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排序方式: 共有941条查询结果,搜索用时 15 毫秒
861.
862.
Mai Sugawara Kaoru Kiyomitsu Tatsuya Namae Toshiya Nakaguchi Norimichi Tsumura 《Artificial Life and Robotics》2017,22(1):51-57
We propose an optical projection system aimed at improving laparoscopic surgery based on three-dimensional (3D) measurement that gives an effective information for robotic-assisted surgery and computer-aided surgery. Laparoscopic surgery, which involves the creation of small ports through the patient’s body for the laparoscope and surgical instruments, such as clamp, is minimally invasive and has generated a growing interest. There are techniques using the stereo laparoscope to obtain depth information. Active sensing when structured light is added to the laparoscope can reconstruct a 3D shape. However, active sensing that requires projection devices for the structured light leads to an increase in size. Large-sized projection and sensing systems affect surgical procedures. The size of the system is also larger than the size of port for the laparoscope. To remove the obstacle for the surgery, it is important to design downsized systems. For active sensing with the structured light, a small-size projection system is required to use a small port for the laparoscope. Therefore, we built the optical projection system toward downsizing the device to stereoscopic vision of the laparoscope using mirrors, and we show a new shape reconstruction method from its active sensing. Our Experimental results demonstrate the effectiveness of this proposed system and method. 相似文献
863.
Kohei Kido Takashi Sumoto Yoshihide Yasui Yoshinobu Nakamura Syuji Fujii 《Advanced Powder Technology》2017,28(8):1977-1981
Dry water is a free-flowing powder consisting of numerous solid particle-stabilized water droplets with typical sizes and volumes of 10?6–10?4 m and 10?3–103 pL, respectively. We describe the first characterization of dry water stabilized with hydrophobic silica nanoparticles, by using laser diffraction droplet size distribution analysis. The water droplet dimensions were measured to be a few tens of micrometers in air, by using the laser diffraction method. These dimensions correspond well with measurements by both laser diffraction and optical microscopy methods for a Pickering-type water-in-n-dodecane emulsion prepared by dispersing dry water in n-dodecane. Optical microscopy confirmed that the dry water consisted of flocs of non-spherical water droplets, and the flocs ranged in size from a few tens of micrometers to a few millimeters in air. On the basis of these results, the flocs of water droplets were proposed to dissociate into individual water droplets under the air blast during droplet size measurement by the laser diffraction method. It was also confirmed that pressurizing the dry water between two glass slides led to encapsulated water leaking from the silica nanoparticle shells. This on-demand pressure-sensitive water leak phenomenon shows a possible usage of the dry waters as a material delivery carrier. 相似文献
864.
Effects of Pb Intercalation on the Structural and Electronic Properties of Epitaxial Graphene on SiC
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Ayhan Yurtsever Jo Onoda Takushi Iimori Kohei Niki Toshio Miyamachi Masayuki Abe Seigi Mizuno Satoru Tanaka Fumio Komori Yoshiaki Sugimoto 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(29):3956-3966
The effects of Pb intercalation on the structural and electronic properties of epitaxial single‐layer graphene grown on SiC(0001) substrate are investigated using scanning tunneling microscopy (STM), noncontact atomic force microscopy, Kelvin probe force microscopy (KPFM), X‐ray photoelectron spectroscopy, and angle‐resolved photoemission spectroscopy (ARPES) methods. The STM results show the formation of an ordered moiré superstructure pattern induced by Pb atom intercalation underneath the graphene layer. ARPES measurements reveal the presence of two additional linearly dispersing π‐bands, providing evidence for the decoupling of the buffer layer from the underlying SiC substrate. Upon Pb intercalation, the Si 2p core level spectra show a signature for the existence of Pb? Si chemical bonds at the interface region, as manifested in a shift of 1.2 eV of the bulk SiC component toward lower binding energies. The Pb intercalation gives rise to hole‐doping of graphene and results in a shift of the Dirac point energy by about 0.1 eV above the Fermi level, as revealed by the ARPES measurements. The KPFM experiments have shown that decoupling of the graphene layer by Pb intercalation is accompanied by a work function increase. The observed increase in the work function is attributed to the suppression of the electron transfer from the SiC substrate to the graphene layer. The Pb intercalated structure is found to be stable in ambient conditions and at high temperatures up to 1250 °C. These results demonstrate that the construction of a graphene‐capped Pb/SiC system offers a possibility of tuning the graphene electronic properties and exploring intriguing physical properties such as superconductivity and spintronics. 相似文献
865.
In this study, we have measured the negative ion mobility in O2 at high pressures with a little amount of H2O concentration between 15 and 17,000 ppb. After that, we carried out a Monte Carlo simulation using mobility of electrons, that of the ions obtained in the measurements, and rate coefficients of ion-molecule reactions. As a result, the mobility value 2.39 cm2/V·s of O4¯ is obtained in ultrahigh purity O2 of which the H2O concentration is between 15 and 100 ppb. Moreover, the mobility decreases with the H2O concentrations at which the ion species are considered to be O2¯·(H2O)n (n = 1, 2, 3). Then, we compared the experimental result with that of the simulation and estimated the ion mobility and rate coefficients of ion molecule reactions. Simulation results using estimated values of the ion mobility and rate coefficients agree well with measurement results. 相似文献
866.
