全文获取类型
收费全文 | 2103篇 |
免费 | 91篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 36篇 |
综合类 | 4篇 |
化学工业 | 587篇 |
金属工艺 | 67篇 |
机械仪表 | 27篇 |
建筑科学 | 102篇 |
矿业工程 | 12篇 |
能源动力 | 35篇 |
轻工业 | 198篇 |
水利工程 | 4篇 |
石油天然气 | 3篇 |
无线电 | 145篇 |
一般工业技术 | 453篇 |
冶金工业 | 208篇 |
原子能技术 | 16篇 |
自动化技术 | 302篇 |
出版年
2023年 | 25篇 |
2022年 | 28篇 |
2021年 | 55篇 |
2020年 | 40篇 |
2019年 | 32篇 |
2018年 | 51篇 |
2017年 | 38篇 |
2016年 | 55篇 |
2015年 | 51篇 |
2014年 | 69篇 |
2013年 | 106篇 |
2012年 | 107篇 |
2011年 | 127篇 |
2010年 | 96篇 |
2009年 | 99篇 |
2008年 | 107篇 |
2007年 | 95篇 |
2006年 | 77篇 |
2005年 | 65篇 |
2004年 | 73篇 |
2003年 | 54篇 |
2002年 | 52篇 |
2001年 | 39篇 |
2000年 | 45篇 |
1999年 | 36篇 |
1998年 | 50篇 |
1997年 | 33篇 |
1996年 | 36篇 |
1995年 | 33篇 |
1994年 | 23篇 |
1993年 | 16篇 |
1992年 | 32篇 |
1991年 | 19篇 |
1990年 | 27篇 |
1989年 | 17篇 |
1988年 | 15篇 |
1987年 | 18篇 |
1986年 | 22篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 13篇 |
1978年 | 8篇 |
1977年 | 16篇 |
1976年 | 20篇 |
1974年 | 10篇 |
1971年 | 11篇 |
排序方式: 共有2199条查询结果,搜索用时 15 毫秒
991.
992.
Cora Weigert Rainer Lehmann Sonja Hartwig Stefan Lehr 《Proteomics. Clinical applications》2014,8(1-2):5-18
Recent years have provided clear evidence for the skeletal muscle as an endocrine organ. Muscle contraction during physical activity has emerged as an important activator of the release of the proteins and peptides called “myokines." Diverse proteomic profiling approaches were applied to rodent and human skeletal muscle cells to characterize the complete secretome, to study the regulation of the secretome during cell differentiation or the release of myokines upon contractile activity of myotubes. Several of the exercise-regulated factors have the potency to mediate an interorgan crosstalk. The paracrine function of the secreted peptides and proteins to regulate muscle regeneration, tissue remodeling, and trainability can have direct effects on whole-body glucose disposal and oxygen consumption. The overall composition and dynamic of the myokinome are still incompletely characterized. Recent advantages in metabolomics and lipidomics will add metabolites and lipids with autocrine, paracrine, or endocrine function to the contraction-induced secretome of the skeletal muscle. The identification of these metabolites will lead to a more comprehensive view described by a new myo(metabo)kinome consisting of peptides, proteins, and metabolites. 相似文献
993.
Aqueous absorbents for absorption of SO2. The removal of SO2 from flue gases is dominated by processes of absorption with aqueous absorbents. Aqueous systems are favourable in contrast to organic absorbents because the water vapour contained in the flue gas does not interfere with the separation. The transport of gaseous SO2 into the liquid phase and the subsequent transformation into sulfite/bisulfite or sulfate after oxidation is typical for the aqueous processes of absorption. Starting from water as absorbent the addition of various basic agents makes an increase in the absorption capacity of the washing solution possible by several orders. Different solubilities of the agents or the resulting compounds, the dependence of the vapour pressure on the concentration and desired and undesired reactions determine the thermodynamics of the processes. The regenerative sodium salt processes as the Wellman-Lord (sodium sulfite) process, the Flakt-Boliden (sodium citrate) process and the sodium phosphate process, the regenerative ammonium sulfite process, the processes producing gypsum and the absorption with oxidation to sulfuric acid are noted. The advantages and limitations of the particular processes are pointed out by means of the vapour liquid equilibria, the solubilities of the salts and the oxidation reactions. 相似文献
994.
Coating and layer composite manufacturing most commonly involves high temperature gradients and intensive heat transfer between the different composite materials. This can be noticed not only for thermal spraying, but also for other coating techniques. The combination of temperature gradients and materials with different thermophysical properties leads to the formation of thermal stresses in the composite, which are superimposed by stress generating effects during coating solidification, phase transformation or recrystallization. The final state of residual stresses affects the structural and functional properties of the coating as well as the component reliability during operation. Therefore, residual stress analysis is an important tool for the optimization of coatings and layer composite manufacturing processes in order to ensure stability of the processes, adhesion and compatibility of the coating, and finally, the reliability of the components in various technical systems.The most common residual stress measurement techniques are described and compared, with the focus on the incremental hole drilling and milling method. The advantages and disadvantages of the methods are discussed with respect to their application on industrial machine parts. The typical application fields for the different methods are given with respect to the specific measurement principles. The incremental hole drilling method is presented in more detail with application examples that illustrate the suitability of this method for the optimization of thermal spraying processes in industrial layer composite manufacturing by managing the heat and mass transfer in a most appropriate way. 相似文献
995.
