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91.
A field ion microscope has been used to investigate the influence of oxygen adsorption on adhesion of W to Au. An adhesion contact in ultrahigh vacuum of the field ion microscope was carried out using a W tip either with or without oxygen adsorption. It was found that adhesion force decreased with increasing oxygen exposures up to 60 Langmuirs (L). With an oxygen exposure of 16 L, an intermediate adhesion resulted. Adhesion is thus dependent upon the coverage of oxygen. The depth of adhesion-induced lattice defects was studied using the field evaporation technique. Over 200 L, adhesion force was not detectable, nor was distortion of W atoms. 相似文献
92.
A Japanese cola was hydrogenated in wash oil with fine iron dust and sulphur as catalyst under a reaction pressure of 12–13 MPa at 420 °C for 2 h and then at 500 °C for 0–20 min. The liquid yield boiling up to 600 °C amounted to 55–66 wt%. Pyridine conversion was ≈ 100 wt%, benzene conversion 82–90 wt% and n-hexane conversion 53–70 wt%. Compared with direct hydrogenation at 500 °C for 10 min the low temperature-long time plus high temperature-short time liquefaction process (the Hokudai process) is a very effective method for obtaining high liquid yield under relatively low hydrogen pressure without coking, using disposable catalyst and non-donor solvent. 相似文献
93.
Emerging technologies for very-large-scale integration (VLSI) process and device architecture are discussed. A new domain of submicron technology for 16 Mbits and beyond has recently been developed on the basis of unique surface chemistry on a cooled substrate in the temperature range from −20 to −130 °C. Reactive ion etching at low temperatures has dramatically improved the anisotropy, pattern shift and selectivity. Also, low temperature remote plasma chemical vapour deposition (CVD) has achieved complete planarization of device surfaces. Pattern projection of thin films has become possible by using excimer-laser-induced cryogenic CVD. All these findings have indicated the significant importance of controlling adsorbate-solid surface interactions in future VLSI process technology. As for device architecture a new type of silicon chip such as a three-dimensional optically coupled common memory will be developed in addition to the conventional high density VLSI memories. 相似文献
94.
Paresh L. Dhepe Masataka Ohashi Shinji Inagaki Masaru Ichikawa Atsushi Fukuoka 《Catalysis Letters》2005,102(3-4):163-169
Mesoporous silicas are modified with sulfonic acid groups either by one-pot or by grafting method. In the hydrolysis of sucrose and starch, the sulfonated mesoporous silicas work as water-tolerant recyclable solid acid catalysts, showing higher conversion and turnover frequency than conventional Amberlyst-15, Nafion-silica and HZSM-5 catalysts. 相似文献
95.
Nakazawa Takashi; Kawai Hikaru; Okamoto Yuko; Fukugita Masataka 《Protein engineering, design & selection : PEDS》1992,5(6):495-503
A tertiary structure prediction is described using Monte Carlosimulated annealing for the peptide fragment corresponding toresidues 1636 of bovine pancreatic trypsin inhibitor(BPTI). The simulation starts with randomly chosen initial conformationsand is performed without imposing experimental constraints usingenergy functions given for generic interatomic interactions.Out of 20 simulation trials, seven conformations show a sheet-likestructuretwo strands connected by a turnalthoughthis sheet-like structure is not as rigid as that observed innative BPTI. It is also shown that these conformations are mostlylooped and exhibit a native- like right-handed twist. Unlikethe case with the C-peptide of RNase A, no conspicuous -helicalstructure is found in any of the final conformations obtainedin the simulation. However, the lowest-energy conformation doesnot resemble exactly the native structure. This indicates thatthe rigid ß-sheet conformation of native BPTI merelycorresponds to a local minimum of the energy function if thefragment with residues 1636 is isolated from the nativeprotein. A statistical analysis of all 20 final conformationssuggests that the tendency for the peptide segments to formextended ß-strands is strong for those with residues1824, and moderate for those with residues 3035.The segment of residues 2529 does not tend to form anydefinite structure. In native BPTI, the former segments areinvolved in the ß-sheet and the latter in the turn.A folding scenario is also speculated from this analysis. 相似文献
96.
