全文获取类型
收费全文 | 334篇 |
免费 | 12篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
化学工业 | 112篇 |
金属工艺 | 9篇 |
机械仪表 | 7篇 |
建筑科学 | 6篇 |
能源动力 | 11篇 |
轻工业 | 28篇 |
石油天然气 | 3篇 |
无线电 | 24篇 |
一般工业技术 | 60篇 |
冶金工业 | 29篇 |
原子能技术 | 5篇 |
自动化技术 | 41篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 24篇 |
2015年 | 11篇 |
2014年 | 26篇 |
2013年 | 27篇 |
2012年 | 30篇 |
2011年 | 20篇 |
2010年 | 15篇 |
2009年 | 24篇 |
2008年 | 17篇 |
2007年 | 19篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 7篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1981年 | 2篇 |
排序方式: 共有347条查询结果,搜索用时 171 毫秒
71.
Nguyen Hien Trang Ken‐Ichiro Shimada Mitsuo Sekikawa Tomotada Ono Masayuki Mikami 《Journal of the science of food and agriculture》2005,85(11):1829-1837
This study was carried out in order to make the Japanese fermented meat sauce shishibishio. The fermentation mixtures (moromi) were prepared by mixing ground pork with salt at one of three levels (15, 20 or 25%), koji (rice fermented with Aspergillus oryzae) and pepper. Commercial enzymes, ie Alcalase or Pectinase 3S, were added in order to accelerate the proteolysis of the moromi. After 3 months of fermentation, counts of viable bacteria were below 300 cfu g?1, and no coliforms was detected in any moromi. Shishibishio obtained after 3 months had an acceptable seasoning with high peptide and free amino acid content, and good hygienic quality; in particular, no unpleasant smell and taste was found. The addition of Alcalase or Pectinase 3S appreciably increased yield of shishibishio and protein recovery from moromi by accelerating the liquefaction and the proteolysis, resulting in the improvement of the sensory quality of the products. The highest yields were, respectively, 49.8 to 50.6%, collected from moromi in which we used 15% salt. Shishibishio with Alcalase had a higher peptide content but a lower total free amino acid content than that with Pectinase 3S. However, there was not much difference in the sensory evaluations for two enzyme treatments. Copyright © 2005 Society of Chemical Industry 相似文献
72.
This article reviews the synthesis of regular and asymmetric star-branched polymers with well-defined structures by methodologies using living anionic polymerization, especially focusing on the synthetic approaches accessible for precisely controlled architectures of star-branched polymers concerning molecular weight, molecular weight distribution, arm number, and composition. The reason for selecting living anionic polymerization from many living/controlled polymerization systems so far developed is that this living polymerization system is still the best to meet the strict requirements for the precise structures of star-branched polymers. Furthermore, we herein mainly introduce a novel and quite versatile stepwise iterative methodology recently developed by our group for the successive synthesis of many-armed and multi-compositional asymmetric star-branched polymers. The methodology basically involves only two sets of the reaction conditions for the entire iterative synthetic sequence. The reaction sequence can be, in principle, limitlessly iterated to introduce a definite number of the same or different polymer segments at each stage of the iteration. As a result, a wide variety of many-armed and multi-compositional asymmetric star-branched polymers can be synthesized. 相似文献
73.
We propose a thin-film bending technique based on the ion-induced bending (IIB) phenomenon, which enables the fabrication of three-dimensional structural devices and arrays, such as micro-electro mechanical system (MEMS) devices. We investigated the IIB phenomenon with various film materials and various ion species. It was found that the distribution of vacancy occurs under ion-irradiation was the important parameter affecting the degree of bending, irrespective of film material and ion-species. Therefore, it was found that the bending angle could be controlled by the distribution of vacancy. Using this technique, a micron-sized region of a standing thin-film array could be produced using conventional ion-implantation equipment used in semiconductor manufacturing. 相似文献
74.
Weiguo Hu Yukihiro Harada Aiko Hasegawa Tomoya Inoue Osamu Kojima Takashi Kita 《Progress in Photovoltaics: Research and Applications》2013,21(4):472-480
We present a theoretical model to incorporate the quantum mechanism of two‐photon transitions into macroscopic operations. The two‐photon transition is described as a two‐step interband–intraband transition within the one‐band envelope‐function framework and is coupled with drift–diffusion as well as the potential distribution. In0.53Ga0.47As/InP superlattices (SLs) are chosen as the initial candidate to simulate intermediate band solar cell operation. In this type of structure, the absorption spectrum of interband and intraband transitions is asymmetric and strongly depends on device structure and operating conditions. Our results also reveal that the intraband transition dominates the detailed balance. Both the intermediate band (IB) configuration and the conversion efficiency are determined by the SL structure. Only well‐designed SLs can form the appropriate IB. Furthermore, an efficiency contour plot has been calculated to guide quantum design: the peak efficiency is 45.61% when the well thickness is 4 nm and the barrier thickness is 2 nm. As the well or barrier thickness increases to 10 nm, the absorption peak of the intraband transition gradually redshifts and narrows, so the efficiency correspondingly decreases to below 40%. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
75.
