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排序方式: 共有238条查询结果,搜索用时 15 毫秒
21.
Shiro Seki Takeshi Kobayashi Nobuyuki Serizawa Yo Kobayashi Katsuhito Takei Hajime Miyashiro Kikuko Hayamizu Seiji Tsuzuki Takushi Mitsugi Yasuhiro Umebayashi Masayoshi Watanabe 《Journal of power sources》2010,195(18):6207-6211
The physicochemical and electrochemical properties of three 1-alkyl-2,3,5-trimethylpyrazolium cation-based room-temperature ionic liquids with various alkyl chain lengths were investigated. The temperature dependences of density, viscosity, and ionic conductivity were obtained by precise measurements. Electrolyte properties of these room-temperature ionic liquids were also examined from the viewpoint of their uses in lithium secondary batteries ([LiCoO2 positive electrode|electrolyte|lithium metal negative electrode]). It was found that the alkyl chain length affects the charge–discharge performances of cells. 相似文献
22.
Soo Woo Kwon Woo Seok Yang H M Lee Woo Kyung Kim Hang Yong Lee Dae Ho Yoon Yo Seung Song 《中国稀土学报(英文版)》2006,24(Z1)
The Ti-doped waveguide-type periodically poled LiNbO3 (PPLN) were fabricated and the dependence of domain wall velocity on an external field applied for domain inversion was investigated. The whole polarization reversal process was computer-controlled to regulate domain wall expansion at a feedback time shorter than 5 μs. The coercive voltage and several values of excess voltage were applied on 500 μm-thick wafers serially connected to a 1-MOhm external resistor which had an effect of the poling current reduction, i.e. the deceleration of domain wall expansion. The domain wall velocity is sensitive to the poling voltage, precisely speaking, to the excess voltage. The domain wall velocities were 28.70, 16.02 and 5.75 μm·s-1 under poling field of 23.5, 22.0 and 21.0 kV·mm-1, respectively. Moreover, average duty cycle of PPLN is about 49.93%. 相似文献
23.
The weak network theory previously developed is applied to explain the failure envelope for the ductile fracture of uncrosslinked amorphous polymers in a constant rate of elongation, with the assumption that the reformed chain requires a lapse of time after its reformation to contribute to maintenance of the network structure. The chain that contributes to maintain the structure is called the ‘structure chain’. The criterion is used that the fracture occurs provided the apparent average force per one ‘structure chain’ reaches a certain critical value. The result agrees well with the failure envelope obtained experimentally. 相似文献
24.
We consider the parameter design problem for a central system coordinating plural semiautonomous subsystems each of which optimizes its own objective under the given parameter from the center. The center makes a decision of the parameter values to be assigned to the subsystems so as to optimize its objective, considering the values of optimized subsystems' performances. Such a parameter design problem is formulated in the framework of a two-level planning problem and becomes an optimization problem including optimal-value functions, and accordingly, a nondifferentiable optimization problem. In this paper, based on Gauvin's studies concerned with the directional derivatives of optimal-value functions, we derive the necessary conditions for the parameter design problem by means of a new theorem of the alternative. The results obtained here are slightly different from the Kuhn-Tucker-like conditions, and are adapted to the structure of the problem. As the computational method for our problem, we propose applying an existing generalized gradient algorithm called the "bundle method" in a class of nondifferentiable optimization methods, and also show a numerical example. 相似文献
25.
PURPOSE: To describe the clinical findings of an autosomal dominant macular dystrophy in a family of Mayan Indian ancestry in Belize, Central America, and to determine its molecular genetic relationship with the original North Carolinian family. METHODS: We performed comprehensive ophthalmic examinations on 56 members of a single family living in Chicago, Illinois, and Belize, Central America. Fundus photography and fluorescein angiography were performed on 17 affected subjects and six affected family members were serially examined over a 12-year period. Blood was collected from 26 individuals, and DNA was extracted for genotyping. Two-point linkage, multipoint linkage, and haplotype analysis was performed. RESULTS: In 17 affected individuals, the clinical features were consistent with the diagnosis of North Carolina macular dystrophy. Multipoint linkage analysis generated a peak lod score of 5.6 in the MCDR1 region. The haplotype associated with the disease was, however, different from that of the original North Carolinian family. CONCLUSIONS: This family has an autosomal dominant macular dystrophy that is clinically indistinguishable from North Carolina macular dystrophy (MCDR1). Our findings indicate that the mutated gene in this Belizean family maps precisely to the same region as that of the North Carolina macular dystrophy (MCDR1) locus. This study provides evidence that MCDR1 occurs in various ethnic groups and that there is no evidence of genetic heterogeneity. 相似文献
26.
