期刊文献+
共找到40篇文章
< 1 2 >
每页显示 20 50 100
Fluoridation routes,function mechanism and application of fluorinated/fluorine-doped nanocarbon-based materials for various batteries:A review
1
作者 Weicui Liu Nanping Deng +5 位作者 Gang Wang Ruru Yu Xiaoxiao Wang Bowen Cheng Jingge Ju Weimin Kang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第10期363-393,I0011,共32页
With the popularity and widespread applications of electronics,higher demands are being placed on the performance of battery materials.Due to the large difference in electronegativity between fluorine and carbon atoms... With the popularity and widespread applications of electronics,higher demands are being placed on the performance of battery materials.Due to the large difference in electronegativity between fluorine and carbon atoms,doping fluorine atoms in nanocarbon-based materials is considered an effective way to improve the performance of used battery.However,there is still a blank in the systematic review of the mechanism and research progress of fluorine-doped nanostructured carbon materials in various batteries.In this review,the synthetic routes of fluorinated/fluorine-doped nanocarbon-based(CF_x)materials under different fluorine sources and the function mechanism of CF_x in various batteries are reviewed in detail.Subsequently,judging from the dependence between the structure and electrochemical performance of nanocarbon sources,the progress of CF_x based on different dimensions(0D–3D)for primary battery applications is reviewed and the balance between energy density and power density is critically discussed.In addition,the roles of CF_x materials in secondary batteries and their current applications in recent years are summarized in detail to illustrate the effect of introducing F atoms.Finally,we envisage the prospect of CF_x materials and offer some insights and recommendations to facilitate the further exploration of CF_x materials for various high-performance battery applications. 展开更多
关键词 Nanocarbon materials Fluorinated/fluorine-doped effect function mechanism Various batteries
下载PDF
Distinct gut microbiomes in Thai patients with colorectal polyps
2
作者 Thoranin Intarajak Ahmad Nuruddin Khoiri +5 位作者 Kanthida Kusonmano Weerayuth Kittichotirat Sawannee Sutheeworapong Supapon Cheevadhanarak Wandee Udomchaiprasertkul Chinae Thammarongtham 《World Journal of Gastroenterology》 SCIE CAS 2024年第27期3336-3355,共20页
BACKGROUND Colorectal polyps that develop via the conventional adenoma-carcinoma sequence[e.g.,tubular adenoma(TA)]often progress to malignancy and are closely associated with changes in the composition of the gut mic... BACKGROUND Colorectal polyps that develop via the conventional adenoma-carcinoma sequence[e.g.,tubular adenoma(TA)]often progress to malignancy and are closely associated with changes in the composition of the gut microbiome.There is limited research concerning the microbial functions and gut microbiomes associated with colorectal polyps that arise through the serrated polyp pathway,such as hyperplastic polyps(HP).Exploration of microbiome alterations asso-ciated with HP and TA would improve the understanding of mechanisms by which specific microbes and their metabolic pathways contribute to colorectal carcinogenesis.AIM To investigate gut microbiome signatures,microbial associations,and microbial functions in HP and TA patients.METHODS Full-length 16S rRNA sequencing was used to characterize the gut microbiome in stool samples from control participants without polyps[control group(CT),n=40],patients with HP(n=52),and patients with TA(n=60).Significant differences in gut microbiome composition and functional mechanisms were identified between the CT group and patients with HP or TA.Analytical techniques in this study included differential abundance analysis,co-occurrence network analysis,and differential pathway analysis.RESULTS Colorectal cancer(CRC)-associated bacteria,including Streptococcus gallolyticus(S.gallolyticus),Bacteroides fragilis,and Clostridium symbiosum,were identified as characteristic microbial species in TA patients.Mediterraneibacter gnavus,associated with dysbiosis