检索结果-南通市图书馆

Petroleum Science 2021年第5期18卷 1305-1322页

作者： ji-yuan Wang Shao-Bin Guo School of Energy Resources China University of GeosciencesBeijing100083China Key Laboratory of Strategy Evaluation for Shale Gas Ministry of Land and ResourcesBeijing100083China

The relationship between hydrocarbon generation and the evolution of shale pore structure and its heterogeneity of continental shale from the Ordos Basin,ch.na was quantitatively studied based on thermal simulation experiment,mercury injection capillary pressure(MICP),gas adsorption,vitrinite reflectance(R_(o))analysis,and hydrocarbon generation test combined with Frenkel-Halsey-Hill(FHH)fractal *** result shows that the pore volume(PV)and specific surface area(SSA)of pores with different pore sizes show a trend of decreasing first and then increasing as the maturity increases in general,R_(o)>1.59%is initially defined as a favorable stage for pore development in continental *** generation has different effects on pore heterogeneity of different *** the n_(2)adsorption,the roughness of small pore surface(D_(1))decreases in the oil window;the complexity of large pore structure(D_(2))increases in the oil window but decreases in the gas *** the MICP,the heterogeneity of small pore(D_(1))increases in the oil window and increases first and then decreases in the gas window;D_(2)remains basically constant during the whole stage and is close to 3,indicating that the heterogeneity of large pores is extremely strong and is not affected by hydrocarbon generation.

关键词： Shale Hydrocarbon generation Pore evolution Fractal dimension

ni-mediated C–n activation of amides and derived catalytic transformations

在线全文

学校读者我要写书评

暂无评论

Science ch.na chemistry 2017年第11期60卷 1413-1424页

作者： yuan Gao ch.ng-Lei ji Xin Hong Department of chemistry Zhejiang UniversityHangzhou 310027China

Amide, as a ubiquitous functional group, is essential in various aspects of chemistry and biology. Although the history of studying amide is rich and fruitful, the synthetic application of amide is very limited due to the inertness of amide C–n bond. Recently,significant advances have been achieved towards the nickel-mediated C–n activation of amides. This approach allows a facile generation of acyl-nickel intermediates, and a number of unique transformations have been designed and realized based on the amide C–n bond activation. Focused on the catalytic transformation, this review summarizes and categorizes the recent advances on the synthetic applications of ni-mediated C–n bond activation of amides.

关键词： C-n activation amide nickel homogeneous catalysis cross coupling

Fabrication of polymer/fluoride-containing salts blend composite membranes for CO_2 separation

在线全文

学校读者我要写书评

暂无评论

Journal of natural Gas chemistry 2010年第6期19卷 560-566页

作者： Pengfei ji Yiming Cao Xingming jie Quan yuan Dalian Institute of chemical Physics Chinese Academy of Sciences Dalian 116023 Liaoning China Graduate University of ch.nese Academy of Sciences Beijing 100049 China

Poly （n,n-dimethylaminoethyl methacrylate）-poly （ethylene glycol methyl ether methacrylate）（PDMAEMA-PEGMEMA） and cesium fluoride （CsF） were blended and used as the separation material of composite *** fiber composite membranes were fabricated by coating the blend on polysulfone （PSf） hollow fiber *** of fluorine ion improved the separation performance of the *** concentration of coating solution was adjusted to obtain a membrane with high *** composite membrane showed good performance with the CO2 permeance of 30.4 GPU （1 GPU=10-6 cm3 （STP）/（cm 2 s cmHg））,and selectivities to CO2/n2,CO2/ch4,CO2/H2 and O2/n2 of 47.2,37.6,1.75 and 4.70,*** fluoride （KF）,due to its low cost,was also used as a substitute of CsF to prepare composite membrane and the permeation data showed that CsF can be replaced by *** effect of operating temperature on the permeation properties of the composite membrane was also investigated.

