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排序方式: 共有289条查询结果,搜索用时 15 毫秒
91.
JZ Chen LH Hu HL Jiang JD Gu WL Zhu ZL Chen KX Chen RY Ji 《Canadian Metallurgical Quarterly》1998,8(11):1291-1296
Comparative molecular field analysis (CoMFA), a three-dimensional quantitative structure-activity relationship (3D-QSAR) paradigm was used to study the correlation between the physicochemical properties and the in vitro bioactivities of ginkgolide analogues. The correlation derived from CoMFA analysis has a good predictive capability. Based on the result of CoMFA analysis, we designed some compounds. Pharmacological assay indicated that three of these new designed compounds are 2 and 4 times more potent than that of ginkgolides. 相似文献
92.
93.
BACKGROUND: The present study was designed to assess the effects of insulin-like growth factor-I (IGF-I) alone and in combination with growth hormone (GH) on differentiation and replication in cultured human granulosa cells. METHODS: Granulosa cells from patients undergoing in vitro fertilization were isolated and cultured for 2 days in culture medium with 10% serum, the medium was removed and the cells were incubated with IGF-I (1, 10 and 100 ng/ml) with or without GH (10 ng/ml) in serum-free medium and in the presence of 3H-methylthymidine (2 microCi/ml). RESULTS: IGF-I alone resulted in a significant dose-dependent increase in medium estradiol (E2) (p<0.05) and progesterone (P) (p<0.001) and suppression of IGF-binding protein-1 (IGFBP-1) (p<0.001), without any increase in [3H]-thymidine incorporation (P=0.10). The combination of IGF-I and GH further increased the release of E2 (p<0.001), and the amount of [3H]-thymidine incorporation (p<0.001). CONCLUSION: These results indicate a synergistic effect of IGF-I and GH on differentiation and replication of human granulosa cells, and thus support a role of both GH and IGF-I in regulation of ovarian function. 相似文献
94.
In a study of 662 sera from a hydatidosis endemic area, the indirect hemagglutination test based on a minimal nonspecificity criterion of positivity and the latex agglutination (LA) test were found to be suitable screening techniques for the detection of sera positive to the arc 5, diagnostic of hydatid infection. The lower nonspecificity of the LA test, its greater simplicity and its excellent correlation with the immunoelectrophoresis test suggest that it is the choice screening technique for use in field surveys or seroepidemiologic studies of hydatid disease. The advantages and limitations of this serologic approach for the detection of human hydatid cyst carriers in field studies are discussed. 相似文献
95.
Valerie Barichello Rickey Y Yada Robert H Coffin 《Journal of the science of food and agriculture》1991,56(3):385-397
Properties of starch granules isolated from different varieties and selections of potato (which vary in their degree of chill sweetening) were examined. Differential scanning calorimetry (DSC) showed an increase in resistance to gelatinisation of isolated starch granules which correlated (r = 0.911) with higher chip scores following storage at 4°C and 12°C. Varying water level content during DSC studies resulted in significantly lower water content required to produce two endotherms for starch isolated from varieties resistant to chill sweetening. These data strongly suggest that starch granule composition might be a factor differentiating the low temperature sweetening sensitive from resistant cultivars, and may provide a screening method for predicting chip colour of potatoes out of storage. 相似文献
96.