and gastrointestinal diseases,was significantly differentially abundant in the HP and TA groups.Functional pathway analysis revealed that HP patients exhibited enrichment in the sulfur oxidation pathway exclusively,whereas TA patients showed dominance in pathways related to secondary metabolite biosynthesis(e.g.,mevalonate);S.gallolyticus was a major contributor.Co-occurrence network and dynamic network analyses revealed co-occurrence of dysbiosis-associated bacteria in HP patients,whereas TA patients exhibited co-occurrence of CRC-associated bacteria.Furthermore,the co-occurrence of SCFA-producing bacteria was lower in TA patients than HP patients.CONCLUSION This study revealed distinct gut microbiome signatures associated with pathways of colorectal polyp development,providing insights concerning the roles of microbial species,functional pathways,and microbial interactions in colorectal carcinogenesis. 展开更多
关键词 Gut microbiome Colorectal adenoma Hyperplastic polyp Full-length 16s rRNA Microbial correlation networks Predicted functional mechanisms
下载PDF
The Most Probable Mechanism Function and Kinetic Parameters of Gibbsite Dissolution in NaOH 被引量:10
3
作者 鲍丽 张廷安 +5 位作者 刘燕 豆志河 吕国志 王晓民 马佳 蒋孝丽 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第4期630-634,共5页
Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH ... Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction. 展开更多
关键词 GIBBSITE kinetic parameter mechanism function integral equation differential equation
下载PDF
Effect and function mechanism of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite 被引量:3
4
作者 王宏涛 赵伟 +3 位作者 储满生 汪燃 柳政根 薛向欣 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期39-47,共9页
The effect of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite(Cr-V-Ti magnetite) was investigated and the function mechanism was simultaneously ana... The effect of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite(Cr-V-Ti magnetite) was investigated and the function mechanism was simultaneously analyzed.The results show that with increasing sinter basicity from 1.71 to 2.36,the softening interval tends to increase from 149.3 ℃ to 181.7 ℃while the melting interval tends to decrease from 178.0 ℃ to 136.7 ℃.The location of cohesive zone moves downwards firstly and then ascends slightly,but the cohesive zone becomes thinner.The softening-melting characteristic value becomes small,which indicates that the permeability of burden column is improved.The dripping ratio of mixed burden tends to increase firstly and then decrease,which comes to the highest value of 74.50%when the sinter basicity is 2.13.The content and the recovery of V and Cr in dripping iron are all increased.The generation amount of components with high melting point in slag becomes little with the increase of sinter basicity,which could improve the permeability of mixed burden.Taking softening-melting behaviors of mixed burden and recovery of valuable elements into account,the proper sinter basicity is no less than 2.13 for smelting mixed burden made from Cr-V-Ti magnetite in blast furnace. 展开更多
关键词 blast furnace sinter basicity Cr-V-Ti magnetite softening-melting behaviors cohesive zone function mechanism
下载PDF
Functional mechanism on stem cells by tea(Camellia sinensis)bioactive compounds 被引量:1
5
作者 Yao Cheng Jiachen Sun +2 位作者 Hui Zhao Hongxing Guo Jianying Li 《Food Science and Human Wellness》 SCIE 2022年第3期579-586,共8页
Camellia sinensis(tea),one of the most popular commercial crops,is commonly applied in all parts of the world.The main active ingredients of tea include polyphenols,alkaloids,polysaccharides,amino acids,aroma and vola... Camellia sinensis(tea),one of the most popular commercial crops,is commonly applied in all parts of the world.The main active ingredients of tea include polyphenols,alkaloids,polysaccharides,amino acids,aroma and volatile constitutes,all of which are potentially responsible for the activities of tea.Stem cells(SCs)are the immature and undifferentiated cells by a varying capacity for proliferation,self-renewal and the capability to differentiate into one or more different derivatives with specialized function or maintain their stem cell phenotype.Herein,a thorough review is conducted of the functional mechanism on SCs by tea bioactive compounds. 展开更多
