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141.
最近,美国Longyear公司利用HD600型小钻机、泵和井下钻具,为美国一家大石油公司在沉积岩中取芯钻探油、气井,井径4 3/8英寸(110毫米),井深8000英尺(2438米)。所钻出的井允许采用石油工业小尺寸的标准测井工具录井。取芯钻进工程为地质师和工程师们掌握井下地质实况提供了宝贵资料。这种钻机搬迁简易,尤其适合于运输条件困难、成本高、地质情况不明的边远地区勘探油、气田之用。 相似文献
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世界范围内,一些石油公司通常用油藏数值模拟作为一种工程手段,对其油气藏进行有效的管理。用大量的网格块建造模型的工作不容易,而大量的模型结果分析了工作更加困难。本文讨论了过去十多年来用于油藏模拟数据分析方法的历史发展过程,并概述了工作站技术的和使用X-Window系统开发一种全新的使用主机计算能力和工作站图形显示能力的方法。本文亦讨论了Saudi Aramco公司开发的几种综合性油藏模拟后处理软件包 相似文献
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Effect of exogenous somatotropin in Holstein calves on mammary gland composition and proliferation 总被引:1,自引:0,他引:1
Huderson BP Velayudhan BT Pearson RE Ellis SE Akers RM 《Journal of dairy science》2011,94(10):5005-5016
Pubertal mammary gland growth and development are hormonally regulated, but the details are poorly understood in calves. Our purpose was to evaluate the effects of exogenous growth hormone (GH) on the biochemical composition of the prepubertal mammary gland, mRNA expression of selected genes, and histological characteristics of the developing parenchyma (PAR). In this experiment, 19 calves (7 ± 4 d of age) were randomly assigned to 1 of 2 treatments: bovine somatotropin (bST, 500 mg; n = 10) or placebo (Sal; 0.9% saline; n = 9). Animals were treated every 3 wk beginning on d 23. Calves were assigned to an early (65 d; tissue harvested after 2 treatment injections) or late collection time (107 d; tissue harvested after 4 treatment injections). Calves were fed milk replacer and calf starter for 8 wk and starter and hay thereafter. Parenchyma and mammary fat pad (MFP) from one udder half were harvested for analysis of protein, lipid, and DNA. Additional tissues were preserved for histological analysis or snap-frozen for quantitative real-time PCR. Somatotropin treatment did not significantly alter the mass of PAR or MFP or the general pattern of development of epithelial structures. Significant increases were observed in protein/100 kg of body weight (BW), total protein, DNA concentration, DNA/100 kg of BW, and total DNA in 107-d calves, and a significant treatment by day interaction was observed for DNA and lipid concentrations in PAR. In MFP, a significant decrease was observed in protein/100 kg of BW in bST-treated calves and in total MFP protein in 65-d calves. A treatment by day interaction was found for total protein, DNA, and protein/100 kg of BW. In PAR, relative expression of ATPase-binding cassette 3 and growth hormone receptor were reduced by bST and both were lower in 107-d-harvest calves. Epithelial cell retention of bromodeoxyuridine (BrdU; possible indicator of stem-like cells) was greatest in 65-d bST-treated calves, and a significant time of sampling response and treatment × time interaction were observed. Expression of the proliferation marker protein Ki67 was numerically higher in bST-treated calves but the difference was nonsignificant. Retention of the BrdU label was reduced in 107-d calves. Exogenous growth hormone given to calves may affect mammary tissue composition and epithelial cell gene expression in subtle ways but exogenous supplementation with bST alone is not likely to alter overall development patterns or affect the mass of mammary parenchymal tissue. Whether such subtle changes have an effect on subsequent development or function is unknown. 相似文献
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Escherichia coli O157:H7 has been associated with numerous outbreaks involving fresh produce. Previous studies have shown that bacteria can be internalized within plant tissue and that this can be a source of protection from antimicrobial chemicals and environmental conditions. However, the types of tissue and cellular locations the bacteria occupy in the plant following internalization have not been addressed. In this study, immunocytochemical techniques were used to localize internalized E. coli O157:H7 expressing green fluorescent protein in germinated mung bean (Vigna radiata) hypocotyl tissue following contamination of intact seeds. An average of 13 bacteria per mm(3) were localized within the sampled tissue. The bacteria were found to be associated with every major tissue and corresponding cell type (cortex, phloem, xylem, epidermis, and pith). The cortical cells located on the outside of the vascular bundles contained the majority of the internalized bacteria (61%). In addition, the bacteria were localized primarily to the spaces between the cells (apoplast) and not within the cells. Growth experiments were also performed and demonstrated that mung bean plants could support the replication of bacteria to high levels (10(7) CFU per plant) following seed contamination and that these levels could be sustained over a 12-day period. Therefore, E. coli O157:H7 can be internalized in many different plant tissue types after a brief seed contamination event, and the bacteria are able to grow and persist within the plant. 相似文献
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A novel, simple geometry for high throughput electrospinning from a bowl edge is presented that utilizes a vessel filled with a polymer solution and a concentric cylindrical collector. Successful fiber formation is presented for two different polymer systems with differing solution viscosity and solvent volatility. The process of jet initiation, resultant fiber morphology and fiber production rate are discussed for this unconfined feed approach. Under high voltage initiation, the jets spontaneously form directly on the fluid surface and rearrange along the circumference of the bowl to provide approximately equal spacing between spinning sites. Nanofibers currently produced from bowl electrospinning are identical in quality to those fabricated by traditional needle electrospinning (TNE) with a demonstrated ~ 40 times increase in the production rate for a single batch of solution due primarily to the presence of many simultaneous jets. In the bowl electrospinning geometry, the electric field pattern and subsequent effective feed rate are very similar to those parameters found under optimized TNE experiments. Consequently, the electrospinning process per jet is directly analogous to that in TNE and thereby results in the same quality of nanofibers. 相似文献