期刊文献+
共找到1,785篇文章
< 1 2 90 >
每页显示 20 50 100
Prediction of Concrete Faced Rock Fill Dams Settlements Using Genetic Programming Algorithm 被引量:3
1
作者 Seyed Morteza Marandi Seyed Mahmood VaeziNejad Elyas Khavari 《International Journal of Geosciences》 2012年第3期601-609,共9页
In the present study a Genetic Programing model (GP) proposed for the prediction of relative crest settlement of concrete faced rock fill dams. To this end information of 30 large dams constructed in seven countries a... In the present study a Genetic Programing model (GP) proposed for the prediction of relative crest settlement of concrete faced rock fill dams. To this end information of 30 large dams constructed in seven countries across the world is gathered with their reported settlements. The results showed that the GP model is able to estimate the dam settlement properly based on four properties, void ratio of dam’s body (e), height (H), vertical deformation modulus (Ev) and shape factor (Sc) of the dam. For verification of the model applicability, obtained results compared with other research methods such as Clements’s formula and the finite element model. The comparison showed that in all cases the GP model led to be more accurate than those of performed in literature. Also a proper compatibility between the GP model and the finite element model was perceived. 展开更多
关键词 CONCRETE faced Rock-Fill DAMS SETTLEMENT Genetic Programming ALGORITHM Finite Element Model
暂未订购
Black fungus derived aerogel with double faced properties 被引量:1
2
作者 Bixing Fang Lina Dong +8 位作者 Xingwei Ding YingZi Ren Zhongsheng Lv Kuan Liu Feng Zhang Wei Zhang Jianjian Deng Hongbo Xin Xiaolei Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第6期1178-1181,共4页
Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbabil... Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects: water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment. 展开更多
关键词 AEROGELS DOUBLE faced PROPERTIES Liquid selective absorption Air and water pollution treatment Antibacterial
原文传递
FACED评分评估慢性阻塞性肺疾病合并支气管扩张患者急性加重期的作用 被引量:2
3
作者 张灿辉 彭志文 +2 位作者 吴建辉 王陈金 薛青 《中国临床新医学》 2018年第1期25-29,共5页
目的分析不同FACED评分评估慢性阻塞性肺疾病(COPD)合并支气管扩张患者急性加重期的作用。方法收集2015-01~2015-12在福建医科大学附属宁德市医院呼吸内科住院的81例COPD合并支气管扩张患者的临床资料,包括年龄、临床症状、胸部高分辨率... 目的分析不同FACED评分评估慢性阻塞性肺疾病(COPD)合并支气管扩张患者急性加重期的作用。方法收集2015-01~2015-12在福建医科大学附属宁德市医院呼吸内科住院的81例COPD合并支气管扩张患者的临床资料,包括年龄、临床症状、胸部高分辨率CT(HRCT)、细菌感染、肺功能、C-反应蛋白(CRP)、血气分析[动脉血氧分压(PO2),动脉血二氧化碳分压(PCO2)]、血清白蛋白等,并随访出院后1年内急性加重次数(急性加重门诊及住院次数)。以FACED评分量表为依据进行评估。结果 1年随访中FACED评分5~7分的COPD合并支气管扩张组的急性加重次数为(8.46±2.10)次,3~4分组的急性加重次数为(6.62±2.41)次,0~2分组的急性加重次数为(2.92±1.49)次,差异具有统计学意义(P<0.05)。FACED评分与急性加重次数相关分析呈正相关(r=0.753)。结论 FACED评分越高的COPD合并支气管扩张患者急性加重越频繁,FACED评分对于辨别频繁加重型COPD患者存在指导意义。 展开更多
关键词 慢性阻塞性肺疾病 支气管扩张 急性加重期 faced评分
暂未订购
Study on the Technique of Double-faced Embroidery on Chinese Palace Fans
4
作者 金韺兰 高汉玉 周启澄 《Journal of China Textile University(English Edition)》 EI CAS 2000年第2期104-107,共4页
Double - faced iso - object embroidery is carried out byusing the uneven intercalated stitch crafts of the parallel- lines stitch as a main body, being accompanied by oth-er stitch crafts and miscellaneous stitches, d... Double - faced iso - object embroidery is carried out byusing the uneven intercalated stitch crafts of the parallel- lines stitch as a main body, being accompanied by oth-er stitch crafts and miscellaneous stitches, done on thesame textile material. This paper deals with the flower -bird double - faced embroidery fan of the Qing Dynasty,from pattern design, stitching formation and techniqueof color arrangement, describes the possible way of mak-ing double - faced embroidery with iso - object effectboth in the front and in the back. 展开更多
关键词 DOUBLE - faced EMBROIDERY STITCH craft Uneven INTERCALATED STITCH EMBROIDERY pattern .
