全文获取类型
收费全文 | 1119篇 |
免费 | 22篇 |
专业分类
电工技术 | 26篇 |
综合类 | 2篇 |
化学工业 | 145篇 |
金属工艺 | 18篇 |
机械仪表 | 21篇 |
建筑科学 | 8篇 |
矿业工程 | 1篇 |
能源动力 | 19篇 |
轻工业 | 68篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 48篇 |
一般工业技术 | 72篇 |
冶金工业 | 651篇 |
原子能技术 | 4篇 |
自动化技术 | 51篇 |
出版年
2024年 | 3篇 |
2022年 | 15篇 |
2021年 | 21篇 |
2020年 | 12篇 |
2019年 | 21篇 |
2018年 | 19篇 |
2017年 | 9篇 |
2016年 | 15篇 |
2015年 | 12篇 |
2014年 | 22篇 |
2013年 | 18篇 |
2012年 | 27篇 |
2011年 | 20篇 |
2010年 | 23篇 |
2009年 | 28篇 |
2008年 | 28篇 |
2007年 | 27篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 21篇 |
1998年 | 181篇 |
1997年 | 123篇 |
1996年 | 97篇 |
1995年 | 53篇 |
1994年 | 34篇 |
1993年 | 57篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1977年 | 22篇 |
1976年 | 35篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1961年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有1141条查询结果,搜索用时 218 毫秒
1.
Deborah Oliveira De Fusco Leonardo Lucas Madaleno Vanildo Luiz Del Bianchi Aline da Silva Bernardo Rafael Roberto Assis Gustavo Henrique de Almeida Teixeira 《International Journal of Food Science & Technology》2019,54(7):2416-2424
Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L−1), osmolality (mOsmol kg−1), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L−1 gallic acid), reducing and total sugars (%) and Na and K contents (mg L−1). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences. 相似文献
2.
3.
Luca Cornolti Simone Martinelli Giovanni Bianchi Alberto Ortona 《Journal of the American Ceramic Society》2019,102(5):2304-2315
In this work, we investigated a procedure which exploits microwave ovens to produce SiC- based components by reactive melt infiltration of silicon into graphite preforms. The employed oven is designed to grant optical access to the sample surface, which allows to measure its temperature evolution though a noncontact pyrometer. This signal was used as a feedback to control the power provided to the preform and as an experimental output whose analysis provides insight into the reaction mechanism. Specifically, it is found that complete infiltration is achieved much before the end of the reaction. The latter is not fully self-sustained as the global reaction rate continuously decreases with time until it is no more able to keep the temperature above the silicon solidification value. At that point, the reaction stops. The analysis of the processed samples proved that this procedure allows producing fully infiltrated samples without material failure by adjusting the heat provided during the infiltration stage rather than by tuning the preform structure and composition, which is the usual approach. The proposed method is less time and energy consuming than the standard one. 相似文献
4.
Guest Editorial: Wireless Mobile Internet 总被引:1,自引:0,他引:1
5.
Y. Rey-Tauriac J. Badoc B. Reynard R.A. Bianchi D. Lachenal A. Bravaix 《Microelectronics Reliability》2005,45(9-11):1349
This paper presents results of reliability investigation of 20 V N-Drift MOS transistor in 0.13 μm CMOS technology. Due to high performances required for CMOS applications, adding high voltage devices becomes a big challenge to guarantee the reliability criteria. In this context, new reliability approaches are needed. Safe Operating Area are defined for switch, Vds limited and Vgs limited applications in order to improve circuit designs. For Vds limited applications, deep doping dose effects in drift area are investigated in correlation to lifetime evaluations based on device parameter shifts under hot carrier stressing. To further determine the amount and locations of hot carriers injections, accurate 2D technological and electrical simulations are performed and permit to select the best compromise between performance and reliability for N-Drift MOS transistor. 相似文献
6.
We discovered that a food aversion could be conditioned in anesthetized sheep. Sheep were allowed to eat a familiar food (alfalfa-grain pellets) for 30 min, and 90 min later they were given either an intraruminal (IR) injection of water (C), an IR injection of LiCl (L), anesthesia followed by an IR injection of water (A), or anesthesia followed by an IR injection of LiCl (A+L). Induction of anesthesia was by an intravenous injection of pentobarbitone sodium, and maintenance of deep anesthesia was by halothane. Sheep were maintained in deep anesthesia for 2 h to ensure that the effects of LiCl on the acquisition of a food aversion, which occur within about 1 h, were completed before they awakened. When tested 5 days later, sheep that received LiCl (treatments L and A+L) consumed less alfalfa-grain pellets than sheep that did not receive LiCl (treatments C and A) (241 g vs. 306 g; p = 0.057). Intake of sheep that were anesthetized (treatments A and A+L) did not differ from that of sheep that were not anesthetized (treatments C and L) (295 g vs. 252 g; p = 0.183). Nor was there an interaction between LiCl and anesthesia (p = 0.423). Thus, we conclude that changes in preferences for foods caused by postingestive feedback occur automatically every time food is ingested (i.e., they are noncognitive), and the kind and amount of feedback is a function of the match between the food's chemical characteristics and its ability to meet the animal's current demands for nutrients. 相似文献
7.
