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81.
MICHAEL R. THORPE ALEXANDRA C. U. FURCH PETER E. H. MINCHIN JENS FÖLLER AART J. E. VAN BEL JENS B. HAFKE 《Plant, cell & environment》2010,33(2):259-271
Phloem transport stops transiently within dicot stems that are cooled rapidly, but the cause remains unknown. Now it is known that (1) rapid cooling depolarizes cell membranes giving a transient increase in cytoplasmic Ca2+, and (2) a rise of free calcium triggers dispersion of forisomes, which then occlude sieve elements (SEs) of fabacean plants. Therefore, we compared the effects of rapid chilling on SE electrophysiology, phloem transport and forisomes in Vicia faba. Forisomes dispersed after rapid cooling with a delay that was longer for slower cooling rates. Phloem transport stopped about 20 s after forisome dispersion, and then transport resumed and forisomes re‐condensed within similar time frames. Transport interruption and forisome dispersion showed parallel behaviour – a cooling rate‐dependent response, transience and desensitization. Chilling induced both a fast and a slow depolarization of SE membranes, the electrical signature suggesting strongly that the cause of forisome dispersion was the transient promotion of SE free calcium. This apparent block of SEs by dispersed forisomes may be assisted by other Ca2+‐dependent sealing proteins that are present in all dicots. 相似文献
82.
Mentalizing is the process by which we make sense of each other and ourselves,
implicitly and explicitly, in terms of subjective states and mental processes.
It is a profoundly social construct in the sense that we are attentive to
the mental states of those we are with, physically or psychologically. Given
the generality of this definition, most mental disorders will inevitably involve
some difficulties with mentalization, but it is the application of the concept
to the treatment of borderline personality disorder (BPD), a common psychiatric
condition with important implications for public health, that has received
the most attention. Patients with BPD show reduced capacities to mentalize,
which leads to problems with emotional regulation and difficulties in managing
impulsivity, especially in the context of interpersonal interactions. Mentalization
based treatment (MBT) is a time-limited treatment which structures interventions
that promote the further development of mentalizing. It has been tested in
research trials and found to be an effective treatment for BPD when delivered
by mental health professionals given limited additional training and with
moderate levels of supervision. This supports the general utility of MBT in
the treatment of BPD within generic mental health services.Borderline personality disorder (BPD) is a complex and serious mental disorder
characterized by a pervasive pattern of difficulties with emotion regulation
and impulse control, and instability both in relationships and in selfimage 1. It represents a serious public health problem,
because it is associated with suicide attempts and self harm, both of which
are consistent targets of mental health services. Recurrent suicidal behaviour
is reported in 69-80% of patients with BPD, and suicide rates are estimated
to be up to 10% 2. BPD is a common condition that is thought to occur globally with a prevalence
of 0.2-1.8% in the general population 3.
Higher prevalence rates are found in clinical populations. Moran et al 4 found a prevalence rate of 4-6% among primary
care attenders, suggesting that people with BPD are more likely to visit their
general practitioner. Chanen et al 5 reported
a prevalence rate of 11% in adolescent outpatients and 49% in adolescent inpatients.
The highest prevalence has been found in people requiring the most intensive
level of care, with a rate of 60-80% among patients in forensic services 6-7. The high prevalence and increased suicide rate in patients with BPD make
an unassailable argument that effective treatment needs to be developed and
that treatment has to be widely available. Whilst a number of treatments for
BPD have been shown to be moderately effective in randomized controlled trials,
it remains of considerable concern that most of them require extensive training,
making them unavailable to most patients. Mentalization based treatment (MBT)
was developed with this in mind. It requires relatively little additional
training on top of general mental health training, and has been implemented
in research studies by community mental health professionals, primarily nurses,
with limited training given modest levels of supervision. 相似文献
83.
ROGER A. HEWITT ANTONIO CHECA GERD E. G. WESTERMANN PETER M. ZABORSKI 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1991,24(3):271-287
Cretaceous Vascoceras and Jurassic Lytoceras show colour markings and etched surfaces representing original organic membranes between the septa. The main difference between the formation of ammonite and Nautilus chambers involved the continuous secretion of a gelatinous cameral liquid to support the ammonite mantle when it moved forward. The gel containing cyclically secreted membranes. here named pseudosepta, resembled the intra-cameral structures of the cuttlebone in Sepia. Pseudoscpta are attached to the shell wall in pseudosutures (Pseudoloben) which are particularly visible in the saddles of the septal suture and tend to mimic them. Their shape suggests reconstruction of posterior mantle shape during translocation. Drag-bands (Schleppstreifen) are spiral markings formed by the overlapping pseudosepta along the axial traces of the foliole folds. The chamber of ammonites was formed by a locally muscular mantle in a tripartite cycle: (1) the mantle initially remained attached to the saddles of the completed septal suture while muscular tissue within the umbilical lobes was contracted and rapidly reattached to the side of the lateral saddles; (2) the whole mantle subsequently crept forward by secreting a gelatinous matrix which contained telescoped membranes, with an adhesive function on pseudolobc flanks; (3) the mantle almost ceased to move within the sites of future lobules, but expanded and crept on before forming the mural and 'gutter' ridges of the septum. □ Ammonites, chamber growth, vascoceratids, LYTOCERAS, Nigeria. 相似文献
84.
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86.
