全文获取类型
收费全文 | 1966篇 |
免费 | 91篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 25篇 |
综合类 | 1篇 |
化学工业 | 416篇 |
金属工艺 | 26篇 |
机械仪表 | 31篇 |
建筑科学 | 126篇 |
矿业工程 | 3篇 |
能源动力 | 84篇 |
轻工业 | 125篇 |
水利工程 | 22篇 |
石油天然气 | 12篇 |
无线电 | 179篇 |
一般工业技术 | 313篇 |
冶金工业 | 286篇 |
原子能技术 | 7篇 |
自动化技术 | 405篇 |
出版年
2023年 | 12篇 |
2022年 | 20篇 |
2021年 | 28篇 |
2020年 | 22篇 |
2019年 | 22篇 |
2018年 | 35篇 |
2017年 | 40篇 |
2016年 | 37篇 |
2015年 | 51篇 |
2014年 | 70篇 |
2013年 | 131篇 |
2012年 | 100篇 |
2011年 | 142篇 |
2010年 | 100篇 |
2009年 | 103篇 |
2008年 | 107篇 |
2007年 | 93篇 |
2006年 | 112篇 |
2005年 | 88篇 |
2004年 | 93篇 |
2003年 | 69篇 |
2002年 | 67篇 |
2001年 | 32篇 |
2000年 | 26篇 |
1999年 | 33篇 |
1998年 | 28篇 |
1997年 | 24篇 |
1996年 | 35篇 |
1995年 | 25篇 |
1994年 | 19篇 |
1993年 | 30篇 |
1992年 | 26篇 |
1991年 | 21篇 |
1990年 | 14篇 |
1989年 | 20篇 |
1988年 | 7篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 6篇 |
1982年 | 17篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 13篇 |
1975年 | 7篇 |
1970年 | 7篇 |
排序方式: 共有2061条查询结果,搜索用时 15 毫秒
61.
Jon J. Camp Cheryl R. Hann Douglas H. Johnson James E. Tarara Richard A. Robb 《Scanning》1997,19(4):258-263
Conventional two-dimensional imaging of the trabecular meshwork (TM) provides limited information about the size, shape, and interconnection of the aqueous channels within the meshwork. Understanding the three-dimensional (3-D) relationships of the channels within this tissue may give insight into its normal function and possible changes present in the eye disease glaucoma. The purpose of our study was to compare laser scanning confocal microscopy with standard 1 μm Araldite-embeddedhistologic sections for 3-D analysis of the trabecular meshwork. In addition, the study was done to determine whether computerized 3-D reconstruction could isolate the fluid spaces of the trabecular meshwork and determine the size of interconnections between the fluid spaces. Confocal microscopy appears comparable to 1 μm Araldite-embedded tissue sections and has the advantage of inherent registration of the serial tissue sections. Three-dimensional reconstruction allowed the isolation of the fluid spaces within the trabecular meshwork and revealed the presence of numerous interconnections between larger fluid spaces. The distribution of these interconnections was randomly arranged, with no predilection for specific regions within the trabecular meshwork. This distribution of constrictions and “expansion chambers” may provide a clue to the mechanism by which subtle histologic changes are associated with increased ocular pressure in glaucoma. 相似文献
62.
63.
64.
65.
66.
Elham Khanipour Steve H. Flint Owen J. McCarthy Matt Golding Jon Palmer Mark Tamplin 《International Journal of Food Science & Technology》2014,49(6):1506-1512
The aim of this study was to evaluate the combined effect of salt (sodium chloride, 0–8% w/v), sorbate (potassium sorbate, 0–4.5% w/v), nisin (0–500 ppm) and lysozyme (0–500 ppm) on the survival of Clostridium sporogenes as a non‐toxigenic surrogate of Clostridium botulinum in terms of the probability of growth by using a central composite rotatable design. The results indicated that salt and sorbate were the most effective factors in preventing the growth of Cl. sporogenes in high‐moisture (>95%) and low‐acid conditions. The probability of growth of Cl. sporogenes in broth was reduced by combinations of salt and sorbate. Nisin and lysozyme had insignificant effects on the probability of growth of Cl. sporogenes (P > 0.05). Lysozyme individually and in combination with nisin had no inhibitory effect on Cl. sporogenes. Overall, the addition of sorbate and lysozyme may allow the salt concentration to be reduced while preventing growth. 相似文献
67.
Jon Luzuriaga Yurena Polo Oier Pastor-Alonso Beatriz Pardo-Rodríguez Aitor Larraaga Fernando Unda Jose-Ramon Sarasua Jose Ramon Pineda Gaskon Ibarretxe 《International journal of molecular sciences》2021,22(7)
Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenerative therapies given their ability to grow in the absence of serum and their realistic possibility to be used in autologous grafts. In this review, we describe the particular advantages of hDPSCs for neuroregenerative cell therapies. We thoroughly discuss the knowledge about their embryonic origin and characteristics of their postnatal niche, as well as the current status of cell culture protocols to maximize their multilineage differentiation potential, highlighting some common issues when assessing neuronal differentiation fates of hDPSCs. We also review the recent progress on neuroprotective and immunomodulatory capacity of hDPSCs and their secreted extracellular vesicles, as well as their combination with scaffold materials to improve their functional integration on the injured central nervous system (CNS) and peripheral nervous system (PNS). Finally, we offer some perspectives on the current and possible future applications of hDPSCs in neuroregenerative cell therapies. 相似文献
68.
Keeseong Park Jon W. Taylor Despina Louca 《Journal of Superconductivity and Novel Magnetism》2014,27(8):1927-1934
The dynamics of the local atomic pair correlations in the FeSe x Te1?x ( x = 0.1, 0.5, and 0.9) system were investigated using the dynamic pair density function analysis obtained from inelastic neutron scattering. Distinct differences are observed between the superconducting and nonsuperconducting compositions, particularly involving the local dynamics of the Fe-Fe correlations. The energy scale of the observed differences is between 25 and 30 meV. In the nonsuperconducting FeSe0.1Te0.9, the Fe-Fe correlations are enhanced with cooling that may signal stronger exchange interactions, while in the superconducting compositions of FeSe0.9Te0.1 and FeSe0.5Te0.5, they are suppressed. 相似文献
69.
70.