全文获取类型
收费全文 | 904篇 |
免费 | 55篇 |
出版年
2023年 | 6篇 |
2022年 | 10篇 |
2021年 | 22篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 25篇 |
2016年 | 31篇 |
2015年 | 33篇 |
2014年 | 37篇 |
2013年 | 65篇 |
2012年 | 67篇 |
2011年 | 65篇 |
2010年 | 42篇 |
2009年 | 34篇 |
2008年 | 48篇 |
2007年 | 60篇 |
2006年 | 33篇 |
2005年 | 42篇 |
2004年 | 26篇 |
2003年 | 34篇 |
2002年 | 41篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 17篇 |
1996年 | 4篇 |
1995年 | 11篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 10篇 |
1971年 | 4篇 |
1970年 | 5篇 |
1967年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有959条查询结果,搜索用时 20 毫秒
71.
Taisuke Kanzaki Shogo Nakade Yuji Wada Shozo Yanagida 《Photochemical & photobiological sciences》2006,5(4):389-394
Electron lifetime (tau) in dye-sensitized solar cells (DSC), using electrolytes containing I-/I3- redox couple, was investigated with quaternary ammonium cations having various alkyl chain lengths, and it was found that the lifetime increased in the order tau(TPA) approximately tau(TBA) < tau(THA) approximately tau(THpA), where tau(TPA), tau(TBA), tau(THA) and tau(THpA) were the lifetimes with tetra-propyl, butyl, hexyl and heptyl ammonium cations respectively. On the other hand, little influence of the cations on electron diffusion coefficients was observed, indicating that the DSCs using these cations have longer electron diffusion length (L). New electrolyte compositions for DSCs were sought with THA+ to increase the lifetime and L without compromising charge injection yield from the dye to TiO2. The electrolyte was applied for DSCs using TiO2 electrode prepared by 150 degrees C sintering. Under one-sun conditions (100 mW cm(-2)), newly prepared electrolytes showed at most 40% increase of energy conversion efficiency in comparison to conventional electrolytes and the highest value was 4.7%, which was the highest among the reported values of low temperature processed DSCs. The increase of the efficiency was achieved by higher short-circuit current induced by longer electron diffusion length and higher open-circuit voltage due to higher electron density. 相似文献
72.
Inoue Y Nomura W Takeuchi Y Ohdate T Tamasu S Kitaoka A Kiyokawa Y Masutani H Murata K Wakai Y Izawa S Yodoi J 《Applied and environmental microbiology》2007,73(5):1672-1675
Thioredoxin, an antioxidant protein, is a promising molecule for development of functional foods because it protects the gastric mucosa and reduces the allergenicity of allergens. To establish a method for obtaining an ample amount of yeast thioredoxin, we found here that thioredoxin is released from Saccharomyces cerevisiae by treatment with 20% ethanol. We also found that Japanese sake contains a considerable amount of thioredoxin. 相似文献
73.
Takahiro Noda Nisha Sulari Kottearachchi Shogo Tsuda Motoyuki Mori Shigenobu Takigawa Chie Matsuura-Endo Sun-Ju Kim Naoto Hashimoto Hiroaki Yamauchi 《Carbohydrate polymers》2007,68(4):793-796
The research presented herein provides valuable data with respect to the phosphorus content of starches from many potato (Solanum tuberosum L.) cultivars using an energy-dispersive X-ray fluorescence technique. In all starches examined, the phosphorus content ranged from 308 to 1244 ppm. Furthermore, the estimation of the starch characteristics of representative samples differing manifestly in their phosphorus content indicated that enhancing the starch phosphate resulted in significant increases in the swelling power, peak viscosity, and breakdown and significant but small increases in the onset and peak temperatures of gelatinization. Other starch quality parameters, such as the amylose content, median granule size, and the gelatinization enthalpy, did not change significantly due to the degree of phosphate substitution of starch. 相似文献
74.
Kanai T Akerboom J Takedomi S van de Werken HJ Blombach F van der Oost J Murakami T Atomi H Imanaka T 《The Journal of biological chemistry》2007,282(46):33659-33670
75.
We examined the influences of regular sexual activity and marital status on salivary testosterone levels in healthy adult
Japanese men. Forty-four men (20–66 years) collected their saliva thrice a day (0900–1000, 1300–1400, and 1700–1800). The
testosterone levels at each collection time negatively correlated with the ages of the participants; therefore, residual testosterone
levels were used for analyses after correcting for age by linear regression. The testosterone-lowering effect of marriage
was marginal and the regular sexual activity more strongly associated with lower testosterone levels in morning saliva. The
possible neurofeedback systems underlying the phenomenon are discussed. 相似文献
76.
Yoshiharu Inoue Wataru Nomura Yoko Takeuchi Takumi Ohdate Shogo Tamasu Atsushi Kitaoka Yoshifumi Kiyokawa Hiroshi Masutani Kazuo Murata Yoshinori Wakai Shingo Izawa Junji Yodoi 《Applied microbiology》2007,73(5):1672-1675
Thioredoxin, an antioxidant protein, is a promising molecule for development of functional foods because it protects the gastric mucosa and reduces the allergenicity of allergens. To establish a method for obtaining an ample amount of yeast thioredoxin, we found here that thioredoxin is released from Saccharomyces cerevisiae by treatment with 20% ethanol. We also found that Japanese sake contains a considerable amount of thioredoxin. 相似文献
77.
Takahashi S Hasumi K Ohnishi A Koshino H Matsumoto S 《Bioorganic & medicinal chemistry》2007,15(1):97-103
78.
Hull JJ Kajigaya R Imai K Matsumoto S 《Bioscience, biotechnology, and biochemistry》2007,71(8):1993-2001
In most female moths, pheromone biosynthesis activating neuropeptide (PBAN) regulates sex pheromone production by stimulating an influx of extracellular Ca(2+). Little is known about the plasma membrane channel or how the PBAN stimulus is communicated to the channel. Fluorescent Ca(2+) imaging techniques confirmed PBAN-induced Ca(2+) influx in the silkworm, Bombyx mori, and showed that the PBAN response is reduced with repeated stimulation. Compounds known to impact Ca(2+) signaling were examined for their effects on sex pheromone production. These experiments demonstrated that the PBAN signal is likely mediated by a store-operated channel (SOC). SOC blockers, SKF-96365 and 2-aminoethoxydiphenyl borate, abolished sex pheromone production, as did flufenamic acid, a blocker of transient receptor potential (TRP) channels. Thapsigargin mimicked the pheromonotropic effects of PBAN. Similar results were seen when PBAN-induced lipase activity was assayed. Conversely, 1-oleoyl-2-acetyl-sn-glycerol and arachidonic acid, activators of diacylglycerol-dependent Ca(2+) channels, had no effect on bombykol production. 相似文献
79.
Haploid sporophytes of Osmunda claytoniana (2n = x = 22) were apogamously produced from calli when cultivated on a hormone-free medium. Flow cytometric analysis showed that
ploidy chimeras were spontaneously produced in a haploid sporophyte of O. claytoniana and those of O. japonica that were obtained in the previous study. In the haploid sporophyte of O. claytoniana, a diploid pinnule and a partially diploid terminal segment were produced in a haploid pinna. In O. japonica, a haploid sporophyte yielded a diploid pinna in a haploid frond, and another haploid sporophyte yielded a diploid pinnule
in a haploid pinna. Diploid chimeras were large in size and could be readily distinguished from other haploid parts of the
fronds. It is likely that the chimeras were produced clonally from a single diploid cell that established chromosome doubling. 相似文献