全文获取类型
收费全文 | 964篇 |
免费 | 85篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 15篇 |
综合类 | 3篇 |
化学工业 | 242篇 |
金属工艺 | 21篇 |
机械仪表 | 48篇 |
建筑科学 | 24篇 |
矿业工程 | 3篇 |
能源动力 | 41篇 |
轻工业 | 129篇 |
水利工程 | 12篇 |
石油天然气 | 11篇 |
无线电 | 78篇 |
一般工业技术 | 181篇 |
冶金工业 | 119篇 |
原子能技术 | 8篇 |
自动化技术 | 118篇 |
出版年
2024年 | 5篇 |
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 46篇 |
2020年 | 38篇 |
2019年 | 42篇 |
2018年 | 43篇 |
2017年 | 46篇 |
2016年 | 49篇 |
2015年 | 30篇 |
2014年 | 42篇 |
2013年 | 83篇 |
2012年 | 45篇 |
2011年 | 65篇 |
2010年 | 53篇 |
2009年 | 45篇 |
2008年 | 45篇 |
2007年 | 32篇 |
2006年 | 26篇 |
2005年 | 25篇 |
2004年 | 24篇 |
2003年 | 22篇 |
2002年 | 13篇 |
2001年 | 18篇 |
2000年 | 16篇 |
1999年 | 16篇 |
1998年 | 30篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 21篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1053条查询结果,搜索用时 328 毫秒
121.
MM Ferreira H Mansinho A Fernandes FS Pereira JA Assis e Santos 《Canadian Metallurgical Quarterly》1994,7(5):307-309
Benign mesothelioma of the pleura is a very rare tumor. The cells responsible originate from either the mesothelium or the submesothelium. This is why such tumors are described in the literature as fibroma of the pleura, mesothelial fibroma, localized fibrous mesothelioma and monophasic spindle cell tumor. Their growth, is very slow taking several years or even decades. In contrast to the more common malignant mesothelioma of the pleura, it is not related to asbestos exposure. This report deals with a 47-year-old woman patient with a giant benign mesothelioma of the pleura in the region of the right thorax, which was completely removed by thoracotomy. 相似文献
122.
M Cendoroglo Neto SA Draibe AE Silva ML Ferraz C Granato CA Pereira RC Sesso AM Gaspar H Ajzen 《Canadian Metallurgical Quarterly》1995,10(2):240-246
Hepatitis B virus (HBV) serum markers (HBsAg, anti-HBs, anti-HBc) and antihepatitis C antibody (anti-HCV) were prospectively followed in haemodialysis and CAPD patients. From January 1987 to January 1990, 185 patients on haemodialysis and 124 on CAPD were analysed. Among patients susceptible to HBV (69 on haemodialysis and 70 on CAPD), there were 17 HBsAg seroconversions on haemodialysis (0.19/patient-year) and 1 on CAPD (0.01/patient-year). A Cox proportional hazards model showed that haemodialysis treatment was the only risk factor significantly associated with HBV infection, thus suggesting transmission through the environment. Regarding hepatitis C, 83 anti-HCV-negative patients on haemodialysis and 46 on CAPD were followed. There were 18 seroconversions on haemodialysis (0.15/patient-year) and two seroconversions on CAPD (0.03/patient-year). Haemodialysis treatment was also the only risk factor significantly associated with a higher risk of HCV infection. The hazard ratio for HCV infection in haemodialysis patients was 5.7 compared to CAPD patients. Nevertheless, for one patient on CAPD treatment transfusions were the only possible source of HCV infection. In conclusion, both viruses were transmitted mainly through the haemodialysis environment, but the role of transfusions could not be excluded. 相似文献
123.
Combined and staged treatment is a new clinical methodology for the orientation of drug addiction cases within families. This methodology resorts to several techniques in a combined way, such as: family therapy and counselling; the use of psychopharmacology and opioide antagonists; as well as individual and group psycho-therapeutics. These are all linked to a personal psycho-social rehabilitation program. This treatment is based on family accessibility and therapeutic community programs. The authors review different contributions and the evolution of different therapeutic modalities. Finally they propose a list for inductions and another for the formal contra-indications for this kind of treatment. 相似文献
124.
