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Selection and Evaluation of Dry and Isentropic Organic Working Fluids Used in Organic Rankine Cycle Based on the Turning Point on Their Saturated Vapor Curves
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作者 ZHANG Xinxin ZHANG Congtian +1 位作者 HE Maogang WANG Jingfu 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第4期643-658,共16页
The organic Rankine cycle(ORC)is a popular technique used in the utilization of low-grade thermal energy.Among wet,dry,and isentropic organic working fluids,the latter two types are more appropriate for ORC systems.In... The organic Rankine cycle(ORC)is a popular technique used in the utilization of low-grade thermal energy.Among wet,dry,and isentropic organic working fluids,the latter two types are more appropriate for ORC systems.In this paper,the definition of turning point on saturated vapor curve of dry fluid and isentropic fluid was given according to the shape of the saturated curve of working fluids in a T-s diagram.On this basis,the model of near-critical region triangle was established.Using this model,the thermodynamic performance of 57 kinds of dry and isentropic organic working fluids in ORC was evaluated.The performance includes the relation between turning point temperature and cycle thermal efficiency,the relation between near-critical region triangle area and cycle thermal efficiency,the relation between near-critical region triangle area and exergy at turning point temperature,the relation between near-critical region triangle area and reciprocal value of slope of saturated vapor curve.Moreover,working fluid selection was also conducted in terms of heat source type.It was found through theoretical analysis results that the popular R123 is an acceptable choice especially for the utilization of closed type heat source.Considering it will be phased out in near future,then cis-butene,butane,trans-butene,and isobutene are worth studying as its successor.Dodecane is worthy of attention and further research and it can be a good choice for utilization of open type heat source. 展开更多
关键词 DRY FLUID ISENTROPIC FLUID turning point saturated vapor curve NEAR-CRITICAL region TRIANGLE ORGANIC Rankine Cycle
Fluid Inclusion and H-O Isotope Geochemistry of the Phapon Gold Deposit, NW Laos: Implications for Fluid Source and Ore Genesis
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作者 Linnan Guo Shusheng Liu +6 位作者 Lin Hou Jieting Wang Meifeng Shi Qiming Zhang Fei Nie Yongfei Yang Zhimin Peng 《地球科学学刊:英文版》 SCIE CAS CSCD 2019年第1期80-94,共15页
The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brit... The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brittle fault system. There are three types of primary ore including auriferous calcite vein type, disseminated type, and breccia type, and the first two are important in the Phapon gold deposit. Based on fluid inclusion petrography and microthermometry, three types of primary fluid inclusions including type 1 liquid-rich aqueous, type 2 vapor-rich aqueous and type 3 daughter mineralbearing aqueous were identified in hydrothermal calcite grains. The ore-forming fluids are normally homogeneous, as indicated by the widespread type 1 inclusions with identical composition. The coexistence of type 1 and type 2 inclusions, showing similar final homogenization temperature but different compositions, indicate that fluid immiscibility did locally take place in both two types of ores. The results of microthermometry and H-O isotopes geochemistry indicate that there are little differences on ore-fluid geochemistry between the auriferous calcite vein-type and disseminated type ores. The oreforming fluids are characterized by medium-low temperatures(157–268 oC) and low salinity(1.6 wt.%–9.9 wt.% NaCl eq.). It is likely to have a metamorphic-dominant mixed source, which could be associated with dehydration and decarbonisation of Lower Permian limestone and Middle–Upper Triassic sandstones during the dynamic metamorphism. The fluid-wallrock interaction played a major role, and the locally occurred fluid-immiscible processes played a subordinate role in gold precipitation. Combined with the regional and ore deposit geology, and ore-fluid geochemistry, we suggest that the Phapon gold deposit is best considered to be a member of the epizonal orogenic deposit class. 展开更多
