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Rheological behavior of hydrolyzed polyacrylamide solution flowing through a molecular weight adjusting device with porous medium

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Chinese Journal of Chemical Engineering 2016年第5期24卷 581-587页

作者： Lvhong zhang Jiangtao Wang Yuqi zhang Bin Jiang xiaoming xiao li Hao School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072China National Engineering Research Center for Distillation Technology Tianfin 300072China

The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sandstone reservoirs in EOR projects. To alleviate the matching problems between the layer permeability and the injected polymer molecular weight, a molecular weight adjusting device with porous medium was designed on the basis of mechanical degradation principle. In terms of four variables （polymer concentration, pore diameter, length of shear component and flow rate ）, the theological behavior of hydrolyzed polyacrylamide （HPAM） solu- tion flowing through the device was investigated in detail. The change of these variables is able to control the shear rate of HPAM solutions through ceramic foam, and achieve the desired degree of shear degradation and the final theological parameters-viscosity loss, viscoelasticity and pressure drop. Therefore, a linear relationship between viscosity loss and shearing rate was established so as to obtain the targeted viscosity easily. Field tests in the Daqing Oil Field showed that the polymer molecular weight could drop 20% to 50%. In a word, the results could guide the industrial application of the novel device and the further study of polymer degradation flowing through the porous medium.

关键词： Molecular weight adjusting device Polymer solution Rheological behavior Mechanical degradation Porous medium

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Enrichment of Nb and Ti from carbonatite pyrochlore ore via calcining-slaking followed by gravity separation

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International Journal of Mining Science and Technology 2022年第3期32卷 615-626页

作者： Shuhui zhang Mingjun Rao Rendong xiao Jinxiang You Guanghui li Tao Jiang School of Minerals Processing&Bioengineering Central South UniversityChangsha 410083China

In this work,a novel process consisting of calcining-slaking followed by gravity separation for the enrichment of niobium(Nb)and titanium(Ti)from carbonatite pyrochlore ore was proposed,validated and compared with the current mainstream flotation *** calcining of the pyrochlore ore,within which the carbonates were transformed into ***,when the calcined ore was slaked,lime was transformed into hydroxide with fine particles which were amenable to gravity *** calcining at 900℃for 60 min,slaking at 90℃for 10 min with a liquid–solid ratio of 3:1(mL/g),approximately 40%of tailings can be removed by gravity separation,the recoveries of Nb and Ti were 94.7%and 91.0%,and the enrichment ratios of Nb and Ti were 1.61 and 1.43,*** new approach exhibits high separation efficiency of carbonate gangue minerals and valuable minerals,satisfactory recoveries of niobium as well as titanium can be achieved.

关键词： Niobium Titanium Pyrochlore ore Calcination Gravity separation

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Vertical 3D Printed Pd/TiO_(2) Arrays for High Efficiency Photo-assisted Catalytic Water Treatment

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Chemical Research in Chinese Universities 2023年第6期39卷 891-901页

作者： FU Chenhao li Dan zhang Jianwei GUO Wei yang He ZHAO Bo CHEN Zhaomin FU xin liANG Zhiqiang JIANG lin Institute of Functional Nano and Soft Materials Laboratory(FUNSOM)and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Soochow UniversitySuzhou 215123P.R.China Shanghai Institute of Satellite Engineering Shanghai 200240P.R.China

Catalytic degradation of organic contaminants is at the frontier of water treatment due to its selectivity,energy savings,and ability to convert harmful contaminants into harmless or even valuable chemical products for ***,achieving sufficiently high performance in the catalytic removal of organic contaminants for practical application is still extremely ***,we report a Pd-decorated TiO_(2)(Pd/TiO_(2))hierarchical vertical array for fast and efficient catalytic water *** a forest-like Pd/TiO_(2) vertical array demonstrates the following distinct advantages over conventional planar or bulk catalytic systems:1)abundant anchoring sites for nanocrystals loading;2)high sunlight absorption;3)efficient mass transfer channels for the reactants and *** a proof of concept,the Pd/TiO_(2) array demonstrated rapid and efficient photo-assisted catalytic reduction of high concentrations of 4-nitrophenol wastewater(2 g/L,ca.14.38 mmol/L)and its feasibility for continuous flow wastewater *** turnover frequency(TOF)value of the Pd/TiO_(2) array was up to 8.00 min^(-1),which was approximately 4.2 times that of planar Pd/TiO_(2) film with the same area(1.91 min^(-1)).Our strategy of incorporating nanocatalysts with a hierarchical vertical array provides a promising approach to boosting the catalytic performance of catalysts for different chemical reactions.

