全文获取类型
收费全文 | 2753篇 |
免费 | 127篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 27篇 |
综合类 | 3篇 |
化学工业 | 753篇 |
金属工艺 | 98篇 |
机械仪表 | 67篇 |
建筑科学 | 106篇 |
矿业工程 | 2篇 |
能源动力 | 83篇 |
轻工业 | 322篇 |
水利工程 | 9篇 |
石油天然气 | 2篇 |
无线电 | 293篇 |
一般工业技术 | 552篇 |
冶金工业 | 112篇 |
原子能技术 | 19篇 |
自动化技术 | 440篇 |
出版年
2023年 | 24篇 |
2022年 | 44篇 |
2021年 | 97篇 |
2020年 | 55篇 |
2019年 | 56篇 |
2018年 | 53篇 |
2017年 | 55篇 |
2016年 | 88篇 |
2015年 | 68篇 |
2014年 | 113篇 |
2013年 | 208篇 |
2012年 | 203篇 |
2011年 | 220篇 |
2010年 | 181篇 |
2009年 | 174篇 |
2008年 | 164篇 |
2007年 | 122篇 |
2006年 | 133篇 |
2005年 | 103篇 |
2004年 | 78篇 |
2003年 | 78篇 |
2002年 | 74篇 |
2001年 | 34篇 |
2000年 | 40篇 |
1999年 | 37篇 |
1998年 | 38篇 |
1997年 | 49篇 |
1996年 | 37篇 |
1995年 | 38篇 |
1994年 | 31篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 22篇 |
1990年 | 14篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 13篇 |
1986年 | 4篇 |
1985年 | 14篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1973年 | 4篇 |
排序方式: 共有2888条查询结果,搜索用时 15 毫秒
111.
112.
Zlatica Marinkovi Giovanni Crupi Alina Caddemi Gustavo Avolio Antonio Raffo Vera Markovi Giorgio Vannini Dominique M. M.‐P. Schreurs 《International Journal of Numerical Modelling》2015,28(4):359-370
Gallium nitride high electron‐mobility transistors have gained much interest for high‐power and high‐temperature applications at high frequencies. Therefore, there is a need to have the dependence on the temperature included in their models. To meet this challenge, the present study presents a neural approach for extracting a multi‐bias model of a gallium nitride high electron‐mobility transistors including the dependence on the ambient temperature. Accuracy of the developed model is verified by comparing modeling results with measurements. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
113.
Thierry Giordano 《Planning Theory & Practice》2013,14(4):480-504
The South African government has named the transition towards a greener economy one of its priorities. Meanwhile it has developed a new multilevel integrated planning process, and announced a massive public infrastructure investment plan. The converging point of these three dynamics should be the integration of green infrastructure principles into the different plans as the foundation of the green transition. This paper uses a policy integration analytical framework to assess whether this convergence is in fact taking shape. It analyses the level of integration of green infrastructure principles into the different plans and suggests options to move the green infrastructure agenda forward. 相似文献
114.
A concept of reactive compatibilizer‐tracer for studying reactive polymer blending processes
下载免费PDF全文
![点击此处可从《American Institute of Chemical Engineers》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Wei‐Yun Ji Lian‐Fang Feng Cai‐Liang Zhang Sandrine Hoppe Guo‐Hua Hu Dominique Dumas 《American Institute of Chemical Engineers》2016,62(2):359-366
A concept called reactive compatibilizer‐tracer is proposed. The latter bears reactive groups capable of reacting with its counterpart on forming a copolymer for in situ compatibilization, and fluorescent labels allowing determining very small amounts of the in situ formed compatibilizer and formation of micelles when it occurs. Owing to this concept, it is shown that a reactive compatibilizer may be very efficient at the beginning of a reactive blending process and may suddenly become completely inefficient, resulting in an abrupt and drastic increase in size of the dispersed phase domains. © 2015 American Institute of Chemical Engineers AIChE J, 62: 359–366, 2016 相似文献
115.