关键词 FLUID inclusion H-O isotopes FLUID SOURCE ore genesis Phapon gold deposit northern Laos
Supercritical Fluid Media in Challenges of Substance and Material Dispersion
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作者 KHAIRUTDINOV Vener GUMEROV Farid KHABRIEV Ilnar 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第3期519-546,共28页
The paper deals with the problem of material dispersion using supercritical fluid media. At the same time, emphasis is made on modifications(SAS, GAS, SEDS and ASES) of the supercritical fluid anti-solvent method of d... The paper deals with the problem of material dispersion using supercritical fluid media. At the same time, emphasis is made on modifications(SAS, GAS, SEDS and ASES) of the supercritical fluid anti-solvent method of dispersion. The results of SAS method implementation for dispersion of pure polycarbonate and polycarbonate doped with "CdSe/CdS-core/shell" quantum dots(carried out in the pressure range of 8.0-25.0 MPa at temperatures of 313.15 K and 358.15 K) are submitted. The range of the operating parameters has been established through the example of pure polycarbonate dispersion, which provides the production of nanoparticles with the size range of 10-100 nm. Encapsulation of Cd Se/Cd S quantum dots into polycarbonate using the SAS method has no effect on optical properties of the encapsulated quantum dots. The results of paracetamol dispersion using the SEDS method are presented. The effect of operating conditions of the paracetamol dispersion process on morphology of the obtained product is described. Co-dispersion of ethylene–vinyl acetate copolymers and low-density polyethylene mixtures by SEDS method has been carried out under pressures of 8.0-25.0 MPa at temperatures of 313 K, 323 K, and 333 K. The comparison of melting and crystallization between the resulting copolymer mixtures and mixtures with the same composition obtained by mixing in the liquid melt, has shown that implementation of SEDS results in an increase of crystallinity degree of the polymer mixtures. 展开更多
关键词 SUPERCRITICAL FLUID MEDIA SUPERCRITICAL FLUID ANTI-SOLVENT method dispersion POLYCARBONATE PARACETAMOL ethylene-vinyl acetate copolymers
《黄帝内经》“膀胱”概念解析
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作者 王燕平 张维波 +1 位作者 李宏彦 叶丰瑶 《中医学报》 CAS 2019年第1期9-14,共6页
《黄帝内经》中'膀胱'在结构上是指下焦之下、以腹膜为其外壁的盆腔空间,其中包括含尿液的尿脬和腹腔液。'膀胱'所藏津液主要指腹腔液,它来自大肠、小肠分泌的水液,通过三焦特别是下焦的网膜结构聚积于盆腔的间隙空间中... 《黄帝内经》中'膀胱'在结构上是指下焦之下、以腹膜为其外壁的盆腔空间,其中包括含尿液的尿脬和腹腔液。'膀胱'所藏津液主要指腹腔液,它来自大肠、小肠分泌的水液,通过三焦特别是下焦的网膜结构聚积于盆腔的间隙空间中,再通过内脏的温度、压力等作用,变成小水颗粒,从腹膜等途径渗入膀胱经,最后通过膀胱经的气化作用转运全身。故不应把《黄帝内经》中的'膀胱'与西医解剖同名之'膀胱'混为一谈。 展开更多
关键词 “膀胱” 《黄帝内经》 津液 腹腔液
SOME PROBLEMS IN RADIATION TRANSPORT FLUID MECHANICS AND QUANTUM FLUID MECHANICS
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作者 Boling Guo Jun Wu 《应用数学年刊:英文版》 2019年第2期111-125,共15页
We introduce the radiation transport equations, the radiation fluid mechanics equations and the fluid mechanics equations with quantum effects. We obtain the unique global weak solution for the radiation transport flu... We introduce the radiation transport equations, the radiation fluid mechanics equations and the fluid mechanics equations with quantum effects. We obtain the unique global weak solution for the radiation transport fluid mechanics equations under certain initial and boundary values. In addition, we also obtain the periodic region problem of the compressible N-S equation with quantum effect has weak solutions under some conditions. 展开更多
关键词 RADIATION transport equation RADIATION FLUID MECHANICS EQUATIONS FLUID MECHANICS EQUATIONS with QUANTUM effects
Numerical optimisation and experimental validation of divided rail freight brake disc crown 预览
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作者 Uros Grivc David Derzic Simon Muhic 《现代交通学报:英文版》 2019年第1期1-10,共10页
