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Purification and properties of β-galactosidase from Tilapia intestine: Digestive enzyme of Tilapia-X
ABSTRACT: β-galactosidase of the intestine of Tilapia nilotica was purified by ammonium sulfate precipitation, followed by PAPTG-Sepharose 4B affinity chromatography, ethylenediamineetetraacetic acid ion-exchange chromatography, polyexchanger PBE 94 chromatofocusing, and Sephadex G-100 gel filtration. β-galactosidase was found to be a single band when examined by poly-acrylamide gel electrophoresis. The purifications of β-galactosidase were 27-fold from the crude extract. β-galactosidase showed optimum activity at pH 5.0 at 40°C, and was specifically found to be able to hydrolyze p -nitrophenyl β-galactopyranoside. It degrades galactan and agarose, and produces galactose. β-galactosidase was strongly inhibited by Hg2+ and PCMB. β-galactosidase is considered to be secreted by the upper and middle parts of the intestine and most of the activity was detected in the intestinal juice. 相似文献
15.
Isao Sawaguchi Shunji Shimizu Kouichi Ichihara Katsumi Toyokawa Osamu Ohkawabata 《Journal of Forest Research》1997,2(1):15-19
The growing condition of afforestation trees and damage to lower-story trees caused by felling and hauling of upper-story
trees in a multi-storied forest in Peninsular Malaysia was surveyed. Seventy months have passed since the planting ofAcacia mangium upperstory trees, which have grown 233 m3/ha in volume. The growth ofShorea leprosula thirty-five months after planting of lower-story trees have reached 5.54 m in height. However, as the ratio of height to
basal diameter exceeds 100:1, trees are tapering to a considerable degree. A backhoe was installed in order to fell the upper-story
trees. From the results of logging, the damage ratio estimation of the lower-story trees was simulated by using the Monte
Carlo method. The damage ratio differed considerably depending on planting patterns, height of upper-story trees and felling
skills. The results of this survey proved that the felling and hauling of upper-story trees would be technically feasible
in the future, except when one row upper-story trees and one row lower-story trees method were employed. 相似文献
16.
Kouichi Ichihara Tosimi Tanaka Isao Sawaguchi Shuji Umeda Katsumi Toyokawa 《Journal of Forest Research》1996,1(1):45-49
This study examines a method for designing an optimum profile of a forest road in a short matter of time. In this method,
a genetic algorithm (GA) searches for points where the gradient changes and dynamic programing (DP) designs the longitudinal
slope. This method can be applied to the ground heights of an actual forest road. The evaluation function of the DP assesses
the total expenditure. The inverse of this function is the fitness function. Crossover and mutation are operators of an evolution
simulation of a GA. They are each repeated 20 times and 420 profiles are designed and assessed, all within about 10 min. A
comparison of the profile designed by the GA with that of an actual forest road shows only one section where the formation
level differed substantially. Overall, both profiles seem to show a high degree of correspondence. From this result, we believe
that the profile designed by the GA is best, or the one of the best. A conventional method takes about 65 h to calculate all
changing points of gradients. However, by using the GA, the calculation time was reduced to about 1/389 that of the coventional
method, showing that the method which uses the GA through the profile design is very useful. 相似文献
17.
Won-Joung Hwang S. Nami Kartal Yuji Imamura Kunio Tsunoda Katsumi Shinoda 《Journal of Wood Science》2007,53(4):332-338
This study describes a laboratory evaluation of the efficacy of two alkylammonium compounds [didecyldimethylammonium tetrafluoroborate
(DBF) and didecyldimethylammonium chloride (DDAC)] when applied via vacuum impregnation or superficial treatment. Treated
wood specimens were tested for their termite and microbial resistance under controlled laboratory conditions. The higher chemical
retentions were needed to suppress the feeding by Coptotermes formosanus ≦3% mass loss in the multichoice test than in the no-choice test. The DBF and DDAC retention levels necessary to meet the
performance requirement ≦3% mass loss after 12-week fungal exposure varied with wood species. The retention level of 3 kg/m3 for DBF and DDAC was generally high to keep the nondurable wood species free of decay. Although there was no difference between
DBF and DDAC in the efficacy against decay and termite attack, the former slightly outperformed the latter as an antimold
and antisapstain agent. 相似文献
18.
Takaaki Fujimoto Kazuhito Kita Kazuko Uchiyama Makoto Kuromaru Hisashi Akutsu Kazuyuki Oda 《Journal of Forest Research》2006,11(3):157-163
Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion
were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F1. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations
between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained
using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of
environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age
for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66.
Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits
at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum
gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at
early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at
a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth
rate because rapid growth will result in a low-density wood product, especially in the early growth period. 相似文献
19.
To determine whether Monochamus alternatus can use the Japanese cedar (Cryptomeria japonica) as a host tree, experiments were conducted in a laboratory using three insect populations of different localities. Adult
females chose Pinus densiflora bolts as oviposition substrate when supplied with cedar and pine bolts simultaneously, whereas some females from one locality
oviposited on cedar bolts when supplied with them exclusively. Seventy-three percent of 40 eggs hatched in cedar bolts. When
the first instar larvae were inoculated on cedar bolts, the development was stunted greatly and all died during the larval
stage. Two of 20 larvae that were inoculated on cedar bolts at the third instar entered the diapause and one larva developed
into an adult female, which produced viable eggs but was much smaller than those obtained from pine bolts. The results did
not exclude the possibility that M. alternatus can use recently killed C. japonica trees as a host. 相似文献
20.
Masahiro MIYABE Azusa GIN Eri ONOZAWA Mana DAIMON Hana YAMADA Hitomi ODA Akihiro MORI Yutaka MOMOTA Daigo AZAKAMI Ichiro YAMAMOTO Mariko MOCHIZUKI Toshinori SAKO Katsutoshi TAMURA Katsumi ISHIOKA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(10):1201-1206
G protein-coupled receptor (GPR) 120 is an unsaturated fatty acid receptor, which is
associated with various physiological functions. It is reported that the genetic variant
of GPR120, p.Arg270His, is detected more in obese people, and this genetic variation
functionally relates to obesity in humans. Obesity is a common nutritional disorder also
in dogs, but the genetic factors have not ever been identified in dogs. In this study, we
investigated the molecular structure of canine GPR120 and searched for candidate genetic
variants which may relate to obesity in dogs. Canine GPR120 was highly homologous to those
of other species, and seven transmembrane domains and two N-glycosylation sites were
conserved. GPR120 mRNA was expressed in lung, jejunum, ileum, colon, hypothalamus,
hippocampus, spinal cord, bone marrow, dermis and white adipose tissues in dogs, as those
in mice and humans. Genetic variants of GPR120 were explored in client-owned 141 dogs,
resulting in that 5 synonymous and 4 non-synonymous variants were found. The variant
c.595C>A (p.Pro199Thr) was found in 40 dogs, and the gene frequency was significantly
higher in dogs with higher body condition scores, i.e. 0.320 in BCS4–5 dogs, 0.175 in BCS3
dogs and 0.000 in BCS2 dogs. We conclude that c.595C>A (p.Pro199Thr) is a candidate
variant relating to obesity, which may be helpful for nutritional management of dogs. 相似文献