全文获取类型
收费全文 | 3304篇 |
免费 | 27篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 213篇 |
金属工艺 | 34篇 |
机械仪表 | 14篇 |
建筑科学 | 20篇 |
矿业工程 | 2篇 |
能源动力 | 52篇 |
轻工业 | 48篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 116篇 |
一般工业技术 | 239篇 |
冶金工业 | 2432篇 |
原子能技术 | 28篇 |
自动化技术 | 129篇 |
出版年
2023年 | 8篇 |
2022年 | 27篇 |
2021年 | 41篇 |
2020年 | 39篇 |
2019年 | 34篇 |
2018年 | 47篇 |
2017年 | 36篇 |
2016年 | 24篇 |
2015年 | 21篇 |
2014年 | 35篇 |
2013年 | 52篇 |
2012年 | 36篇 |
2011年 | 62篇 |
2010年 | 52篇 |
2009年 | 31篇 |
2008年 | 29篇 |
2007年 | 34篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 10篇 |
2003年 | 14篇 |
2002年 | 13篇 |
2001年 | 16篇 |
2000年 | 17篇 |
1999年 | 75篇 |
1998年 | 695篇 |
1997年 | 384篇 |
1996年 | 267篇 |
1995年 | 154篇 |
1994年 | 129篇 |
1993年 | 174篇 |
1992年 | 42篇 |
1991年 | 38篇 |
1990年 | 41篇 |
1989年 | 47篇 |
1988年 | 47篇 |
1987年 | 41篇 |
1986年 | 43篇 |
1985年 | 47篇 |
1984年 | 5篇 |
1983年 | 17篇 |
1982年 | 24篇 |
1981年 | 18篇 |
1980年 | 31篇 |
1978年 | 13篇 |
1977年 | 72篇 |
1976年 | 196篇 |
1975年 | 9篇 |
1974年 | 3篇 |
1955年 | 2篇 |
排序方式: 共有3336条查询结果,搜索用时 15 毫秒
1.
Patel Sapna Kumar Dushyant Chaurasiya Nitesh Kumar Tripathi Shweta 《Semiconductors》2019,53(13):1797-1803
Semiconductors - In the present paper, analytical modeling of surface potential and drain current for hetero-dielectric double gate tunnel FET (HDG-TFET) has been done. The two dimensional (2D)... 相似文献
2.
Deepmala Gupta Arvind Kumar Dwivedi Madhu Tripathi 《Lakes & Reservoirs: Research and Management》2019,24(4):391-393
Knowledge of the length–weight relationships (LWRs) of fish is an important tool to understand fish body form, growth pattern, stock management and their conservation. The present study focused on investigating the length–weight relationships for five catfish species, Pachypterus atherinoides (Bloch, 1794), belonging to family Horabagridae; Batasio batasio (Hamilton, 1822) family Bagridae; Bagarius yarrelli (Sykes, 1839), family Gogangra viridescens (Hamilton, 1822); and Sisor rhabdophorus (Hamilton, 1822) belonging to family Sisoridae. Specimens were collected from the middle stretch of the Ganga River in India from November 2016 to May 2018. A total of 174 specimens of five fish species were collected, and their total lengths were measured to the nearest centimetre and the body weight to the nearest gram. The value of the parameter slope (b) of LWRs of the five species ranged from 2.86 (B. yarrelli) to 3.16 (G. viridescens), with a mean value of 2.99. The results of the present study documented the new maximum total length (TL) for P. atherinoides and S. rhabdophorus. The present study also provides the first reference regarding LWRs for S. rhabdophorus. 相似文献
3.
4.
BACKGROUND: There is controversy over whether colonization with drug-resistant organisms is a contraindication to lung transplantation. METHODS: We undertook a retrospective review of the results of lung transplantation for patients with cystic fibrosis (CF) at Duke University Medical Center. RESULTS: As of May 1996, 21 patients with CF underwent bilateral lung transplantation. The first patient died within 24 h of transplantation from sepsis due to Stenotrophomonas maltophilia. Of the remaining 20 patients, 17 (85%) are alive and in stable condition. The three deaths were related primarily to bronchiolitis obliterans at 4 and 18 months in two patients and to cytomegalovirus pneumonitis at 5 months in the other patient. The 17 surviving patients have been followed up for a mean of 13 months (range, 0.5 to 34 months). Most of them were colonized and infected with multidrug-resistant organisms before transplantation. Following transplantation, 11 patients had complications from infections. One patient had bacteremia due to a panresistant Burkholderia cepacia and was treated successfully. Two patients had bacteremia and wound infection due to Burkholderia gladioli, previously thought to be pathogenic only in plants. Both patients were treated successfully. Of the six patients with Aspergillus fumigatus isolated from cultures before transplantation, only one had invasive disease following transplantation and responded to treatment. CONCLUSION: The organisms present before transplantation were not the primary cause of mortality in our patient population. Our findings suggest that lung transplantation should be considered in CF patients infected with multidrug-resistant organisms. 相似文献
5.
6.
Ovarian mucinous cystadenocarcinoma with mural nodules of anaplastic carcinoma: report of a case and review of the literature 总被引:1,自引:0,他引:1
A decline of cytosol protein kinase C activity was observed in rat myocardial cells at 4 and 8 h after endotoxin administration, and membrane-associated protein kinase C activity rose at the same time. The activity of membrane protein kinase C in aortic smooth muscle cells at 0.5 and 4 h after endotoxin injection was higher than that in control, while cytosol protein kinase C activity was lower. The results indicate that protein kinase C was activated in myocardial cells and aortic smooth muscle cells during various phases of endotoxemia. 相似文献
7.
Dapsone has clinical utility as an anti-inflammatory agent but the mechanism of this action remains unknown. We have previously reported that dapsone inhibits beta2 integrin (CD11b/CD18)-mediated adherence of human neutrophils in vitro and now describe studies designed to discover how dapsone-mediated inhibition of this neutrophil function occurs. Results indicate that dapsone interferes with the activation or function of the G-protein (Gi type) that initiates the signal transduction cascade common to chemotactic stimuli. They also show that dapsone-mediated suppression of this pathway inhibits the generation of second messengers essential to the activation of beta2 integrin molecules, as well as respiratory and secretory functions of neutrophils exposed to chemoattractants. We propose that the inhibition of chemoattractant-induced signal transduction by dapsone suppresses neutrophil recruitment and local production of toxic respiratory and secretory products in the affected skin of dermatitis herpetiformis and other neutrophilic dermatoses. 相似文献
8.
9.
RD Wegner I Henrichs H Joenje T Schroeder-Kurth 《Canadian Metallurgical Quarterly》1996,50(6):479-482
The clinical and cytogenetic data of the first patient proven to belong to the fifth Fanconi anemia complementation group are described. The Turkish boy presented with psychomotoric retardation, growth retardation, retarded bone age, brachycephaly, hypotelorism, epicanthus, syndactyly, brachydactyly, renal dystopia, and cryptorchism. In addition, an asymmetrical skeletal anomaly was seen with a double distal phalanx of the left thumb and hypoplasia of the right thumb. Typical hematological features of the disorder developed, at the age of 2.5 years, about 1 year after diagnosis. Cytogenetic studies confirmed the clinical diagnosis and revealed a spontaneous chromosomal instability and hypersensitivity to the cross-linking agents diepoxybutane and Trenimon. The findings in the patient, who is considered to be the standard for the fifth Fanconi anemia complementation group, are compared with data reported for other patients affected with Fanconi anemia. 相似文献
10.