In this study,numerical optimisation and experimental validation of a divided rail freight brake disc crown made of grey cast iron EN-GJL-250 is presented.The analysed brake disc is used in rail freight wagons and pos... In this study,numerical optimisation and experimental validation of a divided rail freight brake disc crown made of grey cast iron EN-GJL-250 is presented.The analysed brake disc is used in rail freight wagons and possesses a load capacity of 22.5 tons per axle.Two of the divided rail freight brake discs are mounted on each axle.With the aid of numerical analysis,the thermal dissipation properties of the brake disc were optimised and ventilation losses were reduced,and the numerical results were compared with experimental results.A one-way fluid–structure interaction analysis was performed.A computational fluid dynamic model of a divided rail freight brake disc,used to predict air flow properties and heat convection,was incorporated into a finite element model of the disc and used to evaluate the temperature of the disc.A numerical parametrical optimisation of cooling ribs of the brake disc was also performed,and novel optimised cooling ribs were developed.A transient thermal numerical analysis of the brake disc was validated using temperature measurements obtained during a braking test on a test bench.The ventilation losses of the brake disc were measured on a test bench specifically designed for the task,and the losses were compared to the simulation results.The experimentally obtained ventilation losses and temperature measurements compared favourably with the simulation results,confirming that this type of simulation process may be confidently applied in the future.Through systematic optimisation of the divided rail freight brake disc,ventilation losses were reduced by 37% and the mass was reduced by 21%,resulting in better thermal performance that will bring with it substantial energy savings. 展开更多
关键词 Divided RAIL FREIGHT BRAKE DISC Computational fluid dynamics Finite element method COMPUTER-AIDED engineering One-way fluid-structure interaction
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超临界流体色谱在纺织检测中的应用
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作者 郑环达 钟毅 毛志平 《上海纺织科技》 北大核心 2019年第6期1-3,31共4页
随着对纺织品可能带来的环境与生物危害性的日益关注,建立快速响应、高灵敏度的测试分析方法成为纺织产业新的诉求。超临界流体色谱以超临界流体和少量助溶剂为流动相,基于不同化合物在两相间的各异分配系数进行物质分离,其兼具气相色... 随着对纺织品可能带来的环境与生物危害性的日益关注,建立快速响应、高灵敏度的测试分析方法成为纺织产业新的诉求。超临界流体色谱以超临界流体和少量助溶剂为流动相,基于不同化合物在两相间的各异分配系数进行物质分离,其兼具气相色谱和液相色谱的优点,并具有黏度低、传质性好和绿色环保的优势,在低挥发性物质的分析分离上发挥了重要作用。从系统构成、流动相、固定相方面对超临界流体色谱进行了系统介绍。同时,综述了超临界流体色谱在纺织品中致敏染料、聚合物添加剂、荧光增白剂等检测中的应用。 展开更多
关键词 流体 超临界流体 色谱 染料 添加剂 荧光增白剂 纺织品检测
Simultaneous determination of amino acids in different teas using supercritical fluid chromatography coupled with single quadrupole mass spectrometry 预览
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作者 Yang Huang Tiejie Wang +2 位作者 Marianne Fillet Jacques Crommen Zhengjin Jiang 《药物分析学报:英文版》 CAS CSCD 2019年第4期254-258,共5页
Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry... Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties. 展开更多
关键词 Amino ACIDS TEAS SUPERCRITICAL fluid chromatography with SINGLE QUADRUPOLE mass spectrometry (SFCMS)
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Mixture flow of particles and power-law fluid in round peristaltic tube 预览
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作者 Hailin YANG Jianzhong LIN Xiaoke KU 《应用数学和力学:英文版》 SCIE EI CSCD 2019年第6期805-822,共18页
The erythrocyte and blood flowing in the blood vessel can be treated as the two-phase flow of the mixture of particles and a power-law fluid in a peristaltic tube.In the present work, the peristaltic transport of a po... The erythrocyte and blood flowing in the blood vessel can be treated as the two-phase flow of the mixture of particles and a power-law fluid in a peristaltic tube.In the present work, the peristaltic transport of a power-law fluid and the suspension of particles in a tube is investigated by a perturbation method using the long wavelength approximation. The influence of different parameters on the velocity profile and streamlines is explored. Results show that there is a deflection of the flow field when the power-law index n = 0.5 or 1.5 compared with the Newtonian fluid where the trapping zone is symmetric to a certain cross section. The flux rate and reflux of the material are identified,and the conditions under which the reflux appears are determined. Moreover, a reflux phenomenon occurs near the wall. The trapping zone is related to not only the tube geometry and the flow flux but also the fluid properties. Both the length and width of the trapping zone increase with an increase in θ or φ. The trapping zone is more difficult to produce in the shear-thinning fluid than the shear-thickening fluid. 展开更多
