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281.
Kazunari Katayama Sanshiro Kasahara Shinichiro Ishikawa Satoshi Fukada Masabumi Nishikawa 《Fusion Engineering and Design》2011,86(9-11):1702-1705
Tungsten deposits were produced by sputtering method using hydrogen isotope RF plasma, and the density and the incorporated components in the deposits were investigated. The density changed in the range from 14.2 g/cm3 to 6.1 g/cm3, and hydrogen isotope retention changed in the range from 0.25 to 0.05 as (H + D)/W by the difference of deposition conditions. Both the density and hydrogen isotope retention tended to decrease with an increase of pressure. Even though a deuterium gas was used for producing tungsten deposits, not only deuterium but also hydrogen, oxygen and water vapor were incorporated in the deposits. It is considered that the incorporation of these components originated in water vapor unintentionally existing in the vacuum chamber. 相似文献
282.
283.
Methanol decomposition to synthesis gas over supported Pd catalysts prepared from synthetic anionic clays 总被引:2,自引:0,他引:2
Ryuji Shiozaki Takashi Hayakawa Yan-yong Liu Tomoko Ishii Mikio Kumagai Satoshi Hamakawa Kunio Suzuki Tatehiko Itoh Tetsuya Shishido Katsuomi Takehira 《Catalysis Letters》1999,58(2-3):131-140
Supported Pd or Rh catalysts were prepared by the solid-phase crystallization method starting from hydrotalcite anionic clay
minerals based on [Mg6Al2(OH)16CO
2
2−
]·4H2O as the precursors. The precursors were prepared by a coprecipitation method from the raw materials containing Pd2+ and various trivalent metal ions which can replace each site of Mg2+ and Al3+ in the hydrotalcite. Rh3+ was also used for preparing the catalyst as comparison. The precursors were then thermally decomposed and reduced to form
supported Pd or Rh catalysts and used for the methanol decomposition to synthesis gas. Among the precursors tested, use of
Mg–Cr hydrotalcite containing Pd2+ resulted in the formation of efficient Pd supported catalysts for the production of synthesis gas by selective decomposition
of methanol at low temperature. Although Pd2+ cannot well replace the Mg2+ site in the hydrotalcite, the Pd supported catalyst (Pd/Mg–Cr) prepared by the solid-phase crystallization method formed
highly dispersed Pd metal particles and showed much higher activity than that prepared by the conventional impregnation method.
When the precursor was prepared under mild conditions, more fine particles of Pd metal were formed over the catalyst, resulting
in high activity. It is likely that the high activity may be due to the highly dispersed and stable Pd metal particles assisted
by the role of Cr as the co-catalyst.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
284.
Nagatoshi Nishiwaki Tomoya Konishi Shiro Tsukamoto Masahiko Shimoda 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(4):873-876
A palladium catalyst supported on a semiconductor plate underwent the Heck reaction effectively to afford a coupling product.
The catalytic plate was easily recovered from the reaction mixture with tweezers and reused several times without any special
treatment. Comparison of reusability, durability, and treatability of seven kinds of commercially available solid-supported
palladium catalysts and the semiconductor-supported catalyst plate was studied. 相似文献
285.
A Kobayashi K Mori M Konishi K Maeda K Mikasa T Yoneda N Narita R Sano T Masutani 《Canadian Metallurgical Quarterly》1998,72(10):1070-1075
Achromobacter xylosoxidans is a gram-negative bacterium whose natural habitat has not been clearly defined. It has been isolated from ear discharge and the large intestine of humans and from various hospital or environmental water sources. Infection with A. xylosoxidans in humans has been documented, and resulting illnesses include meningitis, pneumonia, cholecystitis, peritonitis and urinary tract infection. Bacteremia due to A. xylosoxidans is rare, and little information on treatment is available. Two cases of bacteremia due to A. xylosoxidans in patients with hemapoietic malignancies are reported herein. Case 1 involved a 70-yr. male whose clinical diagnosis was IgA lambda-type plasmacytoma. Case 2 involved 72-yr. male whose clinical diagnosis was acute lymphatic leukemia (L2). Both patients had been catheterized. Neutropenia was noted and the white blood cell counts were 20/microliter in case 1 and 35/microliter in case 2 when A. xylosoxidans was isolated from the blood culture. We suggest that bacteremia due to A. xylosoxidans may have been related to the presence of the catheter and neutropenia. 相似文献
286.
