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A chronic ulcerative colitis model in rats

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World Journal of Gastroenterology 2000年第1期6卷 150-152页

作者： zheng l Gao ZQ Wang SX Department of Pharmacology National Institutes Pharmaceutical Research and DevelopmentBeijing 102206China Department of Pathology Beijing Medical UniversityBeijing 100083China National Administrative Center of New Drug Research Beijing 100810China

INTRODUCTIONIn recent years,there have been many reports aboutanimal model to investigate drugs for inflammatorybowel diseases (IBD).The experimental animalmodel often used is acetic acid-induced damage ofcolonic *** ... 详细信息

关键词： Subject headings colitis ulcerative disease model animal rats

On the Natural Ecological law of Taoism

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学术界 2015年第4期 313-317页

作者： lu zheng School of International Education and Exchange Zhejiang College of Water Conservancy and Hydropower Hangzhou Zhejiang 310018

The Taoist philosophy on ecological ethics focuses on the independence of the principle that "Tao keeps to nature"and the modern environm ent law; and the integration of the principle that"Tao derives from nature"and the modern law of natural resources show case the Taoist natural philosophy and the ecological ethic principles. Based on the idea of the integration of society and nature and the ecological ethic interaction,this paper discusses the hot points of the present ecological ethic study,attem pting to find the breakthrough of the Taoist philosophy on nature and the value of Taoist philosophy for the ecological cultural renaissance and the peaceful rise of the Chinese nation.

关键词：自然生态法道家哲学调制解调器生态伦理自然资源伦理原则自然哲学文艺复兴

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

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Acta Metallurgica Sinica(English letters) 2007年第3期20卷 187-192页

作者： Z. Sun S.l. zheng Y. Zhang Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.

关键词： chromite KOH thermodynamics decomposition

Numerical and Experimental Studies of Substrate Melting and Resolidification during Thermal Spraying

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Journal of Materials Science & Technology 2003年第z1期19卷 137-140页

作者： H.Zhang G.Wei l.zheng l.li X.Y.Wang A.Vaidya Department of Mechanical Engineering State University of New York at Stony BrookStony BrookNY 11794USA Department of Materials Science and Engineering State University of New York at Stony BrookStony BrookNY 11794USA

A good understanding of melting and resolidification of the substrate will help us to achieve better *** model is developed to investigate the solidification of the droplet,and melting and resolidification of *** molybdenum powder spraying onto three different substrates:a stainless steel,brass(70%Cu)andaluminum by atmospheric plasma spraying has been *** maximum melting depth of the substrate hasbeen measured and compared with the numerical *** results show that the material propertiesof the splat and substrate and melting temperature of the substrate play the important roles on substrate melting.A dimensionless parameter,temperature factor,has been proposed and served as an indicator for substrate melting.

关键词： Thermal spraying Coating Melting Solidification Materials processing

CT arterial portography and CT hepatic arteriography in detection of micro liver cancer

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World Journal of Gastroenterology 1999年第3期5卷 225-227页

作者： li l Wu PH Mo YX lin HG zheng l li JQ lu lX Ruan CM Chen l Sun Yat Sen Univ Med Sci Ctr Canc Dept Imaging & Intervent Radiol Guangzhou 510060 Guangzdong Prov Peoples R China

AIM To recognize the characteristic findings of micrQliver cancer (MlC) and to evaluate the effect of CT arterial portography (CTAP) and CT hepatic arteriography (CTHA) in diagnosis of MlC. METHODS Between April 1996 to December 1998, CTAP and CTHA were performed in 12patients with MlC, which were not detect ed byconventional CT examinations. After CTHA, 3 ml-- 5 ml mixture of lipiodol, doxorubic in andmitomycin C were injected into hepatic arterythrough the catheter, and then followed up by CTthree or four weeks later (lipiodol CT lP-CT).RESUlTS A total of 22 micro--tumors (0 .2 cm 0.6 cm in diameter ) were detected in 12patients, which manifested as small perfusiondefects in CTAP and small round enhancement inCTHA. The rate of detectability of CTAP andCTHA was 68.2% (15/ 22) and 77.3% (17/ 22)respectively, and the rate of the simultaneoususe of both procedures reached 86. 4% (19/ 22 ).All micro--tumors were demonstrated as punctatelipiodol deposit fool in lP--CT. After lP--CT, theelevated serum level of Q-fetoprotein (AFP)dropped to the normal level in all *** The CTAP and CTHA are the mostsensitive imaging methods for detecting microIiver cancer. Confirmed by the change of theelevated serum AFP level and lipiodol depositfool in lP-CT, small perfusion defects in CTAPand punctate enhancement in CTHA may suggestmicro--liver cancer.

关键词： CT arterial portography and CT hepatic arteriography in detection of micro liver cancer

Quantification and timing of porosity evolution in tight sand gas reservoirs:an example from the Middle Jurassic Shaximiao Formation,western Sichuan,China

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Petroleum Science 2015年第2期12卷 207-217页

作者： zheng-Xiang lü Su-Juan Ye Xiang Yang Rong li Yuan-Hua Qing State Key laboratory of Oil and Gas Reservoir Geology &Exploitation Chengdu University of Technology Exploration and Production Research Institute Sinopec Southwest Chengdu Institute of Geology and Mineral Resources PetroChina Tarim Oilfield Company