关键词 peristaltic transport TWO-PHASE FLOW POWER-LAW fluid PERTURBATION method TRAPPING phenomenon
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Stamping Reliability of Rocket Engine Cover Based on Finite Element Anglysis and Experiments 预览
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作者 高辉 丁凡 +2 位作者 杨涛 侯守全 张斌斌 《东华大学学报:英文版》 EI CAS 2019年第3期255-260,共6页
This paper mainly focuses on the simulation and experimental study of the reliability of the solid rocket nozzle cover.The test-bed is designed according to the technical requirements in order to provide different sta... This paper mainly focuses on the simulation and experimental study of the reliability of the solid rocket nozzle cover.The test-bed is designed according to the technical requirements in order to provide different stamping rates and tests for different sizes of covers.The gas source,the four valves and the installation container structure are used to realize the stamping.The installation container is a multistage flange stacking structure to achieve the installation of different sizes of plugging covers,and then the opening process of the plugging cover is recorded by the high speed pressure sensor and the automatic control system.The fluid solid coupling method is used to simulate the impact state of plugging cover in the flow field at 10,20,30 and 35 ms,and the maximum pressure at 35 ms is 1.244 MPa.Then the deformation of aluminum alloy plugging cover is observed by stress analysis and display dynamic method.The maximum value of Von Mises Stress of the simulation result is 277.600 MPa.In the experimental test,the performance of the system is tested with a high strength plugging cover.In the opening state of the two large flux control valves,the pressure in the installation container reaches 1.000 MPa at 35 ms.And then we modify the experimental system with the knowledge of aerodynamic theory.Finally,the plugging cover is installed to carry out the experiment,so as to obtain the reliable stamping rate of the plugging cover.Simulations,blind measurements and measurement results provide strong data for reliability of the plugging cover opening,and provide reliable reference data for rocket engine charge structure and nozzle shape optimization. 展开更多
关键词 plugging cover STAMPING RELIABILITY SIMULATION fluid solid coupling
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Magma chamber growth models in the upper crust: A review of the hydraulic and inertial constraints 预览
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作者 Eugenio Aragon Fernando J. D'Eramo +4 位作者 Lucio P. Pinotti Manuel Demartis Jose Maria Tubia Roberto F. Weinberg Jorge E. Coniglio 《地学前缘:英文版》 CAS CSCD 2019年第3期1211-1218,共8页
Finite volumes of magma moving in confinement, store hydraulic potential energy for the generation, control and transmission of power. The Pascal’s principle in a hydraulic jack arrangement is used to model the verti... Finite volumes of magma moving in confinement, store hydraulic potential energy for the generation, control and transmission of power. The Pascal’s principle in a hydraulic jack arrangement is used to model the vertical and lateral growth of sills. The small input piston of the hydraulic jack is equivalent to the feeder dike, the upper large expansible piston equivalent to the magmatic chamber and the inertial force of the magma in the dike is the input force. This arrangement is particularly relevant to the case of sills expanding with blunt tips, for which rapid fracture propagation is inhibited. Hydraulic models concur with experimental data that show that lateral expansion of magma into a sill is promoted when the vertical ascent of magma through a feeder dike reaches the bottom contact with an overlying, flat rigid-layer. At this point, the magma is forced to decelerate, triggering a pressure wave through the conduit caused by the continued ascent of magma further down (fluid-hammer effect). This pressure wave can provide overpressure enough