检索结果-南通市图书馆

Chinese Chemical Letters 2003年第4期14卷 335-337页

作者： wei ming XU Li ming YU Xian HUANG Department of Chemistry Zhejiang University(Xixi Campus)Hangzhou 310028

Polystyrene-supported benzyl selenide has been prepared. This novel reagent was treated with LDA to produce a selenium stabilized carbanion, which reacted with alkyl halide, followed by selenoxide syn-elimination, to... 详细信息

关键词： Solid phase synthesis polystyrene-supported benzyl selenide substituted olefins.

Numerical analysis of the hydraulic fracture communication modes in fracture-cavity reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2022年第5期19卷 2227-2239页

作者： Jia-wei Kao Shi-ming wei Wen-Zhi Wang Yan Jin State Key Laboratory Petroleum Resources and Prospecting China University of PetroleumBeijing102249China Sinopec Research Institute of Petroleum Engineering Beijing102206China CNPC Engineering Technology R&D Company Limited Beijing102206China

The fracture-cavity carbonate reservoirs in the Tahe Oilfield in China are mainly exploited by *** need the hydraulic fractures to communicate with caves to create a flow ***,due to the existence of the fracture-cavity systems,the hydraulic fracture propagation morphology is complicated,while the propagation characteristics are not *** analyze the hydraulic fracture propagation in fracture-cavity carbonate formations,based on the discontinuous discrete fracture model,we developed a solid-seepage-freeflow coupled fracturing model for fracture-cavity formations,which can simulate the complex interaction behavior of fractures and *** on the simulation results,we found the interaction rule between hydraulic fractures and fracture-cavity systems:the stress concentration around caves is the main factor that determines the fracture propagation *** due to stress concentration is usually not conducive to communication,while natural fractures distributed around caves could break the rejection *** the hydraulic energy in the hydraulic fracture can make fracture propagate directly and reduce the influence of *** steering fracture formed by temporary plugging is beneficial to the communication of fracture-cavity systems in the non-principal stress *** to the simulation results of different fracture-cavity characteristics,we raised four optimization communication modes for fracture-cavity carbonate formation to provide references for fracturing optimization design and parameter optimization.

关键词： Fracture-cavity carbonate formation Hydraulic fracture propagation Numerical simulation Fracture-cave communication Discontinuous discrete fracture model

Zero chiral bulk modes in 3D Weyl metamaterials

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2019年第12期64卷 799-801页

作者： Yang ming Cheng-wei Qiu School of Physics and Electronic Engineering Changshu Institute of TechnologySuzhou 215000China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore

In the Weyl semimetals, a special type of one-way chiral zero mode (CZM) can be supported if a strong magnetic field is applied. The corresponding CZM is related to the zero-order Landau level for relativistic particles in Dirac or Weyl systems. This special energy level can lead to chiral anomaly, which describes the phenomenon of breaking the conservation of chirality [1]. Under the action of an effective magnetic field, the zeroth Landau mode can be expected to propagate only in the chiral direction according to the chirality (left-handed or right-handed) of the Weyl points and the magnetic field direction. Distinguished from the topological insulators, such a one-way propagation mode is a bulk state rather than a surface state or edge state that travels along the interface. Recently, the discovery of Dirac or Weyl degeneracies in the electronic and photonic systems brings opportunities for experimental detection of the chiral zeroth Landau levels [2,3]. Notwithstanding, the chiral Landau level in the 3D photonic system has not been observed yet.

关键词： chiral zero mode(CZM) chirality topological insulators

Influence of initial iron ore particle size on CO2 gasification behavior and strength of ferro-coke

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2020年第8期27卷 875-886页

作者： Run-sheng Xu Shu-liang Deng Heng Zheng wei Wang ming-ming Song wei Xu Fang-fang Wang State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Chair of Metallurgy Montanuniversitat LeobenLeoben A-8700Austria Wuhan Iron and Steel Co. Ltd.Wuhan 430081HubeiChina School of Energy and Power Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800ZhejiangChina

Highly reactive ferro-coke has been widely studied due to its contribution to the energy saving and emission reduction in blast furnace ironmaking. To optimize the coking process of ferro-coke and improve its metallurgical properties, it is necessary to clarify the influence of initial iron ore on the strength, micro-morphology and CO2 gasification reaction behavior of formed ferro-coke. The effects of initial iron ore particle size (0.50–1.00, 0.25–0.50 and 0.074–0.125 mm) on the CO2 gasification reaction of ferro-coke were analyzed using thermo-analysis technique. In addition, the effects of initial iron ore particle size on the strength and morphology of ferro-coke were investigated by drum test, digital microscopy and scanning electron micro-scopy. The results show that iron reduced from iron ore has a great promotion effect on the CO2 gasification reaction of ferro-coke. The smaller the particle size of initial iron ore, the more intense the gasification reaction, and the lower the starting temperature for gasification reaction of ferro-coke. The results of kinetic calculation show that the apparent activation energy of ferro-coke decreases with the decreasing particle size of blended iron ore. The particle size of initial iron ore has a great impact on the strength of ferro-coke. The ferro-coke prepared by 0.25–0.50 mm iron ore presents the best strength in this experiment.

