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排序方式: 共有935条查询结果,搜索用时 31 毫秒
841.
Pascal Barbin Jean‐Luc Cheval Jean‐François Gilis Pierre Strehaiano Patricia Taillandier 《Journal of the Institute of Brewing》2008,114(1):69-75
Yeast Brettanomyces bruxellensis is a contaminant found worldwide and is responsible for red wine spoilage due to the development of animal and phenolic off‐odours. During this study, 24 Brettanomyces bruxellenis isolates were obtained from red wine samples from two French wineries and these were discriminated as 23 strains. Nine strains coming from 2 wineries and 4 vintages were cultivated in synthetic wine medium for 1500 hours and they gave nine different behaviours. Four main growth patterns (with different growth steps and durations) and three main different sugar consumption profiles were obtained. Glucose and fructose were not limiting substrates for all strains. The production level of 4‐ethylphenol was found to vary from strain to strain (from 0.350 to 2.773 mg L?1) and was independent of the biomass concentration. Some strains presented a coupled‐to‐growth production of volatile phenols, others did not. This study showed that different strains of Brettanomyces bruxellensis behaved differently, one from another, under the given conditions taking into consideration several aspects. The results thus demonstrate a large intraspecific diversity. 相似文献
842.
Marciano M. Oliveira J.P. Cruz‐Tirado Douglas F. Barbin 《Comprehensive Reviews in Food Science and Food Safety》2019,18(3):670-689
Food fraud in herbs and spices is an important topic, which has led to new technologies being studied as potential tools for fraud identification. Nontargeted technologies have proven to be a useful tool for the authentication of herbs and spices. The present review focuses on the use of near‐infrared, hyperspectral imaging, Fourier‐transform infrared, Raman, nuclear magnetic resonance, and electron spin resonance spectroscopy for the authentication of spices, which includes the determination of origin and irradiated spices and the identification of adulterants. The methods developed based on vibrational spectroscopy combined with chemometric techniques seem to be promising tools for determining the presence of adulterants and contaminants in herbs and spices. On the other hand, nuclear magnetic resonance seems to be the most efficient technology to determine the origin of herbs and spices although, for some cases, studies with near‐infrared spectroscopy can be a viable substitute. Electron spin resonance spectroscopy is the technique par excellence used for the authentication of irradiated herbs and spices, so its use should be expanded to many more spices’ varieties. Portable devices are preferred by those involved in the food industry, due to its manageability and low cost. Data fusion and big data are shown as promising tools for spice fraud control. In conclusion, spectroscopic techniques show a great efficiency to authenticate spices, although their evaluation must be expanded to other spice varieties, to new strategies of data analysis (as data fusion and big data), and to the use of portable devices. 相似文献
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844.
根据Forrester推算,到目前为止,全球已经有4千万支蓝牙移动电话,超过2000家公司投入蓝牙装置的发展,超过1000种产品已经向蓝牙特殊利益团体(SIG)注册.也就是说,蓝牙已经渐渐的侵入市场之中.但是,一个残酷的现实是,虽然很多产品已经推出,但消费者并没有使用蓝牙功能;也就是说,这项功能尚未得到消费者的足够认可. 相似文献
845.
846.
AF Carpentier L Bernard M Poisson JY Delattre 《Canadian Metallurgical Quarterly》1996,152(10):587-601
Infections of the nervous system remain a significant source of morbidity and mortality in patients with cancer. This paper reviews the main pathogens and emphasizes some of the principles of diagnosis and management of nervous system infections in cancer patients. Due to immunosuppression, diagnosis is more difficult in this group, secondary to the multitude of potential pathogens, and often by their atypical presentations. Fever or headache are often the only symptoms. Clinical history and general examination should guide appropriate studies such as neuroimaging. CSF analysis, cultures, and brain biopsy. Diagnostic evaluation should be pursued rapidly and aggressively since specific treatments can often reduce morbidity and mortality. Bacterial infections are generally due to break-down of the natural barriers and neutropenia. In neutropenia, Pseudomonas aeruginosa, and Enterobacteriae are the most frequent etiology. If all causes of immunodepression are included, Listeria monocytogenes meningitis is the main bacterial infection encountered. Fungal infections have emerged as a major cause of death among cancer patients. The prognosis of cryptococcosis and histoplasmosis meningitis are markedly improved with new antifungal therapy. Aspergillosis and Mucormycosis, which may cause cerebral abcesses and secondary vascular complications, are almost always fatal. The incidence of meningo-cerebral Candidiasis is often underestimated. Similar to Histoplasmosis, it is frequently disseminated. Viral infections are mainly seen in patients with T-lymphocyte defects. Herpes-simplex virus and Varicella-Zoster virus encephalitis should quicky lead to intravenous treatment with Acyclovir. As in AIDS patients, cerebral toxoplasmosis is the most frequent parasitic infection and appropriate therapy greatly reduces morbidity. It should be emphasized that multitude pathogens are often seen in cancer patients. Despite development of new therapeutic agents, central nervous system infections should still be considered life-threatening. Therefore, antibacterial, antifungal, and antiviral prophylaxis should be the rule for all cancer patients. 相似文献
847.
In this paper, 11 case-control studies on the relation between smoking and CHD in China were analysed by means of Meta-analysis. The cumulative casesand controls were 1172 and 2507. The results showed that statistically signiflicant correlation between smoking and CHD was discovered. The pooled OR (smoking vs no-smoking) was 2.20 (95% CI: 1.91-2.55). There was strong dose-response relation between the amount of smoking and the OR in developing CHD. 相似文献
848.
849.
850.
Stroke occurs in all age groups, ranging from the newborn to the elderly. The immature brain is generally believed to be more resistant to the damaging effects of cerebrovascular compromise compared to the more mature brain. However, recent experiments suggest that the correlation between brain damage and age is not linear. To determine the effects of age and development on hypoxic-ischemic brain damage, we developed a model whereby rats of increasing age received identical cerebrovascular insults, and assessed neuropathologic outcome. Male Wistar rats of 1, 3, 6, and 9 weeks and 6 months underwent unilateral common carotid artery ligation and exposure to 12% oxygen for 35 min. Animals were all spontaneously breathing under light halothane anesthesia (0.5%). Core temperatures were maintained at 37 degrees C. Blood pressures were monitored via indwelling carotid artery catheters on the side ipsilateral to the carotid artery ligation. Cerebral blood flow was assessed in separate groups utilizing Laser Doppler flowmetry. Physiologic monitoring revealed that under these experimental conditions, mean arterial blood pressure and cerebral blood flow decreased to the same extent in each of the age groups, verifying that all animals experienced an identical insult. Neuropathologic assessment at 7 days of recovery showed that brain damage was most severe in the 1 and 3 week old animals followed by those that were 6 months. The 6 and 9 week old groups had significantly less injury than the other 3 age groups. Hippocampal damage was most severe in the 3 week and 6 month old rats compared to all other age groups. Our findings contrast previously held beliefs regarding the enhanced tolerance of the immature brain to hypoxic-ischemic damage and demonstrates that, in a physiologically controlled in vivo model of hemispheric global ischemia, (1) the immature brain is, in fact, less resistant to hypoxic-ischemic brain damage than its adult counterpart, (2) the brain damaging effects of hypoxic-ischemia are age dependent, but do not increase linearly with advancing age and development, and (3) the intermediate age groups are more tolerant to hypoxic-ischemic brain injury than either very young or more mature ages. 相似文献