to trigger the initial hydraulic lateral expansion of magma into an incipient sill, and still have enough input inertial force left to continue feeding the hydraulic system. The lateral expansion underneath the strong impeding layer, causes an area increase and thus, further hydraulic amplification of the input inertial force on the sides and roof of the incipient sill, triggering further expansion in a self-reinforcing process. Initially, the lateral pressure increase is larger than that in the roof allowing the sill to expand. However, expansion eventually increases the total integrated force on the roof allowing its uplift into either a laccolith, if the roof preserves continuity, or into a piston bounded by a circular set of fractures. Hydraulic models for shallow magmatic chambers, also suggest that laccolith-like intrusions require the existence of a self-supported chamber roof. In contrast, if the roof of magmatic chambers loses the self-supporting capacity, lop 展开更多
关键词 Pascal’s principle GEOLOGIC HYDRAULIC jack EMPLACEMENT SILLS growth Fluid HAMMER
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Hydrodynamics Analysis of Automatic Feeding and Forming System of Coating Layer 预览
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作者 张斌斌 杨涛 +2 位作者 李继良 丁凡 陈强 《东华大学学报:英文版》 EI CAS 2019年第3期277-283,共7页
The automatic forming device of the cladding layer of the solid rocket engine is a kind of equipment that can automatically complete the coating process of the coating layer.It is mainly composed of the feeding system... The automatic forming device of the cladding layer of the solid rocket engine is a kind of equipment that can automatically complete the coating process of the coating layer.It is mainly composed of the feeding system,the detection system and the automatic control system.The feeding system plays the role of providing the slurry in the coating process.In order to ensure the uniformity and stability of the feeding device,the automatic forming and feeding system of the coating is studied in this paper.The dynamic analysis of the slurry transportation process in the automatic coating system is carried out.In this paper,the feed cylinder is designed in theory.The feeding mode of the servo electric cylinder is adopted.Through the analysis of the hydrodynamic equations,the mixture model is chosen as the basis for the numerical simulation analysis.We use the SolidWorks software to create the geometric model of the feed cylinder.The dynamic analysis of the feed cylinder is carried out by Fluent software,and the convergent residual diagram and the fluid cloud chart are obtained.Fluent software is used for simulation analysis.The simulation results show that the distribution device has stable flow velocity and uniform slurry flow in the feeding process.The effect of scraping and coating process can be guaranteed by the feeding device,which provides a theoretical basis for actual production. 展开更多
关键词 scraping and coating feed feeding system fluid mechanics fluent simulation analysis
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Salinity effects on soil shrinkage characteristic curves of fine-grained geomaterials 预览
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作者 Partha Narayan Mishra Alexander Scheuermann +1 位作者 Thierry Bore Ling Li 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期181-191,共11页
Fine-grained clayey soils are prone to substantial volume changes during desiccation in response to the dynamics of their moisture regime,and are of critical importance in several geotechnical and geoenvironmental eng... Fine-grained clayey soils are prone to substantial volume changes during desiccation in response to the dynamics of their moisture regime,and are of critical importance in several geotechnical and geoenvironmental engineering applications.As such,the complex interactions between the fraction of soil solids and the ionic pore fluid play a critical role in governing such volume changes,and have been the focus in studies dealing with marine geotechnology,mine-tailing ponds,engineered barrier systems,etc.With this in mind,the present investigation evaluates the volume changes and accompanying densification from a saturated slurry state to a constant