Discovery of Highly Potent Dual Orexin Receptor Antagonists via a Scaffold‐Hopping Approach
下载免费PDF全文
![点击此处可从《ChemMedChem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Bibia Heidmann Dr. John Gatfield Dr. Catherine Roch Dr. Alexander Treiber Dr. Simone Tortoioli Dr. Christine Brotschi Dr. Jodi T. Williams Dr. Martin H. Bolli Dr. Stefan Abele Dr. Thierry Sifferlen Dr. François Jenck Dr. Christoph Boss 《ChemMedChem》2016,11(19):2132-2146
Starting from suvorexant (trade name Belsomra), we successfully identified interesting templates leading to potent dual orexin receptor antagonists (DORAs) via a scaffold‐hopping approach. Structure–activity relationship optimization allowed us not only to improve the antagonistic potency on both orexin 1 and orexin 2 receptors (Ox1 and Ox2, respectively), but also to increase metabolic stability in human liver microsomes (HLM), decrease time‐dependent inhibition of cytochrome P450 (CYP) 3A4, and decrease P‐glycoprotein (Pgp)‐mediated efflux. Compound 80 c [{(1S,6R)‐3‐(6,7‐difluoroquinoxalin‐2‐yl)‐3,8‐diazabicyclo[4.2.0]octan‐8‐yl}(4‐methyl‐[1,1′‐biphenyl]‐2‐yl)methanone] is a potent and selective DORA that inhibits the stimulating effects of orexin peptides OXA and OXB at both Ox1 and Ox2. In calcium‐release assays, 80 c was found to exhibit an insurmountable antagonistic profile at both Ox1 and Ox2, while displaying a sleep‐promoting effect in rat and dog models, similar to that of the benchmark compound suvorexant. 相似文献
116.
Wenbo Yu Véronique Gauthier‐Brunet Thierry Cabioc'h Sylvain Dubois 《Journal of the American Ceramic Society》2014,97(7):2308-2313
Ti, TiC, Al and AlN powders were mixed to synthesize Ti2Al(CxNy) (x + y < 1) solid solutions, Ti2AlCx (x < 1) and Ti2AlN‐related end‐members by hot isostatic pressing at 1400°C/80 MPa for 4 h. For the pure carbides, it is demonstrated that single‐phased samples can only be obtained when about 15% of substoichiometry on the carbon site is applied. Such a result likely implies that Ti2AlCx can only exist in a narrow range of carbon composition. Ti2AlN nitride can be synthesized with y = 1. Assuming that vacancy content varies linearly from 0 to 0.15 going from Ti2AlN to Ti2AlC0.85 in the solid solutions, element concentrations have been calculated to synthesize different solid solutions. Thus, it is demonstrated that single‐phased and fully dense Ti2Al(C0.23N0.71), Ti2Al(C0.45N0.45), and Ti2Al(C0.66N0.22) carbonitrides can be synthesized. 相似文献
117.
Jie Li Lyes Bennamoun Laurent Fraikin Thierry Salmon Dominique Toye Raphael Schreinemachers 《Drying Technology》2014,32(14):1706-1717
Convective drying of wastewater sludges and sawdust/sludge mixtures was studied. The first part of this work was an experimental study performed in a cross-flow convective dryer using 500 g of wet material extruded through a disk with circular dies of 12 mm. The results showed that the sawdust addition has a positive impact on the drying process from a mass ratio of 2/8, on a dry basis, with observed drying rates higher than the original sludge. The second part of this work consisted of developing a drying model in order to identify the internal diffusion coefficient and convective mass transfer coefficient from the experimental data. A comparison was made between fitted drying curves, well represented by the Newton's model, and the analytical solutions of the diffusion equation applied to a finite cylinder. Variations of dimensional characteristics, such as the volume and exchange surface of the sample bed, were obtained by X-ray tomography. This technique allowed us to confirm that shrinkage, which is an important phenomenon occurring during sludge and sawdust/sludge mixture drying, must be taken into account. The results showed that both the internal diffusion coefficient and convective mass transfer coefficient were affected by mixing and sawdust addition. The internal diffusion coefficient changed from 7.77 × 10?9 m2/s for the original sludge to 7.01 × 10?9 m2/s for the mixed sludge and then increased to 8.35 × 10?9 m2/s for the mixture of a mass ratio of 4/6. The convective mass transfer coefficient changed from 9.70 × 10?8 m/s for the original sludge to 8.67 × 10?8 m/s for the mixed sludge and then increased to 12.09 × 10?8 m/s for the mixture of a mass ratio of 4/6. These results confirmed that sawdust addition was beneficial to the sludge drying process as the mass transfer efficiency between the air and material increased. Reinforcing the texture of sludge by adding sawdust can increase the drying rate and decrease the drying time, and then the heat energy supply will be reduced significantly. The study also showed that neglecting shrinkage phenomenon resulted in an overestimation for the internal diffusion coefficient for the convective drying of sludges and sawdust/sludge mixtures. 相似文献
118.