Hydroxyl Defect Effect on Reoxidation of Sc‐Doped (Ba,Ca)(Ti,Zr)O3 Fired in Reducing Atmospheres 下载免费PDF全文
Yu‐Ju Kao Che‐Yi Su Christian Pithan Detlev F. Hennings Chi‐Yuen Huang Rainer Waser 《Journal of the American Ceramic Society》2016,99(4):1311-1317
The behavior of grain and grain‐boundary conductivity of acceptor (Sc)‐doped (Ba,Ca)(Ti,Zr)O3 ceramics sintered in moist reducing atmosphere and subsequently reoxidized in dry and moist atmosphere was investigated by means of impedance spectroscopy (IS). In moist firing atmosphere, water vapor was found to react with oxygen vacancies, forming positively charged hydroxyl defects on regular oxygen sites in the crystal lattice. Proton hopping is considered to raise the ionic conductivity significantly. Therefore, hydroxyl defects in turn influence the grain conduction. Hydroxyl defects are also considered to be responsible for alternations of the dielectric maximum at the Curie point. 相似文献
996.
Halogenated Bis(methoxybenzylidene)‐4‐piperidone Curcuminoids with Improved Anticancer Activity 下载免费PDF全文
Florian Schmitt Prof. Dr. Dharmalingam Subramaniam Prof. Dr. Shrikant Anant Prof. Dr. Subhash Padhye Prof. Dr. Gerrit Begemann Prof. Dr. Rainer Schobert Dr. Bernhard Biersack 《ChemMedChem》2018,13(11):1115-1123
A series of readily available curcuminoids with a halogenated bis(4‐methoxy/4,5‐dimethoxybenzylidene)‐4‐piperidone structure were prepared and analyzed for their cytotoxic impact on eight human cancer cell lines of five different entities. The known 3,4,5‐trimethoxybenzylidene curcuminoid 2 a and the new bis‐(3‐bromophenyl) and bis‐(3,5‐dibromophenyl) derivatives 3 c and 3 d proved to be more strongly antiproliferative than the known curcuminoid EF24 against six of these cell lines. Compounds 2 a and 3 c caused a distinct increase of reactive oxygen species, which eventually elicited apoptosis in 518A2 melanoma cells. Compound 2 a arrested 518A2 melanoma cells in G1 phase of the cell cycle and had no effect on the expression of pro‐metastatic matrix metalloproteinases MMP‐2 and MMP‐9, whereas 3 c led to an accumulation of 518A2 cells in the G2/M phase and to a downregulation of MMP‐2 expression. In addition, treatment with 2 a and 3 c resulted in significant inhibition of colony formation in HCT116 cells. Both 2 a and 3 c showed antiangiogenic activity, for example, by inhibiting the formation of sub‐intestinal veins (SIV) in zebrafish embryos. Compound 3 c was also well tolerated by mice and inhibited the growth of HCT116 colon cancer xenografts. 相似文献
997.
NDT techniques for railroad wheel and gauge corner inspection 总被引:5,自引:2,他引:5
Rainer Pohl A. Erhard H. -J. Montag H. -M. Thomas H. Wüstenberg 《NDT & E International》2004,37(2):89-94
The development of non-destructive techniques (NDT) techniques for the in-service inspection of railroad wheels and gauge corners was the main activity of the NDT division VIII. 4 at BAM over the last 2 years. For such different components, two different inspection techniques were fundamentally chosen in order to fulfil the end-user requirements. Firstly the inspection of the wheels—rim and disk—should be carried out without dismantling the wheels and using ultrasonic techniques. On the other hand, the inspection of the railroad track surface at a train speed of about 70 km/h should be guaranteed using eddy current techniques. The above-mentioned tasks were a challenge for the lab staff. The accessibility for the wheel inspection was limited due to several impassable barriers such as sand tubes, etc. Eddy current application focused mainly on the detection of head check defects occurring at the gauge corner of the rail. Investigations carried out also showed, that other types of surface defects (e.g. Belgrospis, wheel burns, short-pitch corrugations, etc.) could easily be detected. Some aspects of the inspection system as well as an overview of test results are presented in the current contribution. 相似文献
998.
A new setup for freeze-substitution and a versatile controlling system has been developed. Our goal was to build a simple system allowing precise control of the physical parameters of freeze-substitution experiments to learn more about their influences on the cellular ultrastructure and immunoreactivity of macromolecules. An improved apparatus for freeze-substitution, based on liquid nitrogen cooling, and a universal software for controlling the complex preparation protocols from cryofixation to final polymerization are described. This controlling system has the following advantages: it allows precise control and registration of temperature profiles, reconstruction of each individual step of previous experiments, and optimization of working conditions. The setup of the freeze-substitution apparatus is designed to run many different substitution media in parallel; freeze-substitution (cryostat), embedding (working platform), and polymerization are carried out at separate places; therefore, more experiments can be done simultaneously. The ergonomic working platform allows exchange of media at controlled temperature and easy handling; survey of the temperature in individual tubes is possible, and the system is protected from water condensation and uncontrolled warming by the deep freezer. 相似文献
999.
Frank Babick Lars Hillemann Michael Stintz Tim Dillenburger Michael Pitz Albert Hellmann Sergiy Antonyuk Siegfried Ripperger Franz J. T. Huber Stefan Will Ruth Wernet Martin Seipenbusch Manuel Gensch Alfred Weber Dennis Kiesler Einar Kruis Rainer Friehmelt Bernd Sachweh 《化学,工程师,技术》2018,90(7):923-936
The performance of particle‐based products depends on a multiple set of particle properties. To monitor them during particle manufacturing, three novel aerosol measurement techniques were developed: wide‐angle light scattering (WALS), three‐dimensional laser scattering (3D‐LSS), and differential aerodynamic particle sizing (DAPS). They measure particle shape, aggregate structure, and particle size, i.e., radius of gyration and aerodynamic diameter. The techniques were tested for rod‐like organic pigments and partially sintered SiO2 aggregates, which were produced by two new aerosol generators. 相似文献