期刊文献+
共找到27篇文章
< 1 2 >
每页显示 20 50 100
星巴克:谁人背后不说人
1
作者 郄婉琳 《课堂内外(高中版)(A版)》 2018年第1期48-49,共2页
有时候,觉得生活像一座围城,找不到一个忙碌的理由。人们来来往往、寻寻觅觅,他们想找到一个独立于家庭和工作之外的第三空间,慰藉心灵,享受人生。于是,就有了星巴克。都市中的世外桃源古朴的装修配以精致的灯饰,蓝色为水,褐色为咖啡的... 有时候,觉得生活像一座围城,找不到一个忙碌的理由。人们来来往往、寻寻觅觅,他们想找到一个独立于家庭和工作之外的第三空间,慰藉心灵,享受人生。于是,就有了星巴克。都市中的世外桃源古朴的装修配以精致的灯饰,蓝色为水,褐色为咖啡的“滤泡”,白色、淡黄色和绿色相得益彰,扑鼻而来浓郁的醇香,是咖啡特有的浪漫。角落里,柔软的沙发旁安静地堆着几本旧书。阳光洒了进来,飘浮在空气中的,是美国爵士乐曲。这份浪漫与安逸,让忙碌的人们不禁停下脚步。星巴克,成为了一个隐匿于都市中的世外桃源。它诞生于西雅图,以咖啡豆起家。 展开更多
关键词 巴克 咖啡豆 围城 舒尔 滤泡 沙发 地堆 第三空间 西雅图 少年心
下载PDF
Analysis of α-amylase Inhibitor Content Change in Pu-erh Tea During Pile-fermentation Process 被引量:9
2
作者 张冬英 黄业伟 +1 位作者 袁文侠 周红杰 《Agricultural Science & Technology》 CAS 2009年第2期142-144,共3页
The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous Count... The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous County of Yunnan Province at various fermentation stages were used as experimental materials to investigate the effect of different fermentation stages on the inhibitory effect to α-amylase; and the change law of the inhibitory effect of c-amylase inhibitor during processing was meanwhile studied by determining the contents of tea polyphenol and amino acid. The results showed that crude meterial of Pu-erh tea presented strong inhibitory effect to α-amylase; this inhibitory effect assumed a de: creasing trend to the minimum at the middle stage of fermentation, whereafter it increased to some extent. Made tea also showed a strong inhibitory effect to α-amylase. During whole processing period, contents of tea polyphenol and amino acid generally assumed a remarkably decreasing trend. Our results provided references for further isolating co-amylase inhibitor from Pu-erh tea and discussing the mechanism of its health care function. 展开更多
关键词 Pu-erh tea PROCESSING α-amylase inhibitor
下载PDF
The Cemented Material Dam: A New, Environmentally Friendly Type of Dam 被引量:24
3
作者 Jinsheng Jia Michel Lino +1 位作者 Feng Jin Cuiying Zheng 《Engineering》 SCIE EI 2016年第4期490-497,共8页
The first author proposed the concept of the cemented material dam (CMD) in 2009. This concept was aimed at building an environmentally friendly dam in a safer and more economical way for both the dam and the area d... The first author proposed the concept of the cemented material dam (CMD) in 2009. This concept was aimed at building an environmentally friendly dam in a safer and more economical way for both the dam and the area downstream. The concept covers the cemented sand, gravel, and rock dam (CSGRD), the rockfill concrete (RFC) dam (or the cemented rockfill dam, CRD), and the cemented soil dam (CSD). This paper summarizes the concept and principles of the CMD based on studies and practices in projects around the world. It also introduces new developments in the CSGRD, CRD, and CSD. 展开更多
关键词 Cemented material dam Cemented sand gravel and rock dam Rockfill concrete dam Cemented rockfill dam Cemented soil dam Material properties
下载PDF
Base-Level Cycles and Episodic Coal Accumulation——Case Study of Dongsheng Coalfield in Ordos Basin 被引量:6
4
作者 YANG Ren-chao HAN Zuo-zhen +1 位作者 LI Zeng-xue FAN Ai-ping 《Journal of China University of Mining and Technology》 2006年第4期439-442,共4页
The advantage of high-resolution sequence stratigraphy, which takes base-levels as reference, is that it can be applied to continental depositional basins controlled by multiple factors and can effectively improve the... The advantage of high-resolution sequence stratigraphy, which takes base-levels as reference, is that it can be applied to continental depositional basins controlled by multiple factors and can effectively improve the accuracy and resolution of sequential stratigraphic analysis. Moreover, the principles of base-level cycles are also suitable for analyzing sequential stratigraphy in continental coal-bearing basins because of their accuracy in forecasting distribution of coal measures. By taking the Dongsheng coalfield in the Ordos basin as an example, the extensive application of base-level cycles in exploration and exploitation of coal is analyzed. The result shows that the Yan’an formation in the Dongsheng area is a long-term base-level cycle which is bordered by nonconformities and made up of five mid-term cycles and 13 short-term cycles. The long-term cycle and the mid-term cycles are obvious in comparison with a transverse profile. The episodic coal accumulation in the Mesozoic Ordos basin means that the deposition of primary matter (peat bogs) of coalification is discontinuous, periodical and cyclical in the evolution of the basin. The episodic accumulation of coal measures in the Yan’an stage is controlled by ascending-descending changes of a long-term cycle and middle-term cycles. Coal measures formed during the early and late periods of the long-term cycle are characterized by multiple layers, big cumulative thickness and poor continuity. Coal measures formed in the mid-term of the long cycle are dominated by good continuity, fewer layers and a small additive thickness, which is favorable for the accumulation of thick and continuous coal measures in the transition stage of mid term base-level cycles. 展开更多
