全文获取类型
收费全文 | 997篇 |
免费 | 25篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 44篇 |
化学工业 | 172篇 |
金属工艺 | 27篇 |
机械仪表 | 23篇 |
建筑科学 | 14篇 |
能源动力 | 25篇 |
轻工业 | 102篇 |
水利工程 | 5篇 |
无线电 | 99篇 |
一般工业技术 | 201篇 |
冶金工业 | 203篇 |
原子能技术 | 34篇 |
自动化技术 | 79篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 12篇 |
2019年 | 5篇 |
2018年 | 11篇 |
2017年 | 16篇 |
2016年 | 16篇 |
2015年 | 16篇 |
2014年 | 21篇 |
2013年 | 54篇 |
2012年 | 35篇 |
2011年 | 54篇 |
2010年 | 44篇 |
2009年 | 42篇 |
2008年 | 35篇 |
2007年 | 34篇 |
2006年 | 24篇 |
2005年 | 37篇 |
2004年 | 41篇 |
2003年 | 27篇 |
2002年 | 32篇 |
2001年 | 25篇 |
2000年 | 28篇 |
1999年 | 20篇 |
1998年 | 89篇 |
1997年 | 55篇 |
1996年 | 30篇 |
1995年 | 22篇 |
1994年 | 22篇 |
1993年 | 17篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1977年 | 6篇 |
1976年 | 12篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有1028条查询结果,搜索用时 15 毫秒
981.
Yokoi KJ Kawasaki K Taketo A Kodaira K 《International journal of food microbiology》2004,96(3):273-279
Lactobacillus gasseri JCM 1130 and JCM 1131(T) exhibited autolytic activity in agar containing autoclaved cells of each strain as substrate. By zymogram analysis of JCM 1131(T), two lytic bands with apparent molecular masses of 54.5 and 35 kDa, were detected. Similarly, JCM 1130 yielded two lytic bands with apparent molecular masses of 35 and 33.5 kDa. In simple buffers as well, JCM 1131(T) suffered a drastic decrease in cell turbidity, but JCM 1130 did not undergo the decrease. The optimal pH for autolysis of JCM 1131(T) was in the range of 6.0-7.0, and the lysis was completely inhibited at pH 4-5. The lysis of JCM 1131(T) was suppressed by NaCl, in a concentration-dependent way. When subjected to UV irradiation or mitomycin C (MMC) treatment, cultures of both strains elicited conspicuous turbidity decrease after 2-4 h of growth, suggesting the occurrence of prophage induction. The 35-kDa lytic band of JCM 1131(T) and the 33.5-kDa protein of JCM 1130 were considerably increased by UV irradiation. 相似文献
982.
Suzuki N Kasahara K Watanabe Y Kinoshita S Hasegawa H Kawasaki T 《Drug development and industrial pharmacy》2003,29(7):805-812
Rapid and slow crystallization methods (A and B) were applied for troglitazone, an equal mixture of four stereoisomers. Differences in the powder x-ray diffractometry patterns and hygroscopic patterns were observed among the samples crystallized by these methods, suggesting that troglitazone has solid-state variation. In this article, troglitazone recrystallized by method A was evaluated to clarify its structural characteristics and physical property. The crystal structure of predried troglitazone recrystallized by method A was proved to be a dihydrate. By drying, it changed reversibly to an anhydrate, which is the same structure as the RS/SR form, keeping the same enantiomer ratio. The solubility of the troglitazone by method A higher than that by method B at all enantiomer levels. But making the troglitazone amorphous equalized the enantiomeric solubilities of the substances by both methods as well as increased the intrinsic solubilities. Troglitazone by both methods was proved to be stable and retained the ratio of the stereoisomers. 相似文献
983.
H Nakamura M Fujiwara M Kawasaki N Nonomura S Takahashi 《Canadian Metallurgical Quarterly》1998,255(6):289-292
Changes in dividing cells of the olfactory epithelium from guinea pigs of different ages were examined by immunohistochemical staining using anti-proliferating cell nuclear antigen antibody. Numerous dividing cells were scattered diffusely in the basal layer of the olfactory epithelium at 1 and 2 months following birth and then gradually decreased with maturation until 4 months. Findings then remained constant between 4 and 24 months. Subsequently, cell numbers were found to decrease as animals became older. The number of olfactory receptor cells did not vary significantly between 1 and 30 months. Although no correlation could be found between the numbers of dividing cells and olfactory receptor cells, it is still possible that the longevity of the olfactory receptor cells changes to maintain the overall size of the neuronal population. 相似文献
984.
