全文获取类型
收费全文 | 475篇 |
免费 | 36篇 |
国内免费 | 16篇 |
专业分类
电工技术 | 16篇 |
综合类 | 41篇 |
化学工业 | 105篇 |
金属工艺 | 18篇 |
机械仪表 | 30篇 |
建筑科学 | 26篇 |
矿业工程 | 41篇 |
能源动力 | 6篇 |
轻工业 | 43篇 |
水利工程 | 12篇 |
石油天然气 | 32篇 |
武器工业 | 1篇 |
无线电 | 23篇 |
一般工业技术 | 54篇 |
冶金工业 | 36篇 |
原子能技术 | 5篇 |
自动化技术 | 38篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 8篇 |
2021年 | 26篇 |
2020年 | 18篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 11篇 |
2016年 | 20篇 |
2015年 | 17篇 |
2014年 | 30篇 |
2013年 | 24篇 |
2012年 | 30篇 |
2011年 | 38篇 |
2010年 | 29篇 |
2009年 | 30篇 |
2008年 | 21篇 |
2007年 | 30篇 |
2006年 | 30篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 15篇 |
2002年 | 19篇 |
2001年 | 9篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 1篇 |
排序方式: 共有527条查询结果,搜索用时 203 毫秒
1.
二氯甲烷作为溶剂广泛应用于制药行业,其挥发性废气对人类健康和大气环境的危害极大。本文采用生物滴滤床对某制药厂浓度范围在0.02~2g/m3的二氯甲烷废气进行了为期132天的中试规模实验。在适宜的停留时间、温度、喷淋量和pH等实验条件下,控制适当的进气浓度可得到高效去除效率并且废气出口浓度达标。实验揭示了生物膜内生物降解是过程的限制因素,结果表明,在喷淋量为1200L/h、进气浓度范围为0.45~0.65g/m3时该生物系统去除效率最高可达98.9%,最大去除负荷可达ECmax=155.25g/(m3·h)。随着进气浓度的增加,去除负荷随之增大,而去除效率下降,废气出口浓度超标,表明生物滴滤系统已处于反应控制。此外,间歇实验表明,该生物系统具有良好的稳定性。指出生物滴滤床的设计、运行取决于当地的二氯甲烷废气排放标准。 相似文献
2.
研究了海藻化工中以氢氧化钙作为钙化剂的新型钙化工艺,使用氢氧化钙+氯化钙作为褐藻酸钠的钙化剂替代传统的单一氯化钙。确定的双钙钙化工艺条件:每升褐藻酸钠胶液(褐藻酸钠质量浓度为2.5 g/L),添加氯化钙溶液29.0 mL(质量分数为5%),添加氢氧化钙溶液13.75 mL(质量分数为5%),复合钙化剂中氯化钙与氢氧化钙物质的量比为1.19∶1。与传统工艺相比,新型钙化工艺褐藻酸钠的产率未有明显变化,得到的褐藻酸钠粘度稍有降低,粘度由275.1 mPa·s降低至241.3 mPa·s;氯化钙使用量降低40%以上,总钙添加量减少19%。双钙钙化工艺实现了对钙化废水的再利用,废水中钙质量浓度经处理由483 mg/L降到20 mg/L左右,电导率由6.84 mS/cm降至4.28 mS/cm;经脱钙处理的钙化废水回用后对产品褐藻酸钠的产率和粘度没有显著影响。新工艺操作简单,不仅有效减少了钙化废水中离子的引入,同时可以实现低成本地脱钙,脱钙后的废水可以作为冲稀水回收利用,减少了水资源的消耗,为海藻化工行业的减排提供了一条新的工艺途径。 相似文献
3.
Dandan LUO Rui ZHANG Shibo WANG M. Zubair IQBAL Ruibo ZHAO Xiangdong KONG 《材料科学前沿(英文版)》2022,16(4):220617
Herein, the rational design micromilieus involved silk fibroin (SF)-based materials have been used to encapsulate the osteoblasts, forming an extracellular coated shell on the cells, which exhibited the high potential to shift the regulation of osteoblasts to osteocytes by encapsulation cues. SF coating treated cells showed a change in cell morphology from osteoblasts-like to osteocytes-like shape compared with untreated ones. Moreover, the expression of alkaline phosphatase (ALP), collagen I (Col I) and osteocalcin (OCN) further indicated a potential approach for inducing osteoblasts regulation, which typically accelerates calcium deposition and cell calcification, presenting a key role for the SF encapsulation in controlling osteoblasts behavior. This discovery showed that SF-based cell encapsulation could be used for osteoblasts behavior regulation, which offers a great potential to modulate mammalian cells’ phenotype involving alternating surrounding cues. 相似文献
4.
