全文获取类型
收费全文 | 437篇 |
免费 | 17篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 187篇 |
金属工艺 | 5篇 |
机械仪表 | 6篇 |
建筑科学 | 25篇 |
能源动力 | 16篇 |
轻工业 | 73篇 |
水利工程 | 3篇 |
武器工业 | 1篇 |
无线电 | 15篇 |
一般工业技术 | 57篇 |
冶金工业 | 7篇 |
自动化技术 | 55篇 |
出版年
2022年 | 20篇 |
2021年 | 31篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 34篇 |
2012年 | 31篇 |
2011年 | 17篇 |
2010年 | 22篇 |
2009年 | 18篇 |
2008年 | 14篇 |
2007年 | 14篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 23篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1973年 | 3篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有455条查询结果,搜索用时 0 毫秒
61.
Tomczyk Monika Osewski Pawel Berger Marie-Helene Diduszko Ryszard Jóźwik Iwona Adamo Giorgio Pawlak Dorota A. 《Journal of Materials Science》2021,56(19):11219-11228
Journal of Materials Science - Zinc oxide (ZnO) nanostructures exhibiting high exciton binding energy and efficient radiative recombination, even at the room temperature, are of increasing interest... 相似文献
62.
Wójcik Natalia A. Tagiara Nagia S. Möncke Doris Kamitsos Efstratios I. Ali Sharafat Ryl Jacek Barczyński Ryszard J. 《Journal of Materials Science》2022,57(3):1633-1647
Journal of Materials Science - Electrical properties of beryllium-alumino-tellurite glasses and glass–ceramics doped with iron ions were studied using impedance spectroscopy. The conductivity... 相似文献
63.
64.
Precolumn isotope dilution analysis in nanoHPLC-ICPMS for absolute quantification of sulfur-containing peptides 总被引:1,自引:0,他引:1
Schaumlöffel D Giusti P Preud'Homme H Szpunar J Łobiński R 《Analytical chemistry》2007,79(7):2859-2868
A novel generic approach based on precolumn isotope dilution nanoHPLC-ICPMS analysis was developed for the accurate absolute quantification of sulfur-containing peptides. A 34S-labeled, species-unspecific sulfur spike (sulfate), noninteracting with analyte peptides under the optimized HPLC condition, was added directly to the chromatographic eluents. Thus a generic sulfur standard permanently present during analysis was used for peptide quantification. Interference-free detection of the 32S and 34S isotopes in ICPMS was achieved by eliminating O2+ ions in a collision cell using Xe gas at 130 microL min-1. The detection limit for sulfur was 45 microg L-1 which corresponded to 1-2 pmol of individual peptides. The method was validated by the analysis of a standard peptide solution showing high accuracy (recovery 103%) and good precision (RSD 2.1%). The combination of nanoHPLC-ICP IDMS with nanoHPLC-ESI MS/MS allowed the precise quantification and identification of sulfur-containing peptides in tryptic digests of human serum albumin and salt-induced yeast protein (SIP18) at the picomole level. 相似文献
65.
Ballihaut G Claverie F Pécheyran C Mounicou S Grimaud R Lobinski R 《Analytical chemistry》2007,79(17):6874-6880
A laser ablation-ICPMS method using an infrared (1030 nm), low-energy (39 microJ/pulse), high repetition rate (10 kHz), femtosecond laser was developed to improve the sensitivity of detection of heteroatom-containing proteins in 1D polyacrylamide gels. A 2-mm-wide lane was ablated by ultrafast (10 cm s(-1)) back-and-forth movement of a 20-microm laser beam parallel to the protein bands while the gel advanced perpendicularly. This procedure resulted in a considerable increase in detection sensitivity (>40-fold) compared to the nanosecond 266-nm laser ablation-ICPMS, mainly because of the much larger amount of ablated material introduced into the plasma on the time scale of the dwell time of the mass spectrometer. The method was applied to the specific detection in the gel of formate dehydrogenase expressed in Escherichia coli and of selenoproteins in Desulfococcus multivorans with detection limits at the low-femtomolar levels. 相似文献
66.
Wesolowski R Sommer A Arndt HD Koert U Reiss P Wimmers S Strauss O 《Chembiochem : a European journal of chemical biology》2007,8(5):513-520
The function of a gramicidin hybrid ion channel in living Chinese hamster ovary (CHO) cells was investigated by the patch clamp method. The synthetic ion channel 1 consists of two cyclohexyl ether amino acids that link two mini-gramicidin strands. With 1 at a concentration of 1.0 microM, an increase in the whole-cell membrane conductance was observed after 1.37 min. The conductance showed larger currents when Cs(+) was used as charge carrier than when Na(+) and K(+) were used. In single-channel recordings with Cs(+) as charge carrier, the substance showed comparable single-channel amplitudes in the membrane of living cells and artificial black lipid bilayers. In addition to functioning as a cation channel, compound 1 appeared to be a water channel. Exposure of the CHO cells to an extracellular hypoosmotic solution did not substantially change the cell volume. Extracellular hypoosmotic conditions in the presence of 1 increased the cell size to 146.5 % that of the control. Thus, the synthetic hybrid channel 1 can function as a cation channel with some Cs(+) specificity, and as a water channel in CHO cells. 相似文献
67.
