全文获取类型
收费全文 | 728篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 30篇 |
金属工艺 | 4篇 |
机械仪表 | 17篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 4篇 |
石油天然气 | 3篇 |
无线电 | 4篇 |
一般工业技术 | 25篇 |
冶金工业 | 631篇 |
原子能技术 | 1篇 |
自动化技术 | 6篇 |
出版年
2023年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 11篇 |
2007年 | 2篇 |
2006年 | 12篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 20篇 |
1998年 | 194篇 |
1997年 | 122篇 |
1996年 | 84篇 |
1995年 | 44篇 |
1994年 | 32篇 |
1993年 | 31篇 |
1992年 | 10篇 |
1991年 | 21篇 |
1990年 | 13篇 |
1989年 | 15篇 |
1988年 | 16篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 7篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 14篇 |
排序方式: 共有732条查询结果,搜索用时 0 毫秒
731.
Removal of hexavalent chromium from wastewater using a new composite chitosan biosorbent 总被引:4,自引:0,他引:4
A new composite chitosan biosorbent was prepared by coating chitosan, a glucosamine biopolymer, onto ceramic alumina. The composite bioadsorbent was characterized by high-temperature pyrolysis, porosimetry, scanning electron microscopy, and X-ray photoelectron spectroscopy. Batch isothermal equilibrium and continuous column adsorption experiments were conducted at 25 degrees C to evaluate the biosorbent for the removal of hexavalent chromium from synthetic as well as field samples obtained from chrome plating facilities. The effect of pH, sulfate, and chloride ion on adsorption was also investigated. The biosorbent loaded with Cr(VI) was regenerated using 0.1 M sodium hydroxide solution. A comparison of the results of the present investigation with those reported in the literature showed that chitosan coated on alumina exhibits greater adsorption capacity for chromium(VI). Further, experimental equilibrium data were fitted to Langmuir and Freundlich adsorption isotherms, and values of the parameters of the isotherms are reported. The ultimate capacity obtained from the Langmuir model is 153.85 mg/g chitosan. 相似文献
732.
CP Chiang JS Huang JT Wang BY Liu YS Kuo LJ Hahn MY Kuo 《Canadian Metallurgical Quarterly》1999,28(2):72-76
Expression of p53 protein was examined in oral squamous cell carcinoma (SCC) from patients who were areca quid (AQ) chewers and/or tobacco smokers, using anti-p53 antibodies with an immunoperoxidase technique. Positive p53 stain was observed in 47 of 81 (58%) cases of oral SCC. p53 overexpression was found to be higher in patients without AQ chewing and smoking habits than in patients with these two habits (80% vs 52%, P=0.076). No significant correlation was found between p53 expression and the patients' age, sex, cancer location, clinical staging, primary tumor TNM status, or histological differentiation of SCC. The Kaplan-Meier analysis showed that the prognosis for patients with p53-negative tumors was significantly better than that for patients with p53-positive tumors (P<0.05). A significant correlation was also observed between positive lymph node status and poor prognosis (P<0.05). These results suggest that p53 may serve as an adjuvant marker of poor survival in patients with oral SCCs in Taiwan. 相似文献