Not Oligomers but Amyloids are Cytotoxic in the Membrane‐Mediated Amyloidogenesis of Amyloid‐β Peptides 下载免费PDF全文
Naoya Itoh Eri Takada Kaori Okubo Dr. Yoshiaki Yano Dr. Masaru Hoshino Dr. Akira Sasaki Prof. Masataka Kinjo Prof. Katsumi Matsuzaki 《Chembiochem : a European journal of chemical biology》2018,19(5):430-433
The formation of neurotoxic aggregates by amyloid‐β peptide (Aβ) is considered to be a key step in the onset of Alzheimer's disease. It is widely accepted that oligomers are more neurotoxic than amyloid fibrils in the aqueous‐phase aggregation of Aβ. Membrane‐mediated amyloidogenesis is also relevant to the pathology, although the relationship between the aggregate size and cytotoxicity has remained elusive. Here, aggregation processes of Aβ on living cells and cytotoxic events were monitored by fluorescence techniques. Aβ formed amyloids after forming oligomers composed of ≈10 Aβ molecules. The formation of amyloids was necessary to activate apoptotic caspase‐3 and reduce the ability of the cell to proliferate; this indicated that amyloid formation is a key event in Aβ‐induced cytotoxicity. 相似文献
97.
Summary 7,7-Dicyanoquinone methides (1a-b) copolymerized spontaneously with substituted -acetoxystyrenes (2a-b) in benzene at 60 °C to give alternating copolymers (poly(1a-b-co-2a-b)) with the molecular weights of 8–60×104 in 42–66% yields. When these copolymers were heated under nitrogen, they eliminated acetic acid quantitatively at around 200 °C to be converted to the copolymers (poly(3a-d)) with olefinic bonds, which were characterized by infrared and nuclear magnetic resonance spectroscopy. Alternating copolymers and the corresponding copolymers with olefinic bonds were amorphous, and capable of being cast from their chloroform solutions into transparent, tough films. 相似文献
98.
Kenichi Okazaki Yukinori Shima Daisuke Kurosaki Hiroyuki Miyake Junichi Koezuka Susumu Kawashima Masataka Shiokawa Hideaki Shishido Shunpei Yamazaki 《Journal of the Society for Information Display》2015,23(12):561-569
A 13.3‐inch 8k4k organic light‐emitting diode display based on a newly developed high‐mobility indium–gallium–zinc–oxide material was fabricated. It was found that the use of a higher‐mobility material decreases the scan driver size and power consumption. Furthermore, such oxide semiconductor layers with a buried channel structure can increase process stability and reliability. 相似文献
99.
Baoping Ren Haiwen Liu Zhewang Ma Masataka Ohira Xuehui Guan Pin Wen Xiaolong Wang 《国际射频与微波计算机辅助工程杂志》2019,29(1)
In this article, a compact dual‐band bandpass filter (BPF) is developed using a hybrid resonant structure, which consists of a microstrip stub‐loaded dual‐mode resonator and a slotline stub‐loaded dual‐mode resonator. These two resonators, both having two controllable resonant modes and one transmission zero (TZ), are analyzed and used to construct two desired passbands of a dual‐band BPF. Multiple TZs are generated by introducing a source‐load coupling, thus improving the selectivity of the passbands. Then, the dual‐band BPF is reshaped to configure a compact diplexer. The inherent TZs of the two proposed resonators are designed to improve the frequency property and port isolation of the diplexer. Finally, a dual‐band BPF and a diplexer with the lower and upper passbands centered at 2.45 and 3.45 GHz, respectively, are designed, fabricated, and measured to verify the proposed structure and method. 相似文献
100.
Asphaltene prepared from a Japanese coal (Akabira, 81.2 wt% C) and coal tar pitch were heat treated under nitrogen or hydrogen. Under nitrogen the initial thermal decomposition produced radicals which abstracted hydrogen from other molecules to stabilize and to produce smaller molecules and gas. The molecules from which hydrogen was abstracted as well as other radicals polycondensed to produce heavier solvent-insoluble fractions. Under hydrogen the radicals were stabilized by hydrogen gas to produce smaller molecules avoiding the production of a heavier fraction. The higher the hydrogen pressure, the smaller was the yield of heavier fraction and the larger the yield of lighter fraction. Higher temperature accelerated the production of the heavier fraction. Donor solvents could reduce the production of the heavier fraction. 相似文献