全文获取类型
收费全文 | 2366篇 |
免费 | 50篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 82篇 |
综合类 | 1篇 |
化学工业 | 521篇 |
金属工艺 | 73篇 |
机械仪表 | 31篇 |
建筑科学 | 37篇 |
能源动力 | 56篇 |
轻工业 | 136篇 |
水利工程 | 5篇 |
无线电 | 210篇 |
一般工业技术 | 358篇 |
冶金工业 | 676篇 |
原子能技术 | 62篇 |
自动化技术 | 180篇 |
出版年
2023年 | 16篇 |
2022年 | 47篇 |
2021年 | 53篇 |
2020年 | 21篇 |
2019年 | 31篇 |
2018年 | 44篇 |
2017年 | 39篇 |
2016年 | 47篇 |
2015年 | 29篇 |
2014年 | 43篇 |
2013年 | 86篇 |
2012年 | 64篇 |
2011年 | 115篇 |
2010年 | 56篇 |
2009年 | 69篇 |
2008年 | 75篇 |
2007年 | 66篇 |
2006年 | 55篇 |
2005年 | 64篇 |
2004年 | 59篇 |
2003年 | 57篇 |
2002年 | 48篇 |
2001年 | 51篇 |
2000年 | 46篇 |
1999年 | 68篇 |
1998年 | 274篇 |
1997年 | 157篇 |
1996年 | 114篇 |
1995年 | 64篇 |
1994年 | 49篇 |
1993年 | 49篇 |
1992年 | 31篇 |
1991年 | 35篇 |
1990年 | 25篇 |
1989年 | 24篇 |
1988年 | 15篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 20篇 |
1984年 | 10篇 |
1983年 | 20篇 |
1982年 | 11篇 |
1981年 | 20篇 |
1980年 | 16篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 23篇 |
1976年 | 27篇 |
1974年 | 9篇 |
1973年 | 7篇 |
排序方式: 共有2428条查询结果,搜索用时 15 毫秒
71.
Masayuki Akiyama Masashi Tatsuzaki Tomomi Michishita Toshikazu Ichiki Masahiro Sumi Michio Ikeda Tetsuya Araki Yasuyuki Sagara 《Food and Bioprocess Technology》2012,5(5):1924-1938
To design a consumer-oriented package that complements the taste and aroma of ready-to-drink chilled-cup coffee beverages by using the food kansei model, the effects of the diameter and the color of drinking straws as well as the cognition terms of coffee on consumer sensory characteristics and preferences were investigated. Variance and factor analyses of the sensory scores for chilled-cup coffee with milk and sugar using straws of different diameters, as rated by consumer panelists, extracted two perceived factors (F1, contribution ratio 36.5%, and F2, 28.6%). A two-dimensional plot of the average F1 and F2 scores of 123 panelists showed that the perceived characteristics of the same taste and aroma varied according to the straw diameter. An image investigation of different straw colors and another sensory evaluation using “black,” “brown,” and “green” straws were also performed. A principal component analysis of the image data revealed that the sensory characteristics of coffee with milk and sugar were imaged from the straw color. The second evaluation suggested that the images of straw colors affected the sensory characteristics. In addition, cluster and multiple-comparison analyses of Internet research data from consumers regarding the cognition terms for coffee exhibited three clusters representing the cognitive characteristics of terms by consumers and by developers and the differences of attractiveness degree on the cognition terms due to the consumers’ personal attributes. These studies provide useful information for the development of packages of chilled-cup coffee beverages. 相似文献
72.
Kenji Ikeda 《Chemical engineering science》1979,34(7):941-949
The cell model approach for the analysis of nonisothermal fixed bed adsorption column has been presented under the assumption that adsorption is controlled by intraparticle diffusion and adsorption equilibrium is nonlinear. The numerical analysis has been carried out by the Runge-Kutta-Gill scheme. With the aid of a HITAC-8800 computer, the influence of controlling variables of the breakthrough curves and temperature curves has been made clear for such parameters as solid phase mass transfer coefficient, overall heat transfer coefficient at the column wall, length of bed and the equilibrium isotherms. A nonisothermal adsorption column can be designed adequately by applying the numerical method developed here according to the cell model approach. 相似文献
73.
