全文获取类型
收费全文 | 1697篇 |
免费 | 47篇 |
出版年
2022年 | 13篇 |
2021年 | 17篇 |
2020年 | 18篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 24篇 |
2015年 | 35篇 |
2014年 | 43篇 |
2013年 | 118篇 |
2012年 | 85篇 |
2011年 | 89篇 |
2010年 | 54篇 |
2009年 | 68篇 |
2008年 | 93篇 |
2007年 | 92篇 |
2006年 | 112篇 |
2005年 | 102篇 |
2004年 | 100篇 |
2003年 | 99篇 |
2002年 | 121篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 26篇 |
1998年 | 19篇 |
1997年 | 21篇 |
1996年 | 20篇 |
1995年 | 17篇 |
1994年 | 16篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 18篇 |
1990年 | 22篇 |
1989年 | 15篇 |
1988年 | 21篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 13篇 |
1982年 | 6篇 |
1981年 | 11篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1972年 | 5篇 |
排序方式: 共有1744条查询结果,搜索用时 712 毫秒
991.
992.
Sleep and Biological Rhythms - 相似文献
993.
994.
Taiki Nagano Toshiaki Hashimoto Akio Nakashima Shin-ichi Hisanaga Ushio Kikkawa Shinji Kamada 《Cell cycle (Georgetown, Tex.)》2013,12(16):2617-2618
Comment on: Oesterle EC, et al. Cell Cycle 2011; 10:1237-48. 相似文献
995.
Takeshi Matsuda Junya Yano Yasuhiro Hirai Shin-ichi Sakai 《The International Journal of Life Cycle Assessment》2012,17(6):743-752
Purpose
Source-separated collection of food waste has been reported to reduce the amount of household waste in several cities including Kyoto, Japan. Food waste can be reduced by various activities including preventing edible food loss, draining moisture, and home composting. These activities have different potentials for greenhouse gas (GHG) reduction. Therefore, we conducted a life-cycle inventory analysis of household waste management scenarios for Kyoto with a special emphasis on food waste reduction activities.Methods
The primary functional unit of our study was ??annual management of household combustible waste in Kyoto, Japan.?? Although some life-cycle assessment scenarios included food waste reduction measures, all of the scenarios had an identical secondary functional unit, ??annual food ingestion (mass and composition) by the residents of Kyoto, Japan.?? We analyzed a typical incineration scenario (Inc) and two anaerobic digestion (dry thermophilic facilities) scenarios involving either source-separated collection (SepBio) or nonseparated collection followed by mechanical sorting (MecBio). We assumed that the biogas from anaerobic digestion was used for power generation. In addition, to evaluate the effects of waste reduction combined with separate collection, three food waste reduction cases were considered in the SepBio scenario: (1) preventing loss of edible food (PrevLoss); (2) draining moisture contents (ReducDrain); and (3) home composting (ReducHcom). In these three cases, we assumed that the household waste was reduced by 5%.Results and discussion
The GHG emissions from the Inc, MecBio, and SepBio scenarios were 123.3, 119.5, and 118.6 Gg CO2-eq/year, respectively. Compared with the SepBio scenario without food waste reduction, the PrevLoss and ReducDrain cases reduced the GHG emissions by 17.1 and 0.5 Gg CO2-eq/year. In contrast, the ReducHcom case increased the GHG emissions by 2.1 Gg CO2-eq/year. This is because the biogas power production decreased due to the reduction in food waste, while the electricity consumption increased in response to home composting. Sensitivity analyses revealed that a reduction of only 1% of the household waste by food loss prevention has the same GHG reduction effect as a 31-point increase (from 50% to 81%) in the food waste separation rate.Conclusions
We found that prevention of food losses enhanced by separate collection led to a significant reduction in GHG emissions. These findings will be useful in future studies designed to develop strategies for further reductions in GHG emissions. 相似文献996.
