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991.
Arikawa K Hirose S 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2007,365(1850):171-183
The performance of existing actuators, such as electric motors, is very limited, be it power-weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control. 相似文献
992.
Miyamoto K Yatake Y Tamura K Terao Y Ohta H 《Journal of Bioscience and Bioengineering》2007,104(4):263-267
We have isolated, purified and characterized arylmalonate decarboxylase (AMDase; EC 4.1.1.76). This is an unique enzyme that gives optically pure arylpropionates from the corresponding arylmalonates. Recently, we have screened similar enzyme producers from soil samples and succeeded in isolating Achromobacter sp. KU1311. The gene encoding the enzyme was cloned and sequenced. The AMDase gene consists of 720 nucleotides, which specifies a 240 amino acid protein with a relative molecular mass of 24,735. This enzyme was purified and its characteristics were compared with those of the hitherto known enzyme from Alcaligenes bronchisepticus KU1201. 相似文献
993.
Yamada T Miyauchi K Ueda H Ueda Y Sugawara H Nakai Y Endo G 《Journal of Bioscience and Bioengineering》2007,104(5):408-415
To solve malodorous odor problems by ammonia emission in composting of cattle dung wastes, we developed an alternative composting method consisting of a hyperthrmophilic pre-treatment reactor (HTPRT) (first step) combined with a general windrow post-treatment system (WPOT) (second step). In this study, physicochemical and microbiological differences in compost materials during the HTPRT-WPOT process and a simple windrow composing process (SWC) were investigated. The HTPRT-WPOT process removed excess ammonia in the compost materials by physical ammonia stripping, and controlled the malodorous ammonia emission. The organic matter evolution index showed that the HTPRT-WPOT process also contributed to accelerate formation of humic acids in composting. Quantitative real-time PCR analyses using Bacterial-, Archaeal- and fungal-protozoan-specific primer sets showed that small subunit ribosomal RNA (SSU rRNA) gene copy numbers differed much between composting materials of these two processes. Particularly, the SSU rRNA gene copy of eukaryotic microbes (fungi-protozoa) in the HTPRT-WPOT process was much higher than in the SWC process. From these results, we conclude that the HTPRT-WPOT process has great advantages for the control of malodorous odor problems caused by ammonia emission, and for high rate of composting evaluated by the humification rate and microbial characterization of the composting materials. 相似文献
994.
Yang C Zhou E Miyanishi S Hashimoto K Tajima K 《ACS applied materials & interfaces》2011,3(10):4053-4058
Active layers of polymer solar cells were prepared by aerosol jet printing of organic inks. Various solvents and additives with high boiling points were screened for the preparation of high-quality polymer films. The effects on device performance of treating the films by thermal and solvent vapor annealing were also investigated. The components of the solvent were important for controlling the drying rate of the liquid films, reducing the number of particle-like protrusions on the film surface, and realizing high molecular ordering in the polymer phases. The optimized solar cell device with poly(3-hexylthiophene) and a C(60) derivative showed a high fill factor of 67% and power conversion efficiency of 2.53% without thermal annealing. The combination of poly[N-9-heptadecanyl-2,7-carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-diethylhexyl-2,5-dihydropyrrolo-[3,4-]pyrrole-1,4-dione] and a C(70) derivative led to power conversion efficiency of 3.92 and 3.14% for device areas of 0.03 and 1 cm(2), respectively. 相似文献
995.
Kana Hirayama Keisuke Yoshino Ryuji Ueno Yoshiaki Iwamura Haigui Yang Dong Wang Hiroshi Nakashima 《Solid-state electronics》2011,60(1):122-127
Ge-MOS capacitors were fabricated by a novel method of ultra-thin SiO2/GeO2 bi-layer passivation (BLP) for Ge surface combined with the subsequent SiO2-depositions using magnetron sputtering. For the Ge-MOS capacitors fabricated by BLP with O2, to decrease oxygen content in the subsequent SiO2 deposition is helpful for improving interface quality. By optimizing process parameters of the Ge surface thermal cleaning, the BLP, and the subsequent SiO2 deposition, interface states density of 4 × 1011 cm−2 eV−1 at around mid-gap was achieved, which is approximately three times smaller than that of non-passavited Ge-MOS capacitors. On the contrary, for the Ge-MOS capacitors fabricated by BLP without O2, interface quality could be improved by an increase in oxygen contents during the subsequent SiO2 deposition, but the interface quality was worse compared with BLP with O2. 相似文献
996.