在线阅读 下载PDF
Editorial's note: The Opportunity and Challenge Faced by Molecular Medicine
5
《Journal of Reproduction and Contraception》 CAS 2002年第2期116-116,共1页
Since 1980’s,life science has been holding a prominent place in the development ofscience and it is expected to become one of the leading disciplines in the 21 century.Currently the development of life science presen... Since 1980’s,life science has been holding a prominent place in the development ofscience and it is expected to become one of the leading disciplines in the 21 century.Currently the development of life science presents the following characteristics:1.The understanding of life was deepened to the molecule level. 展开更多
关键词 The Opportunity and Challenge faced by Molecular Medicine Editorial’s note
暂未订购
The Think Following High Rise——Problem faced and Countermeasures for Export Firms Producing New and High-tech Products
6
作者 王晓春 《中国经贸》 2004年第2期29-29,共1页
China’sexportofnewandhigh-techproductsincreasedbymorethan30percentforthepastsuccessive4years.Indeed,itisnoteasytokeepsuchextraordinarymomentumofhigh-speedriseundercircumstancesofglobalslowpick-upinnewandhigh-techindu... China’sexportofnewandhigh-techproductsincreasedbymorethan30percentforthepastsuccessive4years.Indeed,itisnoteasytokeepsuchextraordinarymomentumofhigh-speedriseundercircumstancesofglobalslowpick-upinnewandhigh-techindustry.However,thehighriseinexportwithdifferenttradeformsadoptedbyvariedcompanieshidanumberofissuestobeconcerned: 展开更多
关键词 EXPORT faced funded RAISE 外经贸企业 steadily GETTING r
在线阅读 下载PDF
Opportunities and Challenges Faced by Realization of World Equilibrium——Speech at the″International Conference for World Equilibrium″held in Cuba
7
作者 He Liansheng Council Member and Research Fellow of CAFIU 《International Understanding》 2003年第1期30-34,共5页
犤Editer’snote犦:The″InternationalConferenceforWorldEquilibrium″washeldinHavanaofCubaonJanuary27-29,2003.Outstandingstatesmen,personages,expertsandscholarsfromover30countriesaswellasleadingmembersofinternationalorg... 犤Editer’snote犦:The″InternationalConferenceforWorldEquilibrium″washeldinHavanaofCubaonJanuary27-29,2003.Outstandingstatesmen,personages,expertsandscholarsfromover30countriesaswellasleadingmembersofinternationalorga-nizationsattendedtheconference.ACAFIUdelegationwerealsopresent.Mr.HeLiansheng,CouncilMemberandResearchFellowofCAFIU,deliveredaspeechonaspecialsubject.Followingisthetextofthespeech: 展开更多
关键词 World Equilibrium International Conference for Opportunities and Challenges faced by Realization of World Equilibrium Speech at the held in Cuba by in of
在线阅读 下载PDF
Challenges faced by SOE reform
8
作者 Chen Jing 《中国远洋航务》 2002年第11期57-58,共2页
State-owned enterprises’(SOE) greater independence from government offices as well as property rights reform have optimized SOEs’ shareholding structure. But the reform has to clear several hurdles before it can be ... State-owned enterprises’(SOE) greater independence from government offices as well as property rights reform have optimized SOEs’ shareholding structure. But the reform has to clear several hurdles before it can be fully realized. In 1998, the central government dismantled ministries that had been the direct administrators of large SOEs. Most functions of those ministries were transferred to industry associations. Only a few considered indispensable were taken over by other government offices. The move has pushed forward the SOE reform to some extent. On the other hand, being State-owned, those enterprises have to find new links with the government. 展开更多
关键词 SOE Challenges faced by SOE reform OVER
在线阅读 下载PDF
Main Problems Faced by Chinese RE Permanent Magnetic Industry
9
《China Rare Earth Information》 2005年第7期1-2,共2页
Under over 50 years' development, Chinese rare earth magnetic industry developed into the global AINiCo, ferrite permanent magnets and NdFeB magnets manufacturing center, and average consumption of magnets per per... Under over 50 years' development, Chinese rare earth magnetic industry developed into the global AINiCo, ferrite permanent magnets and NdFeB magnets manufacturing center, and average consumption of magnets per person in China increased to 1.026 tons in 2003 from 0.217 ton in 1990. Although China has been the large producing country of rare earth permanent magnetic materials, to be the strongest one, there are many problems to solve. Main Problems Faced By Chinese Permanent Magnet 展开更多