Tomasz Kostrzewa Karol Woosewicz Marek Jamrozik Joanna Drzedon Julia Siemiska Dagmara Jacewicz Magdalena Grska-Ponikowska Marcin Koaczkowski Ryszard a
ny Alicja Kuban-Jankowska 《International journal of molecular sciences》2021,22(19)
Breast cancer is the most common cancer of women—it affects more than 2 million women worldwide. PTP1B phosphatase can be one of the possible targets for new drugs in breast cancer therapy. In this paper, we present new curcumin derivatives featuring a 4-piperidone ring as PTP1B inhibitors and ROS inducers. We performed cytotoxicity analysis for twelve curcumin derivatives against breast cancer MCF-7 and MDA-MB-231 cell lines and the human keratinocyte HaCaT cell line. Furthermore, because curcumin is a known antioxidant, we assessed antioxidant effects in its derivatives. For the most potent cytotoxic compounds, we determined intracellular ROS and PTP1B phosphatase levels. Moreover, for curcumin and its derivatives, we performed real-time microscopy to observe the photosensitizing effect. Finally, computational analysis was performed for the curcumin derivatives with an inhibitory effect against PTP1B phosphatase to assess the potential binding mode of new inhibitors within the allosteric site of the enzyme. We observed that two tested compounds are better anticancer agents than curcumin. Moreover, we suggest that blocking the -OH group in phenolic compounds causes an increase in the cytotoxicity effect, even at a low concentration. Furthermore, due to this modification, a higher level of ROS is induced, which correlates with a lower level of PTP1B. 相似文献
68.
Ryszard Zielinski 《时间序列分析杂志》1999,20(4):477-481
A proof is given that the median of the ratios of consecutive observations of a stationary first-order autoregressive process Xt = α X t −1 + Yt with P ( Yt ≥ 0) = P ( Yt ≤ 0) = 1/2 and P ( Xt = 0) = 0 is a median-unbiased estimator of α. 相似文献
69.
The compression specificity of plant tissue 总被引:1,自引:0,他引:1
The aim of this study was to determine the compression characteristics of nonhomogeneous plant materials with a complex morphological structure (beetroots, celery roots, and potato tubers), to compare the analyzed samples with the compression characteristics of reference materials (homogeneous isotropic structural materials: steel coil spring and vulcanized rubber), and to determine the influence of the compression rate on stress in compressed samples. Structural materials and plant materials clearly differed in compression characteristics. Excluding the short initial compression phase, the compression curves for the steel coil spring and vulcanized rubber were straight parallel lines, and the higher the crosshead speed, the higher the lines' location in the diagram. In tests conducted on plant materials, the rate of changes in compression force increased throughout the experiment with an increase in crosshead speed. The greatest variations in compression force resulting from differences in crosshead speed were observed in potato samples. The apparent retardation times determined in the developed rheological model ranged from 0.079 s for the steel coil spring to 6.863 s for potatoes. 相似文献
70.
Ryszard Ukielski 《大分子材料与工程》2001,286(6):337-341
The phenomenon of the occurrence of a middle‐temperature thermal effect in crystallizable multiblock thermoplastic elastomers, the so‐called annealing endotherm has not yet been univocally explained, hence, it was subjected to DSC analysis. The formation of this endotherm in response to the time and temperature of conditioning (stabilisation) of the sample has been followed. The investigations have been performed for a specific polymer system, poly(tetramethylene terephthalate)‐block‐poly(oxytetramethylene)‐block‐polylaurolactam‐(PBT‐b‐PTMO‐b‐PA12)‐n. The specific property of this elastomer is the solubility or a partial solubility of one of the components (PBT block) in the two remaining ones being mutually insoluble. The occurrence of the two different amorphous phases (PBT and PA12) in this elastomer with glass transition temperatures Tg > 20°C is also possible. This specific system permits to observe an interesting phenomenon, since at the points determining the middle‐temperatures of the glass transition temperatures of the elastomer, the two small endotherms are shaping; after proper stabilisation they are approaching each other, and as a result of this process they would form one extreme. This extreme comprises the thermal effect of the dispersion of the mesomorphic aggregates being the intermediate form between the amorphous state and the crystalline state. The mesomorphic aggregates constitute the additional network points of the physical polymer network of the elastomer. 相似文献