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991.
The anodic polarization behaviour of iron whisker crystals was investigated in a neutral solution with or without the presence of chloride ion, with special attention to the role played by surface defects in the dissolution, the passivation and the pitting of iron. The grown whisker used was substantially dislocation-free and the defect density was varied by twisting of whisker. With increase in the angle of twisting, the anodic dissolution current increased in a chloride-free solution, whereas it decreased in a chloride-containing solution. The defect density in the substrate had no remarkable effect on passivation but the thickness of the passive film was slightly increased on twisted whiskers. The anodic polarization curve of a grown whisker in a chloride-containing solution did not exhibit a distinct pitting potential. By twisting of whisker, however, a current rise due to pitting appeared on the polarization curve and the apparent pitting potential shifted in the negative direction with increasing angle of twisting. Potentiostatic polarization experiments in a chloride-containing solution showed the emergence of random current pulses due to the breakdown of passive film and to repassivation. It is highly probable that the breakdown of the passive film occurs at the physical or chemical inhomogeneities in the passive film not associated with dislocation termini but that pitting occurs only when the breakdown occurs at emergent dislocation sites. 相似文献
992.
Satoshi Kawamura Daisuke Tanaka Taisuke Tanaka Daisuke Noguchi Yuichiro Hayakawa Minami Kaneko Ken Saito Fumio Uchikoba 《Artificial Life and Robotics》2018,23(3):380-386
In this paper, we will compare the walking behavior of quadruped and hexapod walking MEMS robots. These robots are fabricated by connecting same modules, which are composed of a couple of independent leg mechanisms. Independent leg mechanisms can actuate the single leg by a single artificial muscle wire. The neural networks IC that mimics real living organisms controls the mechanical systems. The length and weight of the quadruped MEMS robot were 7.2 mm and 95.8 mg, respectively. The quadruped robot showed the walking speed of 24.6 mm/min. The robot tended to lose its balance and the weight balance is quite important for the moving quadruped. On the other hand, the length and weight of the hexapod MEMS robot were 9.0 mm and 162 mg, respectively. The hexapod robot showed stable walking. The speed was 27.0 mm/min. 相似文献
993.
Quenching reactions of singlet oxygen and scavenging reactions of free radicals by α-, β-, λ- and σ-tocopheramines (Toc-amines)
were investigated spectrophotometrically in ethanol and Triton X-100 micellar dispersions. The rate constants of quenching
of singlet oxygen (k
Q
) by α-, β-, λ- and σ-Toc-amines increased as the total electron donating capacity of the methyl groups at the aromatic ring
increased. A plot of logk
Q
vs. peak oxidation potential (E
p) was found to be linear and the slope was negative. Similar results were obtained for scavenging of a phenoxyl radical (PhO.).
The results suggest that charge transfer plays an important role in these reactions. Thek
Q values were found to be 1.30–2.57 times as large ask
Q for α-tocopherol (α-Toc). Although α-Toc has the highest antioxidant activity among natural tocopherols and related phenols,
Toc-amines also can serve as antioxidants. 相似文献
994.
995.
The protective effects of vitamin E (α-tocopherol) and its model compounds, which act as antioxidants, on linoleic acid hydroperoxide-induced
injury to human umbilical vein endothelial cells were examined. When incubated at 50 μM with endothelial cells at 37°C for
24 hr, α-tocopherol protected the cells from injury, and 2,2,5,7,8-pentamethylchroman-6-ol showed a similar protective effect.
Trolox C, a water-soluble vitamin E model compound, had no protective effect. Tocol, a poor antioxidant, proved toxic. During
preincubation, α-tocopherol was incorporated into the cells at 16.6 nmol/ mg protein, while the pentamethylchromanol was incorporated
at 0.5 nmol/mg protein; Trolox C was not incorporated at all. The results suggest that agents having both high antioxidant
activity and lipophilicity can protect endothelial cells from linoleic acid hydroperoxide-induced injury.
Issued as TMIG-I No. 170. 相似文献
996.
Sugai Akihiko Itoh Toshihiro Kaneko Hiroshi Kinjo Noriko Muramatsu Toshio 《Lipids》1986,21(10):666-668
The distribution of pyrophosphatidic acid in mushrooms was investigated. Total lipids of mushrooms were extracted from their
fruit body, and the pyrophosphatidic acid fraction was isolated by DEAE-silica gel column and silicic acid column chromatography.
The presence of pyrophosphatidic acid was tested by thin layer chromatography. Of the 43 species of mushrooms examined, the
acid was found in 30. The pyrophosphatidic acid was identified by chromatography, IR spectroscopy and quantitative degradation
with aqueous pyridine to produce phosphatidic acid. Chemically synthesized pyrophosphatidic acid was used as standard. 相似文献
997.
Synthetic polymer plates (GPs) with high surface energy were prepared by the two-step copolymerization process previously reported, using diethylene glycol bis(allyl carbonate) (CR-39) as M1 monomer and unsaturated sulfonates [sodium vinyl sulfonate (VS?Na+), potassium styrene sulfonate (StS?K+), and sodium 2-sulfoethyl methacrylate (SEM?Na+)] as M2 monomer. The contact angle (θH) of water for the acid-treated (immersed in an aqueous 0.1 N HCl solution for 2 h) GPs decreased in the order StS?K+, VS?Na+, and SEM?Na+. In the case of M2 = SEM?Na+, the θH value was about 20°. By adding NaCl in the immersion solution and changing the pH of the immersion solution, the θH values for the CR-39–SEM?Na+ GPs were lowered to 18.9 and 13.1°, respectively. The θH values for the above GPs were smaller than those for the CR-39–acrylic acid or the CR-39–methacrylic acid GPs in the previous report, whereas the contact angle (θNa) of water for the former after alkali treatment (immersed in an aqueous 0.1 N NaOH solution for 2h) was larger than those for the latter. The former had durability of water wettability superior to the latter because of the difference in dissociation characteristic of the respective functional group. 相似文献
998.
Akio Yamashita Kouhei Toyotaka Masashi Oota Daisuke Kubota Hiroyuki Miyake Yoshiharu Hirakata Shunpei Yamazaki Masahiro Katayama Kenichi Okazaki Junichi Koezuka Hiroshi Matsukizono Yohsuke Kanzaki Seiji Kaneko Naoki Ueda Akihiro Oda Shigeyasu Mori Takuya Matsuo 《Journal of the Society for Information Display》2014,22(4):216-227
We have established a technique for changing part of an active layer of an oxide semiconductor (OS) to a transparent electrode in order to achieve an aperture ratio of 50% or higher and a bezel width of 1 mm in an fringe field switching (FFS) mode LCD panel with a high resolution of 513 ppi. Furthermore, we have prototyped an LCD panel by examining a driving mode that enables low‐frequency driving. 相似文献
999.
1000.
Y. Ohta M. Kitayama K. Kaneko S. Toh F. Shimizu K. Morinaga 《Journal of the American Ceramic Society》2005,88(6):1634-1636
The capacitance of the Na2 O–SiO2 glass was measured in situ during heat treatment at various frequencies, 20, 100, 1, 3, 10, and 30 kHz. It was found that the capacitance of the glass abruptly decreases after a certain duration. The glass was quenched at this stage. It was confirmed by the X-ray diffraction and transmission electron microscopy that this decrease of capacitance was associated with the formation of crystallites in the glass matrix. The size of crystallites was observed to be in the range of about 10 nm. 相似文献