全文获取类型
收费全文 | 1269篇 |
免费 | 52篇 |
专业分类
电工技术 | 11篇 |
综合类 | 1篇 |
化学工业 | 313篇 |
金属工艺 | 27篇 |
机械仪表 | 33篇 |
建筑科学 | 44篇 |
矿业工程 | 2篇 |
能源动力 | 63篇 |
轻工业 | 104篇 |
水利工程 | 6篇 |
石油天然气 | 6篇 |
无线电 | 116篇 |
一般工业技术 | 258篇 |
冶金工业 | 98篇 |
原子能技术 | 11篇 |
自动化技术 | 228篇 |
出版年
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 32篇 |
2020年 | 25篇 |
2019年 | 19篇 |
2018年 | 22篇 |
2017年 | 37篇 |
2016年 | 37篇 |
2015年 | 30篇 |
2014年 | 39篇 |
2013年 | 84篇 |
2012年 | 76篇 |
2011年 | 77篇 |
2010年 | 68篇 |
2009年 | 76篇 |
2008年 | 75篇 |
2007年 | 60篇 |
2006年 | 61篇 |
2005年 | 52篇 |
2004年 | 37篇 |
2003年 | 35篇 |
2002年 | 31篇 |
2001年 | 20篇 |
2000年 | 13篇 |
1999年 | 24篇 |
1998年 | 33篇 |
1997年 | 19篇 |
1996年 | 18篇 |
1995年 | 17篇 |
1994年 | 16篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 12篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 4篇 |
排序方式: 共有1321条查询结果,搜索用时 15 毫秒
61.
Gilles Thibault Gilles Paintaud Hsueh Cheng Sung Laurie Lajoie Edouard Louis the GETAID Celine Desvignes Herv Watier Valrie Gouilleux-Gruart David Ternant 《International journal of molecular sciences》2021,22(11)
The FcγRIIA/CD32A is mainly expressed on platelets, myeloid and several endothelial cells. Its affinity is considered insufficient for allowing significant binding of monomeric IgG, while its H131R polymorphism (histidine > arginine at position 131) influences affinity for multimeric IgG2. Platelet FcγRIIA has been reported to contribute to IgG-containing immune-complexe clearance. Given our finding that platelet FcγRIIA actually binds monomeric IgG, we investigated the role of platelets and FcγRIIA in IgG antibody elimination. We used pharmacokinetics analysis of infliximab (IgG1) in individuals with controlled Crohn’s disease. The influence of platelet count and FcγRIIA polymorphism was quantified by multivariate linear modelling. The infliximab half-life increased with R allele number (13.2, 14.4 and 15.6 days for HH, HR and RR patients, respectively). It decreased with increasing platelet count in R carriers: from ≈20 days (RR) and ≈17 days (HR) at 150 × 109/L, respectively, to ≈13 days (both HR and RR) at 350 × 109/L. Moreover, a flow cytometry assay showed that infliximab and monomeric IgG1 bound efficiently to platelet FcγRIIA H and R allotypes, whereas panitumumab and IgG2 bound poorly to the latter. We propose that infliximab (and presumably any IgG1 antibody) elimination is partly due to an unappreciated mechanism dependent on binding to platelet FcγRIIA, which is probably tuned by its affinity for IgG2. 相似文献
62.
A semi-empirical nonlinear model of moisture content and wet-milling quality degradation in com drying is established. The model uncertainty is expressed as a relative error level which includes a pre-specified percentage of experimental data. An optimal control strategy for batch drying is determined which maximizes the dryer throughput, while simultaneously satisfying two quality constraints on the final state: achieving specified moisture content and wet-milling quality levels. Taking into account the model uncertainty results in a conservative but less efficient control strategy. The performance - robustness compromise is discussed. 相似文献
63.
Hydrolysis of glycosidically bound flavour compounds from oak wood by Oenococcus oeni 总被引:1,自引:0,他引:1
Malolactic fermentation (MLF), which is conducted by lactic acid bacteria (LAB), has a significant influence on the stability and organoleptic quality of wine. Recent studies have shown that when MLF is carried out in oak wood barrels, LAB were also able to interact with wood and increase volatile compound contents such as vanillin during MLF. The release of these compounds indicates that LAB may convert vanillin precursors present in oak wood. In this work, the effect of commercial glycosidases on the released vanillin was firstly studied. This aldehyde is present in wood extracts in monoglycosidic forms where the major glycones are arabinose and xylose. Other aglycons released during MLF in barrels, syringaldehyde and whisky-lactones, can be considered as other sources of aroma. Secondly, strains selected with high activities toward glycoside substrates could hydrolyse vanillin glycoside precursors from oak wood with the same efficiency as commercial enzymes. 相似文献
64.
