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81.
82.
Goussia girellae n. sp. is described from the opaleye fish, Girella nigricans. Merogonic stages were observed in the apices of intestinal epithelial cells, in the lamina propria, and in extra-intestinal sites including liver, gills, and spleen. Gamonts were observed in the intestinal epithelial cells. Only unsporulated oocysts were detected in the intestine, and sporulation occurred when feces containing oocysts were incubated for 48 h in seawater at 21 degrees C. Oocysts are elongated (24.8 x 14.7 micron) with a wall about 200 nm thick and have no residuum, micropyle, or polar granule. Sporocysts are ellipsoid (8.5 x 4.5 micron), have a thin two-layered wall approximately 30 nm thick, and consist of two valves joined by a suture. Although moribund opaleye were also infected with Gyrodactylus sp., Cryptobia sp., Cardicola sp., and epitheliocystis organisms (chlamydia), all fish were heavily infected with G. girellae and morbidity was thus attributed to the coccidium. 相似文献
83.
84.
Experimental measurement of sediment nitrification and denitrification in Hamilton Harbour,Canada 总被引:1,自引:0,他引:1
This research examines the role of sediment nitrification and denitrification in the nitrogen cycle of Hamilton Harbour. The
Harbour is subject to large ammonia and carbon loadings from a waste-water treatment plant and from steel industries. Spring
ammonia concentrations rapidly decrease from 4.5 to 0.5 mg 1−1, while spring nitrate concentrations increase from 1 to 2 mg l−1, by mid-summer. A three-layer sediment model was developed. The first layer is aerobic; in it, oxidation of organics and
nitrification occurs. The second layer is for denitrification, and the third layer is for anaerobic processes. Ammonia sources
for nitrification include diffusion from the water column, sources associated with the oxidation of organics, sources from
denitrification and from anaerobic processes. Diffusion of oxygen, ammonia and nitrate across the sediment-water interface
occurs. Temperature effects are modelled using the Arrhenius concept. A combination of zero-order kinetics for nitrate or
ammonia consumption with diffusion results in a half-order reaction, with respect to the water column loss rate to sediments.
From experimental measurement, the rate of nitrification is 200 mg N 1−1 sediment per day, while that of denitrification is 85 mg N 1–1 sediment per day at 20 °C. The Arrhenius activation energy
is estimated as 15 000 cal/ mole-K and 17 000 cal/ mole-K for nitrification and denitrification, respectively, between 10
°C and 20 °C. Calculations of the flux of ammonia with the sediments, using the biofilm model, compare favourably with experimental
observations. The ammonia flux from the water column is estimated to account for 20% of the observed decrease in water column
stocks of ammonia, while the nitrate flux from the water column is estimated to account for 25% of the total nitrogen produced
by the sediments. 相似文献
85.
PurposeTo review and discuss the methods used for measuring spinal stiffness and factors associated with stiffness, how stiffness is used in diagnosis, prognosis, and treatment decision-making and the effects of manipulative techniques on stiffness.MethodsA systematic search of MEDLINE, EMBASE, CINAHL, AMED and ICL databases was conducted. Included studies addressed one of four constructs related to stiffness: measurement, diagnosis, prognosis and/or treatment decision-making, and the effects of manipulation on stiffness. Spinal stiffness was defined as the relationship between force and displacement.ResultsOne hundred and four studies are discussed in this review, with the majority of studies focused on the measurement of stiffness, most often in asymptomatic persons. Eight studies investigated spinal stiffness in diagnosis, providing limited evidence that practitioner-judged stiffness is associated with radiographic findings of sagittal rotational mobility. Fifteen studies investigated spinal stiffness in prognosis or treatment decision-making, providing limited evidence that spinal stiffness is unlikely to independently predict patient outcomes, though stiffness may influence a practitioner’s application of non-thrust manipulative techniques. Nine studies investigating the effects of manipulative techniques on spinal stiffness provide very limited evidence that there is no change in spinal stiffness following thrust or non-thrust manipulation in asymptomatic individuals and non-thrust techniques in symptomatic persons, with only one study supporting an immediate, but not sustained, stiffness decrease following thrust manipulation in symptomatic individuals.ConclusionsThe existing limited evidence does not support an association between spinal stiffness and manipulative treatment outcomes. There is a need for additional research investigating the effects of manipulation on spinal stiffness in persons with spinal pain. 相似文献
86.
Soil-transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador
87.
88.
Histoproliferative effect of Rauscher leukemia virus on lymphatic tissue. II. Antigen-stimulated germfree and conventional BALB-c mice 总被引:4,自引:0,他引:4
89.
The effects of pH on the kinetics of human liver Ornithine--carbamyl phosphate transferase 总被引:5,自引:0,他引:5
P J Snodgrass 《Biochemistry》1968,7(9):3047-3051
90.
Snodgrass JG Lacy MG Francois Dengah HJ Fagan J Most DE 《Culture, medicine and psychiatry》2011,35(1):26-62
Videogame players commonly report reaching deeply “immersive” states of consciousness, in some cases growing to feel like
they actually are their characters and really in the game, with such fantastic characters and places potentially only loosely connected to offline selves and realities. In
the current investigation, we use interview and survey data to examine the effects of such “dissociative” experiences on players
of the popular online videogame, World of Warcraft (WoW). Of particular interest are ways in which WoW players’ emotional identification with in-game second selves can lead either to better mental well-being, through relaxation
and satisfying positive stress, or, alternatively, to risky addiction-like experiences. Combining universalizing and context-dependent
perspectives, we suggest that WoW and similar games can be thought of as new “technologies of absorption”—contemporary practices that can induce dissociative
states in which players attribute dimensions of self and experience to in-game characters, with potential psychological benefit
or harm. We present our research as an empirically grounded exploration of the mental health benefits and risks associated
with dissociation in common everyday contexts. We believe that studies such as ours may enrich existing theories of the health
dynamics of dissociation, relying, as they often do, on data drawn either from Western clinical contexts involving pathological
disintegrated personality disorders or from non-Western ethnographic contexts involving spiritual trance. 相似文献