关键词 functional mechanism Stem cell Camellia sinensis Bioactive compounds
下载PDF
Microstructure and Mechanical Properties of ZrO_2-Ni Functionally Gradient Material 被引量:1
6
作者 Jingchuan ZHU Zhongda YIN and Zhonghong LAI(Dept. of Metals and Technology, Harbin Institute of Technology, Harbin, 150001. China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1994年第3期188-192,共5页
The fabrication. microstructure and mechanical properties of ZrO2-Ni functionally gradient materials (FGM ) have been studied. FGM as well as non-FG M of ZrO2-Ni system was developed by powder metallurgical process. X... The fabrication. microstructure and mechanical properties of ZrO2-Ni functionally gradient materials (FGM ) have been studied. FGM as well as non-FG M of ZrO2-Ni system was developed by powder metallurgical process. X-ray diffractometer (XRD ). electron probe microanalyzer (EPMA), scanning electron microscope (SEM ) and optical microscope were employed to investigate the crystalline phases. chemical composition and microstructure Experimental results demonstrate that the composition and microstructure of ZrO2-Ni FGM have the expected gradient distribution. There are no distinct interfaces in the FGM due to the gradient change of components. that is, the constituents are continuous in microstructure everywhere. Moreover, Vickers hardness and flexural strength were measured for the common composites as a function of composition. It is made clear that the mechanical properties of the FGM vary corresponding to the constitutional changes as well 展开更多
关键词 FGM PSZ Microstructure and Mechanical Properties of ZrO2-Ni functionally Gradient Material NI
下载PDF
THE MECHANICAL METHOD OF CONSTRUCTING THE DISPLACEMENT FUNCTIONS IN ELASTICITY
7
作者 张鸿庆 冯红 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第4期335-344,共10页
In this Paper we have proven the general solution to the equations of linear operatorsAu=f as u=Cv+e . where v satisfies the equation Dv=g and D is adiagonal matrix. Basing on the consstructive proof of Hilbert Nulls... In this Paper we have proven the general solution to the equations of linear operatorsAu=f as u=Cv+e . where v satisfies the equation Dv=g and D is adiagonal matrix. Basing on the consstructive proof of Hilbert Nullstellensat=. we haregiven the mechanical method of constucting C. D and e.and some of the mechanicalalgorithm displacement functions in elasticity are given by this method also . 展开更多
关键词 elasticity. displacement function. mechanical algorithm Hilbertnullstellensatz
下载PDF
Mechanistic, Energetic and Structural Aspects of the Adsorption of Carmustine on the Functionalized Carbon Nanotubes 被引量:2
8
作者 KHORRAM Rabeeh MORSALI Ali +2 位作者 RAISSI Heidar HAKIMI Mohammad BEYRAMABADI S. Ali 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第10期1639-1646,共8页
Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug carmustine with functionalized carbon nanotube(CNT) have been investigated. Quantum molecular descri... Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug carmustine with functionalized carbon nanotube(CNT) have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug carmustine with functionalized CNT is thermodynamically suitable. NTCOOH and NTCOCl can bond to the NH group of carmustine through OH(COOH mechanism) and Cl(COCl mechanism) groups, respectively. The activation energies, activation enthalpies and activation Gibbs free energies of two pathways were calculated and compared with each other. The activation parameters related to COOH mechanism are higher than those related to COCl mechanism, and therefore COCl mechanism is suitable for covalent functionalization. COOH functionalized CNT(NTCOOH) has more binding energy than COCl functionalized CNT(NTCOCl) and can act as a favorable system for carmustine drug delivery within biological and chemical systems(noncovalent). These results could be generalized to other similar drugs. 展开更多
关键词 carmustine covalent and noncovalent adsorption functionalized carbon nanotubes quantum molecular descriptors reaction mechanisms