Jennifer O'Loughlin Marie Lambert Igor Karp Jennifer McGrath Katherine Gray-Donald Tracie A Barnett Edgard E Delvin Emile Levy Gilles Paradis 《Nicotine & tobacco research》2008,10(3):525-532
Although related to inflammatory markers in adults, little is known about the association between cigarette smoking and C-reactive protein (CRP) in adolescent smokers. We examined the association between high-sensitivity CRP (hs-CRP) concentrations and smoking in youth. We used data from a cross-sectional, province-wide survey of a representative sample of youth conducted in Quebec, Canada, in 1999. Data were collected in self-report questionnaires completed by participants and their parents. Participants provided a fasting blood sample, and anthropometric measures were undertaken by trained technicians. The present analysis pertains to 1,501 adolescents aged 13 and 16 years who completed questionnaires and for whom blood samples were available. The independent association between a six-category indicator of smoking status and elevated hs-CRP, defined as a value at least in the 90th percentile of the age- and sex-specific CRP distribution, was assessed in multiple logistic regression analyses controlling for potential confounders. Relative to never-smokers, the odds ratios (95% confidence intervals) for puffers (i.e., never smoked a whole cigarette), those who smoked but not in the past month, light past-month smokers, moderate past-month smokers, and heavy past-month smokers were 1.04 (0.55-1.98), 1.76 (1.06-2.94), 1.39 (0.70-2.76), 2.07 (0.96-4.42), and 2.40 (1.18-4.88), respectively. Our data suggest a positive association between smoking status and elevated CRP in adolescents, and in particular among heavier past-month smokers. Damage related to cigarette smoking may begin soon after tobacco use initiation, reinforcing the preventive message that no level of smoking is safe in youth. 相似文献
65.
Roland Steim Tayebeh Ameri Pavel SchilinskyChristoph Waldauf Gilles DennlerMarkus Scharber Christoph J. Brabec 《Solar Energy Materials & Solar Cells》2011,95(12):3256-3261
Here we report on organic photovoltaic's (OPV) suitable for low light applications. In this paper, we illustrate the impact of Rs and Rp for indoor and outdoor applications. In addition, we propose a simple physics approach to predict the behavior of organic solar cells under various illumination intensities through electrical modeling. The combination of simulation and modeling allows to define a set of design rules for OPVs under low light illumination. The performance of various organic solar cells under low light intensity is compared with our predictions and excellent correlation is found. OPV shows high performance under low light conditions. 相似文献
66.
The study presents a numerical investigation of the dynamical behavior of a rectangular natural circulation loop with horizontal heat exchanging sections. The study has been developed in a two-dimensional domain considering uniform wall temperatures, UWT, at the horizontal sections and thermally insulated vertical legs as thermal boundary conditions. The governing equations have been solved using a control volume method solving the velocity-pressure coupling with the SIMPLER algorithm. The analysis has been performed for a fixed geometry of the loop and for various Rayleigh numbers, separating the values of Rayleigh for which the system manifests stable and unstable dynamics. In the last case, it is shown that the vortices are responsible for the birth of the oscillations and for the growth of temperature gradients. 相似文献
67.
提出了一种基于Kirchhoff积分的快速地震波场数值模拟算法。在地下弹性介质的速度、反射界面的空间位置及反射率均已知的情况下,可以利川该算法计算三维非均匀弹性介质模型中的反射地震波场。讨论了算法的计算效率和计算精度。针对基丁Kirchhoff积分的二维地震波场模拟计算量巨大这一问题,采用了两种尺度网格单元和限制积分区域等手段,不仅降低了计算量,节省了内存,同时还保待了足够的计算精度。利用数值模拟对算法的有效性进行了验证。 相似文献
68.
BCI Competition 2003--Data set IIa: spatial patterns of self-controlled brain rhythm modulations 总被引:6,自引:0,他引:6
A brain-computer interface (BCI) is a system that should in its ultimate form translate a subject's intent into a technical control signal without resorting to the classical neuromuscular communication channels. By using that signal to, e.g., control a wheelchair or a neuroprosthesis, a BCI could become a valuable tool for paralyzed patients. One approach to implement a BCI is to let users learn to self-control the amplitude of some of their brain rhythms as extracted from multichannel electroencephalogram. We present a method that estimates subject-specific spatial filters which allow for a robust extraction of the rhythm modulations. The effectiveness of the method was proved by achieving the minimum prediction error on data set IIa in the BCI Competition 2003, which consisted of data from three subjects recorded in ten sessions. 相似文献
69.
Musubu Ichikawa Daiki Takekawa Hyeon-Gu Jeon Gilles D.R. Banoukepa 《Organic Electronics》2013,14(3):814-820
We investigated small-molecule-based organic photovoltaic (PV) cells with three different electron-donating material layers, two thiophene/phenylene co-oligomers [α,ω-bis(biphenyl-4-yl)terthiophene (BP3T) and α,ω-diphenyl sexithiophene (P6T)] and copper phthalocyanine (CuPc), and one electron-accepting material layer (C60). A cascade-type energy relay between the three donor layers occurred, and the incident photon-current conversion efficiency improved in the blue light region, where CuPc has very low optical absorption. An increase in P6T photoluminescence intensity in a two-layer sample (BP3T/P6T) on quartz confirmed interlayer excitation transfer (ET) from BP3T and P6T. The bulk heterojunction architecture in our interlayer-ET-based organic PV cell was effective. Moreover, P6T appeared to have a relatively long exciton diffusion length of several tens of nanometers. 相似文献
70.
On Analyzing the Potential of a Layer-2 Multi-hop Authentication and Credential Delivery Scheme for Vehicular Communications 总被引:1,自引:1,他引:0
Christian Tchepnda Hassnaa Moustafa Houda Labiod Gilles Bourdon 《Wireless Personal Communications》2009,51(1):31-52
In this paper we introduce a new security architecture and security mechanisms for vehicular networks providing a layer-2
multi-hop authentication and credential delivery scheme between vehicles and the network operator authentication server. We
present a performance analysis of the proposed solution under various vehicles and Access Points (APs) densities, showing
the potential of our scheme in providing a more efficient, robust and scalable authentication and credential delivery to vehicles
when compared against the classical single-hop scheme. 相似文献