关键词 NdFeB Main Problems faced by Chinese RE Permanent Magnetic Industry RE
在线阅读 下载PDF
Influence of seismic wave type and incident direction on the dynamic response of tall concrete-faced rockfill dams 被引量:4
10
作者 Chen-guang Zhou De-gao Zou Xiang Yu 《Earthquake Science》 2022年第5期343-354,共12页
Owing to the stochastic behavior of earthquakes and complex crustal structure,wave type and incident direction are uncertain when seismic waves arrive at a structure.In addition,because of the different types of the s... Owing to the stochastic behavior of earthquakes and complex crustal structure,wave type and incident direction are uncertain when seismic waves arrive at a structure.In addition,because of the different types of the structures and terrains,the traveling wave effects have different influences on the dynamic response of the structures.For the tall concrete-faced rockfill dam(CFRD),it is not only built in the complex terrain such as river valley,but also its height has reached 300 m level,which puts forward higher requirements for the seismic safety of the anti-seepage system mainly comprising concrete face slabs,especially the accurate location of the weak area in seism.Considering the limitations of the traditional uniform vibration analysis method,we implemented an efficient dynamic interaction analysis between a tall CFRD and its foundation using a non-uniform wave input method with a viscous-spring artificial boundary and equivalent nodal loads.This method was then applied to investigate the dynamic stress distribution on the concrete face slabs for different seismic wave types and incident directions.The results indicate that dam-foundation interactions behave differently at different wave incident angles,and that the traveling wave effect becomes more evident in valley topography.Seismic wave type and incident direction dramatically influenced stress in the face slab,and the extreme stress values and distribution law will vary under oblique wave incidence.The influence of the incident direction on slab stress was particularly apparent when SH-waves arrived from the left bank.Specifically,the extreme stress values in the face slab increased with an increasing incident angle.Interestingly,the locations of the extreme stress values changed mainly along the axis of the dam,and did not exhibit large changes in height.The seismic safety of CFRDs is therefore lower at higher incident angles from an anti-seepage perspective.Therefore,it is necessary to consider both the seismic wave type and incident direction during seismic capacity evaluations of tall CFRDs. 展开更多
关键词 tall CFRD wave analysis vibration analysis seismic wave type incident direction face slab stress
在线阅读 下载PDF
Preparation of{200}crystal faced SnO_(2) nanorods with extremely high gas sensitivity at lower temperature 被引量:3
11
作者 Hong-Yan Xu Zheng-Run Chen +4 位作者 Cai-Yun Liu Qin Ye Xiao-Peng Yang Jie-Qiang Wang Bing-Qiang Cao 《Rare Metals》 SCIE EI CAS CSCD 2021年第8期2004-2016,共13页
Demand for simple and effective gas sensing sensors is growing rapidly due to the growing threat of triethylamine(TEA).Semiconductor tin oxide(SnO_(2))is one of the most widely used sensing materials for metal oxide g... Demand for simple and effective gas sensing sensors is growing rapidly due to the growing threat of triethylamine(TEA).Semiconductor tin oxide(SnO_(2))is one of the most widely used sensing materials for metal oxide gas sensors.In recent years,a lot of binary ternary compound researches have been carried out.In this paper,five different SnO_(2) samples were synthesized by simple synthesis method to understand the internal relationship and obtain different gas sensing characteristics.Based on the low temperature nitrogen adsorption tests and the atomic arrangement model,it can be inferred that different exposed surfaces play a key role in TEA sensing properties.In addition,the TEA sensing activity relationship of SnO_(2) exposed crystal faces is proposed as listed:(200)>(101)>(110). 展开更多
关键词 SnO_(2)gas sensor Exposed crystal faces Atomic arrangement TEA sensing properties
原文传递
Risks Faced by Project Cost Consulting Management and Preventive Countermeasures
12
作者 DING Yangfang 《外文科技期刊数据库(文摘版)工程技术》 2021年第8期449-452,共6页