下载PDF
CLIFFORD ALGEBRA,THEORY OF ITS FUNCTION AND THEIR APPLICATION TO MECHANICS
9
作者 黄思训 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第9期853-866,共14页
As is Wellknown in both elastic mechanics andfluid mechanics, the plane problems are more convenient than space problems. One of the causes is that there has been a complete theory about the complex Junction and the a... As is Wellknown in both elastic mechanics andfluid mechanics, the plane problems are more convenient than space problems. One of the causes is that there has been a complete theory about the complex Junction and the analytic junction, hut in space problems, the case is quite different.We have no effective method to deal with these problems. In this paper, we first introduces general theories of Clifford algebra. Then we emphatically explain Clifford algebra in three dimensions and establish theories of regular Junction in three dimensions analogically to analytic function in plane. Thus we extend some results of plane problem-la three dimensions or high dimensions. Obviously, it is very important for elastic and fluid mechanics. But because Clifford algebra is not a commutative algebra, we can't simply extend the results of two dimensions to high dimensions. The left problems are yet to be found out. 展开更多
关键词 CLIFFORD ALGEBRA THEORY OF ITS function AND THEIR APPLICATION TO MECHANICS
下载PDF
Mechanism Research on the Function of Electric Warmed Needle
10
作者 Pan Yuanxia(The Second People’s Hospital of Wenzhou City,Zhejiang Province. 325000) 《中国针灸》 CAS CSCD 北大核心 1995年第S2期301-302,共2页
MechanismResearchontheFunctionofElectricWarmedNeedle¥PanYuanxia(TheSecondPeople'sHospitalofWenzhouCity,Zheji... MechanismResearchontheFunctionofElectricWarmedNeedle¥PanYuanxia(TheSecondPeople'sHospitalofWenzhouCity,ZhejiangProvince.32500... 展开更多
关键词 Mechanism Research on the function of Electric Warmed Needle
下载PDF
The effect of different doses of vecuronium on respiratoty function and mechanics during laparoscopic cholecystectomy
11
作者 徐世元 《外科研究与新技术》 2003年第2期70-71,共2页
Objective To investigate the effects of different doses of vecuronium on ventilatory function and mechanics of breathing during elective laparoscopic cholecystectomy. Methods Sixty - three ASA Ⅰ - Ⅱ patients aged 29... Objective To investigate the effects of different doses of vecuronium on ventilatory function and mechanics of breathing during elective laparoscopic cholecystectomy. Methods Sixty - three ASA Ⅰ - Ⅱ patients aged 29 -57 yr were randomly divided into 3 groups of twenty-one: group Ⅰ received vecuronium 1 ± ED95 , group Ⅱ 2 ± ED95 and group Ⅲ ± ED95. Patients with respiratory disease were excluded. The patients were premedicated with intramuscular scopolamine 0 . 3 mg and oral diazepam 0 . 1 mg· kg-1 . Anesthesia was induced with fentanyl 2 μg ·kg-1 ,propofol 2 mg·kg-1 and succinylcholine 1. 5 mg· kg-1 and maintained with 1.0% -1.5% isoflurance and intermittent iv boluses of propofol 1 mg·kg when needed. Vecuronium 1 ± ED95 ( group Ⅰ ) or 2 ± ED95 (group Ⅱ ) or 3 ± ED95 (group Ⅲ ) was given iv after succinylcholine when TOF showed that T1 】 70 % . The patients were mechanically ventilated. VT was set at 10 ml ·kg-1 and respiratory rate at 12 bpm. End-tidal PCO2 was maintained at 30 - 展开更多
关键词 of The effect of different doses of vecuronium on respiratoty function and mechanics during laparoscopic cholecystectomy
下载PDF
To improve the mechanical function of bovine jugular vein by external stent
12
作者 高峰 《外科研究与新技术》 2011年第3期177-177,共1页
Objective To increase the mechanic characteristic of bovine jugular veins conduit (BJVC) by combined knitted stent outside made of nylon fiber. Methods Got rid of the cells of BJVC by enzymolysis,then combined a fabri... Objective To increase the mechanic characteristic of bovine jugular veins conduit (BJVC) by combined knitted stent outside made of nylon fiber. Methods Got rid of the cells of BJVC by enzymolysis,then combined a fabric stent with a acellular bovine jugular vein 展开更多
关键词 To improve the mechanical function of bovine jugular vein by external stent