Solid Solubility of Aluminum and Boron in Silicon Carbide 总被引:1,自引:0,他引:1
Solid solubility of aluminum in silicon carbide was studied by the powder X-ray diffraction technique (Debye-Scherrer method). At 2200° C the solubility limit was 1.0 wt%. Measurements of the lattice parameter of Al-saturated samples as a function of temperature gave a heat of solution of 147 kJ/mol. The change in the lattice parameter indicates that Al substitutes for Si. Literature data are interpreted as indicating that B replaces both Si and C. 相似文献
27.
Yuki Hirai Hirosato Monobe Norihiro Mizoshita Masaya Moriyama Kenji Hanabusa Yo Shimizu Takashi Kato 《Advanced functional materials》2008,18(11):1668-1675
Discotic liquid‐crystalline (LC) physical gels have been prepared by combining the self‐assembled fibers of a low‐molecular‐weight gelator and semiconducting LC triphenylene derivatives. The hole mobilities of the discotic LC physical gels measured by a time‐of‐flight method become higher than those of LC triphenylenes alone. The introduction of the finely dispersed networks of the gelator in the hexagonal columnar phases may affect the molecular dynamics of the liquid crystals, resulting in the enhancement of hole transporting behavior in the LC gel state. 相似文献
28.
Intramolecular Locked Dithioalkylbithiophene‐Based Semiconductors for High‐Performance Organic Field‐Effect Transistors 下载免费PDF全文
Sureshraju Vegiraju Bo‐Chin Chang Pragya Priyanka Deng‐Yi Huang Kuan‐Yi Wu Long‐Huan Li Wei‐Chieh Chang Yi‐Yo Lai Shao‐Huan Hong Bo‐Chun Yu Chien‐Lung Wang Wen‐Jung Chang Cheng‐Liang Liu Ming‐Chou Chen Antonio Facchetti 《Advanced materials (Deerfield Beach, Fla.)》2017,29(35)
New 3,3′‐dithioalkyl‐2,2′‐bithiophene ( SBT )‐based small molecular and polymeric semiconductors are synthesized by end‐capping or copolymerization with dithienothiophen‐2‐yl units. Single‐crystal, molecular orbital computations, and optical/electrochemical data indicate that the SBT core is completely planar, likely via S(alkyl)?S(thiophene) intramolecular locks. Therefore, compared to semiconductors based on the conventional 3,3′‐dialkyl‐2,2′‐bithiophene, the resulting SBT systems are planar (torsional angle <1°) and highly π‐conjugated. Charge transport is investigated for solution‐sheared films in field‐effect transistors demonstrating that SBT can enable good semiconducting materials with hole mobilities ranging from ≈0.03 to 1.7 cm2 V?1 s?1. Transport difference within this family is rationalized by film morphology, as accessed by grazing incidence X‐ray diffraction experiments. 相似文献
29.
Mulenko S. A. Stefan N. Skoryk M. A. Popov V. M. Smirnov A. B. Gudymenko O. Yo. 《Journal of Materials Science: Materials in Electronics》2022,33(27):21258-21269
Journal of Materials Science: Materials in Electronics - Semiconductors are considered promising materials for the fabrication of new thermo-sensors. The photons generated by a KrF laser source... 相似文献
30.
Yina Wang Shuoyu Wang Kenji Ishida Yo Kobayashi Masakatsu G. Fujie Takeshi Ando 《Advanced Robotics》2017,31(14):739-752
Walking is the most fundamental requirement for independent living in daily life. An intelligent walking-support robot has been developed for use by people with walking disabilities. To appropriately assist the user, the robot must precisely track the user’s intentions. However, the robot’s tracking accuracy is severely compromised by time-varying friction, center-of-gravity (CoG) shifts, and load changes induced by the user. In a previous study, we proposed a digital acceleration controller with online inertial parameter identification. However, the tracking accuracy was still affected by CoG shifts introduced by the users. To address these issues, the current study investigated a novel dynamic model, wherein all the load and CoG information processed in the inertial matrix was derived and a new digital acceleration controller with parameter estimation was used to compensate for the time-varying friction, CoG shifts, and load changes. Experiments were conducted under different floor and load conditions to demonstrate the improved tracking accuracy of the proposed control method. 相似文献