全文获取类型
收费全文 | 889篇 |
免费 | 22篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 45篇 |
化学工业 | 157篇 |
金属工艺 | 26篇 |
机械仪表 | 15篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 26篇 |
轻工业 | 64篇 |
水利工程 | 2篇 |
无线电 | 115篇 |
一般工业技术 | 153篇 |
冶金工业 | 218篇 |
原子能技术 | 19篇 |
自动化技术 | 63篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 12篇 |
2016年 | 18篇 |
2015年 | 11篇 |
2014年 | 15篇 |
2013年 | 36篇 |
2012年 | 26篇 |
2011年 | 32篇 |
2010年 | 29篇 |
2009年 | 24篇 |
2008年 | 27篇 |
2007年 | 33篇 |
2006年 | 33篇 |
2005年 | 41篇 |
2004年 | 31篇 |
2003年 | 25篇 |
2002年 | 27篇 |
2001年 | 20篇 |
2000年 | 13篇 |
1999年 | 22篇 |
1998年 | 95篇 |
1997年 | 50篇 |
1996年 | 30篇 |
1995年 | 20篇 |
1994年 | 23篇 |
1993年 | 27篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 17篇 |
1989年 | 12篇 |
1988年 | 15篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有914条查询结果,搜索用时 31 毫秒
1.
Abidur Rahman Makoto Kobayashi Kotaro Sugimoto Yuta Endo Manabu Kojima Shigenori Furukawa Takafumi Watanabe Shu Soeda Yuko Hashimoto Keiya Fujimori Hideki Chiba 《International journal of molecular sciences》2021,22(7)
Background: Within the claudin (CLDN) family, CLDN12 mRNA expression is altered in various types of cancer, but its clinicopathological relevance has yet to be established due to the absence of specific antibodies (Abs) with broad applications. Methods: We generated a monoclonal Ab (mAb) against human/mouse CLDN12 and verified its specificity. By performing immunohistochemical staining and semiquantification, we evaluated the relationship between CLDN12 expression and clinicopathological parameters in tissues from 138 cases of cervical cancer. Results: Western blot and immunohistochemical analyses revealed that the established mAb selectively recognized the CLDN12 protein. Twenty six of the 138 cases (18.8%) showed low CLDN12 expression, and the disease-specific survival (DSS) and recurrence-free survival rates were significantly decreased compared with those in the high CLDN12 expression group. We also demonstrated, via univariable and multivariable analyses, that the low CLDN12 expression represents a significant prognostic factor for the DSS of cervical cancer patients (HR 3.412, p = 0.002 and HR 2.615, p = 0.029, respectively). Conclusions: It can be concluded that a reduced CLDN12 expression predicts a poor outcome for cervical cancer. The novel anti-CLDN12 mAb could be a valuable tool to evaluate the biological relevance of the CLDN12 expression in diverse cancer types and other diseases. 相似文献
2.
3.
4.
Dynamic mechanical properties of three‐component composites (acrylic polymer/epoxy/SiO2) in the glass‐transition region 下载免费PDF全文
Hideyuki Uematsu Takashi Nishimoto Shuichi Tanoue Yoshiyuki Iemoto Yuji Aoki Masataka Sugimoto Kiyohito Koyama 《应用聚合物科学杂志》2014,131(13)
In previous studies, we reported the linear and nonlinear rheological properties of three‐component composites consisting of acrylic polymer (AP), epoxy resin (EP), and various SiO2 contents (AP/EP/SiO2) in the molten state. In this study, the dynamic mechanical properties of AP/EP/SiO2 composites with different particle sizes (0.5 and 8 μm) were investigated in the glass‐transition region. The EP consisted of three kinds of EP components. The α relaxation due to the glass transition shifted to a higher temperature with an increase in the volume fraction (?) for the AP/EP/SiO2 composites having a particle size of 0.5 μm, but the α relaxation scarcely shifted for the composite having a particle size of 8 μm as a general result. This result suggested that the SiO2 nanoparticles that were 0.5 μm in size adsorbed a lot of the low‐glass‐transition‐temperature (Tg) component because of their large surface area. The AP/SiO2 composites did not exhibit a shift in Tg; this indicated that the composite did not adsorb any component. The modulus in the glassy state (E′g) exhibited a very weak &phis; dependence for the AP/EP/SiO2 composites having particle sizes of 0.5 and 8 μm, although E′g of the AP/SiO2 composites increased with &phis;. The AP/EP/SiO2 composites exhibited a peculiar dynamic mechanical behavior, although the AP/SiO2 composites showed the behavior of general two‐component composites. Scanning electron microscopic observations indicated that some components in the EP were adsorbed on the surface of the SiO2 particles. We concluded that the peculiar behavior of the AP/EP/SiO2 composites was due to the selective adsorption of the EP component. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40409. 相似文献
5.