This paper presents a new method of unbalanced load flow calculation to improve complexity by the method of advanced symmetrical coordinates. Usually, the electric power system has been calculated only by the positive phase sequence component on the assumption that three‐phase transmission lines and loads are balanced. However, many ultrahigh‐voltage transmission lines are not transposed, and therefore mutual inductances cause negative sequence currents in the trunk transmission system. Negative sequence currents cause heating of generators and transformers, and therefore the three‐phase sequence component should be calculated accurately. We examined the fast computation and good convergence performance of unbalanced load flow calculation by models of three‐phase transmission lines, transformers, and loads. The proposed method is not the phase coordinate system but the method of symmetrical coordinates. This technique decreases numerical complexity by the use of a simplified Jacobian matrix. The convergence performance of this method is inferior to that of the usual Newton–Raphson method. As a consequence, the problem of poor convergence performance is alleviated by a technique for the newly developed deceleration Newton method. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(1): 17–24, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21034 相似文献
997.
Horikoshi S Muratani M Miyabe K Ohmura K Hirowatari T Serpone N Abe M 《Journal of oleo science》2011,60(7):375-383
The influence of moisture content (15% w/w) on the remediation (vaporization) of trichloroethylene (TCE) present in natural sands, chosen as a TCE-polluted model system for soils, was investigated with regard to applied microwave power levels, the depth of the sand sample, and the dielectric factors. The heating process occurring in the sand samples arises through the microwave conduction loss heating and dielectric loss heating mechanisms. The characteristic relevance of the electric and magnetic microwave radiation fields to the heating mechanisms was also examined. Heating by the magnetic microwave radiation field was considerable when magnetite was added to the dry and wet sand samples as the microwave absorber. Optimal microwave conditions are reported for a single-mode microwave applicator. Near-quantitative elimination of the TCE contaminant was achieved for sandy soils within a very short time. 相似文献
998.
Kazuo Nakajima Keisuke Ohdaira Kozo Fujiwara Wugen Pan 《Solar Energy Materials & Solar Cells》2005,88(3):20149
We demonstrated a solar cell system comprising a concave-Si-mirror solar cell and a conventional small Si solar cell set at the focal point of the concave-mirror solar cell. The concave-Si-crystal mirror was prepared by mechanically polishing a single-crystal Si wafer. It was used both as a solar cell and mirror. This system can make effective use of the photons reflected from the concave-mirror solar cell because the number of total photons is the sum of photons from both the mirror solar cell and the small solar cell set at the focal point. When the conventional small solar cell with an efficiency of 13.0% was used, the total conversion efficiency of the present system increased to 12.2% compared with the conversion efficiency of 11.5% for only the concave-Si-mirror solar cell. These results show that the present solar cell system has the capability to achieve high efficiency through the effective use of the photons reflected from conventional solar cells. 相似文献
999.
Analysis of crack propagation due to rebar corrosion using RBSM 总被引:1,自引:0,他引:1
Khoa Kim Tran Hikaru Nakamura Keisuke Kawamura Minoru Kunieda 《Cement and Concrete Composites》2011,33(9):906-917
Cracking behavior due to rebar corrosion in concrete specimens having a single rebar is evaluated experimentally and analytically. In the experiments, in which corrosion was induced electronically, the propagation of cracks (including internal crack patterns and surface crack widths) was monitored. In addition, deformation of the specimen surface was measured using a laser displacement meter. In the analysis, a three-dimensional Rigid-Body-Spring Method (RBSM), combined with a three-phase material corrosion–expansion model, is proposed to simulate crack propagation due to rebar corrosion. The effects of the properties of corrosion products such as elastic modulus, penetration of corrosion products into cracks, and local corrosion after cracking of the concrete are investigated. Cracking behavior due to rebar corrosion is simulated reasonably well. The simulations using RBSM provide insight into the mechanisms of crack initiation and propagation due to rebar corrosion. 相似文献
1000.
Ono K Ban N Ojima M Yoshinaga S Akahane K Fujii K Toyota M Hamada F Kouriyama C Akiba S Kunugita N Shimada Y Kai M 《Radiation protection dosimetry》2011,146(1-3):260-262
A nationwide survey was conducted in Japan on paediatric CT among children of public health and school nurses to examine a possibility for a follow-up study on radiation effects. A survey questionnaire was sent out to 3173 public primary and junior high schools and 317 public health centres during October to December in 2009. According to the collected responses, 410 (16.2 %) children received the CT scans and the total number of CT scans was 585. Most of respondents expressed a high interest in radiation health effects and an intent to participate in the epidemiological study that will follow-up the health conditions of children. This study provides information to discuss the feasibility of the epidemiological study on health effects in children who received CT scans. 相似文献