关键词 Ordos basin Dongsheng coalfield base-level cycle sequential stratigraphy episodic coal accumulation
下载PDF
MULTI-ARC BASIN SYSTEM OF THE KUNLUN OROGENIC BELT AND PAN-CATHYSIAN CONTINENTAL ACCRETION 被引量:1
5
作者 YIN Fuguang, PAN Guitang and LI Xingzhen(Chengdu Institute of Geology and Mineral Resources, Chengdu, SC610081, China) 《Geotectonica et Metallogenia》 2003年第1期145-155,共11页
After Rodinia supercontinent was disintegrated in Late Proterozoic, an ocean, namely, Tethys Ocean, occurred between Gondwana continental group and Pan-Cathaysian continental group from Late Proterozoic to Mesozoic. F... After Rodinia supercontinent was disintegrated in Late Proterozoic, an ocean, namely, Tethys Ocean, occurred between Gondwana continental group and Pan-Cathaysian continental group from Late Proterozoic to Mesozoic. From Early Paleozoic to Mesozoic, Tethys Ocean was subducted toward Pan-Cathaysian block group, which results in backarc expansion, arc-land collision and forearc accretion. When the backarc basin expands and reaches the small oceanic basin, ophiolite melange will be generated. As accretion had already occurred in the south of the continental margin in the earlier stage, the succeeding backarc expansion and the frontal arc position were migrated toward south correspondingly. Therefore, multiple ophiolite belts and magmatic rock belts occurred, and show a trend of decreasing age from north toward south. As the continental margin was split and migrated toward south and reached a high latitude position, i.e., with the shortening and subduction of oceanic crust, the sedimentary bodies at high latitude was accreted continuously toward low latitude area together with the formation of oceanic island, mixing of cold-type and warm-type organism was generated. Moreover,blocks split and separated from Pan-Cathaysian or Gondwana continental group cannot traverse the oceanic median ridge and joins with another continental block. As a result, the Kunlun belt on the SW margin of the Pan-Cathaysian land was resulted from the multi-arc orogenesis such as the backarc seabed expansion, arc-arc collision, arc-land collision oceanic bed, and the continuous southward accretion process. 展开更多
关键词 multi-arc basin system Kunlun orogenic belt Pan-Cathaysian land continental accretion
下载PDF
Accumulation and Mixing of Oils in Jinghu Sag of Subei Basin:Constraints from Thermal Maturity Parameters 被引量:1
6
作者 HAN Zuo-zhen CHANG Xiang-chun +1 位作者 GUO Hai-hua PANG Ling-yun 《Journal of China University of Mining and Technology》 EI 2007年第1期53-57,共5页
Oils in Jinghu sag are abundant with high content of polar compounds and have a low ratio of saturate to aromatic hydrocarbons and a high ratio of resin to asphaltene. The gross composition of oils in the Jinghu sag s... Oils in Jinghu sag are abundant with high content of polar compounds and have a low ratio of saturate to aromatic hydrocarbons and a high ratio of resin to asphaltene. The gross composition of oils in the Jinghu sag suggests typical immature to low mature characteristics. Some compounds with low thermal stability were identified. Light hydrocarbons, a carbon preference index, an odd even index, n-alkane and hopane maturity parameters show mature features and little differences in the maturity level among oils. Sterane isomerization parameters indicate an immature to low mature status of oil. Transfer of the sedimentary center during sedimentation has led to different thermal histories among subsags and thus generated oils with different maturities. On the basis of source analyses, four migration and accumulation patterns with different maturity can be classified. Combined with available information on mergers of source, reservoir and long distance oil lateral migration, mixing conditions were present in the Jinghu sag. Experimental results indicate that maturity variations are caused by mixtures of hydrocarbons with different maturity. 展开更多
关键词 mixed oil MATURITY oil/source correlation BIOMARKER GEOCHEMISTRY
下载PDF
Experimental Study of Preferential Solute Transportation During Dump Leaching 被引量:2
7