关键词： blend composite membrane coating CO2 separation hollow fiber

Mercury accumulation and dynamics in montane forests along an elevation gradient in Southwest ch.na

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第9期34卷 1-10页

作者： Shufang Zeng Xun Wang Wei yuan ji Luo Dingyong Wang College of Resources and Environment Southwest UniversityChongqing 400715China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences&Ministry of Water ConservancyChengdu 610041China

Understanding atmospheric mercury(Hg) accumulation in remote montane forests is critical to assess the Hg ecological risk to wildlife and human health. To quantify impacts of vegetation, climatic and topographic factors on Hg accumulation in montane forests, we assessed the Hg distribution and stoichiometric relations among Hg, carbon(C), and nitrogen(n) in four forest types along the elevation of Mt. Gongga. Our results show that Hg concentration in plant tissues follows the descending order of litter > leaf, bark > root > branch > bole wood, indicating the importance of atmospheric Hg uptake by foliage for Hg accumulation in plants. The foliar Hg/C(from 237.0 ± 171.4 to 56.8 ± 27.7 μg/kg) and Hg/n(from 7.5 ± 3.9 to 2.5 ± 1.2 mg/kg) both decrease along the elevation. These elevation gradients are caused by the heterogeneity of vegetation uptake of atmospheric Hg and the variation of atmospheric Hg ° concentrations at different altitudes. Organic soil Hg accumulation is controlled by forest types, topographic and climatic factors, with the highest concentration in the mixed forest(244.9 ± 55.7 μg/kg) and the lowest value in the alpine forest(151.9 ±44.5 μg/kg). Further analysis suggests that soil Hg is positively correlated to C( r^(2) = 0.66) and n( r^(2) = 0.57), and Hg/C and Hg/n both increase with the soil depth. These stoichiometric relations highlight the combined effects from environmental and climatic factors which mediating legacy Hg accumulation and selective Hg absorption during processes of organic soil mineralization.

关键词： Mercury deposition Montane forest Mercury accumulation Climate impact

Parameter Dependence of Stable Manifolds for nonuniform (μ, ν)-dichotomies

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2013年第6期29卷 1111-1130页

作者： ji Min ZHAnG Meng FAn Xiao yuan ch.nG College of Mathematics Jilin University School of Mathematical Sciences Heilongjiang University School of Mathematics and Statistics Northeast Normal University School of Applied Sciences Harbin University of Science and Technology

We construct stable invariant manifolds for semiflows generated by the nonlinear impulsive differential equation with parameters x＇= A（t）x ＋ f（t, x, λ）, t≠τi and x（τ＋i） = Bix（τi）＋ gi（x（τi）, λ）, i ∈ n in Banach spaces, assuming that the linear impulsive differential equation x＇= A（t）x, t≠τi and x（τ＋i） = Bix（τi）, i ∈ n admits a nonuniform （μ, ν）-dichotomy. It is shown that the stable invariant manifolds are Lipschitz continuous in the parameter λ and the initial values provided that the nonlinear perturbations f, g are sufficiently small Lipschitz perturbations.

关键词： Stable invariant manifolds nonuniform ( μ ν )-dichotomies impulsive differential equations

Recent progress in modelling and simulation technologies of energy efficiency and environmental quality in the built environment

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2022年第7期15卷 1175-1176页

作者： Wenhui ji Yanping yuan Liangliang Sun Xudong Zhao School of Mech.nical Engineering Southwest Jiaotong UniversityNo.111North Section 1Second Ring RoadChengdu 610031China University of Hull School Engineering and Computer ScienceKingston Upon Hull HU67RXN HumbersideUK

The International Conference for Global ch.nese Academia on Energy and Built Environment(ICCEBE)is a premier international event covering a broad range of topics on clean energy utilization,energy efficiency and environmental quality in the built *** conference aims to provide a forum to share cutting-edge achievements in the built environment,and to promote academic collaboration and cooperation among worldwide ch.nese scholars.

关键词： energy modelling collaboration

Hyperhomocysteinemia independently causes and promotes atherosclerosis in LDL receptor-deficient mice

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2014年第1期11卷 74-78页

作者： Hang-yuan GUO Fu-Kang XU Hai-Tao LV Long-Bin LIU Zheng ji Xiao-Ya ZHAI Wei-Liang TAnG Ju-Fang ch Department of Cardiology Shaoxing Hospital of Zhejiang University Shaoxing 312000 Zhejiang Province China