关键词： 3D printing TiO_(2) Hierarchical vertical array Catalytic water treatment 4-Nitrophenol

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Structural basis for the regulatory mechanism of mammalian mitochondrial respiratory chain megacomplex-Ⅰ_(2)Ⅲ_(2)Ⅳ_(2)

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hlife 2024年第4期2卷 189-200页

作者： Laixing zhang Runyu Guo Chun xiao Jiaqi li Jinke Gu Maojun yang Ministry of Education Key Laboratory of Protein Science Beijing Advanced Innovation Center for Structural BiologyBeijing Frontier Research Center for Biological StructureTsinghua-Peking Center for Life SciencesSchool of Life SciencesTsinghua UniversityBeijingChina Department of Biochemistry and Molecular Biology School of Basic Medical SciencesShenzhen University Medical SchoolGuangdongChina Cryo-EM Facility Center Southern University of Science&TechnologyGuangdongChina

Mammalian mitochondrial electron transport chain complexes are the most important and complicated protein machinery in *** this system has been studied for more than a century,its composition and molecular mechanism are still largely *** we report the high-resolution cryo-electron microscopy(Cryo-EM)structures of porcine respiratory chain megacomplex-Ⅰ_(2)Ⅲ_(2)Ⅳ_(2)(MCⅠ_(2)Ⅲ_(2)Ⅳ_(2))in five different conformations,including State 1,State 2,Mid 1,Mid 2,and Mid ***-resolution Cryo-EM imaging,combined with super-resolution gated stimulated emission depletion microscopy(gSTED),strongly supports the formation of MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)in live *** MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)structure contains 141 subunits(70 different kinds of peptides,2.9 MDa)in total with 240 transmembrane *** mutual influence among CⅠ,CⅢ,and CⅣshown in the MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)structure suggests this megacomplex could act as an integral unit in electron transfer and proton *** conformational changes from different states suggest a plausible regulatory mechanism for the MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)activation/deactivation process.

关键词： mitochondria respiratory chain megacomplex cryo-electron microscopy(Cryo-EM) gated stimulated emission depletion microscopy(gSTED)

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Boosting alkaline hydrogen evolution performance by constructing ultrasmall Ru clusters/Na^(+),K^(+)-decorated porous carbon composites

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Nano Research 2023年第7期16卷 8836-8844页

作者： Mingxiu Duan Tie Shu Jingwei li Daliang zhang li-Yong Gan Ke xin Yao Qiang Yuan State-Local Joint Laboratory for Comprehensive Utilization of Biomass Center for R&D of Fine ChemicalsCollege of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025China School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China Multi-scale Porous Materials Center Institute of Advanced Interdisciplinary Studies&School of Chemistry and Chemical EngineeringChongqing UniversityChongqing 400044China College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing 401331China

The construction of efficient and durable electrocatalysts with highly dispersed metal clusters and hydrophilic surface for alkaline hydrogen evolution reaction(HER)remains a great ***,we prepared hydrophilic nanocomposites of Ru clusters(~1.30 nm)anchored on Na^(+),K^(+)-decorated porous carbon(Ru/Na^(+),K^(+)-PC)through hydrothermal method and subsequent annealing treatment at 500℃.The Ru/Na^(+),K^(+)-PC exhibits ultralow overpotential of 7 mV at 10 mA·cm^(-2),mass activity of 15.7 A·mgRu^(-1)at 100 mV,and long-term durability of 20,000 cycles potential cycling and 200 h chronopotentiometric measurement with a negligible decrease in activity,much superior to benchmarked commercial Pt/*** functional theory based calculations show that the energy barrier of H-OH bond breaking is efficiently reduced due to the presence of Na and K ions,thus favoring the Volmer ***,the Ru/Na^(+),K^(+)-PC effectively employs solar energy for obtaining H_(2)in both alkaline water and seawater *** finding provides a new strategy to construct high-performance and cost-effective alkaline HER electrocatalyst.

