全文获取类型
收费全文 | 513篇 |
免费 | 10篇 |
专业分类
电工技术 | 34篇 |
综合类 | 1篇 |
化学工业 | 187篇 |
金属工艺 | 6篇 |
机械仪表 | 13篇 |
建筑科学 | 9篇 |
能源动力 | 26篇 |
轻工业 | 39篇 |
水利工程 | 1篇 |
无线电 | 28篇 |
一般工业技术 | 104篇 |
冶金工业 | 6篇 |
原子能技术 | 21篇 |
自动化技术 | 48篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 6篇 |
2017年 | 12篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 19篇 |
2013年 | 31篇 |
2012年 | 27篇 |
2011年 | 36篇 |
2010年 | 26篇 |
2009年 | 29篇 |
2008年 | 34篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 13篇 |
2004年 | 17篇 |
2003年 | 19篇 |
2002年 | 20篇 |
2001年 | 11篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 14篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有523条查询结果,搜索用时 15 毫秒
61.
Solid oxide fuel cell (SOFC) is highly efficient and is a promising candidate for future power systems. Among the many types of SOFCs which have been reported, the micro tubular design offers improved thermal robustness, with the possibility of rapid start‐up/shut‐down. In this study, a new stack structure for anode‐supported micro tubular SOFCs was developed in which porous MgO matrices were used to position the micro tubular cell elements. This arrangement allowed for electrical interconnection of each cell in a series, using a silver paste and a connecting LSCF paste for the anode and the cathode, respectively, in the MgO support structure. With this technique, the bundle size could be easily increased towards the kW class module design. 相似文献
62.
A wet atomising system has been employed as a novel method to prepare ultrafine Gd‐doped CeO2 (GDC) electrolyte slurries. By changing the fluid flow pressure and repeating the atomisation process several times for the same atomised slurries, we have obtained optimised ultrafine GDC slurry with high‐dispersed and homogeneous distribution. The sizes of the particles of GDC were in the range of tens of nanometres. A highly dense electrolyte layer (membrane) was prepared using the ultrafine GDC slurries for intermediate temperatures microtubular solid oxide fuel cell (SOFC) applications. The SOFC was fabricated by using supporting porous anode tubes of NiO and GDC, and the cathode consisted of La0.6Sr0.4Co0.2Fe0.8O3–y and GDC. A dense 10 μm GDC electrolyte layer was obtained at a lower sintering temperature of 1,250 °C for 1 h. The SOFC was tested with humidified (3% H2O) hydrogen as a fuel and the static air as an oxidant, and the tubular cell maintained its high performance even at 500 °C. 相似文献
63.
Satoru Miyazaki Hisashi Goshima Takaaki Amano Hiroyuki Shinkai Masafumi Yashima Takayuki Wakimoto Masaru Ishii 《Electrical Engineering in Japan》2012,180(2):24-32
In evaluating the uncertainty of the standard measuring system for lightning‐impulse high voltages, which is composed of a standard voltage divider, a digital recorder, and calibrators, step‐response tests of the standard voltage divider may be useful. In this paper, a convolution algorithm is employed to calculate the output impulse voltage waveforms from measured step‐response waveforms. The uncertainties of peak‐value measurement due to the influence of the nominal epoch, uncertainty of the peak‐value measurement due to dispersion of the AC scale factor, and uncertainty of the virtual front‐time measurement due to long‐term stability are evaluated. Furthermore, the error of the virtual front time of the output waveforms is discussed. The front part of the step‐response waveform, t≤ T30%, does not influence the error of the virtual front time. Therefore, for the standard voltage divider, the step‐response parameters, that is, the experimental response time, partial response time, settling time, and overshoot, have almost nothing to do with the error of the virtual front time. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(2): 24–32, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21279 相似文献
64.
Sherif A. El‐Safty Adel A. Ismail Hideyuki Matsunaga Takaaki Hanaoka Fujio Mizukami 《Advanced functional materials》2008,18(10):1485-1500
General design of optical chemical nanosensors is needed to develop efficient sensing systems with high flexibility, and low capital cost for control recognition of toxic analytes. Here, we designed optical chemical nanosensors for simple, high‐speed detection of multiple toxic metal ions. The systematic design of the nanosensors was based on densely patterned chromophores with intrinsic mobility, namely, “building‐blocks” onto three‐dimensional (3D) nanoscale structures. The ability to precisely modify the nanoscale pore surfaces by using a broad range of chromophores that have different molecular sizes and characteristics enables detection of multiple toxic ions. A key feature of this building‐blocks design strategy is that the surface functionality and good adsorption characteristics of the fabricated nanosensor arrays enabled the development of “pool‐on‐surface” sensing systems in which high flux of the metal analytes across the probe molecules was achieved without significant kinetic hindrance. Such a sensing design enabled sensitive recognition of metal ions up to sub‐picomolar detection limits (~10?11 mol dm?3), for first time, with rapid response time within few seconds. Moreover, because these sensing pools exhibited long‐term stability, reversibility and selectivity in detecting most pollutant cations, for example, Cr(VI), Pb(II), Co(II), and Pd(II) ions, they are practical and inexpensive. The key result in our study is that the pool‐on‐surface design for optical nanosensors exhibited significant ion‐selective ability of these target ions from environmental samples and waste disposals. 相似文献
65.