Sumiyoshi W Nakakita S Miyanishi N Yamada K Hasehira K Nakakita Y Hirabayashi J 《Glycobiology》2012,22(8):1031-1041
There is increasing interest in biologics, i.e. human-originated biological pharmaceutics. Most of the protein drugs developed so far, such as immunoglobulins and erythropoietin, are secreted glycoproteins; as a result, any non-human-type glycans, such as αGal and NeuGc, derived from animal cells and sera must be removed to circumvent undesirable immunogenic reactions. In this study, we made an extensive search for potential xenoantigenic glycans among a panel of mammalian sera. As a result, sera belonging to the order Artiodactyla, i.e. bovine, lamb and goat sera, were found to contain substantial amounts of hypersialylated biantennary glycans closely associated with a type-I lactosamine structure containing a unique tetrasaccharide, Siaα2-3Galβ1-3(Siaα2-6)GlcNAc. In all three Artiodactyla sera, the most abundant structure was Siaα2-3Galβ1-3(Siaα2-6)GlcNAcβ1-2Manα1-3[Siaα2-6Galβ1-4GlcNAcβ1-2Manα1-6]Manβ1-4GlcNAcβ1-4GlcNAc. A dually hypersialylated biantennary structure, Siaα2-3Galβ1-3(Siaα2-6)GlcNAcβ1-2Manα1-3[Siaα2-3Galβ1-3(Siaα2-6)GlcNAcβ1-2Manα1-6]Manβ1-4GlcNAcβ1-4GlcNAc, was also abundant (10%) in bovine serum. The amount of hypersialylated glycans among total sialylated glycans was 46, 26 and 23% in bovine, lamb and goat sera, respectively. On the other hand, such structures could not be detected in the sera of other animals including human. The biological functions and the immunogenicity of the hypersialylated glycans in these animals remain to be elucidated; however, it is worth noting that glycoproteins biosynthesized from Artiodactyla cells and those contaminated with bovine serum might enhance undesirable antigenicity in human patients. 相似文献
997.
Moritaka H Sawamura S Kobayashi M Kitade M Nagata K 《Bioscience, biotechnology, and biochemistry》2012,76(3):429-435
The relation between the rheological properties and the swallowing characteristics of vegetable juices fortified with 0-30.0% carrot puree (CP) was evaluated. The apparent viscosity of vegetable juices increased with increasing CP concentrations, and a increases in yield stress were observed at and above 17.5% CP. In a sensory evaluation, texture perceived in the oral cavity varied as between vegetable juices with >17.5% CP and those with <12.5% CP. The maximum velocity in the pharyngeal region was classified into three same-quality subgroups: vegetable juices with 0-12.5% CP, with 10.0-25.0% CP, and with 17.5-30.0% CP. It significantly decreased with increasing CP concentrations. 相似文献
998.
Yamamoto T Niwa S Tokumasu M Onishi T Ohno S Hagihara M Koganei H Fujita S Takeda T Saitou Y Iwayama S Takahara A Iwata S Shoji M 《Bioorganic & medicinal chemistry letters》2012,22(11):3639-3642
A structure-activity relationship study of 6-unsubstituted-1,4-dihydropyridine and 2,6-unsubstituted-1,4-dihydropyridine derivatives was conducted in an attempt to discover N-type calcium channel blockers that were highly selective over L-type calcium channel blockers. Among the tested compounds, (+)-4-(3,5-dichloro-4-methoxy-phenyl)-1,4-dihydro-pyridine-3,5-dicarboxylic acid 3-cinnamyl ester was found to be an effective and selective N-type calcium channel blocker with oral analgesic potential. 相似文献
999.
1000.
Kota Ogawa Asano Ishikawa Takashi Kanbe Shin-ichi Akimoto Toru Miura 《Zoomorphology》2012,131(3):197-207
Wing polymorphisms observed in many Insecta are important topics in developmental biology and ecology; these polymorphisms are a consequence of trade-offs between flight and other abilities. The pea aphid, Acyrthosiphon pisum, possesses 2 types of wing polymorphisms: One is a genetic wing polymorphism occurring in males, and the other is an environmental wing polyphenism seen in viviparous females. Although genetic and environmental cues for the 2 wing polymorphisms have been studied, differences in their developmental regulation have not been elucidated. In particular, there is little knowledge regarding the developmental processes in male wing polymorphism. Therefore, in this study, the development of flight apparatuses and external morphologies was compared among 3 male wing morphs (winged, wingless, and intermediate). These male developmental processes were subsequently compared with those of female wing morphs. Developmental differences between the male and female polymorphisms were identified in flight muscle development and degeneration but not in wing bud development. Furthermore, the nymphal periods of wingless and intermediate males were significantly shorter than that of winged males, indicating the adaptive significance of male winglessness. Overall, this study indicates that the male and female wing polymorphisms are based on different regulatory systems for flight apparatus development, which are probably the result of different adaptations under different selection pressures. 相似文献