作者 YIN Sheng-hua WU Ai-xiang 《Journal of China University of Mining and Technology》 EI 2006年第4期416-420,共5页
The production of dump leaching of the Dexing Copper Mine was affected by a preferential solution flow. Formative mechanism of the preferential solution flow was investigated by analyzing the relationship between both... The production of dump leaching of the Dexing Copper Mine was affected by a preferential solution flow. Formative mechanism of the preferential solution flow was investigated by analyzing the relationship between both dump permeability and surface tension and ore diameter. The preferential solution flow occured in the fine ore area when the application rate was low. The preferential solution flow entered into the coarse ore area because the negative pore water pressure disappeared with an increase of the application rate. The preferential solute transportation experiment was conducted by selecting NaCl as mineral. Results of the experiment showed that the concentration of the outflow solution reduced over time. The concentration of the coarse ore area outflow solution was greater than that of the fine ore area. The process of NaCl leaching can be divided into two stages. NaCl was carried out directly by diffusion--convection during the first stage, so the leaching rate increased sharply. But in the second stage, only a small amount of NaCl dissolved in the immobile water. The leaching rate increased slowly because NaC1, dissolved in the immobile water, can only be leached by diffusion. 展开更多
关键词 dump leaching preferential solution flow SOLUTE preferential transportation application rate leaching rate
下载PDF
Observed deformation characteristics of a deep excavation for the spring area in Jinan,China 被引量:1
8
作者 ZHANG Ding-wen SHU Ji-cheng SUN Jian-ping 《Journal of Mountain Science》 SCIE CSCD 2017年第3期581-594,共14页
The observed deflections and internal forces of pile-anchor retaining excavation were studied in spring area in Jinan city of China. Based on field measured data, the ground surface settlement, deflection of retaining... The observed deflections and internal forces of pile-anchor retaining excavation were studied in spring area in Jinan city of China. Based on field measured data, the ground surface settlement, deflection of retaining piles and wall, internal force analysis of concrete piles, axial anchoring forces, groundwater table, and the deformation of surround building and pipelines were investigated. The results indicates that the combining application of concrete piles, jet grouting columns and anchors support system can effectively control excavation-induced surface ground settlements. The field maximum lateral wall deflections are between 0.o2% and o.19% of the excavation depth due to the competitive site conditions. The bending moment-depth relationship curve is S-type. Groundwater leakage results in the sharp drop in groundwater level, which is part of the reasons for the adjacent building settlement. The axial anchoring forces of the upper layer of anchors increase gradually during the excavation, but those of the lower layer of anchors slightly reduced firstly and then tend to be stable during the excavation procedure. In comparison with the histories of excavation cases, the small lateral wall deflection in this study results from the favorable site condition and the relative rigidity of the retaining structure system. 展开更多
关键词 Spring area EXCAVATION Pile anchor system Ground settlement Horizontal displacement
下载PDF
DEEP TECTONOTHERMAL MECHANISM FOR THE TECTONIC EXTENSION OF THE EASTERN ASIAN CONTINENTAL MARGIN
9
作者 ZHANG Jian and SHI Yaolin(Laboratory of Computational Geodynamics, Graduate School of the Chinese Academy of Sciences,Beijing 100039, China) 《Geotectonica et Metallogenia》 2003年第1期156-164,共9页
The continental marginal extension concept developed by Chinese geologists recently may be applied to the explanation about the Cenozoic extension and divergent movement of the Eastern Asian continental margin. From t... The continental marginal extension concept developed by Chinese geologists recently may be applied to the explanation about the Cenozoic extension and divergent movement of the Eastern Asian continental margin. From the viewpoint of continental marginal extension, this paper discusses the deep tectonothermal mechanism of the tectonic extension of the Eastern Asian continental margin.The Eastern Asian continental margin is an extensional belt with intensive magmatism and structural deformation, geophysically characterized by continual earthquakes and obvious geothermal anomaly.Seismic tomographical results about the Eastern Asian continental margin imply that the Pacific Plate is subducted toward the Eurasian Plate at a low angle and the diving Pacific Plate lies on the surface of the 670-km phase transitional zone. We interpret this feature to be resulted from retrogressive subduction followed by continental marginal extension. Our thermal modeling and geodynamical computation results suggest that the retrogressive subduction occurred at about 76Ma and the withdrawal of the trench served to supply the volume for the continental growth, which led to the formation of the growing front of the Eastern Asian continental margin. The growth width of the Eastern Asian continental margin is about 700 km. 展开更多