T. Morita H. Takahashi M. Shimizu K. Kawasaki 《Fatigue & Fracture of Engineering Materials & Structures》1997,20(1):85-92
Abstract— The factors affecting the fatigue strength of nitrided titanium were clarified. The fatigue strength depended strongly on the fracture strength of the compound layer formed on the surface by nitriding. We found a Hall-Petch relationship between the fatigue strength of nitrided titanium and the grain size. The findings indicated that the reduction in the fatigue strength by nitriding results from both the formation of the compound layer possessing low fracture strength and grain growth occurring from ordinary nitriding. Furthermore, low-temperature nitriding (620°C, 24 h) was proposed to suppress grain growth. This treatment method improved not only the wear resistance and the corrosion resistance but also the fatigue strength of titanium. 相似文献
985.
986.
K Kanai M Kako T Kumada H Tsubouchi T Aikawa M Kojima H Harada T Kawasaki M Nakashima H Okamoto S Mishiro 《Canadian Metallurgical Quarterly》1998,143(8):1545-1554
Efficacy of standard regimens (e.g., 3-6 MU for 24 weeks) of alfa-IFN therapy for chronic hepatitis C has been limited, particularly in patients with HCV/1b. To see if higher-dose longer term treatment is more effective, we tried a 9 MU 60-week regimen. HCV/1b-infected chronic hepatitis patients received 9 MU IFN alpha 2a everyday but Sunday for 2 weeks and thrice a week for next 10 weeks, and 76 patients became HCV RNA-negative while 81 remained positive. The RNA-negative patients were then randomized to receive 3 MU (group I, n = 37) or 9 MU (group II, n = 39) for 48 weeks. Of the RNA-positive patients, only those with normal ALT received another 9 MU 48-week treatment (group III, n = 45). Sustained responders (SR) were defined as those with negative RNA and normal ALT 6 months after the therapy. SR rates based on intent-to-treat principle did not differ significantly between groups I and II (30% vs 41%), but those based on the protocol-compatible cases showed a significantly lower than those in group II. Adverse effects of IFN, developed more frequently in groups II and III than in group I, were mostly reversible. In conclusion, our results encourage 9 MU 60-week IFN alpha treatment in HCV/1b-infected patients with careful attention to adverse effects, and suggest that the treatment should be discontinued if HCV RNA does not disappear within 12 weeks. 相似文献
987.
T Kawasaki N Hashimoto T Kikuchi H Takahashi M Uchiyama 《Canadian Metallurgical Quarterly》1997,24(3):317-321
During 1994, 603 cases of bacterial meningitis were reported in Italy. Seventy-five percent of cases with determined etiology was due to three agents: Neisseria meningitidis (33.4%), Streptococcus pneumoniae (23.4%) and Haemophilus influenzae (18.6%). The majority of cases due to N. meningitidis and H. influenzae occurred in subjects below five years of age (35.7% and 84.8%, respectively) while S. pneumoniae accounted for 52.8% of meningitis cases in subjects older than 44 year of age. The estimated incidence of N. meningitidis on the national population in 1994 was 0.27 per 100,000. Serogroup B accounted for 62.5% of the serotyped isolates, group C for 23.1%, group A for 7.2%, group W135 for 3.6%, group Y for 1.8%. All tested meningococcal strains were susceptible to penicillin as well as to rifampin. Incidence of meningococcal meningitis in 1994 has been low suggesting that its relative importance compared to other bacteria causing meningitis is likely to change in the future. Therefore, extended surveillance on bacterial meningitis by other etiological agents has to be maintained and implemented in order to undertake the appropriate control measures and evaluate their effect. 相似文献
988.
This paper describes the performance of NASDA's various space solar cells by comparing flight data and ground test data. We first present the flight data from the Solar Cell Monitor on Engineering Test Satellite-VI. We then describe the ground irradiation tests of solar cells performed in collaboration with the Japan Atomic Energy Research Institute. Then discuss the radiation effects on solar cells, and present other flight data of solar cells and optical data of the coverglass from other satellites in addition. Finally, we describe the future plan to obtain flight data on various solar cells. 相似文献
989.
The Gmicro/200, a microprocessor that has been developed as part of Japan's TRON (The Real-Time Operating Nucleus) project, is described. This microprogram-based processor with six-state pipeline, 730000 transistors and on-chip caches will serve in an engineering workstation or a high-speed graphics accelerator system. The authors discuss features of the instruction set; memory management; handling of exceptions, interrupts and traps; and the implementation of the Gmicro/200 相似文献
990.