In recent years, China's economic development has driven the development of the construction industry. The project cost consulting business has developed rapidly, creating a good environment for local economic dev... In recent years, China's economic development has driven the development of the construction industry. The project cost consulting business has developed rapidly, creating a good environment for local economic development. Project cost consulting management can effectively improve the scientificity of project decision-making and maximize economic and social benefits. In the process of this work, we should pay attention to risk prevention and control measures to give full play to its value. Next, the article discusses the risks and preventive countermeasures faced by the project cost consulting management. 展开更多
关键词 project cost consulting management facing risks preventive countermeasures
原文传递
Parameter sensitivity and inversion analysis of a concrete faced rock-fill dam based on HS-BPNN algorithm 被引量:9
13
作者 SUN PengMing BAO TengFei +3 位作者 GU ChongShi JIANG Ming WANG Tian SHI ZhongWen 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第9期1442-1451,共10页
Considering the complex nonlinear relationship between the material parameters of a concrete faced rock-fill dam(CFRD) and its displacements, the harmony search(HS) algorithm is used to optimize the back propagation n... Considering the complex nonlinear relationship between the material parameters of a concrete faced rock-fill dam(CFRD) and its displacements, the harmony search(HS) algorithm is used to optimize the back propagation neural network(BPNN), and the HS-BPNN algorithm is formed and applied for the inversion analysis of the parameters of rock-fill materials. The sensitivity of the parameters in the Duncan and Chang's E-B model is analyzed using the orthogonal test design. The case study shows that the parameters φ0, K, Rf, and Kb are sensitive to the deformation of the rock-fill dam and the inversion analysis for these parameters is performed by the HS-BPNN algorithm. Compared with the traditional BPNN, the HS-BPNN algorithm exhibits the advantages of high convergence precision, fast convergence rate, and strong stability. 展开更多
关键词 parameter sensitivity analysis harmony search algorithm back propagation neural network parameter inversion concrete faced rock-fill dam
原文传递
Key technical problems of extra-high concrete faced rock-fill dam 被引量:3
14
作者 MA HongQi1? & CAO KeMing2 1Yunnan Huaneng Lancang River Hydropower Co., Ltd., Kunming 650011, China 2East China Investigation, Design & Research Institute, Hangzhou 310014, China 《Science China(Technological Sciences)》 SCIE EI CAS 2007年第z1期20-33,共14页
This paper summarizes the main technical points related to 100 m-height-scale concrete faced rock-fill dams and analyzes the main problems and their causes occurring during construction of 200 m-height-scale concrete ... This paper summarizes the main technical points related to 100 m-height-scale concrete faced rock-fill dams and analyzes the main problems and their causes occurring during construction of 200 m-height-scale concrete faced rock-fill dams. This paper has raised the key technical problems which need to study for construction of 300 m-height-scale concrete faced rock-fill dams based on the main experiences on the extra-high concrete faced rock-fill dams built after the year of 2000. 展开更多
关键词 CONCRETE faced rock-fill DAM extra-high DAM KEY TECHNOLOGY
原文传递
SOLVING THE PROBLEMS OF SUBJECT SPECIALIST KNOWLEDGE FACED IN THE ATTSR PROJECT 被引量:3
15
作者 Huang Ping Chongqing University 《Chinese Journal of Applied Linguistics》 1999年第1期55-62,共8页
ESP teachers teaching English for mixed subject -specialist groups meet problems such as selecting teach-ing materials,dealing with the subject matter,and teaching methods.The experience in the ATTSR(Advanced Teacher ... ESP teachers teaching English for mixed subject -specialist groups meet problems such as selecting teach-ing materials,dealing with the subject matter,and teaching methods.The experience in the ATTSR(Advanced Teacher Training in Specialist Reading)project may be a reference point for colleagues whomeet with the same problems.In this paper the author will suggest methods to solve these problems intraining this group:using different subject 展开更多
关键词 ESP SOLVING THE PROBLEMS OF SUBJECT SPECIALIST KNOWLEDGE faced IN THE ATTSR PROJECT
原文传递
Triple faced oxide:Electric-field controlled dual-ion switch
16
