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21.
We developed a fluorescence‐quenching‐based assay system to determine the hydrolysis activity of endo‐β‐N‐acetylglucosaminidases (ENGases). The pentasaccharide derivative 1 was labeled with an N‐methylanthraniloyl group as a reporter dye at the non‐reducing end and with a 2,4‐dinitrophenyl group as a quencher molecule at the reducing end. This derivative is hydrolyzed by ENGase, resulting in an increase in fluorescence intensity. Thus, the fluorescence signal is directly proportional to the amount of the tetrasaccharide derivative, hence allowing ENGase activity to be evaluated easily and quantitatively. Using this system, we succeeded in measuring the hydrolysis activities of ENGases and thus the inhibitory activities of known inhibitors. We confirmed that this assay system is suitable for high‐throughput screening for potential inhibitors of human ENGase that might serve as therapeutic agents for the treatment of N‐glycanase 1 (NGLY1) deficiency.  相似文献   
22.
We developed a fully automated electrophoresis system for rapid and highly reproducible protein analysis. All the two-dimensional (2D) electrophoresis procedures including isoelectric focusing (IEF), on-part protein staining, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and in situ protein detection were automatically completed. The system comprised Peltiert devices, high-voltage generating devices, electrodes, and three disposable polymethylmethacrylate (PMMA) parts for IEF, reaction chambers, and SDS-PAGE. Because of miniaturization of the IEF part, rapid IEF was achieved in 30 min. A gel with a tapered edge gel on the SDS-PAGE part realized a connection between the parts without use of a gluing material. A biaxial conveyer was employed for the part relocation, sample introduction, and washing processes to realize a low-maintenance and cost-effective automation system. Performances of the system and a commercial minigel system were compared in terms of detected number, resolution, and reproducibility of the protein spots. The system achieved high-resolution comparable to the minigel system despite shorter focusing time and smaller part dimensions. The resulting reproducibility was better or comparable to the performance of the minigel system. Complete 2D separation was achieved within 1.5 h. The system is practical, portable, and has automation capabilities.  相似文献   
23.
The rapid hydrolysis of potato starches differing in phosphorus content, as well as sweet potato, cassava and yam starches, was accomplished by treatment of gelatinised starches with bacterial liquefying α-amylase at 50 °C for 1 h, followed by Bacillus licheniformis α-amylase at 55 °C up to 24 h, and then by glucoamylase at 40 °C for a further 24 h. Among the potato starches, the high-phosphorus starches showed higher starch resistant capacity than the medium-phosphorus starches, as well as other tuber and root starches. The hydrolysis rate of tuber and root starches was not greatly influenced by their amylose content and median granule size. Only glucose was detected in the almost completely hydrolysed tuber and root starch samples, indicating that the concomitant enzymes treatment could hydrolyse both the α-1,4 and α-1,6 linkages of the starches examined.  相似文献   
24.
β-Casomorphin-7 (BCM) is a degradation product of β-casein, a milk component, and has been suggested to affect the immune system. However, its effect on mucosal immunity, especially anti-tumor immunity, in cancer-bearing individuals is not clear. We investigated the effects of BCM on lymphocytes using an in vitro system comprising mouse splenocytes, a mouse colorectal carcinogenesis model, and a mouse orthotopic colorectal cancer model. Treatment of mouse splenocytes with BCM in vitro reduced numbers of cluster of differentiation (CD) 20+ B cells, CD4+ T cells, and regulatory T cells (Tregs), and increased CD8+ T cells. Administration of BCM and the CD10 inhibitor thiorphan (TOP) to mice resulted in similar alterations in the lymphocyte subsets in the spleen and intestinal mucosa. BCM was degraded in a concentration- and time-dependent manner by the neutral endopeptidase CD10, and the formed BCM degradation product did not affect the lymphocyte counts. Furthermore, degradation was completely suppressed by TOP. In the azoxymethane mouse colorectal carcinogenesis model, the incidence of aberrant crypt foci, adenoma, and adenocarcinoma was reduced by co-treatment with BCM and TOP. Furthermore, when CT26 mouse colon cancer cells were inoculated into the cecum of syngeneic BALB/c mice and concurrently treated with BCM and TOP, infiltration of CD8+ T cells was promoted, and tumor growth and liver metastasis were suppressed. These results suggest that by suppressing the BCM degradation system, the anti-tumor effect of BCM is enhanced and it can suppress the development and progression of colorectal cancer.  相似文献   
25.