volume state of a reference fine-grained geomaterial,kaolin,subjected to evaporative dewatering.For this purpose,several parametric studies involving determination of soil shrinkage characteristic curves(SSCCs)of kaolin under the influence of varied salt constituents and concentrations of pore fluid are performed.Furthermore,a critical assessment of SSCCs depicting progressive shrinkage and volume change behaviour of geomaterials is provided,followed by the analysis of experimentally obtained SSCCs of the kaolin to explore the impacts of pore fluid salinity.Moreover,the SSCCs are parameterised with a predictive model and the fitting parameters are used to quantitatively demonstrate the salinity-dependent volume change response of a representative finegrained porous system. 展开更多
关键词 KAOLIN PORE fluid salinity Soil shrinkage CURVES PORE space dynamics GEOTECHNICAL engineering
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Effects of the number of particles and coordination number on viscous-flow agglomerate sintering
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作者 Mohammadmahdi Kamyabi Khashayar Saleh +1 位作者 Rahmat Sotudeh-Gharebagh Reza Zarghami 《中国颗粒学报:英文版》 SCIE EI CAS CSCD 2019年第2期76-83,共8页
The process of sinteri ng of several particles in con tact via a viscous flow mecha nism was studied numerically using computational fluid dynamics. The volume of fluid technique within a finite volume method was used... The process of sinteri ng of several particles in con tact via a viscous flow mecha nism was studied numerically using computational fluid dynamics. The volume of fluid technique within a finite volume method was used to simulate bridge formation between particles, as well as densification at different configurational states of the particles. The method was validated by comparing results for two-particle coalescence with the literature.The effect of the numberof particles on agglomerati on kin etics was studied by comparing bridge growth rate for systems having different numbers of particles in a chain. Although increasing the number of particles led to a decrease in the local bridge growth rate and to slower equilibration, there were no marked differences, when the overall volume of the system was considered. The effect of coordination number on the densification rate was directly studied by changing the number of particles in contact with a central particle.Increasing the coordination nurnbec caused the overall rate of densificatio n to in crease, but delayed equilibration, analogous to steric effects. These findi ngs describe the con figurational state of agglomerates, typical of mesoscale caking. In a multi-scale study, they can be used to characterize caking at a bulk scale to partly address the lack of experimental data in this field. 展开更多
关键词 CAKING AGGLOMERATION SINTERING VISCOUS flow mechanism Volume of fluid COORDINATION number
液体边界层对平板结构振动阻尼效应分析
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作者 李锦 胡奇 +1 位作者 李遇春 付小莉 《力学季刊》 CSCD 北大核心 2019年第2期283-292,共10页
本文分析了液体边界层对平板振动的阻尼效应,基于液体的Stokes边界层理论,建立了考虑液体边界层阻尼效应的平板振动单自由度系统运动方程,利用Laplace变换方法求解了运动方程,得到了平板结构的位移响应解答,制作了一个单自由度质量-弹... 本文分析了液体边界层对平板振动的阻尼效应,基于液体的Stokes边界层理论,建立了考虑液体边界层阻尼效应的平板振动单自由度系统运动方程,利用Laplace变换方法求解了运动方程,得到了平板结构的位移响应解答,制作了一个单自由度质量-弹簧系统来测量水体粘滞阻尼效应,并将理论与试验结果进行了对比分析,表明Stokes边界层理论能较好模拟水体的粘滞阻尼特性,边界层阻尼明显减小了结构的动力响应,本文最后讨论了所提的分析方法的适用范围. 展开更多
关键词 液体 边界层 平板振动 阻尼效应
Geological and geochemical characteristics of the Baogudi Carlintype gold district(Southwest Guizhou, China) and their geological implications
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作者 Songtao Li Yong Xia +9 位作者 Jianzhong Liu Zhuojun Xie Qinping Tan Yimeng Zhao Minghua Meng Lijin Tan Rong Nie Zepeng Wang Guanghong Zhou Haiyan Guo 《中国地球化学学报:英文版》 EI CAS CSCD 2019年第4期587-609,共23页