Hidetaka Yoshikawa Katsuya Fukuyama Yoichiro Nakahara Takehisa Konishi Nobuyuki Ichikuni Yasuko Yoshikawa Noboru Akuzawa Yoichi Takahashi Keiko Nishikawa 《Carbon》2003,41(15):2931-2938
The structure of bromine residue compounds was investigated by X-ray absorption fine structure (XAFS) in order to interpret where and how bromine is present in carbons with different degrees of graphitization. The residue compounds can be classified into three groups, as obtained from X-ray absorption near edge structure (XANES) spectra and the values of the intramolecular distance rBr–Br determined by extended X-ray absorption fine structure (EXAFS). In Group I, prepared from the host carbons heat treated at temperatures higher than 1900 °C, bromine exists in the interlayer space of graphite in the form of Br2 molecules with interaction of the π electrons of graphite. In Group III, from carbon heat treated at 1000 °C, most of the bromine probably reacts with carbon atoms having a dangling bond or functional groups. For Group II, where the host carbons are heat treated at intermediate temperatures, it is likely that bromine exists in undeveloped defects with a unique electronic state. 相似文献
287.
Mechanical activation-assisted self-propagating high-temperature synthesis (MA-SHS) in air was successfully applied to the
synthesis of the powder mixtures of ZrB2 and ZrC as a precursor of the ZrB2–ZrC composite. When the powder mixtures of Zr/B/C = 4/2/3–6/10/1 in molar ratio were mechanically activated (MA) by ball
milling for 45–60 min and then exposed to air, they self-ignited spontaneously and the self-propagating high-temperature synthesis
(SHS) was occurred to form ZrB2 and ZrC. The ZrB2–ZrC composites were produced from these MA-SHS powders by spark plasma sintering (SPS) at 1800 °C for 5–10 min and showed
the fine and homogeneous microstructure composed of the <5 μm-sized grains. The mechanical properties of the composites evaluated
by Vickers indentation method showed the values of Vickers hardness of 13.6–17.8 GPa and fracture toughness of 2.9–5.1 MPa·m1/2, depending on the molar ratio of ZrB2/ZrC. Thus, the better microstructure and mechanical properties of the ZrB2–ZrC composites were obtained from the MA-SHS powder mixtures, compared with those obtained from the MA powder, the mixing
powder and the commercial powder mixtures. 相似文献
288.
Our newly developed “barrel-sputtering” technique has been employed for the surface coating of solid substrates with complex shapes such as bolts, nuts, and screws. The entire surface of the iron bolts and nuts including the flank and the root in the thread is homogeneously coated with the Au film. SEM measurements reveals that the surface of the Au film is very smooth. In the SEM measurements of the cross-sectional area, it is found that the Au film possess uniform thickness without any significant defects and/or pits. The Au film coating can also be successfully conducted on polycarbonate bolts and small SUS screws. The results provide evidences that the sputter deposition takes place in “three-dimensionally.” 相似文献
289.
Super-hydrophobic surface has been prepared onto biodegradable polymer by a combination of transcribing microscopic structure of a water-repellent leaf and a chemical treatment. An aroid leaf has been chosen for the preparation of the super-hydrophobic surface since the leaf has concavity microscopic structure, which is easy to handle for a material use. The microscopic pattern was transcribed onto poly(ε-caprolactone) (PCL) sheet by using replica method, then it was further treated by soaking in a mixture of acetone/methanol solution. The resultant PCL having the microscopic concavity pattern showed high water contact angle of 148° and also showed antibacterial property for filamentous fungi. 相似文献
290.
It is reported that laser-processing is effective to repair the heat checks, which are fine shallow cracks on a surfaceof die-casting dies. 相似文献