下载PDF
Influence of oxygen-rich hot air composite gas medium on sintering performance and function mechanism
13
作者 Min Gan Hao-xiang Zheng +9 位作者 Xiao-hui Fan Zhi-yun Ji Qiang Li Ming Wu Yi-fan Wang Xiao-long Wang Yu-feng Wu Xu-ling Chen Zeng-qing Sun Xiao-xian Huang 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2024年第5期1071-1081,共11页
Hot air sintering technology is used to improve the quality and production efficiency of sintered ore.However,the current thick layer condition highlights the disadvantage of the low oxygen potential of the hot air si... Hot air sintering technology is used to improve the quality and production efficiency of sintered ore.However,the current thick layer condition highlights the disadvantage of the low oxygen potential of the hot air sintering layer.Therefore,it is considered to use oxygen enrichment sintering to improve the environment of hot air sintering.Traditional sintering,hot air sintering,and oxygen-rich hot air sintering were compared through sintering cup experiments,and the influence of hot air and oxygen-rich hot air on sintering indexes was clarified.Hot air reduced the vertical sintering velocity,while improved the yield and tumbler index.Oxygen-rich hot air sintering contributed to improving the vertical sintering velocity while ensuring the quality of sintered ore,thus comprehensively improving production efficiency.Under the action of hot air,the highest temperature of the sintering layer increased and the high-temperature holding time was prolonged.After oxygen enrichment,the combustion efficiency of fuels in the upper layer of materials was promoted,which optimized heat distribution in the middle and lower layers of materials and increased the content of calcium ferrite in the sintered ore,thus strengthening the sintering process. 展开更多
关键词 Iron ore sintering Hot air sintering Oxygen enrichment function mechanism
原文传递
Kinetics of AlOOH dissolving in caustic solution studied by high-pressure DSC 被引量:2
14
作者 鲍丽 张廷安 +5 位作者 豆志河 吕国志 郭永楠 倪培远 吴许建 马佳 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第1期173-178,共6页
Mechanism functions and kinetic parameters of AlOOH(boehmite or diaspore) dissolving in sodium hydroxide solution were researched.The mixture of boehmite or diaspore and caustic solution was scanned by high-pressure... Mechanism functions and kinetic parameters of AlOOH(boehmite or diaspore) dissolving in sodium hydroxide solution were researched.The mixture of boehmite or diaspore and caustic solution was scanned by high-pressure differential scanning calorimetry(DSC) instrument with heating rate of 10 ℃/min,and differential equation method was used to analyse the DSC curves,combining with iterative method and linear least square method.The most probable mechanism functions for both boehmite or diaspore and caustic solution reactions were logically selected from 30 types of non-isothermal kinetics differential equations,according to the calculated results obtained by Matlab program.The most probable differential mechanism function of boehmite dissolving in caustic solution is f(α)=1-α,which reveals the first-order reaction with apparent activation energy of 79.178 kJ/mol and the preexponential constant 1.031×108 s-1.The function,f(α)=2(1-α)3/2,can describe the dissolution of diaspore sample in sodium hydroxide solution.The calculated results of kinetic parameters are apparent activation energy of 73.858 kJ/mol,preexponential constant of 5.752×107 s-1 and reaction order of 1.5. 展开更多
关键词 differential mechanism function BOEHMITE DIASPORE apparent activation energy preexponential constant
下载PDF
A critical review on the health promoting effects of mushrooms nutraceuticals 被引量:12
15
作者 Gaoxing Ma Wenjian Yang +3 位作者 Liyan Zhao Fei Pei Donglu Fang Qiuhui Hu 《Food Science and Human Wellness》 SCIE 2018年第2期125-133,共9页