关键词 the Eastern Asian continental margin tectonothermal modeling retrogressive subduction continental marginal growth
下载PDF
Field observations of debris-flow initiation processes on sediment deposits in a previous deep-seated landslide site 被引量:4
10
作者 Fumitoshi IMAIZUMI Satoshi TSUCHIYA Okihiro OHSAKA 《Journal of Mountain Science》 SCIE CSCD 2016年第2期213-222,共10页
Although information regarding the initiation processes of debris flows is important for the development of mitigation measures,field data regarding these processes are scarce.We conducted field observations of debris... Although information regarding the initiation processes of debris flows is important for the development of mitigation measures,field data regarding these processes are scarce.We conducted field observations of debris-flow initiation processes in the upper Ichinosawa catchment of the Ohya landslide,central Japan.On 19 June 2012,our videocamera monitoring systems recorded the moment of debris-flow initiation on channel deposits(nine surges) and talus slopes(eight surges).The initiation mechanisms of these surges were classified into three types by analyzing the video images: erosion by the surface flow,movement of deposits as a mass,and upward development of the fluid area.The first type was associated with the progress of surface flow from the upper stream on unsaturated channel deposits.The second type was likely caused by an increase in the pore water pressure associated with the rising in the groundwater level in channel deposits;a continuous water supply from the upper stream by the surface flow might have induced this saturation.The third type was associated with changes in the downstream topography caused by erosion.The flow velocity of most surges was less than 3 m s^(-1) and they usually stopped within 100 m from the initiation point.Surges with abundant pore fluid had a higher flow velocity(about 3- 5 m s^(-1)) and could travel for alonger duration.Our observations indicate that the surface flow plays an important role in the initiation of debris flows on channel deposits and talus slopes. 展开更多
关键词 Debris flow Initiation zone Field monitoring Ohya landslide
下载PDF
Seismic hazard mitigation for nuclear power plant
11
作者 Frieder Seible 《Engineering Sciences》 EI 2013年第3期2-9,共8页
The seismic safety of nuclear power plan(tNPP)has always been a major consideration in the site selection,design,operation,and more recently recertification of existing installations. In addition to the actual NPP and... The seismic safety of nuclear power plan(tNPP)has always been a major consideration in the site selection,design,operation,and more recently recertification of existing installations. In addition to the actual NPP and all their operational and safety related support systems,the storage of spent fuel in temporary or permanent storage facilities also poses a seismic risk. This seismic risk is typically assessed with state-of-the-art modeling and analytical tools that capture everything from the ground rupture or source of the earthquake to the site specific ground shaking,taking geotechnical parameters and soilfoundationstructureinteraction (SFSI) into account to the non-linear structural response of the reactor core,the containment structure,the core cooling system and the emergency cooling system(s),to support systems,piping systems and non-structural components,and finally the performance of spent fuel storage in the probabilistically determined operational basis earthquake (OBE) or the safe shutdown earthquake (SSE) scenario. The best and most meaningful validation and verification of these advanced analytical tools is in the form of full or very large scale experimental testing,designed and conducted in direct support of model and analysis tool calibration. This paper outlines the principles under which such calibration testing should be conducted and illustrates with examples the kind of testing and parameter evaluation required. 展开更多