A. Cassimi L. Maunoury B. Huber H. Lebius J.M. Ramillon T. Ikeda T.M. Kojima Y. Yamazaki N. Bundaleski 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(4):674-677
Multiply charged ion beam transmission through insulating capillaries is today a very active field of research. Thanks to the work of several groups during the last five years, several features of this unexpected process have been evidenced. The open challenge is to understand and control the self-organized charging-up of the capillary walls, which leads finally to the ion transmission. Up to now, the specific charge distribution on the inner surface, as well as the dynamics of the build-up, are still to be understood. While capillaries usually studied are microscopic pore networks etched in different materials, our concern is in macroscopic single capillaries made of glass. With a length of several centimeters and a diameter of a few micrometers at the exit, these capillaries have nevertheless the same aspect ratio as the etched pores (length/diameter ≈ 100). One of the leading goals of this research on single capillaries is to produce multi-charged ion beams with diameters smaller than a micrometer (nano-beams). These glass capillaries offer the opportunity to be used as an ion funnel due to their amazing properties of guiding and focusing highly charged ion beams without altering neither their initial charge state nor the beam emittance (<10−3 π mm mrad). However, the understanding of the underlying process is not complete and relies on models assuming charge patches distributed along the capillary and which still need to be tested. We present the first observation imaging the dynamics of the charging-up process in single glass capillaries. During the build-up of the self-organized charge deposition on the capillary walls, the 230 keV Xe23+ transmitted beam is deflected back and forth several times as the outgoing current increases. This is in agreement with the picture of charge patches created sequentially along the capillary and thus deflecting the beam until a stationary state is reached. 相似文献
74.
Kazuki Tajima Yasusei Yamada Shanhu Bao Masahisa Okada Kazuki Yoshimura 《Solar Energy Materials & Solar Cells》2008,92(2):120-125
All-solid-state switchable mirror glass was prepared by magnetron sputtering. The device exhibited the multi-layer structure of Mg4Ni/Pd/Ta2O5 on WO3/ITO/glass substrate. The Mg4Ni, Pd, and Ta2O5 in the device acted as optical switches, proton injector and solid electrolyte, respectively. Reactive DC magnetron sputtering was employed as a new deposition method for Ta2O5 electrolyte thin film for the device. The transmittance of the device, at a wavelength of 670 nm using reactive DC-sputtered Ta2O5 thin film, reached 0.1% (a reflective state) to 48% (a transparent state). The transmittance change occurred in less than 40 s when 5 V was applied, and the switching speed was 60 times faster than that of the device using reactive RF-sputtered Ta2O5 thin film. 相似文献
75.
76.
S. Y. Kim M. Harada H. Tomiyasu Y. Ikeda Y. Y. Park 《Progress in Nuclear Energy》2000,37(1-4):399-404
The structural and kinetic studies of U(VI) complex with benzamidoxime(Hba) as ligand in CD3COCD3 have been studied by means of 1H and 13C NMR. The Hba molecule was found to coordinate to UO22+ in the form of anionic benzamidoximate (ba), and the number of ba coordinated to UO22+ was determined to be 3 by analyzing the chemical shift of 13C NMR signal for Hba in the presence of UO22+. The exchange rate constants(kex) of ba in [UO2(ba)3] were determined by the NMR line-broadening method. The kinetic parameters were obtained as follows: kex(25°C) = 3.1 × 103s−1, ΔH≠ = 35.8 ± 3.5 KJ mol−1, and ΔS≠ = −65 ± 13.7 J K−1 mol−1. The UV-visible absorption spectra of solutions containing UO22+ and Hba were also measured. The molar extinction coefficient of the complex was found to be extremely large compared with those of UO2(L)52+ (L = unidentate oxygen donor ligands) complexes. This is due to the strong electron withdrawing of UO22+ from Hba and suggests that an interaction between UO22+ and Hba is very strong. Such a high affinity of monomeric amidoxime to UO22+ reasonably explains the high adsorptibility of amidoxime resin to U(VI) species, and is considered to result in the high recovery of U(VI) species from sea water using amidoxime resin. 相似文献
77.