关键词： Ferro-coke Iron ore Particle size Strength Gasification reaction

A novel triple responsive smart fluid for tight oil fracturing-oil expulsion integration

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

Petroleum Science 2023年第2期20卷 982-992页

作者： ming-wei Gao ming-Shan Zhang Heng-Yi Du ming-wei Zhao Cai-Li Dai Qing You Shun Liu Zhe-Hui Jin Shandong Key Laboratory of Oilfield Chemistry(China University of Petroleum(East China)) Qingdao266580ShandongPR China Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongPR China Department of Civil and Environmental Engineering University of AlbertaEdmontonAlbertaT6G 1H9Canada Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs Engineering Research Center of Development and Management for Low to Ultra-low Permeability Oil&Gas Reservoirs in West China(Ministry of Education)Xi'an Shiyou UniversityXi'an710065ShaanxiPR China School of Energy Resources China University of GeosciencesBeijing100083PR China

The traditional multi-process to enhance tight oil recovery based on fracturing and huff-n-puff has obvious deficiencies,such as low recovery efficiency,rapid production decline,high cost,and complexity,***,a new technology,the so-called fracturing-oil expulsion integration,which does not need flowback after fracturing while making full use of the fracturing energy and gel breaking fluids,are needed to enable efficient exploitation of tight oil.A novel triple-responsive smart fluid based on“pseudo-Gemini”zwitterionic viscoelastic surfactant(VES)consisting of N-erucylamidopropyl-N,N-dimethyl-3-ammonio-2-hydroxy-1-propane-sulfonate(EHSB),N,N,N′,N′-tetramethyl-1,3-propanediamine(TMEDA)and sodium p-toluenesulfonate(NaPts),is ***,the rheology of smart fluid is systematically studied at varying conditions(CO_(2),temperature and pressure).Moreover,the mechanism of triple-response is discussed in ***,a series of fracturing and spontaneous imbibition performances are systematically *** smart fluid shows excellent CO_(2)-,thermal-,and pressure-triple responsive *** can meet the technical requirement of tight oil fracturing construction at 140°C in the presence of 3.5 MPa CO_(2).The gel breaking fluid shows excellent spontaneous imbibition oil expulsion(∼40%),salt resistance(1.2×104 mg/L Na+),temperature resistance(140°C)and aging stability(30 days).

关键词： Fracturing-oil expulsion integration Tight oil Triple responsive smart fluid "Pseudo-gemini"zwitterionic surfactant Fracturing fluid Spontaneous imbibition

High-temperature chlorination of gold with transformation of iron phase

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2016年第11期35卷 881-886页

作者： Zheng-Yao Li wei-wei Wang Kun Yue ming-Xing Chen School of Civil and Environmental Engineering University of Science and Technology Beijing

Gold in cyanide tailings from Shandong Province is mainly encapsulated by hematite and magnetite at distribution rates of 76.49 % and 10.88 %, ***-reduction one-step roasting of cyanide tailings was conducted under the following conditions： calcium chloride dosage of 6 %, bituminous coal dosage of 30 %, calcium oxide dosage of 10 %（all dosages are *** mass of cyanide tailings） at 1000 ℃ of roasting temperature. X-ray diffraction（XRD）, scanning electron microscopy（SEM）, and chemical-phase analysis were performed to investigate the effects of iron phase transformation on the high-temperature chlorination of *** indicate that the lattice structure of hematite undergoes expansion, pulverization, and reorganization when hematite is reduced to magnetite, which leads to42.03 % gold exposure, and the high-temperature chlorination rate of gold is 41.17 % at the same time. The structure of wustite formed by the reduction in magnetite is porous and loose, and thus 44.02 % of gold is exposed. The high-temperature chlorination rate of gold is increased by41.98 percentage points. When wustite is reduced to metallic iron, 4.42 % of gold is exposed, and the hightemperature chlorination rate of gold is increased by3.38 percentage points. Accordingly, the high-temperature chlorination of gold mainly occurs in two stages, in which Fe_2O_3 is reduced to Fe_3O_4, and Fe_3O_4 is reduced to Fe_xO finally.