关键词 seismic design seismic safety probabilistic hazard large scale testing full scale testing
下载PDF
Initial Experimental Result of Accurately Controlled Routinely Operated Signal System (ACROSS)
12
作者 LiaoChengwang ZhuangCantao LiangHongsen 《Earthquake Research in China》 2003年第3期265-273,共9页
The principle of Accurately Controlled Routinely Operated Signal System (ACROSS) is introduced in this paper. A sample machine is made and tested. The experiment shows that the signal stacking technique is effective i... The principle of Accurately Controlled Routinely Operated Signal System (ACROSS) is introduced in this paper. A sample machine is made and tested. The experiment shows that the signal stacking technique is effective in improving signal to noise ratio and the sompi cepstrum method is applicable to deconvolute a set of travel times of wave elements from accurate transfer function data in frequency domain. 展开更多
关键词 ACROSS Signal stacking technique Sompi cepstrum method
下载PDF
A Computer Model for Selecting Equipment in Earth-Fill Dam Projects
13
作者 Hamed Nabizadeh Rafsanjani 《Journal of Civil Engineering and Architecture》 2011年第5期465-470,共6页
Selecting right equipment has been playing an important role in the success of construction projects. This paper presents a computer model, ESCMODEL, for equipment selection in Earth-fill dam projects. The proposed mo... Selecting right equipment has been playing an important role in the success of construction projects. This paper presents a computer model, ESCMODEL, for equipment selection in Earth-fill dam projects. The proposed model is capable of assisting the users in making decisions to determine the size, number, type and schedule of presence of dozers, loaders, graders, excavators, trucks, sheepsfoot rollers and smooth wheel rollers. ESCMODEL can contribute to resolve this selection process through the application of an optimization technique, based on nonlinear programming. Three actual case studies of earth-fill dam projects are presented in order to illustrate the effectiveness and performance of the model. 展开更多
关键词 Construction equipment equipment selection optimization technique nonlinear programming earth-fill dam projects
下载PDF
INFLUENCE OF UNCERTAINTY OF ROCK PROPERTIES ON SEISMIC RESPONSES OF REACTOR BUILDINGS
14
作者 李忠诚 李忠献 《Transactions of Tianjin University》 EI CAS 2006年第1期50-55,共6页
The influence of the dispersion and uncertainty of the dynamic shear wave velocity and Poisson's ratio of soil in a hard rock site was investigated on the seismic response of reactor building structure. The analysis ... The influence of the dispersion and uncertainty of the dynamic shear wave velocity and Poisson's ratio of soil in a hard rock site was investigated on the seismic response of reactor building structure. The analysis is performed by considering the soil-structure interaction effects and based on the model of the reactor building in a typical pressurized water reactor nuclear power plant (NPP). The numerical results show that for the typical floor selected, while the relative increment ratio of the dynamic shear wave velocity varies from -30% to 30% compared to the basis of 1 930 m/s, the relative variation of the horizontal response spectra peak value lies in the scope of ±10% for the internal structure, and the relative variation of the frequency corresponding to the spectra peak is 0.0% in most cases. The relative variation of the vertical response spectra peak value lies in the scope of - 10% to 22%, and the relative variation of the frequency corresponding to the Spectra peak lies in the scope of - 22% to 4%. The analysis indicates that the dynamic shear wave velocity and the Poisson's ratio of the rock would affect the seismic response of structure and the soil-structure interaction effects should be considered in seismic analysis and design of NPP even for a hard rock site. 展开更多
关键词 reactor building seismic response floor response spectra dynamic shear wave velocity Poisson's ratio sensitivity analysis
下载PDF
Debris Flow Formation Process and Critical Hydrodynamic Conditions in the Meizoseismal Area of the Wenchuan Earthquake 被引量:5
15
作者 WANG Jun YU Yan +2 位作者 PAN Hua-li QIAO Cheng OU Guo-qiang 《Journal of Mountain Science》 SCIE CSCD 2015年第3期699-710,共12页