关键词： hydrogen evolution reaction decorated porous carbon ultrasmall Ru clusters electrocatalysts solar-to-hydrogen

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Effect of different levels of corn steep liquor addition on fermentation characteristics and aerobic stability of fresh rice straw silage

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Animal Nutrition 2016年第4期2卷 345-350页

作者： xinxin li Wenbin Xu Jinshan yang Hongbo Zhao Hangshu xin Yonggen zhang College of Animal Science and Technology Northeast Agricultural University Institute of New Rural Development Northeast Agricultural University

The object of this study was to determine the proper mixing ratio of fresh rice straw to corn steep liquor(CSL) to obtain a high protein content silage feed. The following experimental silages were generated: the control(C1), composed of fresh rice straw without CSL additive, mixed with CSL in the ratios of 4:1(C4),3:1(C3) and 2:1(C2). Lactic acid bacteria(LAB) inoculant was applied at the rate of 50 mL/kg(fresh basis)of forage to achieve a final application rate of 1 x 10~6 cfu/g of fresh matter(FM). Duplicate silos for each treatment were opened after 0,3, 7,10,20,30,45 and 60 d for microbiological and chemical analysis. The results showed that the addition of CSL significantly increased crude protein(CP) contents, and decreased neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents of treatments after 60 d of ensiling(P xing fresh rice straw with CSL at addition levels of 4:1(C4) and 3:1(C3) can improve the fermentation quality and nutrient composition of fresh rice straw silage. However, a large proportion of CSL(C3) had a negative impact on the aerobic stability of fresh rice straw.

关键词： Corn steep liquor Fresh rice straw Lactic acid bacteria Mixing ratio Silage

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Enhanced absorption process in the thin active region of GaAs based p-i-n structure

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Chinese Physics B 2021年第9期30卷 542-546页

作者： Chen Yue Xian-Sheng Tang yang-Feng li Wen-Qi Wang xin-xin li Jun-yang zhang Zhen Deng Chun-Hua Du Hai-Qiang Jia Wen-xin Wang Wei Lu yang Jiang Hong Chen Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China University of Academy of Sciences Beijing 100049China Center of Material and Optoelectronics Engineering University of Academy of SciencesBeijing 100049China Songshan Lake Material Laboratory Dongguan 523808China State Key Laboratory for Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of the active region within a p–n junction. In this paper, Ga As based p–i–n samples with the active region varied from 100 nm to 3 μm were fabricated and it was observed that the external quantum efficiencies are higher than the typical results, indicating a new mechanism beyond the established theories. We proposed a theoretical model about the abnormal optical absorption process in the active region within a strong electric field, which might provide new theories for the design of the solar cells,photodetectors, and other photoelectric devices.

关键词： photoelectric p-n junction absorption coefficient

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Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil

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Chinese Journal of Aeronautics 2016年第4期29卷 1084-1095页

作者： li Benkai li Changhe zhang Yanbin Wang Yaogang Jia Dongzhou yang Min School of Mechanical Engineering Qingdao Technological University

Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM-III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that (1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient; (2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient; (3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil; (4) viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils; (5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature; (6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and (7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 degrees C grinding temperature, and 42.7% energy ratio coeffi

关键词： Base oil Carbon chain length Energy ratio coefficient Grinding force Grinding temperature MQL grinding Vegetable oil Viscosity

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Behavioral responses for evaluating the attractiveness of specific tea shoot volatiles to the tea green leafhopper, Empoaca vitis

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Insect Science 2012年第2期19卷 229-238页

作者： Dan Mu lin Cui Jian Ge Meng-xin Wang li-Fang liu xiao-Ping Yu Qing-He zhang Bao-Yu Han Tea Research Institute of Chinese Academy of Agricuitural Sciences Zhejiang Provincial Key Laboratory of Biometrology and Inspection&Quarantine College of Life Sciences of China Jiliang UniversityHangzhouChina Sterling International Inc.SpokaneWAUSA