Background Hyperhomocysteine is an independent risk factor of coronary heart disease （chD）. However, whether hyperhomocys teine affects the progression of atherosclerosis is unclear. In the present study, we examined the effect of hyperhomocysteine on the forma tion of atherosclerosis in low-density lipoprotein receptor-deficient （LDLr ） mice. Methods Forty-eight 7-week-old LDLr/ mice were assigned to the following groups： mice fed a standard rodent diet （control group）, mice fed a high-methionine diet （high-methionine group）, mice fed a high-fat diet （high-fat group）, and mice fed a diet high in both methionine and fat （high-methionine and high-fat group）. At the age of 19, 23, and 27 weeks, four mice at each interval in every group were sacrificed. Results At the end of the study, mice did not show atherosclerotic lesions in the aortic sinus and aortic surface until 27 weeks old in the control group. However, atherosclerotic lesions developed in the other three groups at 19 weeks. The amount of atherosclerotic lesions on the aortic surface was lower in the high-methionine group than in the high-fat group （P 〈 0.001）. Atherosclerotic lesions on the aortic surface in the high-methionine and high-fat group were the most severe. The mean area of atherosclerotic lesions in the aortic sinus compared with atherosclerotic lesions on the aortic surface was lower in the high-methionine group than in the high-fat group （P 〈 0.001）. Atherosclerotic lesions in the aortic sinus in the high-methionine and high-fat group were the most severe. Conclusions Homocysteinemia accelerates atherosclerotic lesions and induces early atherosclerosis independently in LDLrmice. Reducing the level of homocysteinemia may be beneficial for prevention and treatment of chD.

关键词： Atherosclerosis Homocysteine Low-density lipoprotein Hyperhomocysteinemia

Casoratian Solutions to a non-isospectral Differential-Difference Kadomtsev-Petviashvilli Equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第9期50卷 557-560页

作者： ji jie ZHAnG Da-Jun ch.n Deng-yuan College of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 China Department of Mathematics Shanghai University Shanghai 200444 China

In this paper, a non-isospectrai differential-difference Kadomtsev-Petviashvilli equation （n-D△KPE） is presented. Then, the Casoratian solutions of the n-D△KPE are obtained by generalizing Casoratian conditions of... 详细信息

关键词： n-D△KPK Wronskian technique Casoratian condition

Function synthesis algorithm based on RTD-based three-variable universal logic gates

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2017年第10期18卷 1654-1664页

作者： Mao-qun YAO Kai YAnG ji-zhong SHEn Cong-yuan XU Hangzhou Institute of Service Engineering Hangzhou Normal University College of Information Science & Electronic Engineering Zhejiang University

Compared with complementary metal–oxide semiconductor(CMOS), the resonant tunneling device(RTD) has better performances; it is the most promising candidate for next-generation integrated circuit devices. The universal logic gate is an important unit circuit because of its powerful logic function, but there are few function synthesis algorithms that can implement an n-variable logical function by RTD-based universal logic gates. In this paper, we propose a new concept, i.e., the truth value matrix. With it a novel disjunctive decomposition algorithm can be used to decompose an arbitrary n-variable logical function into three-variable subset functions. On this basis, a novel function synthesis algorithm is proposed, which can implement arbitrary n-variable logical functions by RTD-based universal threshold logic gates(UTLGs), RTD-based three-variable XOR gates(XOR3s), and RTD-based three-variable universal logic gate(ULG3s). When this proposed function synthesis algorithm is used to implement an n-variable logical function, if the function is a directly disjunctive decomposition one, the circuit structure will be very simple, and if the function is a non-directly disjunctive decomposition one, the circuit structure will be simpler than when using only UTLGs or ULG3s. The proposed function synthesis algorithm is straightforward to program, and with this algorithm it is convenient to implement an arbitrary n-variable logical function by RTD-based universal logic gates.

关键词： Resonant tunneling device(RTD) Disjunctive decomposition algorithm Universal logic gate Truth value matrix Function synthesis algorithm

SEM Observation of the Wing Membrane of Beipiaopterus ch.nianus (Pterosauria)

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2005年第6期79卷 766-769页

作者： LU Junch.ng KOBAYASHI Yoshitsugu yuan ch.ngxi ji Shu＇an ji Qiang Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Hokkaido University Museum Hokkaido UniversityN10 W8 Kita Ku Sapporo Hokkaido 060-0810 Japan

The cross-section and surface structures of wing membranes from the ctenochasmatid pterosaur Beipiaopterus ch.nianus were observed through a scanning electron microscope （SEM）. The results show that the wing membrane contains a high density of blood vessels, implying strong thermoregulatory function, similar to that of a bat wing membrane. This is the first comparison of the microstmctures of pterosaur wing membranes with those of the modem bat. It is inferred that a bat-like physiology exists, at least in relatively small pterosaurs suggesting that these pterosaurs were warm-blooded, active fliers.

关键词： Beipiaopterus wing membrane microstructures SEM