全文获取类型
收费全文 | 537篇 |
免费 | 22篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 183篇 |
金属工艺 | 12篇 |
机械仪表 | 21篇 |
建筑科学 | 19篇 |
矿业工程 | 1篇 |
能源动力 | 16篇 |
轻工业 | 94篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 21篇 |
一般工业技术 | 100篇 |
冶金工业 | 34篇 |
原子能技术 | 4篇 |
自动化技术 | 47篇 |
出版年
2024年 | 3篇 |
2023年 | 3篇 |
2022年 | 28篇 |
2021年 | 39篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 29篇 |
2017年 | 16篇 |
2016年 | 25篇 |
2015年 | 24篇 |
2014年 | 23篇 |
2013年 | 37篇 |
2012年 | 32篇 |
2011年 | 21篇 |
2010年 | 16篇 |
2009年 | 16篇 |
2008年 | 18篇 |
2007年 | 20篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 13篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 10篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1977年 | 2篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1971年 | 1篇 |
1906年 | 5篇 |
1905年 | 1篇 |
排序方式: 共有559条查询结果,搜索用时 15 毫秒
1.
Cz. Woźniak 《Acta Mechanica》1989,78(1-2):81-94
Summary In this paper a new high efficiency C-O grid coupled with the potential flow solver based on the finite volume technique is given. It significantly reduces the CPU time and increases the computational efficiency. In order to improve the accuracy of traditional potential method a shock point operator is used to account for entropy correction. Some calculated results of 2D inviscid, viscous/inviscid interaction and 3D inviscid flow indicate that nonisentropic potential method produces results closer to Euler solution as well as experimental data, while its computational efforts are nearly the same as the usual isentropic potential method.With 9 Figures 相似文献
2.
Influence of geosynthetic reinforcement on the load-settlement characteristics of two-layer subgrade
The possibility of realistic prediction of two-layer subgrade load-settlement characteristics is discussed. The case of improvement of the soft subgrade properties using the geosynthetic reinforcement placed at the boundary between two different subgrade layers is analysed. In the first part of the paper, a short review of the main conclusions from experimental results dealing with the influence of geosynthetic reinforcement on the load-settlement characteristics of subgrade is presented. Then, the results of using the selected analytical membrane-action model to describe the reinforcement action in soil are discussed. The model is verified on the basis of data obtained from previously published laboratory tests. Particular attention is devoted to influencing some basic initial parameters on the accuracy of obtained results. Important problems which need intensive investigations are identified. 相似文献
3.
Victor Chabanenko Roman Puźniak Adam Nabiałek Sergei Vasiliev Vladimir Rusakov Loh Huanqian Ritta Szymczak Henryk Szymczak Jan Jun Janusz Karpiński Vitaly Finkel 《Journal of Low Temperature Physics》2003,130(3-4):175-191
We present a study of magneto-thermal instabilities in polycrystalline MgB2 superconductor, by magnetic hysteresis loop measurements and by investigations of magnetic flux dynamics with a miniature Hall probe. Temperature and magnetic field ranges where the flux jumps may be observed have been determined. On the basis of measurements of the magnetic flux dynamics, an average magnetic diffusivity describing the process of the flux jump is estimated. This parameter is compared with the thermal and magnetic diffusivities calculated on the basis of available data for thermal conductivity, heat capacity and resistivity. It is shown that the estimated value of the field of the first flux jump is influenced significantly by the field dependence of specific heat. In order to explain the observed phenomenon, the temperature reached by the sample during the flux jump at different magnetic fields is calculated. 相似文献
4.
Processes of heat and mass exchange which take place in the course of wetting and drying of cereal grain cause internal stress, the result of which are endosperm cracks. This damage, invisible to the naked eye and difficult to detect, causes specific effects, physical as well as biological. Spring wheat grain, cv. Henika, of an initial moisture content of 10% and varied endosperm structure (vitreous and mealy), was subjected to the process of wetting, and then dried under various thermal conditions. Internal damage to grain, caused by those processes, was detected by means of X-ray techniques. The extent of damage was described by means of suitable numerical indexes. Analysis of the results obtained revealed that, irrespective of the methods of grain treatment (wetting or drying), vitreous kernels suffered more extensive damage than mealy ones. The most extensive destruction of endosperm was observed following the drying of grain of high moisture content at high temperature. 相似文献
5.
6.
Dorota Butkiewicz Magorzata Krzeniak Agnieszka Gdowicz-Kosok Monika Giglok Magorzata Marszaek-Zeczak Rafa Suwiski 《International journal of molecular sciences》2021,22(11)
For non-small cell lung cancer (NSCLC), radiotherapy (RT) and platinum-based chemotherapy (CHT) are among the main treatment options. On the other hand, radioresistance and cytotoxic drug resistance are common causes of failure. The epidermal growth factor receptor (EGFR) plays an important role in radioresponse and therapy resistance. We hypothesized that single nucleotide polymorphisms (SNPs) in the EGFR gene might affect individual sensitivity to these treatments, and thus, therapy outcome and prognosis. The association between functional EGFR SNPs and overall (OS), locoregional recurrence-free (LFRS), and metastasis-free (MFS) survival was examined in 436 patients with unresectable NSCLC receiving RT and platinum-based CHTRT. In a multivariate analysis, the rs712830 CC homozygotes showed reduced OS in the whole group (p = 0.039) and in the curative treatment subset (p = 0.047). The rs712829 TT genotype was strongly associated with decreased LRFS (p = 0.006), and the T-C haplotype was a risk factor for locoregional recurrence in our patients (p = 0.003). The rs2227983 GG alone and in combination with rs712829 T was an indicator of unfavorable LRFS (p = 0.028 and 0.002, respectively). Moreover, significant independent effects of these SNPs on OS, LRFS, and MFS were observed. Our results demonstrate that inherited EGFR gene variants may predict clinical outcomes in NSCLC treated with DNA damage-inducing therapy. 相似文献
7.
8.
9.
Paweł Piszcz Magdalena Woźniak Monika Asztemborska Bronisław K. Głód 《Food Analytical Methods》2014,7(7):1474-1480
The present investigation reports on the application of a new antioxidant activity assay for the examination of flavonoids. It has been shown that the high-performance liquid chromatography with electrochemical detection (HPLC–ED) measurements allow to obtain additional information about the antioxidative properties of pure compounds by measuring their half-wave potential, the chromatographic peak height, and the product of the peak height and exponent of potential. In comparison to the classical electrochemical measurements, the HPLC–ED is characterized by a much smaller detection limit. The results were compared with the standard photometric measurement based on 1,1-diphenyl-2-picrylhydrazyl radicals. The possible antioxidant activity forecasting is also discussed. 相似文献
10.
Michał Chojnacki Stanisław Jóźwiak Krzysztof Karczewski Zbigniew Bojar 《Intermetallics》2011,19(10):1555-1562
An attempt to modify sintering of iron and aluminium elemental powders with use of small additions of Mg and MgH2 was presented in this paper. The kinetics of such modified sintering was investigated using DSC technique, XRD analysis and SEM observations. Significant changes in the mechanism of exothermal formation reaction of Fe–Al intermetallic phases in compositions doped with magnesium and its hydride was observed. Initiation temperature of Self-propagating High-temperature Synthesis (SHS) reaction was pronouncedly shifted to lower value as compared with undoped composition. Influence of additions on the SHS reaction kinetics parameters was also calculated with use of the JMA model and changes of the Avrami exponent value of specific phase formation was noticed. Positive effect of MgH2 addition on partial homogeneity of final product was also studied. 相似文献