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151.
152.
Junpei Sakurai Mitsuhiro Abe Masahiro Ando Yuko Aono Seiichi Hata 《Precision Engineering》2011,35(4):537-546
This paper presents a search for Ni–Nb–Zr thin film amorphous alloys for use as optical glass device molding die materials. To efficiently search for candidate materials, we used a combinatorial method to evaluate thermal stability. First, compositionally spread Ni–Nb–Zr libraries were fabricated by combinatorial arc plasma deposition (CAPD). To evaluate thermal stability, the Ni–Nb–Zr amorphous CAPD samples in the libraries were annealed in vacuum at 723 K, representing the molding temperature for glass devices, for various time periods. The phases of the annealed CAPD samples were identified using X-ray diffractometry (XRD). From XRD identification, candidate amorphous compositions with high thermal stabilities were screened. Sputter-deposited samples with the same candidate amorphous compositions were subsequently fabricated. Other desired properties for optical glass device molding die materials, including mechanical strength, linear expansion coefficient, oxidation resistance, machinability and anti-sticking properties to molten glass, were evaluated. The investigation revealed Ni36Nb39Zr25 to be a suitable composition for a new glass lens molding die material. This material exhibited a high fracture stress, σf, of 1.3 GPa, good heat resistance, good oxidation resistance, similar linear expansion coefficient as glass, good machinability, and excellent anti-sticking properties to molten glass. 相似文献
153.
Tatsuya SakamotoTsutomu Iida Naoki FukushimaYasuhiko Honda Mitsuhiro TadaYutaka Taguchi Yohiko MitoHirohisa Taguchi Yoshifumi Takanashi 《Thin solid films》2011,519(24):8528-8531
Fabrication of sintered undoped n-type Mg2Si, initiated from pre-synthesized all-molten polycrystalline Mg2Si powder, was carried out using a Plasma Activated Sintering technique. The thermoelectric properties were evaluated from room temperature up to 861 K. The maximum dimensionless figure of merit was estimated to be 0.60 at 861 K. For output power measurements, the length and cross-sectional area of Mg2Si elements equipped with Ni electrodes were varied from 6 to 15 mm and 2 × 2 to 4 × 4 mm2, respectively. For the 3 × 3 × 7.5 mm3 element, the maximum output power density was 1.43 Wcm-2 with the temperatures of the cool and hot sides being 373 K and 873 K (ΔT = 500 K), while the highest output power was 203 mW for the sample of 4 × 4 × 7.5 mm3 at ΔT = 500 K. The results of aging tests for 11,000 h with the hot side at 873 K and the cool side at 373 K under atmospheric conditions showed that the fabricated device elements possess sufficient durability at high power-generation operating temperatures. 相似文献
154.
Kenta Fujii Takeshi Ueki Kazuyuki Niitsuma Masayoshi Watanabe Mitsuhiro Shibayama 《Polymer》2011,52(7):1589-10614
The structure and lower critical solution temperature (LCST) phase behavior of well-defined poly(benzyl methacrylate) (PBnMA) solution using 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide, [C2mim][NTf2] ionic liquid (IL) as a solvent have been studied by dynamic light scattering (DLS) and small-angle neutron scattering (SANS) at various temperatures. The SANS profiles observed for fully deuterated IL ([C2mim]-d11[NTf2]) containing PBnMA were kept practically unchanged in the temperature range between 298 and 363 K, while they suddenly changed at 363 K. This indicates that the LCST behavior of PBnMA-IL solution is a first-order phase transition, which is consistent with the DLS results. The SANS profiles below 363 K were well represented by the theoretical Debye scattering function with inter-molecular interaction and the radius of gyration, Rg was estimated to be almost constant, i.e., ∼45 Å. The SANS result obtained here was compared with those in aqueous PNIPAm solutions as a typical LCST system, and some differences between IL and aqueous solution systems are pointed out. It is found that thermodynamic quantities (ΔHdemix, ΔSdemix and ΔGdemix) from the homogeneous solution to the phase separation states strongly depend on the solvation of the PBnMA polymer by the IL ([C2mim] cation and [NTf2] anion). We propose an LCST phase separation mechanism in the polymer-IL solution. 相似文献
155.
