全文获取类型
收费全文 | 4126篇 |
免费 | 28篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 13篇 |
综合类 | 16篇 |
化学工业 | 55篇 |
金属工艺 | 13篇 |
机械仪表 | 28篇 |
建筑科学 | 25篇 |
矿业工程 | 19篇 |
能源动力 | 12篇 |
轻工业 | 67篇 |
水利工程 | 4篇 |
石油天然气 | 6篇 |
武器工业 | 1篇 |
无线电 | 46篇 |
一般工业技术 | 64篇 |
冶金工业 | 3721篇 |
原子能技术 | 10篇 |
自动化技术 | 64篇 |
出版年
2025年 | 8篇 |
2024年 | 12篇 |
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 28篇 |
2020年 | 14篇 |
2019年 | 22篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 16篇 |
2014年 | 19篇 |
2013年 | 35篇 |
2012年 | 27篇 |
2011年 | 24篇 |
2010年 | 21篇 |
2009年 | 25篇 |
2008年 | 17篇 |
2007年 | 14篇 |
2006年 | 15篇 |
2005年 | 26篇 |
2004年 | 13篇 |
2003年 | 9篇 |
2002年 | 13篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 113篇 |
1998年 | 1220篇 |
1997年 | 706篇 |
1996年 | 415篇 |
1995年 | 251篇 |
1994年 | 197篇 |
1993年 | 212篇 |
1992年 | 39篇 |
1991年 | 25篇 |
1990年 | 42篇 |
1989年 | 36篇 |
1988年 | 48篇 |
1987年 | 37篇 |
1986年 | 35篇 |
1985年 | 35篇 |
1983年 | 4篇 |
1982年 | 15篇 |
1981年 | 19篇 |
1980年 | 25篇 |
1978年 | 12篇 |
1977年 | 83篇 |
1976年 | 149篇 |
1975年 | 11篇 |
1955年 | 3篇 |
排序方式: 共有4164条查询结果,搜索用时 15 毫秒
41.
42.
43.
Cryotherapy is used in treatment of chronic rhinitis and pharyngitis. The effect of cryotherapy on the qualitative and quantitative composition of the microflora was studied. Staphylococci prevailed in the rhinitis patients, streptococci, Clebsiella and Neisseria being registered more rarely. The staphlococcal isolates were highly sensitive to monomycin, neomycin, erythromycin and levomycetin. The results of the dynamic study showed that the flora composition did not significantly change during cryotherapy and the sensitivity level of the staphylococcal isolates to the antibodies remained unchanged. 相似文献
44.
SA Gelfand 《Canadian Metallurgical Quarterly》1977,83(5-6):480-487
The precision of the Rinne test at 128-2048 Hz was studied in 100 ears with confirmed conductive pathologies. The number of negative (diagnostic) Rinnes decreased significantly with fall in frequency. While there were significantly more negative than positive Rinnes at 128 and 256 Hz, there were significantly more positive results at higher frequencies; indicating that the Rinne is not reliably diagnostic above 256 Hz. However, the possibility of vibrotactile responses must be remembered with low frequency tuning forks. Also, conductive lesions manifested as high tone air-bone gaps will not be identified with low frequency Rinne tests. Air-bone gaps of 25 to 40 dB, depending on frequency, are necessary for the Rinne to identify the presence of conductive components in most cases. Gaps of 25-30 dB for 128 Hz; 35-40 dB for 256 Hz; 55-60 dB for 512 Hz; and 45-50 dB for 1024 Hz, are necessary for the Rinne to meet a 75% correct detection criterion. The 2o48 Hz Rinne does not attain even chance detection. The Rinne test cannot be validly employed as a criterion against which other measures can be evaluated. 相似文献
45.
46.
47.
Aspergillus terreus infection limited to the L1-2 disk space and first and second lumbar vertebrae developed in a patient not predisposed to invasive aspergillosis. The observation of morphologically distinct secondary spores (aleuriospores) on microscopic examination of open biopsy specimens permitted a preliminary identification of A terreus, which was confirmed by culture. The infection was eradicated with amphotericin B in a total dose of 3 gm. Aspergillus terreus is usually a saprophyte. The present case and four others collected from the literature establish this species as an invasive pathogen. 相似文献
48.
Peng Zheng;Piyush Raj;Lintong Wu;Takayuki Mizutani;Miklos Szabo;William A. Hanson;Ishan Barman; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(6):2305110
Functional disorders of the thyroid remain a global challenge and have profound impacts on human health. Serving as the barometer for thyroid function, thyroid-stimulating hormone (TSH) is considered the single most useful test of thyroid function. However, the prevailing TSH immunoassays rely on two types of antibodies in a sandwich format. The requirement of repeated incubation and washing further complicates the issue, making it unable to meet the requirements of the shifting public health landscape that demands rapid, sensitive, and low-cost TSH tests. Herein, a systematic study is performed to investigate the clinical translational potential of a single antibody-based biosensing platform for the TSH test. The biosensing platform leverages Raman spectral variations induced by the interaction between a TSH antigen and a Raman molecule-conjugated TSH antibody. In conjunction with machine learning, it allows TSH concentrations in various patient samples to be predicted with high accuracy and precision, which is robust against substrate-to-substrate, intra-substrate, and day-to-day variations. It is envisioned that the simplicity and generalizability of this single-antibody immunoassay coupled with the demonstrated performance in patient samples pave the way for it to be widely applied in clinical settings for low-cost detection of hormones, other molecular biomarkers, DNA, RNA, and pathogens. 相似文献
49.
Sharat Chandra Barman Md. Abu Zahed Md. Sharifuzzaman Seok Gyu Ko Hyosang Yoon Joong San Nah Xing Xuan Jae Yeong Park 《Advanced functional materials》2020,30(14)
Current immunosensors have an insufficient number of binding sites for the recognition of biomolecules, which leads to false positive or negative results. In this research, a facile, cost‐effective, disposable, and highly selective electrochemical immunosensing platform is developed based on cationic polyelectrolyte polyallylamine (PAAMI) anchored laser‐ablated graphene (LAG). Here, for the first time, PAAMI is introduced to stabilize LAG flakes, while retaining the intrinsic thermal and electronic properties of the substrate by noncovalent π–π interaction and electrostatic physical absorption. The sensing platform offers a suitable number of anchoring sites for the immobilized antibodies by providing ? NH2 functional groups. The proper grafting of PAAMI is confirmed through X‐ray photoelectron spectroscopy and Raman spectroscopy. The immunosensing platform is applied to detect immunoglobulin (IgG) biomarkers as a proof of concept. Under optimized conditions, the sensing platform exhibits a linear range of 0.012–15 and 15–352 ng mL?1 with a limit of detection of 6 pg mL?1 for IgG detection with high selectivity. Based on the analysis, the developed immunosensing platform can be used for point‐of‐care detection of IgG in clinical diagnostic centers. Furthermore, the developed strategy is well suited for the detection of other cancer biomarkers after immobilizing the relevant antibodies. 相似文献
50.