Laurent Veron Marie-Caroline De Bignicourt Thierry Delair Christian Pichot Bernard Mandrand 《应用聚合物科学杂志》1996,60(2):235-244
Radical-initiated polymerization of N-(2,2 dimethoxyethyl)-N-methylacrylamide has been carried out either in chloroform or methanol using 2,2′-azobisisobutyronitrile as an initiator, allowing us to prepare acetal containing water-soluble polymers. A kinetic study in both solvents showed that this monomer fairly homopolymerized (kp · kt−1/2 = 1 mol−1/2 L1/2 s−1/2). Static light scattering was used to characterize the molecular weight of these polymers. In addition, the Mark–Houwink–Sakurada relationship was established based on viscosity measurements performed at 25°C in water. Recovery of the aldehyde moieties on the polymer was achieved under mild conditions using a diluted inorganic solution. The analysis of the formation of aldehyde groups was performed by 1H- and 13C-NMR. The covalent binding of oligodeoxyribonucleotides was carried out in water/acetonitrile mixtures with subsequent NaBH4 reduction of the imine bonds so as to stabilize the polymer/oligodeoxynucleotide conjugates. © 1996 John Wiley & Sons, Inc. 相似文献
119.
Chamekh Ould M'bareck Michel Metayer Dominique Langevin Sadok Roudesli 《应用聚合物科学杂志》1996,62(1):161-165
The miscibility of poly(vinyl alcohol) (PVA) and poly(styrenesulfonic acid) (PSSA) in dilute aqueous solutions was studied by a viscosimetric method. At a constant molecular weight of PSSA, it was found that the miscibility of both polymers increases with the molecular weight and the number of acetate groups of the PVA samples (1 and 12% unhydrolyzed sites). Moreover, this miscibility increases slightly with the total mixture concentration in the interval 1–2 g/dL. By comparison of the results of reduced viscosity of PVA/PSSA and PVA/poly(sodium styrenesulfonate) (PSSNa) mixtures, it has been deduced that the miscibility of two polymers is due mainly to intermolecular interactions between the hydroxyl and sulfonic groups of PVA and PSSA, respectively. These groups act as acceptors and donors of hydrogen bonds which are the responsible for polymers' miscibility. © 1996 John Wiley & Sons, Inc. 相似文献
120.
Catherine Lefranc-Millot Dominique Vercaigne-Marko Pascal Dhulster Bertrand Fertin Bernard Quinque Didier Guillochon 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,66(1):79-85
A method for the production of bovine colostral F(ab′)2 fragments at pilot-plant scale was developed. Optimum yield of immunoglobulins in colostral whey was obtained after rennet treatment of first milking colostrum. Pepsin digestion was carried out directly on the colostral whey at pH 3·8 for 4 h, which led to the complete digestion of immunoglobulins into F(ab′)2 fragments. Elimination of β-lactoglobulin, the main immunogenic protein, was achieved by anion exchange on Duolite A560 at pH 6·0. The preparation was diafiltered with a 5000 Da membrane and the retentate spray-dried. The powder obtained contained approximately 34% F(ab′)2 fragments, with an antibody activity three times higher than the initial colostrum. 相似文献