Abstract: The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics... Abstract: The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics. This paper was to propose a debris flow formation process and explore the permeability characteristics and critical hydrodynamic conditions of the loose deposits triggered by the earthquake. The Guo Juanyan gully (31005'27" N to 31005'46" N, 103036'58" E to 103037'09" E) in Du Jiangyan City, located in the meizoseismal areas of the Wenchuan earthquake, was chosen as the study area and the disaster-prone environment was analyzed. The formation process of the debris flow was first proposed using a stability analysis, and then, the permeability characteristics of loose deposits were determined via in situ permeability experiments. Finally, the critical 1 h rainfall was simulated through a distributed hydrological model and verified by field observations. The formation process of debris flow could be divided into three stages based on the relationship between the hydrodynamic force and loose deposit resistance. The critical 1 h rainfall amounts under three antecedent moisture conditions (I-dry, Ⅱ-normal and Ⅲ-wet) were 52 mm/h, 43 mm/h and 34 mm/h, respectively. This study proposed a debris flow formation process in the meizoseismal areas of the Wenchuan earthquake based on the stability analysis and defined the rainfall threshold for debris flow early warning at the local level, which is significant for debris flow mitigation and risk management. 展开更多
关键词 Wenchuan Earthquake Debris flow Disaster-prone environment Permeabilitycharacteristics Hydrodynamic condition
下载PDF
The Reasons of Rupture Reactor Cooling Systems as a Result of Earthquake
16
作者 Konstantin Proskuryakov 《Journal of Energy and Power Engineering》 2013年第7期1238-1243,共6页
Destructions at Fukushima Daiichi NPP (nuclear power plant) caused by earthquake have shown that design level of seismic influences on the equipment has been exceeded. The accident demonstrated the need for stricter... Destructions at Fukushima Daiichi NPP (nuclear power plant) caused by earthquake have shown that design level of seismic influences on the equipment has been exceeded. The accident demonstrated the need for stricter regulations to ensure the seismic resistance of NPP and the need to develop and implement additional anti-seismic procedures in the course of their operation. To proof seismic reliability of NPP systems and components must be made special studies of logarithmic decrement of systems NPP and components. The correct definition of coolant thermodynamics parameters and acoustic parameters are necessary to evaluate logarithmic decrement of coolant systems NPP and their components and consequently for providing of NPP seismic reliability. The proof of presence of a gas phase in the coolant inside reactor is of great importance for practice because of its influence on coolant acoustical parameters and consequently on range of frequency of seismic-acoustical resonance type interaction. Results are obtained by using of known methods in oscillation theory, general acoustics, thermodynamic, electro-mechanical analogies. As well as using experimental data obtained from the vibration dynamical controls reactor WWER-1000. 展开更多
关键词 Quality factor COOLANT acoustic resonance SEISMIC logarithmic decrement.
下载PDF
The Length-weight Relationship of Diplodus vulgaris / (Teleostei, Sparidae) from Benghazi Coast (Libya)
17
作者 Abdalla Nassir Elawad Anwaar M. Saeid Ramadan A. S. Ali 《Journal of Life Sciences》 2016年第2期59-65,共7页
Length-weight relationships (LWRs) were determined for fish species Diplodus vulgaris from the Benghazi coast along the eastern Mediterranean Sea coast of Libya. Samples were collected using trammel nets. The parame... Length-weight relationships (LWRs) were determined for fish species Diplodus vulgaris from the Benghazi coast along the eastern Mediterranean Sea coast of Libya. Samples were collected using trammel nets. The parameters a and b from the LWR formula W = aLb were estimated. The values of the exponent b of the length-weight relationships in all categories range between 2.295 in September to 3.208 in August. The total number of fish samples investigated were 290, from which 179 were males, 41 females and 70 fishes immature. The sex ratio male to female were 4.3:1. In January, August and Females the slope "b" close to equal 3, were the categories exhibited isometric relationship, in September, October and November were slope "b" not equal 3, which the categories exhibited negative allometric relationship. The mean observed length of male was 18.29 cm at mean observed weight 114.8 g, and mean observed length of female was 19.15 cm at mean observed weight 133.97 g.The general equation for the length-weight relationship for both sex was: W = 0.03835L277, for male was: W = 0.036 L274, for female, W = 0.016 L302. 展开更多
关键词 Diplodus vulgaris ALLOMETRIC ismeteric Benghazi coast sex ratio.