Satoshi Wada Hiroaki Yasuno Takuya Hoshina Hirofumi Kakemoto Yoshikazu Kameshima Takaaki Tsurumi 《Journal of Electroceramics》2008,21(1-4):198-201
Barium titanate (BaTiO3) crystallites with various particle sizes from 22 to 500 nm were prepared by the two-step thermal decomposition method of barium titanyl oxalate. Various characterizations revealed that these particles were impurity-free, defect-free, dense BaTiO3 particles. The powder dielectric measurement clarified that the dielectric constant of BaTiO3 particles with a size of around 58 nm exhibited a maximum of over 15,000. To explain this size dependence, the THz region dielectric properties of BaTiO3 fine particles, especially Slater mode frequency, were measured using the far infrared (FIR) reflection method. As the result, the lowest Slater mode frequency was obtained at 58 nm. This tendency was completely consistent with particle size dependence of the dielectric constant. 相似文献
66.
Takaaki Koyanagi Yutai Katoh Caen Ang Derek King Greg E. Hilmas William G. Fahrenholtz 《Journal of the American Ceramic Society》2019,102(1):85-89
The response of polycrystalline TiB2 to neutron irradiation was investigated. The material was fabricated using isotopically enriched 11B powders to minimize helium production via the 10B(n, α)7Li reaction. Neutron irradiation was conducted at temperatures of ~200°C and ~600°C to a fast fluence of 2.4 × 1025 n/m2 (>0.1 MeV). The material exhibited some swelling, but less swelling at the higher irradiation temperature. No macroscopic damage was observed in the irradiated material, although moderate irradiation-induced micro-cracking was found in the irradiated TiB2. This study demonstrated improved radiation resistance of isotopically tailored TiB2 compared with natural boron TiB2, which exhibited macroscopic fracture by irradiation. 相似文献
67.
Youichirou Higashi Takaaki Aratake Takahiro Shimizu Shogo Shimizu Motoaki Saito 《International journal of molecular sciences》2021,22(15)
Stroke is a major cause of death worldwide, leading to serious disability. Post-ischemic injury, especially in the cerebral ischemia-prone hippocampus, is a serious problem, as it contributes to vascular dementia. Many studies have shown that in the hippocampus, ischemia/reperfusion induces neuronal death through oxidative stress and neuronal zinc (Zn2+) dyshomeostasis. Glutathione (GSH) plays an important role in protecting neurons against oxidative stress as a major intracellular antioxidant. In addition, the thiol group of GSH can function as a principal Zn2+ chelator for the maintenance of Zn2+ homeostasis in neurons. These lines of evidence suggest that neuronal GSH levels could be a key factor in post-stroke neuronal survival. In neurons, excitatory amino acid carrier 1 (EAAC1) is involved in the influx of cysteine, and intracellular cysteine is the rate-limiting substrate for the synthesis of GSH. Recently, several studies have indicated that cysteine uptake through EAAC1 suppresses ischemia-induced neuronal death via the promotion of hippocampal GSH synthesis in ischemic animal models. In this article, we aimed to review and describe the role of GSH in hippocampal neuroprotection after ischemia/reperfusion, focusing on EAAC1. 相似文献
68.
Takaaki Koyanagi Takashi Nozawa Yutai Katoh Lance L. Snead 《Journal of the European Ceramic Society》2018,38(4):1087-1094
For the development of silicon carbide (SiC) materials for next-generation nuclear structural applications, degradation of material properties under intense neutron irradiation is a critical feasibility issue. This study evaluated the mechanical properties and microstructure of a chemical vapor infiltrated SiC matrix composite, reinforced with a multi-layer SiC/pyrolytic carbon–coated Hi-NicalonTM Type S SiC fiber, following neutron irradiation at 319 and 629?°C to ~100 displacements per atom. Both the proportional limit stress and ultimate flexural strength were significantly degraded as a result of irradiation at both temperatures. After irradiation at 319?°C, the quasi-ductile fracture behavior of the nonirradiated composite became brittle, a result that was explained by a loss of functionality of the fiber/matrix interface associated with the disappearance of the interphase due to irradiation. The specimens irradiated at 629?°C showed increased apparent failure strain because the fiber/matrix interphase was weakened by irradiation-induced partial debonding. 相似文献
69.
Computational Visual Media - Quantitatively evaluating the psychological and perceptual effects of objects is an important issue, but is difficult. In cognitive studies, the psychological potential... 相似文献
70.
Takashi Nozawa Takaaki Koyanagi Yutai Katoh Hiroyasu Tanigawa 《Journal of the European Ceramic Society》2019,39(8):2634-2647
SiC/SiC composites are promising structural candidate materials for various nuclear applications over the wide temperature range of 300–1000 °C. Accordingly, irradiation tolerance over this wide temperature range needs to be understood to ensure the performance of these composites. In this study, neutron irradiation effects on dimensional stability and mechanical properties to high doses (11–44 dpa) at intermediate irradiation temperatures (?600 °C) were evaluated for Hi-Nicalon Type-S or Tyranno-SA3 fiber–reinforced SiC matrix composites produced by chemical vapor infiltration. The influence of various fiber/matrix interfaces, such as a 50–120 nm thick pyrolytic carbon (PyC) monolayer interphase and 70–130 nm thick PyC with a subsequent PyC (?20 nm)/SiC (?100 nm) multilayer, was evaluated and compared with the previous results for a thin-layer PyC (?20 nm)/SiC (?100 nm) multilayer interphase. Four-point flexural tests were conducted to evaluate post-irradiation strength, and SEM and TEM were used to investigate microstructure. Regardless of the fiber type, monolayer composites showed considerable reduction of flexural properties after irradiation to 11–12 dpa at 450–500 °C; and neither type showed the deterioration identified at the same dose level at higher temperatures (>750 °C) in a previous study. After further irradiation to 44 dpa at 590–640 °C, the degradation was enhanced compared with conventional multilayer composites with a PyC thickness of ?20 nm. Multilayer composites have shown comparatively good strength retention for irradiation to ?40 dpa, with moderate mechanical property degradation beginning at 70–100 dpa. Irradiation-induced debonding at the F/M interface was found to be the major cause of deterioration of various composites. 相似文献