78.
Seok Su Sohn Alisson Kwiatkowski da Silva Yuji Ikeda Fritz Krmann Wenjun Lu Won Seok Choi Baptiste Gault Dirk Ponge Jrg Neugebauer Dierk Raabe 《Advanced materials (Deerfield Beach, Fla.)》2019,31(8)
Severe lattice distortion is a core effect in the design of multiprincipal element alloys with the aim to enhance yield strength, a key indicator in structural engineering. Yet, the yield strength values of medium‐ and high‐entropy alloys investigated so far do not substantially exceed those of conventional alloys owing to the insufficient utilization of lattice distortion. Here it is shown that a simple VCoNi equiatomic medium‐entropy alloy exhibits a near 1 GPa yield strength and good ductility, outperforming conventional solid‐solution alloys. It is demonstrated that a wide fluctuation of the atomic bond distances in such alloys, i.e., severe lattice distortion, improves both yield stress and its sensitivity to grain size. In addition, the dislocation‐mediated plasticity effectively enhances the strength–ductility relationship by generating nanosized dislocation substructures due to massive pinning. The results demonstrate that severe lattice distortion is a key property for identifying extra‐strong materials for structural engineering applications. 相似文献
79.
Tajima T Takiguchi N Kato J Ikeda T Kuroda A Ohtake H 《Journal of Bioscience and Bioengineering》2003,96(2):149-153
The nematode Caenorhabditis elegans exhibits chemotaxis toward a wide variety of chemicals including water-soluble molecules and volatile organic compounds. We have previously discovered that C. elegans wild-type strain N2 is strongly attracted by cycloheximide which has long been known as a bitter tastant for humans and other mammals. We describe here the isolation and initial characterization of the first mutants which were defective specifically in their attraction to cycloheximide. In our screenings, we selected two mutants that were defective in chemotaxis to cycloheximide but normal in their attraction to NH4Cl and histidine. These mutants also avoided quinine hydrochloride, CuSO4 and high concentrations of NaCl similar to the wild-type strain N2. Furthermore, no observable defect was detected in their attraction to volatile odorants such as isoamyl alcohol and diacetyl. Dye-filling experiments suggested that they have no morphological defect in the sensory endings of the amphid neurons. 相似文献
80.
Ikeda K Pant B Mishiro A Ozawa K Masujima T Sugiyama M 《Journal of Bioscience and Bioengineering》2000,90(5):574-576
Mitotic index (MI), defined as the ratio (%) of the mitotic-phase-arrested cell number to the total cell number, is higher in the presence of colcemid than in its absence. MI is reduced by anti-tumor agents used in conjunction with colcemid. The ratio of MI, which is defined by the dose of colcemid to that of the supplement with etoposide as an anti-tumor agent and is designated MIR, was 10% at an exposure of 2 h, suggesting that etoposide blocks the cell cycle before 2 h of the mitotic phase. Thus, we established a convenient method to identify a target point in the cell cycle for anti-tumor agents using colcemid. RBL-2H3, a mammalian cell line, exhibited a large number of 2-fold swollen nuclear envelopes after exposure to etoposide. The G2-index, which is the ratio of the number of swollen nuclei to the total number of nuclei, was higher when the cells were incubated with etoposide than without it. In this study, we suggest that the measurement of the G2-index contributes to the screening of putative anti-tumor agents. 相似文献