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101.
Photodarkening was investigated in CdS-doped glasses using luminescence and electron spin resonance (ESR). Photodarkening depends on manufacturers of glasses. The main origin of the difference in photodarkening is attributable to the difference in glass composition. 相似文献
102.
Dense samples of the higher boride YB22C2N have been fabricated through the spark plasma sintering (SPS) method with different sintering aids. YB22C2N is a representative of a series of newly discovered rare-earth borocarbonitrides, which may be the long-awaited n-type counterpart of boron carbide, “B4C.” The effect of Si, SiC, Al, and TiC additions on the sintering process of YB22C2N has been studied. The best sintered bodies with densities higher than 90% of theoretical density were obtained by means
of SPS at 1700°C. We show that the additive choice and pressure have an effect on grain size and density. An investigation
of the effect of atmosphere on the sintering behavior has also been carried out. It was found that sinterability is enhanced
under nitrogen atmosphere. Thermoelectric properties of the materials sintered with additives have been evaluated, and we
discuss their dependences on the fabrication process route. 相似文献
103.
Yu Yan Jiang Eiji Yanai Kazumi Nishimura Huilai Zhang Nobuyuki Abe Masahiko Shinohara Kaoru Wakatsuki 《Fire Safety Journal》2010
Research and development of firefighters’ protective clothing relies on a large number of fire disaster experiments in order to assess the thermal performance. It would be substantially advantageous to substitute a virtual numerical experiment for a real one in terms of time, cost and safety. The present article reports the development of an integrated numerical simulator that makes possible the estimation of burn injuries originating from fire disasters. In the simulator, a general-purpose computational fluid dynamics program computes the fluid flow and heat transfer in an in situ fire event, while a one-dimensional program calculates the radiative–conductive heat transfer through the clothing and human skin. A data interface combines the two simulations by loose coupling so as to give the real-time burn injury progress output. The predicted surface heat fluxes and burn degrees agree with experimental measurements reasonably well. Possible numerical error sources are discussed that call for potential improvements in the future. 相似文献
104.
L Wang K Yokoyama H Takahasi N Kase Y Hanya K Yashiro M Miyaji K Nishimura 《International journal of food microbiology》2001,71(1):75-86
The partial sequences of the mitochondrial (mt) cytochrome b gene (402 bp) were determined for species of Aspergillus section Flavi. On the basis of identities of DNA sequences, 77 strains were divided into seven DNA types, from D-1 to D-7. The type strains of A. sojae, A. parasiticus, A. flavus and A. oryzae together, A. tamarii, and A. nomius were placed in DNA types D-1. D-2, D-4, D-5 and D-7, respectively. These species could be differentiated from each other. Furthermore, two other DNA types, D-3 and D-6 were found. DNA type D-3 was closely related to A. parasiticus (D-2) and included one strain that deposited as A. flatus var. flavus and produced aflatoxins B and G. DNA types D-6 included one strain named A. flavus and closely related to A. tamarii. The observations of conidial wall texture by SEM (Scanning Electron Microscopy) supported the relationships derived from the cytochrome b gene. The production of aflatoxins was also examined. Using the DNA sequence of cytochrome b gene, several strains were reidentified. The derived amino acids sequences were all the same in the studied strains. The mt cytochrome b gene is useful and reliable in distinguishing and identifying the species in Aspergillus section Flavi. 相似文献
105.
106.
M Shigemoto S Nishi Y Ogawa N Isse N Matsuoka T Tanaka N Azuma H Masuzaki H Nishimura Y Yoshimasa K Hosoda K Nakao 《Canadian Metallurgical Quarterly》1997,137(5):511-513
OBJECTIVE: Although the molecular mechanism of obesity has been poorly understood, recent studies indicate that leptin plays a critical role in regulating both food intake and body weight. Because obesity decreases the sensitivity to insulin, the human ob gene is presumed to be one of the candidate genes for non-insulin-dependent diabetes mellitus (NIDDM) associated with obesity. Although the protein coding region in the ob gene has been screened for mutations, the promoter region and the non-coding first exon have not yet been studied. We investigated the involvement of the human ob gene, especially mutations at the promoter region and the non-coding first exon, in the development of NIDDM associated with obesity. SUBJECTS: The study group comprised 60 Japanese obese subjects with NIDDM (body mass index (BMI) 43.6 > or = BMI > or = 26.4, 29.0+/-0.41 (mean+/-S.E.M.)) and 24 obese individuals with impaired glucose tolerance (IGT) (30 > or = BMI > or = 26.4, 27.1+/-0.22). METHODS: Mutations at both the promoter region and all three exons in the human ob gene were screened by the single-stranded conformational polymorphism analysis. When aberrantly migrated bands were recognized, the PCR-amplified DNA fragment was directly sequenced. RESULTS: In the protein coding region a silent mutation in the second exon was detected. The non-coding first exon and the about 100 bp 5'-flanking region of the gene which contains a proximal CCAAT/enhancer-binding protein site were screened, but no mutations were found. CONCLUSION: These results suggest that no mutations in either the promoter region at the about 100 bp 5'-flanking region of the gene, or in any of the three exons, are involved in the development of NIDDM or IGT associated with obesity. 相似文献
107.
