全文获取类型
收费全文 | 5314篇 |
免费 | 190篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 55篇 |
综合类 | 2篇 |
化学工业 | 1065篇 |
金属工艺 | 56篇 |
机械仪表 | 93篇 |
建筑科学 | 195篇 |
矿业工程 | 3篇 |
能源动力 | 155篇 |
轻工业 | 565篇 |
水利工程 | 43篇 |
石油天然气 | 43篇 |
无线电 | 268篇 |
一般工业技术 | 536篇 |
冶金工业 | 1635篇 |
原子能技术 | 14篇 |
自动化技术 | 785篇 |
出版年
2024年 | 11篇 |
2023年 | 46篇 |
2022年 | 116篇 |
2021年 | 171篇 |
2020年 | 103篇 |
2019年 | 138篇 |
2018年 | 144篇 |
2017年 | 118篇 |
2016年 | 187篇 |
2015年 | 91篇 |
2014年 | 168篇 |
2013年 | 322篇 |
2012年 | 257篇 |
2011年 | 320篇 |
2010年 | 236篇 |
2009年 | 249篇 |
2008年 | 221篇 |
2007年 | 171篇 |
2006年 | 126篇 |
2005年 | 93篇 |
2004年 | 98篇 |
2003年 | 79篇 |
2002年 | 81篇 |
2001年 | 47篇 |
2000年 | 36篇 |
1999年 | 92篇 |
1998年 | 583篇 |
1997年 | 328篇 |
1996年 | 189篇 |
1995年 | 126篇 |
1994年 | 88篇 |
1993年 | 123篇 |
1992年 | 37篇 |
1991年 | 28篇 |
1990年 | 27篇 |
1989年 | 26篇 |
1988年 | 28篇 |
1987年 | 15篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 18篇 |
1979年 | 3篇 |
1978年 | 9篇 |
1977年 | 29篇 |
1976年 | 57篇 |
1962年 | 1篇 |
排序方式: 共有5513条查询结果,搜索用时 0 毫秒
1.
Fernando J. Muzzio Marcos Llusa Christopher L. Goodridge Nhat-Hang Duong Elizabeth Shen 《Powder Technology》2008,186(3):247-254
This paper investigates the effects of processing and equipment parameters of a ribbon blender (i.e. loading method of lubricant, fill level, blade speed and blade design) on magnesium stearate homogeneity. A core sampling technique is used to obtain at least one hundred samples per sampling event, which are extracted throughout the blender and yield a thorough characterization of the entire bed. The results presented here can be used as a guideline to develop appropriate blending processes and characterization protocols for ribbon blenders. 相似文献
2.
3.
4.
Fernando J Beltrn F Javier Rivas Olga Gimeno 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(9):973-984
Photocatalytic ozonation (1O3 + VUV + TiO2), ozonation (O3), catalytic ozonation (O3 + TiO2), ozone photolysis (O3 + VUV), photocatalysis (TiO2 + VUV) and photolysis (VUV) have been compared in terms of formation of intermediates, extent of, mineralization (TOC, COD, chloride, nitrate) and kinetics in the aqueous treatment of three phenols (phenol, p‐chlorophenol and p‐nitrophenol). In all cases, photocatalytic ozonation led to lower degradation times for chemical oxygen demand and total organic carbon removal. Intermediates formed were similar in the different oxidation systems with some exceptions. They can be classified into three different types: polyphenols (resorcinol, catechol, hydroquinone), unsaturated carboxylic acids (maleic and fumaric acids) and saturated carboxylic acids (glyoxylic, formic and oxalic acids). First order kinetic equations have been checked for the oxidation processes studied in the case of the parent compound. Rate constants of these systems have also been calculated. Copyright © 2005 Society of Chemical Industry 相似文献
5.
6.
KL Hopkins PK Dickson TI Ball RR Ricketts PA O'Shea CR Abramowsky 《Canadian Metallurgical Quarterly》1997,32(10):1476-1479
Fetus-in-fetu is an unusual condition in which a vertebrate fetus is enclosed within the abdomen of another fetus. These occurrences are usually benign. This report describes an instance of malignant recurrence after resection of a fetus-in-fetu. 相似文献
7.
Qualitative urinalysis methods of monitoring cocaine use may over-detect frequency of use, possibly decreasing the ability of clinical trials to detect effective treatments. Quantitative urinalysis and newly developed criteria for identifying new cocaine use were evaluated as alternative measures of cocaine use. Urine specimens collected in a cocaine dosing study in non-treatment-seeking subjects (n = 5) and a cocaine treatment trial (n = 37) were analyzed for the cocaine metabolite, benzoylecgonine, with qualitative and quantitative methods. Pharmacokinetic criteria ('New Use' rules) were applied to quantitative data to identify occasions of new cocaine use. Results were compared to known cocaine administrations in the laboratory study and to self-reported drug use and qualitative urinalysis for subjects in the clinical trial. New Use criteria correctly identified cocaine administrations in the cocaine dosing study in all but a small number of specimens. In the clinical trial, quantitative urinalysis and estimated New Uses provided more information about patterns and frequency of use than qualitative urinalysis in the different treatment conditions in the clinical trial. Interpretation of quantitative urinalysis with New Use rules appears to be a useful method for monitoring treatment outcome and may be more accurate than traditional qualitative urinalysis in estimating frequency of cocaine use. 相似文献
8.
PURPOSE: We describe a new method of using a Foley catheter to assist vesicourethral anastomosis during radical retropubic prostatectomy. MATERIALS AND METHODS: A total of 81 patients underwent radical retropubic prostatectomy with this technique. Followup ranged from 4 to 48 months. Peri-catheter urethrograms were performed at 3 weeks. Patients were evaluated specifically for bladder neck contracture, urinary continence and prolonged catheterization. RESULTS: Bladder neck contracture, occurred in 4.9% of the patients and 87.6% were completely continent of urine. Only 1 patient required extended postoperative catheterization. CONCLUSIONS: Use of a Foley catheter for vesicourethral anastomosis is consistent and simple, and provided good surgical results in our experience. 相似文献
9.
KL Hardie S Kinlay DB Hardy J Wlodarczyk JS Silberberg PJ Fletcher 《Canadian Metallurgical Quarterly》1997,27(6):649-652
Minimally invasive plastic surgery has expanded beyond the original confines of aesthetic applications to encompass all our endeavors in an attempt to restrict the size of surgical scars, limit postoperative discomfort, and hasten recovery of function. This evolution has already delineated methods to raise our workhorse muscle flaps and has negated the risks of laparotomy for various visceral flaps. It is then only a logical progression to use these endoscopic techniques to harvest fascial flaps so as to avoid the notorious donor site morbidity of the fasciocutaneous flap, which has certainly hindered the rapid acceptance of these otherwise valuable flaps. Endoscopic-facilitated elevation of a local adipofascial flap is described for which little or no additional skin incisions need ever be made. 相似文献
10.