键词： Central heating Coal cinder Soil properties Element composition Morphology and structure

Effects of Long-term K Fertilizer Application on the Crop Yield and K Distribution of Soil Aggregates in a Paddy-Upland Rotation System

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Meteorological and Environmental Research 2019年第1期10卷 64-69页

作者： Song Meifang Hu Yitao Huang Shuai He Junfeng Chen Fowen Zou Jialong li jifu Engineering Research Center of Ecology and Agricultural Use of Wetland Ministry of Education/College of AgricultureYangtze University Jingzhou Agricultural Technology Promotion Center

[Objective]A long-term paddy-upland experiment was conducted to evaluate the effects of the recommended amount of potassium( K)fertilizer on crop yield,distribution of soil aggregate,and soil available K content. It was mainly to ascertain the distribution of K in the soil aggregate components in the paddy-upland rotation system,and then to provide theoretical basis for soil structure improvement,K pool management,and reasonable application of K fertilizer. [Method]There were 2 treatments selected,namely,NP(-K) treatment and NPK( + K) treatment in this study. Then the effects of K fertilizer application on the yield,available K content,and aggregate distribution in the middle rice-winter rape rotation system were analyzed. [Result]The results showed that the output of the crop rotation was affected by the year and fertilization. Compared with NP(-K),the average yield increases of rice and winter rape after application of K fertilizer were 0.51 and 0.33 t/hm2,with the increments of 7.5%and 14. 1% respectively. The long-term application of K fertilizer( 7 a) had no significant effects on the distribution of soil aggregates but could significantly increase the water-soluble K content and available K content at depths of 20-30 and 30-40 cm,and available K content of aggregates in each particle size. In addition,the balance of available K at the 10-20 and 30-40 cm of soil layers was the most significant through calculation of surplus-deficit value of available K in agglomerates of different soil layers. [Conclusion]Compared with the initial available K content in the farmland in 2011,the current K fertilizer application could lead to that farmland K content continues to decline. Therefore,we should pay attention to straw returned and supplement of organic K fertilizer,to maintain crop rotation system's productivity and soil K balance.

关键词： Paddy-upland rotation Potassium (K) fertilizer Yield Soil aggregate Available K content