As a new biobased epoxy resin system, epoxidized soybean oil (ESO) was cured with tannic acid (TA) under various conditions. When the curing conditions were optimized for the improvement of the thermal and mechanical properties, the most balanced properties were obtained when the system was cured at 210°C for 2 h at an epoxy/hydroxyl ratio of 1.0/1.4. The tensile strength and modulus and tan δ peak temperature measured by dynamic mechanical analysis for the ESO–TA cured under the optimized condition were 15.1 MPa, 458 MPa, and 58°C, respectively. Next, we prepared biocomposites of ESO, TA, and microfibrillated cellulose (MFC) with MFC contents from 5 to 11 wt % by mixing an ethanol solution of ESO and TA with MFC and subsequently drying and curing the composites under the optimized conditions. The ESO–TA–MFC composites showed the highest tan δ peak temperature (61°C) and tensile strength (26.3 MPa) at an MFC content of 9 wt %. The tensile modulus of the composites increased with increasing MFC content and reached 1.33 GPa at an MFC content of 11 wt %. Scanning electron microscopy observation revealed that MFC was homogeneously distributed in the matrix for the composite with an MFC content of 9 wt %, whereas some aggregated MFC was observed in the composite with 11 wt % MFC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
156.
Horiguchi T. Kurashima T. Tateda M. Ishihara K. Wakui Y. 《Lightwave Technology, Journal of》1992,10(9):1196-1201
A technique based on Brillouin gain spectroscopy is proposed to evaluate tensile and compressive strain variation in optical fibers. This technique is applied to characterize fiber strain in bent slot-type optical-fiber cables. Fiber ribbons containing four optical fibers each are stranded through the cable. When the cable is bent, two types of strain are created in the fiber. It was found from experimental results that the first strain, which was induced by the elongation and compression of the fiber ribbon along its length, was drastically reduced, while the second strain, which was created by bending the fiber ribbon in its plane surface, remained 相似文献
157.
A far-field pattern (FFP) technique using an optical fibre probe to measure the mode-field diameters of single-mode fibres is described. The endface separation between the test fibre and the probe fibre can be reduced to a tenth of the fibre/detector separation in the conventional scanning detector method 相似文献
158.
This paper deals with theoretical treatments for the deformation mechanism of liquid crystal rods by light scattering under Hv polarization condition, when the rods oriented by a shear flow are acted on by a rectangular electric pulse along the direction of the velocity gradient of flow. As in one example, the calculations were carried out to check whether the complicated orientational behaviour of superstructures such as rods and/or spherulites cause significant effect on the profile of Hv light scattering patterns. In the present system, the orientation distribution function of rods was obtained as the solution of the rotational diffusion equation for rotational ellipsoidal particles. In actual calculations for light scattering patterns, the orientational fluctuation with respect to the rod axis is considered to explain the circular type pattern under no external excitation which has been reported in previous experiments. When the orientation functions provide curves showing two peaks by the proper choice of parameters concerning electric field strength and velocity gradient, the corresponding Hv light scattering pattern showed four small dull lobes in the vertical direction indicating the preferential orientation of rods with respect to the shear flow direction in addition to the four sharp large lobes in the horizontal direction indicating the preferential orientation of rods with respect to the electric field direction. This indicates that the Hv light scattering pattern influences the two kinds of orientation of rods. 相似文献
159.
Modeling mean flow and turbulence characteristics in gas-agitated bath with top layer 总被引:2,自引:0,他引:2
Olusegun J. Ilegbusi Manabu Iguchi Keiji Nakajima Mitsuhiro Sano Mitsuru Sakamoto 《Metallurgical and Materials Transactions B》1998,29(1):211-222
A numerical study is presented of the flow characteristics in a gas-agitated water bath in the presence of a top layer of
dissimilar fluid. Two systems are considered, comprised separately of silicon and normal pentane as the top layer, to simulate
slag cover in a real steelmaking process. The mathematical model involves solution of transport equations for the variables
of each phase, with allowance for interphase transfer of momentum. Turbulence is assumed to be a property of the carrier (liquid)
phase and represented through solution of additional transport equations for the turbulence kinetic energy, k, and its rate of dissipation, ɛ. The model also accounts for turbulence modulation by the bubbles through enhancement of the source terms in the equations
for k and ɛ. The predicted mean and fluctuating velocities, stresses, and turbulence production are generally in the consensus of the
experimental data. Both mean flow and turbulence characteristics are found to be suppressed in the water/silicon system of
smaller density ratio, indicating enhanced re-entrainment of the top layer, than the water/normal pentane system. 相似文献
160.
Mitsuhiro Kondo M.E. Hideo Maeda B.E. Mikio Mizuguchi M.E. 《JOM Journal of the Minerals, Metals and Materials Society》1990,42(11):36-37
The two most widely industrialized techniques for aluminum refining are the three-layer electrolytic refining process and the segregation process. The three-layer process uses molten salt electrolysis to produce aluminum of greater than 99.99% purity. The segregation process produces aluminum of 99.98–99.99% purity. Although aluminum refined by the segregation process has a somewhat lower purity than that produced by the other methods, the segregation process has become increasing common since it consumes less energy. Ultrahigh-purity aluminum (99.9999%), which has uranium and thorium impurities reduced to less than 1 ppb, can also be produced. 相似文献