Tomoya Daito Hiroshi Nishikawa Tadashi Takemoto Takashi Matsunami 《Microelectronics Reliability》2013
Solder joints are required to have high impact strength for use in portable electronic products. To make solder joints with high impact strength, qualitative evaluation methods of impact strength are required. Ball impact tests have been widely adopted in evaluating the impact strength of solder joints because of their easy implementation. Impact load curves obtained from ball impact tests are used as an evaluation indicator of impact strength of solder joint. However, a relation between fracture behavior and impact load curve has not yet been clarified, and an explanation of the impact load curve has not yet been provided in detail. In addition to this, detailed study about the relation between IMC layer thickness and impact strength has not been performed, although the IMC layer thickness formed at the interface would significantly affect the impact strength of the solder joint. This study aimed to explain the impact load curve in the ball impact test and to reveal the effect of the IMC layer thickness on the impact strength of the solder joint. Sn–3.0Ag–0.5Cu solder was reflowed on an electroless Ni–P plated Cu substrate (Ni–P), and a ball impact test was then carried out to evaluate the impact strength. This study found that the ball impact test is effective to evaluate the interfacial strength of solder joints. In the impact load curve, it is estimated that the solder bump keeps deforming until the interfacial crack initiates (maximum load), and the interfacial crack initiates after the maximum load and propagates along the interface between the solder and Ni–P. The suitable evaluation of impact strength became possible by measuring the correspondence relation between the deformation distance of the solder bump after fracture and the energy until maximum load and the relation between the area fraction of the residual solder on the fractured pad and the energy after maximum load. And, it is proved that the impact strength decreased with increasing aging time because the growth of the IMC layer remarkably degraded the interfacial strength of the solder joint. 相似文献
76.
A theoretical and experimental study is conducted to investigate the detached volume from a pendant drop on the surface of a sphere. Observation of drop detachment by high‐speed video camera reveals that the movement of the upper part of the neck of the drop is quite slow compared to that of the detaching lower part. The surface profile of the upper part was calculated approximately as a static problem using the axisymmetric Laplace equation. Using the drop profile, the system energy, including the work done by the solid–liquid wetting behavior, was calculated. Based on the condition of minimum energy, the volume of the detached part V was calculated. The volume V increases with the sphere diameter and approaches the value for the pendant drop attached to a plate. In addition, V is strongly dependent on the wettability between the sphere and the liquid and decreases with the receding contact angle. The detached volume of the water drop was measured for spheres of porous brick of various diameters. The experimental and theoretical results were found to be in good agreement. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20305 相似文献
77.
A method was developed for speciation of iodine in solid materials using X-ray absorption near-edge structure (XANES). This method was used to identify the iodine species (mainly inorganic iodine) in environmental samples. It was shown that the XANES spectra of iodide and iodate sorbed within solid materials can be simulated by the linear combination of the spectra of iodide and iodate ions in water. The distribution coefficient (Kd) between soil and water was obtained independently for iodide and iodate, based on iodine speciation both in the solid phase, by XANES, and in the aqueous phase, by HPLC-ICP-MS. It was found that the Kd of iodate is larger than that of iodide by a factor of more than six, showing the more soluble nature of iodide. It was suggested that iodate can form in soil even when iodide is injected into the soil-water system under conditions within the iodide-stable field of the Eh-pH diagram of iodine. This is caused by the much higher affinity of iodate for solid surfaces than iodide. In soil samples under various water saturation conditions, or various Eh conditions, the iodide fraction in water increases with decreasing Eh, which results in an increase in the dissolved total iodine fraction in soil water. The speciation method using XANES was also applied to iodine in a natural soil sample and marine ferromanganese oxides. It is suggested that iodine K-edge XANES is a promising tool for determining the iodide/iodate ratio in natural solid samples, which contributes to better understanding of the behavior of iodine at the Earth's surface. 相似文献
78.
Dr. Atsushi Yoshimori Yasunobu Asawa Enzo Kawasaki Tomohiko Tasaka Seiji Matsuda Dr. Toru Sekikawa Satoshi Tanabe Dr. Masahiro Neya Dr. Hideaki Natsugari Dr. Chisato Kanai 《ChemMedChem》2021,16(6):955-958
Discoidin domain receptor 1 (DDR1) inhibitors with a desired pharmacophore were designed using deep generative models (DGMs). DDR1 is a receptor tyrosine kinase activated by matrix collagens and implicated in diseases such as cancer, fibrosis and hypoxia. Herein we describe the synthesis and inhibitory activity of compounds generated from DGMs. Three compounds were found to have sub-micromolar inhibitory activity. The most potent of which, compound 3 (N-(4-chloro-3-((pyridin-3-yloxy)methyl)phenyl)-3-(trifluoromethyl)benzamide), had an IC50 value of 92.5 nM. Furthermore, these compounds were predicted to interact with DDR1, which have a desired pharmacophore derived from a known DDR1 inhibitor. The results of synthesis and experiments indicated that our de novo design strategy is practical for hit identification and scaffold hopping. 相似文献
79.
This paper aims to demonstrate that the basic framework of the „new geographical economics” is well suited to explain various
phenomena associated with the dynamics of frontier economies, such as the „massive mobilization of resources” and the so-called
„flying geese pattern” of Asia‘s development. The discussion is based on the monopolistic competition model of spatial economy
which we are currently developing with Paul Krugman. 相似文献
80.
D. Shimura R. Sekikawa K. Kotani M. Uekawa Y. Maeno K. Aoyama H. Sasaki T. Takamori K. Masuko S. Nakaya 《Photonics Technology Letters, IEEE》2006,18(16):1738-1740
We have succeeded in developing a low-cost bidirectional optical subassembly chip using a silicon microlens for fiber-to-the-home application. The main optical elements of the bidirectional function were automatically aligned and integrated on a silicon optical bench. The cost of subassembly was markedly lowered both by reducing the part number and simplifying the assembly process. The prototype bidirectional optical component was successfully fabricated on the basis of the proposed chip. A receiver minimum sensitivity of -28.5 dBm was experimentally demonstrated even at 75 /spl deg/C. 相似文献