Rickey Y. Yada Neil Buck Richard Canady Chris DeMerlis Timothy Duncan Gemma Janer Lekh Juneja Mengshi Lin David Julian McClements Gregory Noonan James Oxley Cristina Sabliov Lyubov Tsytsikova Socorro Vázquez‐Campos Jeff Yourick Qixin Zhong Scott Thurmond 《Comprehensive Reviews in Food Science and Food Safety》2014,13(4):730-744
The NanoRelease Food Additive project developed a catalog to identify potential engineered nanomaterials (ENMs) used as ingredients, using various food‐related databases. To avoid ongoing debate on defining the term nanomaterial, NanoRelease did not use any specific definition other than the ingredient is not naturally part of the food chain, and its dimensions are measured in the nanoscale. Potential nanomaterials were categorized based on physical similarity; analysis indicated that the range of ENMs declared as being in the food chain was limited. Much of the catalog's information was obtained from product labeling, likely resulting in both underreporting (inconsistent or absent requirements for labeling) and/or overreporting (inability to validate entries, or the term nano was used, although no ENM material was present). Three categories of ingredients were identified: emulsions, dispersions, and their water‐soluble powdered preparations (including lipid‐based structures); solid encapsulates (solid structures containing an active material); and metallic or other inorganic particles. Although much is known regarding the physical/chemical properties for these ingredient categories, it is critical to understand whether these properties undergo changes following their interaction with food matrices during preparation and storage. It is also important to determine whether free ENMs are likely to be present within the gastrointestinal tract and whether uptake of ENMs may occur in their nanoform physical state. A practical decision‐making scheme was developed to help manage testing requirements. 相似文献
97.
98.
T Yada O Hiramatsu A Kimura M Goto Y Ogasawara K Tsujioka S Yamamori K Ohno H Hosaka F Kajiya 《Canadian Metallurgical Quarterly》1993,72(5):939-946
We developed a portable needle-probe videomicroscope with a charge-coupled device (CCD) camera to visualize the subendocardial microcirculation. In 12 open-chest anesthetized pigs, the sheathed needle probe with a doughnut-shaped balloon and a microtube for flushing away the intervening blood was introduced into the left ventricle through an incision in the left atrial appendage via the mitral valve. Images of the subendocardial microcirculation of the beating heart magnified by 200 or 400 on a 15-in. monitor were obtained. The phasic diameter change in subendocardial arterioles during cardiac cycle was from 114 +/- 46 microns (mean +/- SD) in end diastole to 84 +/- 26 microns in end systole (p < 0.001, n = 13, ratio of change = 24%) and that in venules from 134 +/- 60 microns to 109 +/- 45 microns (p < 0.001, n = 15, ratio of change = 17%). In contrast, the diameter of subepicardial arterioles was almost unchanged (2% decrease, n = 5, p < 0.01), and the venular diameter increased by 19% (n = 8, p < 0.001) from end diastole to end systole. Partial kinking and/or pinching of vessels was observed in some segments of subendocardial arterioles and venules. The percentage of systolic decrease in the diameter from diastole in the larger (> 100 microns) subendocardial arterioles and venules was greater than smaller (50-100 microns) vessels (both p < 0.05). In conclusion, using a newly developed microscope system, we were able to observe the subendocardial vessels in diastole and systole.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
99.
Although it is well documented that child maltreatment exerts a deleterious impact on child adaptation, much less is known about the precise etiological pathways that eventuate in child abuse and neglect. This paper reports on a multimethod ecological study of the relationship between neighborhood structural factors and child maltreatment reports in African American and European American census tracts. The study had two major components. First, in an aggregate analysis, the effects of four measures of community structure (impoverishment, child care burden, instability, and geographic isolation) on child maltreatment report rates were examined separately for predominantly African American (n = 94) and predominantly European American (n = 189) census tracts. Impoverishment in particular had a significantly weaker effect on maltreatment rates in African American than in European American neighborhoods. Second, focused ethnographies were conducted in four selected census tracts with child maltreatment report rates in the highest and lowest quartiles. Ethnographic data point to the importance of the social fabric in accounting for differences in child maltreatment report rates by predominant neighborhood ethnicity. 相似文献
100.
Vocal fold palsy is a cause of dysphonia. Due to incomplete glottic closure during phonation, patients with a unilateral vocal fold palsy present with a weak and breathy voice and recurrent aspiration. To lessen the clinical manifestations of unilateral vocal fold palsy, polytetrafluoroethylene (Teflon) paste is one agent which has been injected into the paraglottic region, thus causing the vocal fold to move more medially. One of the complications associated with Teflon paste injection is migration of the paste into the surrounding tissues. We present a patient with idiopathic left vocal fold palsy who underwent Teflon injection to the vocal fold and subsequently developed a precricoid nodule, mimicking a cartilaginous swelling. 相似文献