下载PDF
Comparative analysis of seismic response characteristics of pile-supported structure
18
作者 孔德森 李纯洁 +1 位作者 张伟伟 孟庆辉 《Journal of Central South University》 SCIE EI CAS 2010年第6期1370-1375,共6页
In order to analyze the seismic response characteristics of pile-supported structure,a computational model considering pile-soil-structure interaction effect was established by finite element method.Then,numerical imp... In order to analyze the seismic response characteristics of pile-supported structure,a computational model considering pile-soil-structure interaction effect was established by finite element method.Then,numerical implementation was made in time domain.At the same time,a simplified approximation for seismic response analysis of pile-soil-structure system was briefly presented.Furthermore,comparative study was performed for an engineering example.Through comparative analysis,it is shown that the results obtained by the simplified method well agree with those achieved by the finite element method.These results show that spectrum characteristics and intensity of input earthquakes are two important factors that can notablely influence the seismic response characteristics of superstructure.When the input ground motion acceleration amplitude gradually increases from 1 to 4 m/s2,the acceleration of pier top will increase,but it will not be simply proportional to the increase of input acceleration amplitude. 展开更多
关键词 pile-supported structure pile-soil interaction seismic response spectrum characteristics finite element method
下载PDF
Volume and Toxic Composition of Leachate from an Open Dump
19
作者 O. Buenrostro R. Alfaro +1 位作者 I. Israde L. Marquez 《Journal of Environmental Science and Engineering》 2011年第9期1131-1140,共10页
In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective... In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective of the present study was to evaluate the impact of leachate from a dump on surface water systems. Physical, chemical, and bacteriological characteristics and the volume of leachate were measured. The site of study is located in Zinaprcuaro, Michoac^m, Mexico, and was chosen due to the water supplies were in line with the dump, thus conforming a system to test for movement of toxins. Leachate and water from three ponds located at different distances to the dump were sampled during three months of a year to measure physicochemical and bacteriological parameters, according to the standard methods of the American Public Health Association; the concentration of heavy metals was measured by atomic absorption spectrometry. Most characteristics exceed the maximum permissible limits established for the Mexican legislation regarding wastewater discharges and drinking water. Likewise, analysis of variance showed statistically significant differences between concentrations of pollutants in relation to the distance from the dump of sampled sites and with season of sampling, thus confirming the contamination of water by dump leachate. 展开更多
关键词 Toxic composition LEACHATE solid waste open dump
下载PDF
Study of Space Reactors for Exploration Missions
20
作者 Elisa Cloquet Jean-Marc Ruault +5 位作者 Frederic Masson Jean-Pierre Roux Nicolas Paris Brice Cazale Laurent Manifacier Christine Poinot-Salanon 《Journal of Energy and Power Engineering》 2014年第8期1393-1408,共16页
Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for fl... Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for flexible manned missions to Mars requiring several megawatts, nuclear electric propulsion might be the only option offering a reasonable mass in low earth orbit. Despite the existence of low power experiences--SNAP10 in the 60's or Buk/Topaz in the 60-80's--no high power reactor has been developed: investment cost, long term timeframe, high technological challenges and radioactive hazards are the main challenges we must overtake. However, it seems reasonable to look at the technical challenges that have to be overcome for a next generation of nuclear electric systems for space exploration. This paper will present some recent studies going on in France, on space reactors for exploration. Three classes of power have been considered: 10 kWe, 100 kWe, and several megawatts. Available data from previous studies and developments performed in Russia, USA, and Europe have been collected and gave us a large overview of potential technical solutions. This was the starting point of a trade-off analysis aiming at the selection of the best options, with regards to the technological readiness level in France and Europe. The resulting preliminary designs will be presented and critical technologies needing maturation activities will be highlighted. 展开更多
关键词 Spatial nuclear reactor nuclear energy nuclear propulsion
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部