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排序方式: 共有182条查询结果,搜索用时 31 毫秒
41.
Ghasem Mohammadi Taida Juliana Adorian Gholamreza Rafiee 《Aquaculture Nutrition》2020,26(5):1476-1492
The present research explored the effects of Bacillus subtilis on water quality, growth, immune responses, endotoxemia and protection against lipopolysaccharide (LPS) damages in Nile tilapia Oreochromis niloticus under biofloc system. B. subtilis was added at 0, 1, 2, 3 and 4 grams (1.19 × 108 CFU/g) per kg of basal diet, named T1 (control), T2, T3, T4 and T5, respectively, and fed to fish (14.82 ± 0.42 g) for 50 days. The concentrations of TAN, NO2 and NO3 were significantly reduced, and fish fed probiotics displayed significantly better growth performances versus the control, concomitantly with significantly enhanced activities of digestive enzymes. They also showed significantly declined serum glucose and cholesterol vice versa significantly improved immune responses (total protein, albumin, globulin, lysozyme, alternative complement, protease, immunoglobulins, alkaline phosphatase and respiratory burst), antioxidant capacity (superoxide dismutase, total antioxidant capacity, malondialdehyde) and skin mucus parameters (total protein, lysozyme, alternative complement, protease, immunoglobulins). Meanwhile, significantly lower endotoxin (LPS) concentrations were detected in the intestines and serum of fish fed probiotics. LPS challenge induced profound oxidative stress and impaired immune responses. Interestingly, probiotic alleviated LPS‐induced damages and restored mentioned parameters. In conclusion, B. subtilis effectively enhanced fish production, immunity and protection against LPS‐induced damages in tilapia under biofloc system. 相似文献
42.
Asad Mohammadi Zarejabad Mohammad Ali Jalali Mohammad Sudagar Somayeh Pouralimotlagh 《Fish physiology and biochemistry》2010,36(3):655-659
The effect of environmental salinity on hematological parameters of great sturgeon Huso huso juveniles was studied. Five-month-old juveniles (mean body weight 28.3 ± 2.1 g) were subjected to 0, 3, 6, 9, and 12 ppt
salinities. The hematological parameters were assessed after a period of 20 days rearing at these salinities. After transfer
from fresh water to brackish water, red blood cells, hematocrit, haemoglobin and mean corpuscular haemoglobin decreased, but
mean corpuscular volume increased. Mean corpuscular haemoglobin concentration, white blood cells, monocyte counts, and eosinophil
counts showed no significant variations with increase in environmental salinity. An increase was found in lymphocyte counts
according to the increase of salinity from 0 to 12 ppt, while the fresh water control group maintained basal levels. Decrease
in neutrophil counts was observed in great sturgeon with increase in environmental salinity. These data show significant effect
of salinity on the blood parameters of great sturgeon. 相似文献
43.
M. Fazlollahi Mohammadi S. G. H. Jalali Y. Kooch D. Said-Pullicino 《Eurasian Soil Science》2016,49(12):1366-1374
In order to evaluate the variability of the soil profiles at two shapes (concave and convex) and five positions (summit, shoulder, back slope, footslope and toeslope) of a slope, a study of a virgin area was made in a Beech stand of mountain forests, northern Iran. Across the slope positions, the soil profiles demonstrated significant changes due to topography for two shape slopes. The solum depth of the convex slope was higher than the concave one in all five positions, and it decreased from the summit to shoulder and increased from the mid to lower slope positions for both convex and concave slopes. The thin solum at the upper positions and concave slope demonstrated that pedogenetic development is least at upper slope positions and concave slope where leaching and biomass productivity are less than at lower slopes and concave slope. A large decrease in the thickness of O and A horizons from the summit to back slope was noted for both concave and convex slopes, but it increased from back slope toward down slope for both of them. The average thickness of B horizons increased from summit to down slopes in the case of the concave slope, but in the case of convex slope it decreased from summit to shoulder and afterwards it increased to the down slope. The thicknesses of the different horizons varied in part in the different positions and shape slopes because they had different plant species cover and soil features, which were related to topography. 相似文献
44.