FD Fuchs 《Canadian Metallurgical Quarterly》1996,67(4):267-269
We have treated 50 patients with stage III, VI malignant tumors confirmed by pathology. The patients were divided into two groups. One group was treated by combination of chemotherapy and traditional Chinese medicine (treatment group); the other only by chemotherapy (control group). The effect of cancer treatment was evaluated according to the criteria of WHO. The results showed that the effective rate was 80% in treatment group and 52% in control group. The pain relieving rate was 68% in treatment group and 40% in control group (P < 0.01). This fact demonstrates that the application of traditional Chinese medicine can invigorate blood circulation, eliminate blood stasis, soften hardness and dissolve the mass, nourish blood and increase vigor. This kind of application can not only enhance the effect of cancer treatment but also increase the cancer pain relieving rate. 相似文献
8.
IEEE 802.11-saturation throughput analysis 总被引:1,自引:0,他引:1
To satisfy the emerging need of wireless data communications, the IEEE is currently standardizing the 802.11 protocol for wireless local area networks. This standard adopts a CSMA/CA medium access control protocol with exponential backoff. We present a simple analytical model to compute the saturation throughput performance in the presence of a finite number of terminals and in the assumption of ideal channel conditions. The model applies to both basic and request-to-send/clear-to-send (RTS/CTS) access mechanisms. Comparison with simulation results shows that the model is extremely accurate in predicting the system throughput 相似文献
9.
M Drlicek G Bianchi G Bogliun B Casati W Grisold C Kolig U Liszka-Setinek L Marzorati E Wondrusch G Cavaletti 《Canadian Metallurgical Quarterly》1997,244(2):85-89
PURPOSE: To determine the association between lipids, microalbuminuria and systemic blood pressure. Urinary albumin excretion rate (AER) was determined in timed overnight urine samples by radioimmunoassay. Microalbuminuria was defined when two out of three urine samples had AER ranging 20-200 micrograms/min. Lipids were determined by colorimetric methods (total cholesterol, HDL cholesterol and triglycerides). METHODS: Fifty patients with insulin dependent diabetes mellitus (28 females, 22 males) aged 21.9 +/- 7 years and with diabetes duration of 6.8 +/- 5.8 years attending the outpatients diabetes clinic were studied cross-sectionally. RESULTS: Microalbuminuria was present in 12% of our patients. A high systolic blood pressure (SBP) was found in microalbuminuric patients (p = 0.003). No difference concerning serum lipids were found in comparison between normo and microalbuminuric patients, although 20% of all patients had increased cholesterol and LDL cholesterol and 4% had high HDL cholesterol and triglycerides levels. Stepwise multiple regression analysis showed that SBP was the only significant independent variable to influence AER (r = 0.42 r2 = 0.18 p = 0.002). CONCLUSION: Although in our study, microalbuminuria was associated only with SBP, the independent alteration of lipids in young IDDM patients must be considered as a possible additional risk factor for cardiovascular disease. 相似文献
10.
AK Souid MC Ziemba AS Dubansky M Mazur M Oliphant FD Thomas M Ratner PD Sadowitz 《Canadian Metallurgical Quarterly》1993,72(6):2042-2048
The authors presented the cases of two children with inflammatory myofibroblastic (IMF) tumor and reviewed the literature to facilitate the preoperative recognition, delineate the clinical features, and describe the natural history of this entity. The first child had IMF tumor arising from the mesentery of the small intestine. He presented with an abdominal mass associated with severe inflammatory response manifested by fever, impaired growth, thrombocytosis, and microcytic, hypochromic anemia. After surgical resection, his fever resolved and his growth rate and the laboratory abnormalities normalized. Five months after initial diagnosis, the fever, anemia, and thrombocytosis recurred along with two tumors arising from the omentum and the abdominal soft tissue. After the second surgery, he remains free of recurrent disease for 30 months. The second child presented with a lung mass that was radiologically indistinguishable from pulmonary sequestration. After surgical resection, she remains free of recurrent disease for 18 months. IMF tumor should be considered in any solid tumor that occurs in association with a chronic inflammatory response. IMF tumor should also be considered in the differential diagnosis of pulmonary sequestration. 相似文献