Extensive elucidations focusing on the efficient health promoting properties and high nutritional values of mushrooms have been expanded dynamically from the past few decades.Due to its high quality of proteins,polysa... Extensive elucidations focusing on the efficient health promoting properties and high nutritional values of mushrooms have been expanded dynamically from the past few decades.Due to its high quality of proteins,polysaccharides,unsaturated fatty acids,mineral substances,triterpenes sterols and secondary metabolites,mushrooms have always been appreciated for their vital role in protecting and curing various health problems,such as immunodeficiency,cancer,inflammation,hypertension,hyperlipidemia,hypercholesterolemia and obesity.Moreover,investigations in recent years have revealed the correlations between the health-promoting benefits and gut microbiota regulating effects induced by the mushrooms intake.Researches on the immense role in the nutritional and health benefits displayed by mushrooms have become an emergent task to study.The present article overviewed and compiled the latest information correlated to the health benefits and underlying functional mechanisms of mushroom nutraceuticals,and concluded that the supplementation of mushrooms as a dietary composition could become a natural adjuvant for the prevention and treatment of several health diseases. 展开更多
关键词 MUSHROOMS Bioactive nutraceuticals Health benefits functional mechanisms Gut microbiota regulation
下载PDF
Preparation of basic magnesium carbonate and its thermal decomposition kinetics in air 被引量:2
16
作者 刘欣伟 冯雅丽 李浩然 《Journal of Central South University》 SCIE EI CAS 2011年第6期1865-1870,共6页
The thermal decomposition process of basic magnesium carbonate was investigated. Firstly, Basic magnesium carbonate was prepared from magnesite, and the characteristics of the product were detected by X-ray diffracti... The thermal decomposition process of basic magnesium carbonate was investigated. Firstly, Basic magnesium carbonate was prepared from magnesite, and the characteristics of the product were detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Subsequently, the thermal decomposition process of basic magnesium carbonate in air was studied by thermogravimetry-differential thermogravimetry (TG-DTG). The results of XRD confirm that the chemical composition of basic magnesium carbonate is 4MgCO3·Mg(OH)2·4H2O. And the SEM images show that the sample is in sheet structure, with a diameter of 0.1-1 μm. The TG-DTG results demonstrate that there are two steps in the thermal decomposition process of basic magnesium carbonate. The apparent activation energies (E) were calculated by Flyrm-Wall-Ozawa method. It is obtained from Coats-Redfem's equation and Malek method that the mechanism functions of the two decomposition stages are D3 and A1.5, respectively. And then, the kinetic equations of the two steps were deduced as well. 展开更多
关键词 basic magnesium carbonate TG-DTG thermal decomposition KINETICS mechanism function
下载PDF
Research advances in allelopathy of Quercus L. 被引量:2
17
作者 Li Guang-de Jia Li-ming Li Xiao-wen 《Forestry Studies in China》 CAS 2007年第4期287-294,共8页
The term allelopathy refers to biochemical interaction between all types of plants including microorganisms through production of chemical compounds that escape into the environment and exist widely in Quercus L. The ... The term allelopathy refers to biochemical interaction between all types of plants including microorganisms through production of chemical compounds that escape into the environment and exist widely in Quercus L. The development of investigations into types of allelochemicals, their compounding and spreading pathways, as well as expression of allelopathy in Quercus L. are reviewed in this paper: We have closely and systematically emphasized the functional mechanisms of allelopathy in forest plants for our next research project on allelopathy in Quercus L. 展开更多
关键词 Quercus L. ALLELOPATHY functional mechanism
下载PDF
Development and Evaluation of a New Nanometer Based Spacer NMS-I 被引量:2
18
作者 Cheng Rongchao Wang Ruihe Cao Huilian Bu Yuhuan Cheng Yuanfang 《Petroleum Science》 SCIE CAS CSCD 2007年第1期49-54,共6页