The diagenesis and porosity evolution of the Middle Jurassic Shaximiao sandstones were analyzed based on petrographic observations, X-ray diffractometry, scanning electron microscopy observations, carbon and oxygen stable isotope geochemistry, fluid inclusion mi- crothermometry, and thermal and burial history modeling results. The point count data show that secondary pores （av. 5.5 %） are more abundant than primary pores （av. 3.7 %） and are thus the dominant pore type in the Shaximiao sandstones. Analysis of porosity evolution indicates that alteration of sandstones mainly occurred during two paragenetic stages. Mechanical compaction and cementa- tion by early chlorite, calcite, and quartz typically decrease the depositional porosity （40.9 %） by an average of 37.2 %, leaving porosity of 3.7 % after stage I （〈85 ℃, 175-145 Ma）. The original intergranular porosity loss due to compaction is calculated to be 29.3 %, suggesting that mechanical compaction is the most significant diagenetic process in primary porosity destruction. Stage II can be further divided into two sub-stages （Stage IIa and Stage IIb）. Stage IIa （85-120 ℃, 145-125 Ma） is characterized by late dissolution, which enhanced porosity by 8.8 %, and the porosity increased from 3.7 % to 12.5 %. During stage IIb （〉120 ℃, 125-0 Ma）, the precipitation of late chlorite, calcite, quartz, and kaolinite destroyed 3.3 % porosity, leaving porosity of 9.2 % in the rock today.

关键词： Diagenesis Porosity evolution -Tight gas sandstones Jurassic Western Sichuan

Formation of interfacial Al-Ce-Cu-W amorphous layers in aluminum matrix composite through thermally driven solid-state amorphization

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International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 970-979页

作者： zheng lü Chang-hui Mao Jian Wang Qiu-shi liang Shu-wang Ma Wen-jing Wang Advanced Electronic Materials Institute GRIMAT Engineering Institute Co.Ltd.Beijing 101407China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

Interfacial Al-Ce-Cu-W amorphous layers formed through thermally driven solid-state amorphization within the(W+Ce O2)/2024 Al composite were *** elemental distributions and interfacial microstructures were examined with an electron probe microanalyzer and a high-resolution transmission electron microscope,*** consolidation of composites consisted of two thermal processes:vacuum degassing(VD)and hot isostatic pressing(HIP).During consolidation,not only the three major elements(Al,W,and Ce)but also the alloying elements(Mg and Cu)in the Al matrix contributed to *** VD and HIP temperatures of 723 K and763 K,interfacial amorphous layers were formed within the *** diffusion processes were necessary for interfacial amorphization:(a)long-range diffusion of Mg from the Al matrix to the interfaces during VD;(b)long-range diffusion of Cu from the Al matrix to the interfaces during HIP;(c)short-range diffusion of W toward the Al matrix during *** newly formed interfacial Al-Ce-Cu-W amorphous layers can be categorized under the Al-Ce-TM(TM:transition metals)amorphous system.

关键词： aluminum matrix composite consolidation interfaces diffusion solid-state amorphization

African swine fever and meat prices fluctuation:An empirical study in China based on TVP-VAR model

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Journal of Integrative Agriculture 2021年第8期20卷 2289-2301页

作者： lI Hui-shang HU Chen-pei lÜzheng lI Mei-qi GUO Xin-zhu Agricultural Information Institute/Key laboratory of Big Agri-Data of Ministry of Agriculture and Rural Affairs Chinese Academy of Agricultural SciencesBeijing 100081P.R.China International Statistical Information Center National Bureau of StatisticsBeijing 100826P.R.China School of Statistics and Mathematics Central University of Finance and EconomicsBeijing 100081P.R.China

African swine fever(ASF),a fatal disease outbroken in China in August 2018,has widely attracted social concern especially in the information *** occurrence of ASF led to an imbalance between supply and demand in pork and other meat *** a result,meat prices fluctuated greatly during the past year in *** measure ASF quantitatively,the internet public concern index about ASF was created using web crawler *** relationships between ASF and meat prices were analyzed based on time-varying parameter vector auto-regressive(TVP-VAR)*** results showed that there were some differences in the impact size,direction and duration of ASF on the prices of pork,chicken,beef and mutton,and the characteristics of time variability and heterogeneity were *** the same time,the impact of ASF on meat prices is not consistent with the trend and degree of *** impulse intensity is strongly correlated with the strength and duration of ASF,and it is generally weak in the early stage and much stronger in the middle and late *** results indicate that macro regulations,monitoring and early-warning system,standardizing production and circulation,and the public opinion monitoring and guidance about ASF should be given more attention in future to stabilize the market expectations and to promote a smooth functioning of the livestock markets.

关键词： African swine fever meat prices dynamic transmission TVP-VAR model

THERMODYNAMIC STUDY OF CHROMITE CAUSTIC FUSION PROCESS

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Acta Metallurgica Sinica(English letters) 2001年第1期14卷 47-55页

作者： S.l. zheng and Y. Zhang (Institute of Chemical Metallurgy, the Chinese Academy of Sciences, Beijing 100080, China) Institute of Chemical Metallurgy the Chinese Academy of Sciences

A new method for chromate cleaning production, named chromite caustic fusion process, is advanced by Institute of Chemical Metallurgy, the Chinese Academy of Sciences. With sodium hydroxide as reaction medium, the new process is composed of three procedures: liquid phase oxidation of chromite, metastable phase separation and carbonation ammonium transition. Generally illustrating the new process and its features, this paper mainly studies the thermodynamics of chromite oxidation. The new process has much better practical results than the conventional chromate production process in which sodium carbonate is used as reaction medium. The superiority is also shown through thermodynamic studies.

关键词： Melting Oxidation Recycling Sodium compounds Thermodynamics