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991.
John Berard 《Primates; journal of primatology》1999,40(1):159-175
Considerable controversy exists on the nature of the relationship between male dominance rank and reproductive activity. The
nature of this relationship has important implications for understanding the manner in which males compete for access to limited
resources. Behavioral data on mating patterns were collected over a four-year period from one social group of rhesus macaques
on Cayo Santiago. Correlations between dominance rank and reproductive activity were not stable over a four-year period, but
changed yearly. Positive, significant correlations were present in the first two years of the study while non-significant
correlations were found in the second two years. The variation found in the correlations between rank and mating activity
could be accounted for by changes in the mating frequencies of different classes of males. The long-term resident males had
declines in ejaculation frequencies over the duration of the study. Males who immigrated into the group had yearly increases
in reproductive behavior over three consecutive years. Maturing natal males also increased their levels of reproductive activity
from year-to-year. Combining these mating patterns over time resulted in shifting the proportions of matings away from the
long-term residents and in favor of the new males. High-ranking males had an advantage in reproductive activity over the first
two years of the study, as measured by both the total number of ejaculations and the mean number of ejaculation per male.
New males, comprised of recent immigrants and maturing natal males, had a greater level of reproductive activity over the
last two years. These results suggest that the effect of rank on reproductive activity is variable and that males utilize
alternative tactics to attain access to limited resources. Simple one-factor models explaining the relationship between rank
and reproductive activity must be replaced with models explaining how alternate strategies affect male competition and reproductive
success in primates. 相似文献
992.
T. Togashi Taizo Motomura Terunobu Ichimura Paul Alan Cox 《Sexual plant reproduction》1999,12(3):158-163
The role of phototactic behavior of gametes was tested experimentally in the slightly anisogamous marine green alga Monostroma angicava Kjellman, and the effect of phototaxis on mating efficiency was discovered. Both male and female gametes showed positive
phototaxis in response to a white light source. In contrast, they did not respond to a red light source. Their swimming velocity
did not differ between these two illuminating light sources. It was, therefore, suggested that the search ability of the gamete
itself might not vary between phototactic and non-phototactic conditions. The number of zygotes formed during the mating process
may be expressed as the product of the number of encounters between male and female gametes and the fraction of encounters
that result in sexual fusion. In this study, with high densities of male and female gametes mixed in test tubes, almost all
minor (fewer in number) gametes fused sexually within 10 min. After dilution of the gamete suspensions by half, mating efficiency
in test tubes illuminated by white light from above was higher than that in dark controls. This suggests that male and female
gametes gathered at the water surface through their positive phototaxis, thus increasing the rate of encounters. Mating efficiency
also decreased if the test tubes were illuminated from above by white light and also shaken. Since negative phototaxis is
clearly shown in planozygotes, we suggest that positive phototaxis of male and female gametes in M. angicava is an adaptive trait for increasing the rate of gametic encounters rather than for the dispersal of zygotes as previously
reported for zoospores of some marine algae.
Received: 12 February 1999 / Revision accepted: 24 May 1999 相似文献
993.
994.
Active female courtship behavior and male nutritional contribution to female fecundity in Bruchidius dorsalis (Fahraeus) (Coleoptera: Bruchidae) 总被引:3,自引:0,他引:3
Koh-ichi Takakura 《Population Ecology》1999,41(3):269-273
Mating behavior and the male's contribution to female fecundity were studied in the bean weevil Bruchidius dorsalis (Fahraeus) (Coleoptera: Bruchidae) in comparison with two other species, Callosobruchus chinensis (which infests stored beans) and Kytorhinus sharpianus (which feeds on wild legumes). Only females of B. dorsalis showed multiple mating and characteristic precopulatory behavior that appeared to solicit the male's nutritious secretion.
In contrast, all females of the other two species did not copulate multiply and did not show such precopulatory behavior.
In B. dorsalis, the decrement of male body weight just after copulation indicated that seminal fluid weighing as much as approximately 7%
of the male's body weight was transferred to the female. Fecundity was more than eight times higher in females that had copulated
ten times than in females that had copulated only once, indicating that males paid most of the nutritional cost of egg production.
These facts suggest that the sex role is reversed in B. dorsalis.
Received: May 22, 1998 / Accepted: July 19, 1999 相似文献
995.
高原鼠兔交配期及交配行为模式的研究 总被引:6,自引:3,他引:3
1985至1988年在青海湖黑马河地区,以耳标法对高原鼠兔(Ochotona curzoniae)的交配期及交配行为模式进行了研究。该鼠繁殖期一般是从3月底或4月初开始到7月上旬或8月上旬结束,时间长达3-4个月。在繁殖期中有3-5个交配期。配偶间雄鼠对雌鼠有跟随,接吻,嗅吻肛门区和爬跨抚摸一系列反复“求爱”行为。雌鼠呈现“脊椎前凸”和外生殖器反射行为。雄鼠交配时以前肢紧紧夹住雌鼠腰部,3-5次盆部抽动,一次较深的推进即为射精。每次交配时间约3-5秒,多次交配射精。还发现该鼠有临产交配行为。 相似文献
996.