I Mikami M Yamamoto H Nishimura K Koizumi M Gomibuchi S Tanaka 《Canadian Metallurgical Quarterly》1998,46(7):634-638
Fifty-five samples of pus were collected from 51 acute, non-perforated, two spontaneously ruptured and two recurrent peritonsillar abscesses (35 males and 18 females; median age 18 years) and analysed regarding (i) aerobic and anaerobic bacteria (standard culturing), (ii) morphology of bacteria and inflammatory cells (direct microscopy of acridine orange-stained material), and (iii) the percentage of bacteria coated with immunoglobulins IgG, secretory IgA (SIgA) and IgM and complement cleavage product C3b (immunofluorescence assay). Seventy-one per cent of the abscesses harboured a mixed bacterial flora of various aerobes and anaerobes. In none of the cases with a single bacterial species (27 per cent) could immunoglobulin- or complement-coated bacteria be found. In abscesses with a mixed flora, 18 per cent harboured IgG-coated, 15 per cent SIgA-coated, five per cent IgM-coated and five per cent C3b-coated bacteria, respectively. All pus samples contained inflammatory cells in abundance but they were mostly deformed and only occasionally could intracellular bacteria be recognized. Insufficient immunoglobulin-coating of bacteria might be an important aetiopathogenic factor in the development of a peritonsillar abscess. Bactericide in the abscesses is accomplished chiefly by protective mechanisms not dependent on antigen recognition by antibodies. 相似文献
108.
H Iwamoto F Katoh T Gotoh S Nishimura Y Ono Y Nishio E Fukuhara T Murakami 《Canadian Metallurgical Quarterly》1998,39(5):589-595
Histochemical studies of mammary gland sections obtained from healthy lactating Prim' Holstein cows contained numerous corpora amylacea, mainly located in active alveoli. Observations by electron microscopy revealed a cauliflower shape, with a fibrillar or multilayered organization. Mineral studies confirmed the presence of high calcium levels (12.3% of dry matter) and phosphorus (7.4%) in the corpora amylacea composition. These bodies stained positive to Von Kossa silver nitrate and to Periodic acid-Schiff. However, depending on the gland of origin, corpora amylacea stained positive or negative to Congo red. Histochemical studies seemed, therefore, insufficient to determine the presence or absence of amyloid. The amount of total protein varied by approximately 25%. Immunoblotting and analysis of the amino acid sequence of a peptidic fragment obtained from corpora amylacea gave clear evidence of the occurrence of caseins, beta-lactoglobulin and alpha-lactalbumin. However, the comparison between the amino acid composition of corpora amylacea and those of the main milk proteins indicated the presence of other proteins. Electrophoretic analysis also gave evidence of the presence of several other proteins, i.e. glycoproteins. Therefore, it is probable that corpora amylacea composition is much more complex than previously reported. 相似文献
109.
T Hasegawa K Ishihara H Fujii T Nishimura B Umeda 《Canadian Metallurgical Quarterly》1998,47(5):543-549
This study was carried out as an attempt to evaluate the relationship between the results of nasal patency examinations and selected anthropometric measurements of nasal cavities in children with complete primary and secondary cleft palate. The examined group consisted of 130 children with cleft palate treated by means of surgery in early childhood owing to their clefts. Concerning the diagnostic methods the study group was divided into two subgroups. Group I consisted of 75 children in whom face photographs in frontal and axial projections towards the external nasal aperture were analysed. Group II consisted of 55 children in whom by means of P-A teleradiography projection the total area, the maximum height and width of nasal cavity were measured separately for the side with cleft and without cleft. The assessment of nasal patency tests using the objective method--active anterior rhinomanometry was carried out. 相似文献
110.
K Suzuki T Furukawa Y Koyama T Sagawa M Nishimura M Yamanaka 《Canadian Metallurgical Quarterly》1998,32(5):819-825
The 32P-post-labelling assay for DNA adduct quantification gives the opportunity to examine endogenous exposure to DNA reactive compounds. Most human biomonitoring studies applied white blood cells (WBC) or cells obtained by broncho-alveolar lavages (BAL) as source of DNA, but still it is not clear what cell type represents the most reliable indicator for exposure to cigarette smoke-associated genotoxins. At first, we examined DNA adduct levels by means of nuclease P1 (NP1) enriched 32P-post-labelling in separated WBC subpopulations after in vitro incubations for 18 h with 10 microM benzo[a]pyrene (B[a]P). DNA adduct levels were highest in monocytes (10.7 +/- 2.9 adducts/10(8) nucleotides, n = 8), followed by lymphocytes (5.9 +/- 1.7, n = 8), and granulocytes (0.5 +/- 0.2, n = 8). Secondly, aromatic-DNA adduct levels were determined in BAL cells and WBC-subsets from (non-)smoking volunteers. In smoking individuals, adduct levels were in the ranking order: BAL cells (3.7 +/- 1.0, n = 5) > monocytes (2.0 +/- 0.5, n = 8) > or = lymphocytes (1.6 +/- 0.4, n = 8) > granulocytes (0.8 +/- 0.2, n = 8) by NP1-enrichment and monocytes (9.0 +/- 3.2, n = 5) > or = lymphocytes (8.0 +/- 2.1, n = 6) > granulocytes (2.1 +/- 0.3, n = 7) by butanol-enriched 32P-post-labelling. Aromatic-DNA adduct levels were significantly higher in WBC-subsets of smokers as compared with non-smokers, except for DNA adducts in granulocytes using butanol enrichment. Thirdly, dose-response relationships were investigated in mononuclear white blood cells (MNC, i.e. monocytes plus lymphocytes) and BAL-cells of a larger group of smoking individuals (n = 78). Adduct levels in MNC were related to daily exposure to cigarette-tar (r = 0.31, P < 0.01). Adduct levels in BAL cells seemed to be correlated with pack-years, but after correction for age this relationship was lost. Butanol extraction resulted in 5-6-fold higher DNA adduct levels in MNC, whereas butanol extraction of BAL-DNA of the same individuals yielded only 2-fold higher adduct levels. The two enrichment procedures of 32P-post-labelling were correlated in BAL cells (r = 0.86, P < 0.001, n = 12). We conclude that particularly MNC are good surrogates for the detection of smoking-related DNA adducts. 相似文献