Poly(l-lactide) (PLLA) polymers having terminal n-alkyl groups with a wide variety of lengths (C0–C22) were synthesized by ring-opening polymerization of l-lactide in the presence of coinitiators of l-lactic acid (C0), 1-hexanol (C6), 1-dodecanol (C12), and 1-docosanol (C22) and their segmental mobility and non-isothermal and isothermal crystallization behavior were investigated by differential scanning calorimetry (DSC) and wide-angle X-ray diffractometry (WAXD). Glass transition and cold crystallization temperatures of melt-quenched samples during heating decreased with an increase in the length of terminal n-alkyl groups. The enhanced PLLA segmental mobility and hydrophobic interaction-based accelerated PLLA nucleation by the presence of terminal long n-alkyl groups should have caused the accelerated non-isothermal and isothermal crystallization of PLLA segments traced by cold crystallization temperature during heating and by radial growth rate of spherulites, respectively. The crystallization accelerating effect became higher with the length of terminal n-alkyl groups. The effects of the length of terminal n-alkyl group on the crystalline growth mechanism of PLLA at the lowest crystallizable temperature was insignificant, whereas the effects of the length of terminal n-alkyl group on the nucleation mechanism of PLLA chains were significant and insignificant for PLLA having Mn of 6–7 × 103 of 2 × 104 g mol−1, respectively. WAXD measurements revealed that the transition crystallization temperature at which crystalline modification changes from δ-form to α-form was affected by the length of terminal n-alkyl group for PLLA having Mn of 6–7 × 103 g mol−1, but was not altered by the length of terminal n-alkyl group for PLLA having Mn of 2 × 104 g mol−1. 相似文献
6.
In this study, we investigate the transport of dust particles, its vertical distribution, and the associated meteorological conditions during an Asian dust event that was observed in Seoul, Korea on May 29-31, 2008. This study analyzes data from ground-based and space-borne 2-wavelength polarization lidars, particulate mass concentrations, and synoptic weather data. Surface meteorological station observations of dust phenomena, dust transport model, and weather maps consistently show that the dust particles were transported from the source regions (Inner Mongolia, Man-Ju, and Ordos areas) to Korea via the northeastern part of China. Network observations of the PM10 concentrations in Korea revealed that a majority of the heavy dust particles traveled across South Korea from the northwest to the southeast direction with a horizontal scale of 250-300 km and a traveling speed of approximately 40 km h− 1. This extraordinary dust event, in terms of its intensity and timing during the year, occurred due to the blockage of an unusually intensified low-pressure system in the northeastern part of China as well as high-pressure system centered over the Sea of Okhotsk and the Kuril Islands. The low values of the particle depolarization ratio (δ532) (≤0.05) and color ratio (CR) during the pre-dust period indicate the presence of spherical, non-dust, and relatively small particles. The mean δ532 value was approximately 0.123 ± 0.069 between altitudes of ground ~ 2.8 km, and 0.161 ± 0.049 for near-surface dust layer (ground ~ 1.2 km). This value is quite similar to that obtained during the 3-year SNU-Lidar measurements in Seoul (δ532 ~0.136 ± 0.027). The value of δ532 during the 2nd multilayered dust episode ranged between 0.081 and 0.120 for near-surface dust layers, and between 0.076 and 0.114 for elevated dust layers. The CALIPSO measurements of β532, δ532, and CR also revealed the presence of dense dust aerosols along the transport route. 相似文献
7.
Takatoshi Shindo Hideki Motoyama Toru Miki Mikihisa Saito Akiyori Matsueda Noriyasu Honma Tomohito Hida Kazuo Shinjo Kiyotaka Hayashi Hayato Awazu Katsuhisa Makabe Masato Fujikawa Satoshi Kurihara Masashi Sato 《IEEJ Transactions on Electrical and Electronic Engineering》2016,11(Z2):S28-S33
Nine electric power companies in Japan have been collecting lightning data with lightning location systems. Five years of the lightning data (2009–2013) are summarized and analyzed in this paper. The recent annual number of lightning flashes of which the current is more than 10 kA in Japan is around 1 million. The variations of lightning occurrence characteristics by areas, seasons, and so on, are clarified. Meteorological conditions that may affect lightning occurrence are also discussed. Furthermore, we show that there is a clear correlation between the number of lightning strikes and the outage rate of transmission lines. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
8.
9.
A simple low-vacuum coater has been fabricated by using a vacuum resin degassing chamber, in which an aluminum effusion cell is heated by a soldering iron. Our developed vacuum coater presents the versatile methods for depositing paraffin wax for skin-coating the sensing layers of quartz crystal microbalance (QCM). As the increase of the cell temperature, the thickness and inhomogeneity of the wax films were increased. Impedance analyses revealed that the energy dissipation of the QCM was remarkably enhanced with the amount of wax. It was also revealed that the as-deposited wax was fluidic until coagulation by heat radiation. This surface skin coating enhanced the ethyl acetate (EA) sorption capabilities of the polyethylene-sputtered QCM sensor, whereas, it reduced the EA sorption capacity of the d-phenylalanine-sputtered QCM sensor. 相似文献
10.