The newly discovered Baogudi gold district is located in the southwestern Guizhou Province,China,where there are numerous Carlin-type gold deposits.To better understand the geological and geochemical characteristics o... The newly discovered Baogudi gold district is located in the southwestern Guizhou Province,China,where there are numerous Carlin-type gold deposits.To better understand the geological and geochemical characteristics of the Baogudi gold district,we carried out petrographic observations,elemental analyses,and fluid inclusion and isotopic composition studies.We also compared the results with those of typical Carlin-type gold deposits in southwestern Guizhou.Three mineralization stages,namely,the sedimentation diagenesis,hydrothermal(main-ore and late-ore substages),and supergene stages,were identified based on field and petrographic observations.The main-ore and late-ore stages correspond to Au and Sb mineralization,respectively,which are similar to typical Carlin-type mineralization.The mass transfer associated with alteration and mineralization shows that a significant amount of Au,As,Sb,Hg,Tl,Mo,and S were added to mineralized rocks during the main-ore stage.Remarkably,arsenic,Sb,and S were added to the mineralized rocks during the late-ore stage.Element migration indicates that the sulfidation process was responsible for ore formation.Four types of fluid inclusions were identified in ore-related quartz and fluorite.The main-ore stage fluids are characterized by an H2O–NaCl–CO2–CH4±N2system,with medium to low temperatures(180–260℃)and low salinity(0–9.08%NaCl equivalent).The late-ore stage fluids featured H2O–NaCl±CO2±CH4,with low temperature(120–200℃)and low salinity(0–7.48%Na Cl equivalent).The temperature,salinity,and CO2and CH4concentrations of ore-forming fluids decreased from the main-ore stage to the late-ore stage.The calculated δ^13C,d D,and δ^18O values of the ore-forming fluids range from-14.3 to-7.0%,-76 to-55.7%,and 4.5–15.0%,respectively.Late-ore-stage stibnite had δ^34S values ranging from-0.6 to 1.9%.These stable isotopic compositions indicate that the ore-forming fluids originated mainly from deep magmatic hydrothermal fluids,with minor contributions from strata.Collec 展开更多
关键词 ELEMENTAL geochemistry Fluid inclusions Stable isotopes CARLIN-TYPE GOLD deposits Baogudi GOLD DISTRICT SOUTHWESTERN GUIZHOU
CFD predictions for hazardous area classification
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作者 Andrey Oliveira de Souza Aurelio Moreira Luiz +4 位作者 Antonio Ta ver nard Pereira Neto Antonio Carlos Brandao de Araujo Heleno Bispo da Silva Sidinei Kebler da Silva Jose Jailson Nicacio Alves 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第1期21-31,共11页
This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANSYS CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugi... This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANSYS CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugitive emissions of flammable gases.The multidimensional statistical sampling technique Latin Hypercube was used, which defined 100 simulations of random methane gas leak conditions.The CFD model proved to be robust in predicting the extension and volume of the explosive atmosphere for orifice diameters from 0.1 to2.5 mm, pressure from 0.1 MPa to 12 MPa and temperatures from 0 ℃ to 400 ℃.It was found that the calculation domain must be parameterized 8 m in length for each millimeter of the diameter of the source of release to ensure the predictions.In order not to lose precision for very small diameters, the mesh was parameterized with 50 elements along the orifice diameter.It was proved that gravity does not influence the extension and volume of the explosive atmosphere at sonic emissions.The deviation from the ideal gas behavior in the reservoir,achieved by applying the Soave–Redlich–Kwong equation of state, also has not significantly influenced the extension and volume of the explosive atmosphere.The results showed that the size of the explosive atmosphere varies directly with the diameter of the source emission and reservoir pressure, and inversely with the temperature of the reservoir.The diameter of the source is the parameter that has the major effect on the extension of the explosive atmosphere, followed by the pressure and lastly the temperature of the reservoir. 展开更多
关键词 COMPUTATIONAL FLUID DYNAMICS COMPUTER simulation Safety Fugitive EMISSIONS Classified area Flammable gas CLOUD
Synthesis of the fluid machinery network in a circulating water system
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作者 Wei Gao Xiao Feng 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第3期587-597,共11页