The tea green leafhopper, Empoasca vitis Gothe, is one of the most serious insect pests of tea plantations in China's Mainland. Over the past decades, this pest has been controlled mainly by spraying pesticides. Insecticide applications not only have become less effective in controlling damage, but even more seriously, have caused high levels of toxic residues in teas, which ultimately threatens human health. Therefore, we should seek a safer biological control approach. In the present study, key components of tea shoot volatiles were identified and behaviorally tested as potential leafhopper attractants. The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography-mass spectrometry （GC-MS）：（E）-2-hexenal, （Z）-3-hexen-1- ol, （Z）-3-hexenyl acetate, 2-ethyl-1-hexanol, （E）-ocimene, linalool, nonanol, （Z）-butanoic acid, 3-hexenyl ester, decanal, tetradecane, β-caryophyllene, geraniol and hexadecane. In Y-tube olfactometer tests, the following individual compounds were identified：（E）-2- hexenal, （E）-ocimene, （Z）-3-hexenyl acetate and linalool, as well as two synthetic mixtures （called blend 1 and blend 2） elicited significant taxis, with blend 2 being the most attractive. Blend 1 included linalool, （Z）-3-hexen-l-ol and （E）-2-hexenal at a 1： 1：1 ratio, whereas blend 2 was a mixture of eight compounds at the same loading ratio：（E）-2-hexenal, （Z）- 3-hexen-l-ol, （Z）-3-hexenyl acetate, 2-penten-l-ol, （E）-2-pentenal, pentanol, hexanol and 1-penten-3-ol. In tea fields, the bud-green sticky board traps baited with blend 2, （E）-2- hexenal or hexane captured adults and nymphs of the leafhoppers, with blend 2 being the most attractive, foUowed by （E）-2-hexenal and hexane. Placing sticky traps baited with blend 2 or （E）-2-hexenal in the tea fields significantly reduced leathopper populations. Our results indicate that the bud-green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the

关键词： attractant behavior green leaf volatiles tea green leafhopper tea shoot volatiles

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Application of the WHO Growth Reference (2007) to Assess the Nutritional Status of Children in China

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Biomedical and Environmental Sciences 2009年第2期22卷 130-135页

作者： YAN-PING li xiao-QI HU JING-ZHAO xiao-GUANG yang AND GUAN-SHENG MA National Institute for Nutrition and Food Safety Chinese Center for Disease Control and Prevention Beijing 100050 China

Objective To assess the nutrition status of children and adolescents in China using the WHO growth reference （2007） in comparison with that defined by the International Obesity Task Force （IOTF） and the Working Group on Obesity in China （WGOC）. Methods Overweight and obesity were defined by age-, sex-, specific BMI reference developed by WHO （2007）, IOTF （2000）, and WGOC （2004）, respectively. Stunting and thinness were defined as height and BMI less than two standard deviations （SD） of the WHO growth reference （2007）, respectively. Data of children and adolescents aged 5 to 19 years （n=54 857, 28 273 boys, 26 584 girls） from the 2002 China National Nutrition and Health Survey （CNNHS） were used in the study. Results The prevalence of overweight, obesity, stunting and thinness among Chinese children and adolescents aged 5-19 years was 5.0%, 1.2%, 13.8%, and 7.4%, respectively when the WHO growth reference （2007） was used, whereas the estimated absolute total number affected by these 4 conditions were 14.6, 3.7, 40.6, and 21.8 million, respectively. The prevalence of overweight and obesity was 18.1% in large cities, while the stunting prevalence was 25.1% in rural 4. Obesity prevalence assessed by the WHO growth reference was higher than that as assessed by the IOTF reference, and obesity prevalence assessed by the WGOC reference was lower than that as assessed by the IOTF reference. Conclusion The nutritional status of children and adolescents is not equal in different areas of China. Stunting is still the main health problem of the poor, while overweight and obesity are the main health problems in large cities.

关键词： WHO Obesity Stunting Children Adolescents China

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