Tereza Neuma de Castro Dantas Leocadia Terezinha Cordeiro Beltrame Afonso Avelino Dantas Neto Maria Carlenise Paiva de Alencar Moura 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(6):645-650
One of the major environmental problems in the textile dyeing industry is the removal of color from effluents. The present study deals with color removal from effluents using microemulsions. The wastewater used in this study was the reactive exhausted dye liquor from a dyeing house containing Procion Yellow H‐E4R (CI Reactive Yellow 84), Procion Blue H‐ERD (CI Reactive Blue 160) and Procion Red H‐E3B (CI Reactive Red 120). Color removal was determined by CIE L*a*b* (CIELAB) color space, CIE L*a*b* color difference, ΔE*ab, and absorbance. Color removal greater than 95% was achieved, attaining values lower than the consent requirements established by the Environmental Agency. It was observed that pH is an important parameter in color removal and effluent pH correction from 10.44 to 9 before extraction improved results. The results obtained were modeled using the Scheffé net method and evaluated through the construction of isoresponse diagrams by correlation graphics between experimental values and those obtained through use of model equations, providing an experimental error of less than 2%. The optimized method very efficiently removed all dyes contained in the effluent. The same microemulsion phase recovered after the extraction process can be used at least a further 14 times and all the extractions gave good color removal. Copyright © 2004 Society of Chemical Industry 相似文献
125.
FA Atik GJ Lopes Filho Mde M Linhares J Seda Neto NS Mansur 《Canadian Metallurgical Quarterly》1998,116(4):1781-1783
The authors report a case of a 25 year old Brazilian man with a history of crampy abdominal pain in the left iliac fossa for 2 weeks, abdominal distention, mucous diarrhea and anorexia. The patient presented signs of hemodynamic instability and a hard mass palpated in the left iliac fossa presented peritoneal irritation. At laparotomy, fecal peritonitis and a punched-out perforation of the midsigmoid colon were found. A left hemicolectomy was performed with terminal colostomy. Specimen examination revealed a thickened rectosigmoid wall, narrow lumen and multiple mucosal polyps. Microscopically, chronic granulomatous colitis with Schistosoma mansoni eggs confirmed the etiology. To the authors' knowledge, this is the first case of obstruction complicated with perforation due to mansoni schistosomiasis reported in the literature. 相似文献
126.
The interplay of transverse and longitudinal fluctuations of a stripe is analyzed using bosonization techniques. We show the existence of a charge-density-wave instability for quarter-filled stripes if the underlying lattice potential has a zigzag symmetry. Our results are in accordance with the observation of static stripes formation in underdoped La2–x–y
Nd
y
Sr
X
CuO4 exactly at the onset of the low-temperature-tetragonal transition. 相似文献
127.
128.
CA Funayama M De F Turcato R Moura-Ribeiro GM Rocha JM Pina Neto MV Moura-Ribeiro 《Canadian Metallurgical Quarterly》1995,53(4):799-801
A rare case of recurrent meningitis due to congenital anterior sacral meningocele and agenesis of the sacral and coccygeal vertebrae is described. An autosomal dominant inheritance is demonstrated for lower cord malformation, and environmental factors (chromic acid or fumes) are discussed. 相似文献
129.
Among many waterborne diseases the giardiasis and cryptosporidiosis are of particular public health interest, because Giardia cysts and Cryptosporidium oocysts can persist for long periods in the environment, and both pathogenic protozoa have been implicated as the cause of many outbreaks of gastroenteritis in the last 25 years. In order to evaluate the efficiency of cysts and oocysts' removal by the activated sludge process, and by UV reactor in inactivating cysts and oocysts in one wastewater treatment plant (WWTP) of Campinas, three sampling points were selected for study: (1) influent, (2) treated effluent without UV disinfection and (3) treated effluent with UV disinfection. Giardia spp. cysts prevailed with higher density in the three different sample types. Cryptosporidium spp. oocysts were observed in only two samples of influent and just one sample of treated sewage with UV disinfection. In the animal infectivity assay for Giardia spp, one mouse of the UV treated group revealed trophozoites in intestinal scrapings. The results of the present study indicate that treatment by activated sludge process delivered a reduction of 98.9% of cysts and 99.7% of oocysts and UV disinfection was not completely efficient regarding the inactivation of Giardia cysts in the case of the WWTP studied. 相似文献
130.
P. R. S. Gomes T. J. P. Penna
R. Liguori Neto
J. C. Acquadro C. Tenreiro P. A. B. Freitas E. Crema N. Carlin Filho M. M. Coimbra 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1989,280(2-3):395-401The in-beam and off-beam gamma-ray spectroscopy method, as a tool for the study of nuclear fusion between heavy ions, is described. These methods allow the study of the production and decay of the compound nucleus, inelastic scattering and transfer reactions. In this work we report the determination of fusion cross sections at energies near and below the Coulomb barrier for a series of systems: targets of 46,50Ti, 59Co and 64,66Zn bombarded by 14N and 16O projectiles. Cross sections from 0.4 to 1000 mb were measured. 相似文献