In view of the inadequate cementing quality in the cementation for long isolation intervals ofoil and gas wells, and considering the field practice in Tarim Oilfield, a nanometer material LC-212 was introduced as the ... In view of the inadequate cementing quality in the cementation for long isolation intervals ofoil and gas wells, and considering the field practice in Tarim Oilfield, a nanometer material LC-212 was introduced as the base stock to experimentally develop a new spacer system NMS-I, in combination with other materials, including a chemical gel plugging agent, carboxymethyl cellulose and barite. Experimental results indicated that the system had a wide adjustable range of density, good rheological property, static stability and compatibility with cement slurry. It also showed no flocculating or thickening effect on the water-base drilling fluid and low-density cement system. Meanwhile, the capacity of lost circulation control and the influence of the spacer on the second interfacial cementing strength were evaluated by a self-made lost circulation simulator and shearing test facility. The results showed that the spacer had favorable plugging and flushing effect, and the second interfacial cementing strength can be greatly improved. Moreover, based on the experiments, the mechanisms of spacer function were analyzed. The results obtained from the investigation offer a novel approach to resolving some practical problems in cementing jobs. 展开更多
关键词 CEMENTING SPACER nanometer material lost circulation control mechanism of spacer function
下载PDF
Non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution 被引量:1
19
作者 朱小峰 张廷安 +4 位作者 王艳秀 吕国志 张伟光 王聪 赵爱春 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第10期1634-1639,共6页
Carbonation decomposition of hydrogarnet is a significant reaction of the calcification-carbonation new method for alumina production by using low-grade bauxite.In this work,non-isothermal decomposition kinetics of hy... Carbonation decomposition of hydrogarnet is a significant reaction of the calcification-carbonation new method for alumina production by using low-grade bauxite.In this work,non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution was studied by high-pressure differential scanning calorimetry(HPDSC) at different heating rates of 2,5,8,10,15 and 20 K·min^(-1),respectively.The activation energy(E_α) was calculated with the help of isoconversional method(model-free),and the reaction mechanism was determined by the differential equation method.The calculated activation energy of this reaction was 115.66 kJ·mol^(-1).Furthermore,the mechanism for decomposition reaction is Avrami-Erofeev(n=1.5),and the decomposition process is diffusion-controlled. 展开更多
关键词 HYDROGARNET Differential scanning calorimetry(DSC) Activation energy Mechanism function CARBONATION ALUMINA
下载PDF
Advances in Studies on Pharmacological Functions of Ligustilide and their Mechanisms 被引量:1
20
作者 Jin-ying YANG Hu-hu CHEN +4 位作者 Jiang WU Su-xiao GONG Chang-qing CHEN Tie-jun ZHANG Min-jie WANG 《Chinese Herbal Medicines》 CAS 2012年第1期26-32,共7页
The article reviewed the research progress of ligustilide in recent years and elaborated its pharmacological functions and mechanisms in detail, especially in ischemic brain injury. Its mechanism includes reducing cer... The article reviewed the research progress of ligustilide in recent years and elaborated its pharmacological functions and mechanisms in detail, especially in ischemic brain injury. Its mechanism includes reducing cerebral infarct volumes and improving neurobehavioral deficits, anti-oxidant and anti-apoptosis, antithrombotic activity, calcium channel blockers function, and effect on erythropoietin. Other pharmacological effects of ligustilide including inhibiting vascular smooth muscle cell proliferation, anti-inflammatory and analgesic effects, effects on LPS-induced endotoxic shock, inhibiting constriction effect, suppression of the central nervous system, and ameliorating the memory impairment induced by scopolamine and so on, are also introduced. Ligustilide has potential pharmacological value, which provides a reference for its further research and development. 展开更多
关键词 cerebral infarct ischemic brain injury LIGUSTILIDE neurobehavioral deficit pharmacological function and mechanism
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部