全文获取类型
收费全文 | 829篇 |
免费 | 39篇 |
专业分类
868篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 17篇 |
2014年 | 29篇 |
2013年 | 41篇 |
2012年 | 64篇 |
2011年 | 45篇 |
2010年 | 33篇 |
2009年 | 41篇 |
2008年 | 54篇 |
2007年 | 55篇 |
2006年 | 49篇 |
2005年 | 44篇 |
2004年 | 48篇 |
2003年 | 35篇 |
2002年 | 48篇 |
2001年 | 15篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 13篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 16篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有868条查询结果,搜索用时 15 毫秒
861.
Asami Tadao; Robertson Masumi; Yamamoto Shin; Yoneyama Koichi; Takeuchi Yasutomo; Yoshida Shigeo 《Plant & cell physiology》1998,39(3):342-348
Biological activities of an abscisic acid (ABA) analog, RCA-7a[l-(3-carboxyl-5-methylphenyl)-l-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexene],carrying a phenyl group in the side chain are reported. ( +)-RCA-7a was approximately 3-fold less active than ( + )-ABAin the inhibition of 相似文献
862.
Needle surface area inCryptomeria japonica was measured using a newly proposed cut method. Sample needles of various lengths were taken from foliage shoots belonging
to various height layers of nine trees growing at three sites. Needles were cut into small pieces with a hand-made cutter
made of razor blades and washers. By measuring the circumference and thickness of each piece, its lateral area was calculated
and summed to give the total surface area of the needle. For estimating the surface area of a needle (s), two linear parameters of needle size termedy
n*
and /were proposed:y
n*
was the distance between the needle tip and the uppermost point of attachment of the needle to the shoot, whilel was the distance between the needle tip and the lowermost point of attachment. The power-form relationship betweens andl was superior to thes-y
n*
relationship, since the former did not differ significantly among shoots of different diameter. Based on thes-l relationship, the total surface area of a shoot was estimated from thel-census of the shoot. Specific leaf area of a shoot (SLA), defined as half of the shoot surface area divided by the dry weight of the shoot, decreased from 90 to 3 [cm2g(dry wt)−1] with the diameter of the woody tissue of the foliage shoot. 相似文献
863.
Shigeki Hoshino Masumi Abe Hiroko Shogen Jiro Yasuda Takayuki Miyazawa 《Microbiology and immunology》2013,57(7):543-546
Koala retrovirus (KoRV) is a unique gammaretrovirus that is currently endogenizing into its host and considered to be associated with leukemia, lymphoma and immunosuppression in koalas (Phascolactos cinereus). In this study, it was demonstrated that WWP2 or WWP2‐like E3 ubiquitin ligases possessing the WW domain closely related to WWP2 and Vps4A/B are involved in KoRV budding. These data suggest that KoRV Gag recruits the cellular endosomal sorting complex required for transport machinery through interaction of the PPPY L ‐domain with the WW domain(s) of WWP2 and that progeny virions are released from cells by utilizing the multivesicular body sorting pathway. 相似文献
864.
The photoinduced formation of pileus primordia inFavolus arcularius involves two essential light processes and an inserting dark process. The nature of these elementary proceses in epileate
stipes was examined by the use of high temperature under a 1-h light-7-h dark-continuous light regimen. Epileate stipes were
exposed to a temperature treatment of 37°C for 15 min after the beginning of pileus primordium formation, which disrupted
the photomorphogenetic progress without any after-effects. When high temperature was applied in the first light process or
the early phase of the dark process, it completely voided the established career. A temperature-sensitive key dark reaction
may have occurred in the period of 0–2 h. When high temperature was applied during the late phase of the dark period, it caused
only a delay in pileus primordium, formation, suggesting that the high temperature might only retard the progression of the
dark morphogenetic reaction in this period. In addition, the early phase of the second light process was effectively disrupted
by the use of high temperature, but sensitivity to high temperature gradually decreased with the progress of pileus differentiation. 相似文献
865.
Gen Murakami Tadashi Nakasone Keiichi Akita Yutaka Kato Iwao Sato Kazuyuki Shimada 《Journal of morphology》1994,221(1):75-86
The primary divisions of the spinal nerve in the brown caiman characteristically show the following features: (1) the medial ramus was lies in the thoraco-lumbar and caudal regions, and (2) the first cervical and hypoglossal nerves form a single nerve complex from which the ventral and dorsal rami extend. Intramuscular injections of horseradish peroxidase (HRP) established the positions of motoneurons whose axons followed the primary rami. In the ventral horn of the thoracic and caudal spinal cord, the motoneurons of the medial ramus lie ventrally. These motoneurons lie between the epaxial and hypaxial motoneurons. At the spinomedullary junction, the pools of motoneurons innervating the infrahyoid, lingual, and dorsal muscles have a somatotopic organization similar to that observed in the thoraco-lumbar and caudal regions. Thus clear somatotopic organization of the motoneurons that innervate the axial musculature exists at all spinal levels. © 1994 Wiley-Liss, Inc. 相似文献
866.
867.
We studied the characteristics of the rhythmicity of heart rate (HR), body temperature (BT), and locomotor activity (LA) in conscious and unrestrained guinea pigs using a telemetry system. HR and/or LA in some guinea pigs clearly showed circadian rhythms, but in others there were no significant daily patterns; BT did not show significant daily rhythms. These results suggest that guinea pigs might have different individual characteristics of rhythmicity, and we should, therefore, be careful when using guinea pigs in chrono-biomedical research. We believe that the results of this study may be useful for future biomedical studies using guinea pigs. 相似文献
868.
Shin Tanikawa Keiko Suzuki Machiko Ono Hiroyuki Akita 《Journal of Molecular Catalysis .B, Enzymatic》2004,31(4-6):103-110
Lipase-meditated separation of six hardly separable mixtures of structural isomers was carried out. It has become apparent that the hydrolysis rate of the C(5)-acetoxyl group of methyl (±)-5-acetoxy-4-aryl-(2E)-pentenoate possessing the ortho-substituents in the aromatic ring was slower than that of the corresponding compound with no substituents at the ortho-position. The hydrolysis rate of the C(5)-acetoxyl group of methyl (±)-5-acetoxy-2-aryl-(3E)-pentenoate possessing a remote reaction site from the ortho-substituents in the aromatic ring was proved to be faster than that of methyl (±)-5-acetoxy-4-aryl-(2E)-pentenoate. 相似文献