适用于蚜虫等微小昆虫的飞行磨系统 总被引:3,自引:0,他引:3
介绍了一套采用计算机进行控制和数据采集的适用于蚜虫等微小昆虫的飞行磨系统。该系统能同时对32头昆虫进行飞行测试,并对测试数据进行自动分析处理。利用该飞行磨系统对不同日龄禾缢管蚜的飞行能力进行了初步测试。结果表明,禾缢管蚜在第1至第5日龄的飞行能力最强,明显高于第7和第9日龄。平均飞行时间在各日龄之间差异不显著,但平均飞行速度随日龄的增加而逐渐降低。本文对飞行磨结构、数据采集接口板电路原理和软件流程设计等方面均进行了较为详细的介绍。并简要介绍了不同日龄禾缢管蚜的飞行能力测试结果。对开展微小型昆虫的飞行行为学研究具有较为重要的参考价值。 相似文献
997.
M. J. Weissburg 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1999,185(3):229-238
Chemosensory neurons of female fiddler crabs (genus Uca) display greater sensitivity to mixtures of food-related stimuli than do neurons in males. This phenomenon represents an
interesting contrast to other sex-specific systems, which tend to be in response to cues associated with mating and parental
care. This study examined the responses of chemosensory neurons in males and females to ten individual stimuli to determine
if sex-specific responses were restricted to a few key compounds, or if the heightened sensitivity of females was broadly
distributed. Neurons in males and females responded well to all stimuli, and although fiddler crabs are primarily herbivorous,
highly efficacious physiological stimulants included amino acids and amines as well as carbohydrates most closely associated
with plant material. The chemosensory neurons are characterized by broad tuning and relatively high response thresholds, when
compared to other crustaceans. Most importantly, the investigations revealed a robust pattern in which female neurons displayed
elevated responses to all stimuli. Tuning breadth was not shown to be sex-specific, nor were there detectable differences
in over-all response profiles. The most likely explanation for these patterns is that the broad sex-specificity in Uca is produced via fundamental alterations in cellular properties associated with chemosensory transduction.
Accepted: 29 June 1999 相似文献
998.
We found evidence that a nematode (Skrjabinoclava morrisoni)
adaptivelymanipulates the behavior of its intermediate host (the amphipod
Corophiumvolutator) to increase its likelihood of transmission to
itsfinal host (the semipalmated sandpiper, Calidris pusilla). We
foundthat male and female amphipods parasitized by nematodes increasedtheir
surface activity in the field during daytime, but notduring nighttime hours.
Increased surface activity is knownto increase susceptibility of amphipods to
predation by sandpipersduring the day, but not at night, when sandpipers do
not feedvisually. Also, as predicted by the manipulation hypothesis,only
late-stage (infective) larvae of nematodes were associatedwith behavioral
changes of amphipods. We found no evidence thatparasites were associated with
other amphipod behaviors in thelaboratory, such as trail complexity, distance
traveled, orburrow-probing activity of crawling males as would be expectedif
parasitized hosts altered their own behavior. Survivorshipof amphipods was
also unaffected by parasitism, which may favorparasite transmission. Thus,
behavioral changes of parasitizedhosts were simple, and their expression was
context-dependentand related to likelihood of predation. We argue that
maturationtimes of nematodes in relation to migration schedules of sandpipers
providea narrow window of opportunity and may explain why nematodes
manipulateamphipod behavior. 相似文献
999.
Many authors have reported that, under elevated risk of predation,male
guppies (Poecilia reticulata) alter their behavior fromcourtship to
forced copulation (gonopodial thrusts not precededby sigmoid displays). This
shift is presumed to benefit thebrightly colored male, whose intense courting
activity mightotherwise increase his risk of detection and attack by
predators.However, there is some evidence that females engaged in
reproductiveactivity with males may be even more vulnerable to predatorsthan
the males themselves, which suggests an alternative hypothesis:females in
high-risk situations are less receptive to male courtship,and this leads
males to change their behavior. We tested thishypothesis by providing either
males and females separately,or both sexes concurrently, with information
about elevatedpredation risk from a cichlid (Crenicichla sp.). We
found thatwhen only females were provided with information about increased
risk,males performed fewer courtship displays and fewer thrusts.They did not
perform more forced copulations in any treatmentgroup. Nonetheless, our
results suggest that the female's perceptionof predation risk can be at least
as important as the male'sin changing male mating behavior. 相似文献
1000.
Behavioral responses to biopsy sampling of four species of northwestern Atlantic balaenopterid whales summering in the estuary and Gulf of St. Lawrence, Quebec, from 1990 to 1995 were studied to determine if this technique was an important disturbance to the whales. A total of 447 biopsy samples were taken using a small punch-type biopsy tip fired from a crossbow. Biopsies were successfully taken from 91.2% of the whales approached. Whales displayed no reaction to 45.2% of the successful biopsy attempts. Whales that responded to biopsy sampling typically resumed their normal behavior immediately or within a few minutes. Most humpback whales displayed a hard tail flick, and the majority of fin and blue whales submerged following biopsy sampling. Significantly different frequencies and intensities of responses were found between whale species. Minke and humpback whales were found to be more sensitive to biopsy sampling than fin and blue whales. Response frequencies were similar between females and males for all species, with the exception of fin whales where females had a higher response frequency than males. Biopsy sample length, i. e., penetration depth, did not explain variations in response intensity but may influence response frequency to biopsy sampling. Group size, geographical region, and number of biopsies taken per whale were not factors that explained variation in behavioral responses. The biopsy technique was found to be an efficient method for obtaining high-quality whale skin and blubber samples with limited behavioral disturbance to balaenopterid whales. 相似文献