Cdric H. G. Neutel Jhana O. Hendrickx Wim Martinet Guido R. Y. De Meyer Pieter-Jan Guns 《International journal of molecular sciences》2020,21(23)
Background: Autophagy is a highly conserved catabolic homeostatic process, crucial for cell survival. It has been shown that autophagy can modulate different cardiovascular pathologies, including vascular calcification (VCN). Objective: To assess how modulation of autophagy, either through induction or inhibition, affects vascular and valvular calcification and to determine the therapeutic applicability of inducing autophagy. Data sources: A systematic review of English language articles using MEDLINE/PubMed, Web of Science (WoS) and the Cochrane library. The search terms included autophagy, autolysosome, mitophagy, endoplasmic reticulum (ER)-phagy, lysosomal, calcification and calcinosis. Study characteristics: Thirty-seven articles were selected based on pre-defined eligibility criteria. Thirty-three studies (89%) studied vascular smooth muscle cell (VSMC) calcification of which 27 (82%) studies investigated autophagy and six (18%) studies lysosomal function in VCN. Four studies (11%) studied aortic valve calcification (AVCN). Thirty-four studies were published in the time period 2015–2020 (92%). Conclusion: There is compelling evidence that both autophagy and lysosomal function are critical regulators of VCN, which opens new perspectives for treatment strategies. However, there are still challenges to overcome, such as the development of more selective pharmacological agents and standardization of methods to measure autophagic flux. 相似文献
5.
6.
7.
In nature, calcium deposition is a common biological process in mammals that shapes mechanical structures and creates the functions of bones and teeth, and causes calculi formation. Spontaneous tumor calcification and regional lymph node calcification in colorectal cancer, lung cancer, and glioblastoma have been proven to be benign prognostic factors in the clinic. In line with this concept, we introduce the idea and lead the compound development of artificially inducing bionic calcification around the surface of cancer cells. This process is shown to have excellent effects in the inhibition of growth and metastases of cervical, breast, and lung tumors, as well as superb performance in early-stage diagnosis. Therefore, we predict that this concept may open the door for cancer targeting calcification therapy and diagnosis and provide an outlook for a new avenue in anticancer drug development. 相似文献
8.
介绍了白银有色集团股份有限公司铜业公司含砷酸性废水的处理情况.针对系统存在的问题,技术人员采用石灰-铁盐+双氧水工艺对废水处理系统进行改造.改造后废水处理系统出水达到GB 25467—2012《铜、镍、钴工业污染物排放标准》,废水中ρ(As)低于0.5 mg/L,全部回用于循环水系统补水、石灰乳制备等生产工序,实现了废水"零"排放. 相似文献
9.
Anastasia V. Ponasenko Maria V. Khutornaya Anton G. Kutikhin Natalia V. Rutkovskaya Anna V. Tsepokina Natalia V. Kondyukova Arseniy E. Yuzhalin Leonid S. Barbarash 《International journal of molecular sciences》2016,17(9)
Severe bioprosthetic mitral valve calcification is a significant problem in cardiovascular surgery. Unfortunately, clinical markers did not demonstrate efficacy in prediction of severe bioprosthetic mitral valve calcification. Here, we examined whether a genomics-based approach is efficient in predicting the risk of severe bioprosthetic mitral valve calcification. A total of 124 consecutive Russian patients who underwent mitral valve replacement surgery were recruited. We investigated the associations of the inherited variation in innate immunity, lipid metabolism and calcium metabolism genes with severe bioprosthetic mitral valve calcification. Genotyping was conducted utilizing the TaqMan assay. Eight gene polymorphisms were significantly associated with severe bioprosthetic mitral valve calcification and were therefore included into stepwise logistic regression which identified male gender, the T/T genotype of the rs3775073 polymorphism within the TLR6 gene, the C/T genotype of the rs2229238 polymorphism within the IL6R gene, and the A/A genotype of the rs10455872 polymorphism within the LPA gene as independent predictors of severe bioprosthetic mitral valve calcification. The developed genomics-based model had fair predictive value with area under the receiver operating characteristic (ROC) curve of 0.73. In conclusion, our genomics-based approach is efficient for the prediction of severe bioprosthetic mitral valve calcification. 相似文献
10.
Adrian Sequeira Liam Morris Brijesh Patel Lucas Duvall Deepa Gali Denisse Menendez Guy Alexander 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(1):212-214
The dialysis patient is prone to elevations in the calcium phosphorus product and hyperparathyroidism, which contributes to valvular and vascular calcification. We present the case of a young lady on chronic dialysis that developed mitral calcification complicated by severe mitral stenosis, caseous calcification and retinal embolization. She subsequently required mitral valve replacement. 相似文献