Levels of eight harmful elements, i.e., antimony, arsenic, barium, cadmium, chromium, lead, mercury and selenium, were investigated in 45 baby toys and 10 paints, which were mainly made of polyvinyl chloride. All samples contained barium at levels of 0.3-3,700 mg/kg, several samples contained cadmium (0.2-26 mg/kg), chromium (0.5-280 mg/kg) and lead (1.5-1,300 mg/kg), and one sample contained antimony (5.3 mg/kg). They might have been used as colorants of the toy materials and paints. They were then evaluated using the migration test of ISO 8124-3, in which samples were ground up, and then soaked in 0.07 mol/L HCl at 37 degrees C for two hours. Barium, cadmium, chromium and lead migrated from some of the samples, but at levels lower than the migration limits required by ISO 8124-3. Compared with the Japanese official method, the ISO method resulted in higher migration, but there are significant differences in the migration limits, test method, and so on between them. Further investigation is needed in this area.  相似文献   
26.
We examined whether the perception of the colorfulness of an image is influenced by the adaptation of the visual system to natural and shuffled images with different degrees of saturation. In the experiment, observers first became adapted to several images with different levels of saturation and then their colorfulness perception of a test image was measured. The results show that their perception of colorfulness was influenced by their adaptation to the saturation of images. The effect was stronger following adaptation to natural images than to images consisting of a shuffled collage of randomized color blocks, which suggests that the naturalness of the spatial structure of an image affects the strength of the effect.  相似文献   
27.
The possibility of using ammonia as a hydrogen carrier is examined for the reaction between magnesium ammine complex MgCl2(NH3)6 and lithium hydride LiH. Sample was milled at low temperature of −40 °C to avoid decomposition of MgCl2(NH3)6 during the milling. The effects of milling time, milling speed (revolutions per minute), and catalysts on hydrogen storage properties were investigated by thermogravimetry, thermal desorption mass spectroscopy, and X-ray diffraction experiments. Experimental results indicated that a milled composite of Mg(NH3)6Cl2 and catalyzed-LiH desorbed the ∼100% H2 gas even at 125 °C in a closed system. The reverse reaction also proceeded by separately cooling MgCl2 at lower temperature than 100 °C and heating LiNH2 at 300 °C in the closed system.  相似文献   
28.
To test the effects of the annual fluctuation of the environmental factors on the starch properties in potato tuber development, starches were isolated from potato cultivars grown for ten consecutive years (2001–2010) on the experimental farm in Memuro, Hokkaido, the northernmost island of Japan. The median granule size, phosphorus content, and rapid visco‐analyzer pasting properties, peak viscosity, breakdown, and pasting temperature of these starches were analyzed. Daily temperature and precipitation records in Memuro were obtained from the Japan Meteorological Agency. Moreover, the correlation coefficients of yearly accumulated temperature and precipitation from flowering to harvesting with all the starch quality parameters were calculated. No relationships of accumulated temperature with median granule size, peak viscosity, and breakdown were found. The low phosphorus content was slightly associated with the high accumulated temperature. The pasting temperature was significantly and positively correlated with the accumulated temperature, suggesting that the pasting temperature strongly responds to the environmental temperature during potato tuber development. In contrast, all the starch quality parameters were almost irrespective of the precipitation during potato tuber development.  相似文献   
29.
While the space volume of mufflers in a venting system gets constrained, shape optimization to maximize the muffler's performance becomes important and essential. This paper presents a genetic algorithm (GA) for the optimal shape design of mufflers. The four‐pole matrix method which was adopted in evaluating the acoustic performance of sound transmission loss (STL) is used in conjunction with the GA techniques. Case studies of the full band noise inside a venting system are exemplified by the reactive mufflers. Before the GA operation, several examples are tested and compared with the experimental data for accuracy check of the mathematical models. Consequently, GA can provide a quick and effective way for a muffler design work. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
30.
Robust classical conditioning modifies responding to the unconditioned stimulus (US) in the absence of the conditioned stimulus (CS), a phenomenon the researchers called conditioning-specific reflex modification. Unconditioned responses (URs) to periorbital stimulation varying in intensity and duration were assessed before and after 1, 3, or 6 days of paired, explicitly unpaired, or no presentations of tone and electrical stimulation. After 3 days of pairings, conditioned responding (CRs) reached 94%, and there was an increase in latency to the peak of URs. The peak latency increase was replicated in a 2nd experiment where rabbits reached asymptotic conditioning during 6 days of pairings. There was also a conditioning-specific increase in the amplitude of URs. There were no UR changes as a function of low level of CRs following 1 day of pairings. Data suggest that there are learning-specific changes in pathways mediating the US/UR, as well as in those mediating the CS/CR. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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