关键词： Cyanide tailings Chlorination-reduction one-step roasting Transformation of iron phase Gold

Evaluation of Harvest Aid Chemicals for the Cotton-Winter Wheat Double Cropping System

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2013年第2期12卷 273-282页

作者： DU ming-wei REN Xiao-ming TIAN Xiao-li DUAN Liu-sheng ZHANG ming-cai TAN wei-ming LI Zhao-hu State Key Laboratory of Plant Physiology and Biochemistry/Engineering Research Center of Plant Growth Regulator Ministry of Education/College of Agronomy and Biotechnology China Agricultural University

Timing of harvest is critical for mechanical picking in cotton production, especially in those regions with double cropping system. Appropriate and safe harvest aids will improve timing and facilitate harvest of cotton in the double cropping system. Three defoliants （dimethipin, thidiazuron, and thidiazuron-diuron） and one boll opener （ethephon） were included in this research. They were evaluated for their effects on defoliation, boll opening, seedcotton yield, seed quality, and fiber quality of field grown cotton when used alone or as a mixture in 2009 and 2010. Defoliation and/or boll opening were increased by all three defoliants and ethephon, especially by mixtures of a defoliant and ethephon. First harvest of seedcotton was significantly increased with defoliant-ethephon mixtures. No significant adverse effects were observed on boll weight, lint percentage, seed quality, and fiber properties. It was estimated that tank mixes of ethephon and one of the three defoliants can improve the adjusted gross revenue. Boll opening can be used as an alternative indicator for the adjusted gross revenue, because, it was linearly and positively correlated with the relative adjusted gross revenue and convenient in measurements. Wheat seedling growth was not affected by thidiazuron, whereas its seedling emergence, root dry weight, relative water content, and electrolyte leakage were adversely affected by dimethipin and thidiazuron- diuron when concentration was above 340 and 100 g （a.i.） ha-1, respectively. 90% defoliation and 80% boll opening were observed with the high rate of thidiazuron-ethephon mixture, but no adverse effects on winter wheat. The results suggested that tank mixes of ethephon with thidiazuron can be used effectively and safely in the cotton-winter wheat double cropping system to improve yield without adverse effects on seed quality and fiber quality.

关键词： cotton defoliation boll opening double cropping system

Conjugate Points on a Type of Kahler Manifolds

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 1175-1184页

作者： wei ming LIU Fu Sheng DENG Department of Mathematics and Physics Beijing Institute of Petrochemical Technology School of Mathematical Sciences Graduate University of Chinese Academy of Sciences

We study conjugate points on a type of Khler manifolds, which are submanifolds of Grassmannian manifolds. And then we give the applications to the study of the index of geodesics and homotopy groups.

关键词： Conjugate points Jacobi equation Khler manifolds

Resource allocation algorithm with limited feedback for multicast single frequency networks

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第2期13卷 146-154页

作者： ming-wei TANG Xiao-xiang WANG MOE Key Laboratory of Universal Wireless Communications Beijing University of Posts and TelecommunicationsBeijing 100876China

The single frequency network (SFN) can provide a multimedia broadcast multicast service over a large coverage area. However, the application of SFN is still restricted by a large amount of feedback. Therefore, we propose a multicast resource allocation scheme based on limited feedback to maximize the total rate while guaranteeing the quality of service (QoS) requirement of real-time services. In this scheme, we design a user feedback control algorithm to effectively reduce feedback load. The algorithm determines to which base stations the users should report channel state information. We then formulate a joint subcarrier and power allocation issue and find that it has high complexity. Hence, we first distribute subcarriers under the assumption of equal power and develop a proportional allocation strategy to achieve a tradeoff between fairness and QoS. Next, an iterative water-filling power allocation is proposed to fully utilize the limited power. To further decrease complexity, a power iterative scheme is introduced. Simulation results show that the proposed scheme significantly improves system performance while reducing 68% of the feedback overhead. In addition, the power iterative strategy is suitable in practice due to low complexity.

关键词： Multicast Single frequency networks (SFN) Orthogonal frequency division multiplexing access (OFDMA) Resource allocation

Applications of covalent organic frameworks(COFs)：From gas storage and separation to drug delivery

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2017年第6期28卷 1135-1143页

作者： ming-Xue Wu Ying-wei Yang International Joint Research Laboratory of Nano-Micro Architecture Chemistry (NMAC) College of Chemistry Jilin University Changchun 130012 China

Covalent organic frameworks（COFs） are an emerging class of porous covalent organic structures whose backbones were composed of light elements（B,C,N,O,Si） and linked by robust covalent bonds to endow such material with desirable properties,i.e.,inherent porosity,well-defined pore aperture,ordered channel structure,large surface area,high stability,and *** expected,the abovementioned properties of COFs broaden the applications of this class of materials in various fields such as gas storage and separation,catalysis,optoelectronics,sensing,small molecules adsorption,and drug *** this review,we outlined the synthesis of COFs and highlighted their applications ranging from the initial gas storage and separation to drug delivery.

关键词： Covalent organic frameworks Drug delivery Porous materials Synthesis