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81.
82.
The population dynamics of annual shoots in four clonal patches of Miscanthus sinensis was surveyed in terms of clone persistence. Over a study period of 3 years, a stable net shoot number was attained through a balanced replacement of old shoots by tillering 2–3 times a year. The birth rate was significantly correlated with the average monthly temperature. This suggests that a warm climate advances the date of tillerings, and shoots become taller as they emerge earlier. Five cohorts were identified, corresponding to shoots that were born in spring, early summer, summer, autumn and early winter. The autumn cohorts were more numerous and had a greater longevity than the other cohorts; they were thus were best suited for overwintering and, consequently, maintaining the population from one generation to the next. The shoots of earlier cohorts grew too tall to survive the cold of winter, which might cause freezing injury, while later cohorts shoots excelled in overwintering because of their shortness. However, if the delayed shoots are very short, they will also have difficulty in surviving the early season of growth. Therefore, M. sinensis shoots have an optimum size for survival. 相似文献
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84.
To clarify the influence of dietary tin deficiency on growth and mineral status, the following two different synthetic diets were fed to male Wistar rats: group 1--a diet containing 1.99 micrograms tin/g; group 2--a diet containing 17 ng tin/g. The rats in group 2 showed poor growth, lowered response to sound, and alopecia, with decreased food efficiency compared with rats in group 1. The changes of mineral concentrations in tissues observed in group 2, compared with group 1, are summarized as follows: calcium concentration in lung increased; magnesium concentration in lung decreased; iron concentrations in spleen and kidney increased; iron concentration in femoral muscle decreased; zinc concentration in heart decreased; copper concentrations in heart and tibia decreased; manganese concentrations in femoral muscle and tibia decreased. These results suggest that tin may be essential for rat growth. 相似文献
85.
Katsuhiko Yokoi Mieko Kimura Yoshinori Itokawa 《Biological trace element research》1996,51(2):199-208
The effects of low dietary rubidium on plasma biochemical parameters and mineral levels in tissues in rats were studied. Eighteen male Wistar rats, weighing about 40 g, were divided into two groups and fed the diets with or without supplemental rubidium (0.54 vs 8.12 mg/kg diet) for 11 wk. Compared to the rats fed the diet with supplemental rubidium, the animals fed the diet without rubidium supplementation had higher urea nitrogen in plasma; lower rubidium concentration in tissues; lower sodium in muscle; higher potassium in plasma, kidney and tibia, and lower potassium in testis; lower phosphorus in heart and spleen; lower calcium in spleen; higher magnesium in muscle and tibia; higher iron in muscle; lower zinc in plasma and testis; and lower copper in heart, liver, and spleen, and higher copper in kidney. These results suggest that rubidium concentration in tissues reflects rubidium intake, and that rubidium depletion affects mineral (sodium, potassium, phosphorus, calcium, magnesium, iron, zinc, and copper) status. 相似文献
86.
87.
88.
Biopolymer flocculant produced by an Enterobacter sp. 总被引:11,自引:0,他引:11
Haruhiko Yokoi Takashi Yoshida Shingo Mori Jun Hirose Sachio Hayashi Yoshiyuki Takasaki 《Biotechnology letters》1997,19(6):569-573
A new biopolymer flocculant was produced by Enterobacter sp. BY-29. Flocculating activity increased in the presence of Al , Fe or Fe . The flocculant had flocculating activity not only in inorganic suspensions of kaolin and active carbon but also in organic suspensions of cellulose and yeast. The flocculant was an acidic polysaccharide consisting of glucose, galactose, xylose and galacturonic acid, and its MW was about 2.5 ¥ 10 6 Da. 相似文献
89.
Isao Yokoi Yukiko Namba Hideaki Kabuto Kazunori Inada Motoyuki Iida Akitane Mori Norio Ogawa 《Neurochemical research》1996,21(10):1187-1192
Since nitric oxide (NO) is synthesized by nitric oxide synthase (NOS) froml-arginine (Arg) which has an amidino group in its molecule, we, examined the effect of 29 kinds of Arg analogues on neuronal
NOS (nNOS) activity in the rat brain. None of the Arg analogues acted as a substrate for nNOS. Diamidinocystamine, hirudonine,
and guanethidine inhibited nNOS activity to 67.3%, 64.2% and 74.1%, respectively, but their inhibitory efficiency was lower
than NG-monomethyl-l-arginine (to 36.5%) which is a well known NOS inhibitor. Dimethylguanidine and N-benzoylguanidine also significantly inhibited
nNOS activity to 88.0% and 90.7%, respectively. Whereas almost all of the NOS inhibitors previously reported were synthesizdd
by substituting the amidino nitrogen of Arg, none of these new inhibitors were substituted at this position. Furthermore,
hirudonine, which is a naturally occurring compound, was thought to act as an agonist at polyamine binding site of the N-methyl-d-aspartate type of glutamate receptor complex. It is also interesting that guanethidine, an antihypertensive agent, inhibit
nNOS activity. These new drugs are useful for the investigation not only of the chemical nature of nNOS but also of the physiologic
function of NO. 相似文献
90.
Hiromichi Yokoi Yoshihiro Tsuruo Tadayuki Miyamoto Kouki Kitagawa Shiroh Futaki Kazunori Ishimura 《Histochemistry and cell biology》1996,106(4):359-366
The localization of 5α-reductase was immunohistochemically studied in the anterior pituitary of male rats, using a polyclonal
antibody against 5α-reductase rat type 1. The immunoreactive cells were concentrated in the central region and on the border
of the intermediate lobe in the anterior pituitary, but not in the intermediate or posterior lobe. The immunoreaction was
located mostly in the cytoplasm and occasionally in the cell nuclei. The immunoreactive cells showed alterations in size and
number and in the intensity of the immunoreaction after gonadectomy. One week after castration, the cells became larger and
the immunoreactivity increased. Two weeks after castration, the number of immunoreactive cells increased. Double immunostaining
using antiluteinizing hormone β-subunit or anti-follicle stimulating hormone β-subunit antibody revealed that most of the
cells containing 5α-reductase were gonadotrophs. Electron microscopically, the immunoreactive cells showed lamelliform rough
endoplasmic reticulum and a depletion of secretory granules 1 week after castration. One week later, the rough endoplasmic
reticulum was developed and dilated and the number of secretory granules increased. These results suggest that 5α-reductase
is located in the gonadotrophs of rat anterior pituitary and that it is involved in the feedback regulation of gonadotropin
secretion by androgens. 相似文献