Li Yang Hao Wu Liang Zhang Wenfeng Zhang Luying Li Tappei Kawakami Katsuaki Sugawara Takafumi Sato Gaojie Zhang Pengfei Gao Younis Muhammad Xiaokun Wen Boran Tao Fei Guo Haixin Chang 《Advanced functional materials》2021,31(13):2008116
The discovery of type-II Weyl semimetal states in layered transition metal dichalcogenides Td-WTe2 indicates great potential for novel electronic, spintronic, and quantum devices. Theoretically, the interaction between the topological states and the magnetic ordered states of Td-WTe2 enables the modulation of Weyl semimetal states by an external magnetic field. However, currently, ferromagnetism in layered Td-WTe2 is still elusive and rarely observed. In this research, ferromagnetic order into WTe2 using magnetic chromium (Cr) doping with a two-step Te flux strategy is introduced. The Curie temperature (Tc) and the ferromagnetic moment are well tuned with a Cr doping concentration. The Tc of the Cr-doped layered Td-WTe2 could be regulated from 182 to 283 K, which is close to room temperature. The saturation magnetic moment could be changed from 2.26 to 4.20 emu g–1, which is stronger than most values reported for these materials. Most intriguingly, the Cr-doped layered Td-WTe2 single crystals still exhibit semimetallic behavior and they possess very large magnetoresistance with obvious Shubnikov de Haas (SdH) quantum oscillations and an anomalous Hall effect. The findings offer feasible ways to induce and tune ferromagnetic orders in layered Td-WTe2 and thus to control its topological phase with external magnetic fields. 相似文献
867.
In this study, a fuzzy logic‐based model for predicting the ultimate strength of FRP‐confined circular reinforced concrete (RC) columns is presented. The adaptive neuro‐fuzzy inference system (ANFIS) model was generated using valid experimental data with seven input variables. Input parameters were considered in such a way that all the parameters affecting the compressive strength of the column were simultaneously involved. Different models for compressive strength of fiber reinforced polymer (FRP)‐confined concrete including the model in American Concrete Institute (ACI), to calculate the maximum stress endured by the column under axial load, were presented and compared with the results of the ANFIS model. Also, for similarity to other models, the ACI equation for calculating the maximum compressive strength tolerated by a column was considered without reducing coefficients as ACI‐N and was compared with other models. The results obtained from the ANFIS model were compared with results from other models. ANFIS model showed the highest accuracy among all models in predicting the experimental results. 相似文献
868.
Shigeru Fujita Hideki Hara Kenji Sugawara Tetsuo Kinoshita Norio Shiratori 《Applied Intelligence》1998,9(1):57-70
A next generation distributed system is expected to adapt to various changes of both the users' requirements and the operational conditions of environment where the distributed system operates. The aim of our research is to establish a new design model of an adaptive distributed system (ADS) to deal with various changes occurred in the system environment. In this paper, we propose an agent-based architecture of ADS, based on the agent-based computing paradigm. Then, we implement a prototype of the ADS with respect to videoconferencing applications and also evaluate the adaptive functions of the ADS realized on the basis of the proposed architecture. 相似文献
869.
Synthesis of high-performance composites by in situ polycondensation and their mechanical properties
Kohei Sanui Yoshiko Kiyohara Masahiro Rikukawa Naoya Ogata 《Reactive and Functional Polymers》1996,30(1-3):293-298
High-performance composites of vinylpyridine-styrene copolymers and polyamic acid (PAA) were prepared by the so-called ‘in situ polymerization method’. Poly(4-vinylpyridine-co-styrene) (P4VPy-St) and poly(2-vinyl pyridine-co-styrene) (P2VPy-St) were used as flexible matrix polymers. A molecular composite could be obtained from a polymer pair having an attractive interaction such as a coulombic interaction. Their morphologies were observed by scanning electron microscopy (SEM); mechanical properties of these composites were studied by tensile tests. The PAA content dependence of tensile strength for the composite films obtained by the in situ polymerization method was investigated. The tensile strength of the resulting composite was about 1.5 times higher than that of PAA film. The coulombic interaction between the pyridine moiety in the matrix copolymer and resulting PAA enhanced both the miscibility and mechanical properties of the composites. Furthermore, a polyimide (PI) structure was formed by stepwise heat-treatment and greatly enhanced the tensile strength of the composite films. 相似文献
870.
Masami Mori Tohru Kineri Kohei Kadono Toru Sakaguchi Masaru Miya Hajimu Wakabayashi Toshio Tsuchiya 《Journal of the American Ceramic Society》1995,78(9):2391-2394
Gold-dispersed BaTiO, thin films were prepared by the rf magnetron sputtering method. The atomic ratio of Ba to Ti in the films was varied and the effects on the linear and nonlinear optical properties were investigated. As the atomic ratio increased, the value of χ(3) /α532 for the gold-dispersed BaTiO3 thin films slightly increased. It was found that the increase in the value of χ(3) /α532 is due mainly to a change in the crystalline state of the BaTiO3 matrix. However, it was also found that the atomic ratio had a smaller effect on the value of χ(3) /α532 than did the refractive index of the matrix. 相似文献