《Science Foundation in China》 CAS 2017年第3期56-56,共1页
Subject Code:A04With the financial support from the National Natural Science Foundation of China,a research team led by Associate Professor Yu Pu(于浦)at the Department of Physics,Tsinghua University recently publishe... Subject Code:A04With the financial support from the National Natural Science Foundation of China,a research team led by Associate Professor Yu Pu(于浦)at the Department of Physics,Tsinghua University recently published their seminal work in Nature(2017,546:124—128).The work,titled“Electric-field control 展开更多
关键词 Triple faced oxide:Electric-field controlled dual-ion switch
原文传递
Triple faced oxide:Electric-field controlled dual-ion switch
17
《Science Foundation in China》 CAS 2017年第4期41-,共1页
With financial support from the National Natural Science Foundation of China,a research team led by Associate Professor Yu Pu(于浦)at the Department of Physics in Tsinghua University published their seminal work recen... With financial support from the National Natural Science Foundation of China,a research team led by Associate Professor Yu Pu(于浦)at the Department of Physics in Tsinghua University published their seminal work recently in the prestigious journal Nature(2017,546:124-128).The work。 展开更多
关键词 Triple faced oxide:Electric-field controlled dual-ion switch
原文传递
Human-faced Jade Ornament
18
作者 Zhang Yinwu 《Women of China》 1994年第1期44-44,共1页
Jade was considered an elegant stone in ancient China. People began wearing jade ornaments as decorations as early as the Neolithic Period. This grey jade ornament, two centimeters long, was made during the third cult... Jade was considered an elegant stone in ancient China. People began wearing jade ornaments as decorations as early as the Neolithic Period. This grey jade ornament, two centimeters long, was made during the third cultural period 展开更多
关键词 ELEGANT faced ancient Dragon PHOENIX CHARM woman women
原文传递
Seismic cracking analyses of two types of face slab for concrete-faced rockfill dams 被引量:2
19
作者 KONG XianJing ZHANG Yu +2 位作者 ZOU DeGao QU YongQian YU Xiang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第4期510-522,共13页
Estimating the cracking capacity of the face slab and recommending effective crack-control measures are important for the anti-seismic safety of concrete-faced rockfill dams(CFRDs). In this paper, two-dimensional anal... Estimating the cracking capacity of the face slab and recommending effective crack-control measures are important for the anti-seismic safety of concrete-faced rockfill dams(CFRDs). In this paper, two-dimensional analyses of CFRDs are performed to simulate the seismic cracking behavior of conventional reinforced concrete(RC) face slab and a type of composite face slab. The composite face slab is composed of a ductile fiber-reinforced cement-based composite(DFRCC) layer and an RC substrate. For this purpose, a co-axial rotating smeared crack model for concrete and DFRCC is coupled with the generalized plasticity model for the rockfill material, and then implemented in a finite element program. The results show that during strong earthquakes,an RC slab is more likely to develop a penetrating macro-crack in its thickness dimension. In contrast, the crack-controlling composite slab demonstrates excellent resistance to seismic cracking, and no penetrating macro-cracks are observed. Major harmful cracks that form in the concrete substrate are stopped by the DFRCC layer in composite slabs. 展开更多
关键词 CFRD face slab seismic cracking failure DFRCC
原文传递
The development of the natural rubber sector is faced with difficulties
20
《China Chemical Reporter》 2007年第14期17-17,共2页
1.Limited land resources restrict de-velopmentThe natural rubber sector is a typicalresource-constrained sector.The landarea suitable for rubber planting isvery limited in China-only 970 thou-sand hectares-and 70% of ... 1.Limited land resources restrict de-velopmentThe natural rubber sector is a typicalresource-constrained sector.The landarea suitable for rubber planting isvery limited in China-only 970 thou-sand hectares-and 70% of it is alreadyin use.The remaining area is mostlyalready in productive use,plantedwith other tropical crops.It is there-fore not very feasible to increase theoutput of natural rubber by expand-ing the planting area. 展开更多
关键词 RUBBER SECTOR faced EXPAND PLANTING productive tho
全文增补中
上一页 1 2 90 下一页 到第
使用帮助 返回顶部