Energy consumption of the fluid machinery network in a circulating water system takes up a large part of energy consumption in the process industry,so optimization on the network will enhance the economic and environm... Energy consumption of the fluid machinery network in a circulating water system takes up a large part of energy consumption in the process industry,so optimization on the network will enhance the economic and environmental performance of the industry.In this paper,a synthesis approach is proposed to obtain the optimal network structure.The effective height curves are used as tools to perform energy analysis,so that the potential placement of water turbines and auxiliary pumps can be determined with energy benefit.Then economic optimization is carried out,by the mathematical model with the total cost as the objective function,to identify the branches for water turbines and auxiliary pumps with economic benefit.In this way,the optimal fluid machinery network structure can be obtained.The results of case study indicate that the proposed synthesis approach to optimize the fluid machinery network will obtain more remarkable benefits on economy,compared to optimizing only the water turbine network or pump network.The results under different flowrates of circulating water reveal that using a water turbine to recover power or adding an auxiliary pump to save energy in branches are only suitable to the flowrate in a certain range. 展开更多
关键词 FLUID MACHINERY NETWORK SYNTHESIS approach Flowrate RANGE NETWORK STRUCTURE
船用钢/复合材料组合系统的内损耗组成分析 预览
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作者 唐宇航 梅志远 陈志坚 《振动.测试与诊断》 EI CSCD 北大核心 2019年第1期15-24,218共11页
利用阻尼性能优越的复合材料进行潜艇减振降噪设计已比较普遍,钢/复合材料板壳组合系统结构作为典型的施工单元件形式,其阻尼性能密切关系到结构在共振区的响应。从黏弹性阻尼理论出发,描述了阻尼耗散机理,基于统计能量的角度对系统内... 利用阻尼性能优越的复合材料进行潜艇减振降噪设计已比较普遍,钢/复合材料板壳组合系统结构作为典型的施工单元件形式,其阻尼性能密切关系到结构在共振区的响应。从黏弹性阻尼理论出发,描述了阻尼耗散机理,基于统计能量的角度对系统内损耗因子组成进行了论述,指出多种材料组合下系统的结构损耗与材料组成、振型相关,声辐射损耗受流体介质、壳板性质等影响较大。进一步完成了钢板、玻纤增强树脂壳板在4种工况下的内损耗因子测试,结合数值计算,总结了试验模型的损耗因子组成规律,并预报了其边界损耗因子。结果表明:相同结构型式及边界条件下,空气中的声辐射损耗仅为水中的1/40左右;在非刚性连接形式下,边界损耗对系统的内损耗因子贡献较大,对于钢板模型,该连接形式与自由边界相比所表征出的总体阻尼性能相差几十倍。 展开更多
关键词 内损耗因子 边界损耗 钢结构 复合材料壳板 流体 阻尼
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Three-dimensional VOF simulation of droplet impacting on a superhydrophobic surface 预览
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作者 Jin Sun Qi Liu +2 位作者 Yunhong Liang Zhaohua Lin Chunbao Liu 《生物设计与制作(英文)》 CSCD 2019年第1期10-23,共14页
It is very important to analyze and study the motion process of droplets impacting superhydrophobic surface, which is of great significanee to understand the mechanism of superhydrophobic surface and guide the design ... It is very important to analyze and study the motion process of droplets impacting superhydrophobic surface, which is of great significanee to understand the mechanism of superhydrophobic surface and guide the design and manufacture of superhydrophobic surface. Taking by three-dimensional volume of fluid (VOF) simulation coupling coupled level set (CLS) algorithm, on the one hand, we simulate the morphological changes in the process of droplet impingement, as well as the internal velocity and the pressure distribution;on the other hand,we focus on the effects of droplet impact velocity, surface wettability, surface tension on the dynamics of the droplets. The CLSVOF model inherits the advantages of the VOF model for accurately constructing the phase interface and inherits the advantage that the level set can accurately calculate the surface tension, which improves the accuracy of the calculation of the droplet impact on the superhydrophobic surface. The computed results distinctly demonstrated there were four stages: falling, spreading, shrinking and rebounding. The time history of each stage agreed well with the pictures captured by high-speed camera, which indicated the computational fluid dynamics scheme was effective. Moreover, the motion mechanism of the droplets impacting on the solid surface is elaborated, which was helpful to control the solid-liquid interface to achieve a variety of solid interface characteristics. 展开更多
关键词 SUPERHYDROPHOBIC DROPLET impact COMPUTATIONAL FLUID dynamic VOF
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