Abstract: We assessed dispersal behavior of 78 radiotagged adult spotted salamanders (Ambystoma maculatum) at a 36-hole golf course in southeastern Connecticut, USA. Lake of Isles Golf Course is atypical of most golf courses in North America because it is much larger (461 ha) than average 18-hole golf courses (54 ha) and deciduous forests accounted for 70% landscape composition on the course. We tracked individuals an average of 164 days as they emigrated from 3 seasonal pools surrounded by golf course fairways and one pool located in contiguous forest (control pool) from March through December 2004. Males and females dispersed similar distances at the control pool, averaging 71 ± 10 m. However, females migrating across the golf course dispersed twice as far (214 ± 25 m) as males on the golf course (102 ± 15 m) and both genders at the control pool. Over 40% the salamanders at the golf course crossed fairways; thus, fairways were not a dispersal barrier to adult spotted salamanders. Previous researchers have suggested establishing a 164-m life zone around breeding ponds to protect pond-breeding amphibian populations. Our results suggest that strategies that protect core upland habitat within 164 m of wetland boundaries would include 82% of adult males and only 50% of adult females. Empirical estimates based on our telemetry study suggest that core terrestrial habitat would have to extend 370 m to protect 95% of adult females, which is much farther than previous estimates. 相似文献
87.
Responses of cetaceans to anthropogenic noise 总被引:2,自引:0,他引:2
DOUGLAS P. NOWACEK LESLEY H. THORNE† DAVID W. JOHNSTON‡ PETER L. TYACK§ 《Mammal Review》2007,37(2):81-115
- 1 Since the last thorough review of the effects of anthropogenic noise on cetaceans in 1995, a substantial number of research reports has been published and our ability to document response(s), or the lack thereof, has improved. While rigorous measurement of responses remains important, there is an increased need to interpret observed actions in the context of population‐level consequences and acceptable exposure levels. There has been little change in the sources of noise, with the notable addition of noise from wind farms and novel acoustic deterrent and harassment devices (ADDs/AHDs). Overall, the noise sources of primary concern are ships, seismic exploration, sonars of all types and some AHDs.
- 2 Responses to noise fall into three main categories: behavioural, acoustic and physiological. We reviewed reports of the first two exhaustively, reviewing all peer‐reviewed literature since 1995 with exceptions only for emerging subjects. Furthermore, we fully review only those studies for which received sound characteristics (amplitude and frequency) are reported, because interpreting what elicits responses or lack of responses is impossible without this exposure information. Behavioural responses include changes in surfacing, diving and heading patterns. Acoustic responses include changes in type or timing of vocalizations relative to the noise source. For physiological responses we address the issues of auditory threshold shifts and ‘stress’, albeit in a more limited capacity; a thorough review of physiological consequences is beyond the scope of this paper.
- 3 Overall, we found significant progress in the documentation of responses of cetaceans to various noise sources. However, we are concerned about the lack of investigation into the potential effects of prevalent noise sources such as commercial sonars, depth finders and fisheries acoustics gear. Furthermore, we were surprised at the number of experiments that failed to report any information about the sound exposure experienced by their experimental subjects. Conducting experiments with cetaceans is challenging and opportunities are limited, so use of the latter should be maximized and include rigorous measurements and or modelling of exposure.
88.
89.
Abstract The vertical stratification of insect species assemblages inhabiting tropical rainforests is well established but few have examined whether these patterns are reflected in vertical stratification of body size or feeding guilds. We used Malaise and Flight Interception Traps to sample beetle assemblages from five locations, at both canopy and ground zones of a tropical lowland rainforest site near Cape Tribulation, Australia. Beetles from 4 years of sampling were sorted to Family and morphospecies, and allocated to one of five feeding guilds. Within feeding guilds the number of species and individuals, from canopy‐ and ground‐caught traps were compared. The body lengths of species were measure and compared within feeding guilds and families. Herbivores was the dominant guild but was not the majority of all species or individuals. Most beetle species (69%) were less than 5 mm in length and the mean size of canopy‐caught species was greater than that for ground‐caught species. This was probably due to slightly more species of plant feeders (herbivores and xylophages) present in the canopy, which were significantly larger than saprophages, fungivores and predators. Among feeding guilds, there were few overall canopy–ground differences. These results contrast with species composition results presented elsewhere where strong differences between the canopy and the ground were evident. We suggest that our guild groupings may have been too coarse to detect fine‐scale differences and that resource partitioning may have also masked faunal stratification. We propose that fine‐scale differences in resources between the canopy and the ground, together with strong microclimate gradients, are likely to be important in structuring the vertical stratification of insect assemblages at the level of species, but not with respect to functional groups. 相似文献
90.
Abstract Broadscale habitat use by Eastern Curlews (Numenius madagascariensis) in their non‐breeding range in eastern Australia was assessed using low tide surveys on feeding grounds, where 60 skilled volunteers made repeated counts of the birds on intertidal flats, across 41% (9500 ha) of the intertidal habitat within Moreton Bay, Australia. We analysed 32 defined sections of intertidal flat, of roughly equal area (mostly 200–400 ha), which varied greatly in their curlew density (2–47 birds per 100 ha) and also in substrate and other environmental features. Sites with the least resistant substrates had densities three times those with the most resistant substrates. Of 10 environmental characteristics measured for each site, substrate resistance was the best predictor of curlew density (r2 = 0.45). Characteristics that were poor predictors included distance to the nearest roost, level of human disturbance and distance to urban settlement. For a finer‐scale assessment, microhabitat use and feeding behaviour were recorded during low tide within 12 intertidal flats, which varied in size (23–97 ha), substrate, topography and other features. Across all flats, curlews strongly preferred to feed relatively close (0–50 m) to the low‐water line. They fed on a variety of substrates (including sand, sandy‐mud, mud and seagrass) in broadly similar proportions to their occurrence in the habitat. There was a statistically significant preference for sand, although its magnitude was not strong. These results indicate that curlews select habitat most strongly at a between‐flat rather than within‐flat scale. 相似文献