A feeding trial was conducted to evaluate the effect of replacing fish meal protein with fermented soybean meal (FSM) on the growth performance, feed utilization, amino acid profile, body composition, morphological parameters, activity of antioxidant and digestive enzymes of black sea bream (Acanthopagrus schlegeli) juvenile. Five isonitrogenic and isolipidic diets were prepared with levels of 0 (control), 80, 160, 240 and 320 g kg?1 FSM. Triplicate groups (40 fish per tank) of juvenile black sea bream with initial weight of 1.17 ± 0.04 g were hand‐fed to visual satiation at three meals per day for 8 weeks. The fish fed diets containing different levels of FSM had no significant differences regarding survival and specific growth rate compared with control group. Feed and protein efficiency ratios of fish fed diet containing 320 g kg?1 FSM were significantly lower than those of control group. Daily feed intake and daily protein intake of fish fed diet containing 240–320 g kg?1 were significantly higher than those of control group. Hepatosomatic index and condition factor of fish were not affected by different dietary FSM level. Fish fed diets containing 240–320 g kg?1 FSM had significantly higher visceral somatic index than control group. Whole body proximate and amino acid compositions of fish were not affected by dietary FSM level. The activity of digestive enzymes in the intestine was not affected by dietary FSM level. The activity of glutathione peroxidase in liver was significantly higher for fish fed the diet containing 160 g kg?1 FSM compared with control group. This study showed that up to 40% fish meal in the diets of juvenile black sea bream could be replaced by fermented soybean meal with supplementation of methionine, lysine and taurine. 相似文献
45.
We used a goal programming technique to determine the optimal harvest volume for the Iranian Caspian forest. We collected data including volume, growth, wood price at forest roadside, and variable harvesting costs. The allometric method was used to quantify seques- trated carbon. Regression analysis was used to derive growth models. Expected mean price was estimated using wood price and variable harvesting costs. Questionnaire was used to determine the constraints and the equation coefficients of the goal programming model. The optimal volume was determined using the goal programming method according to multipurpose forest management. LINGO software was used for analysis. Results indicated that the optimum volumes of species were 250.25 m3.ha-1 for beech, 59 m3.ha-1 for hornbeam, 73 m3.ha-1 for oak, 41 m3.ha-1 for alder, and 32 m3.ha-1 for other species. The total optimum volume is 455.25 m3.ha-1. 相似文献
46.
Forest fires are an important environmental concern worldwide, affecting the soil, forests and human lives. During the process of burning, soil nutrients are depleted and the soil is subsequently more vulnerable to erosion. Nowadays it is necessary to identify the factors influencing the occurrence of fire and fire hazard areas, in order to minimize the frequency of fire and avert damage. Logistic regression was used to study the forest fire risk and identify the most influential factors in the occurrence of forest fires. Climatic variables (temperature and annual precipitation), human factors (distance from streams and farmland) and physiography (land slope and elevation) were considered and their correlation with the occurrence of fires investigated. Results of model validation and sensitivity of various areas to fire were examined with the ROC coefficient and Hosmer–Lemeshow test. The estimated coefficients for the independent variables indicated that the probability of occurrence of fire is negatively related to land slope, site elevation and distance from farmlands, but is positively related to amount of annual precipitation. 相似文献
47.
Tropical Animal Health and Production - Separation of autosomal and sex-linked direct additive genetic effects has significant role in sheep breeding programs. Hence, this study was conducted to... 相似文献
48.
Reza Mohammadi Kouresh Nader Mahmoodi Reza Haghparast Stefania Grando Maryam Rahmanian Salvatore Ceccarelli 《Journal of Crop Science and Biotechnology》2011,14(4):281-288
This study was carried out to identify superior barley genotypes for the rainfed areas of western Iran using a participatory
varietal selection (PVS) approach. Three field experiments were conducted in two randomly selected farmers’ fields and in
one rainfed research station in the 2006–07 cropping season with 69 genotypes (including one local and one improved check).
Several univariate and multivariate methods were used to analyze qualitative (farmers’ scores) and quantitative (grain yield)
data. Individual farmers’ scores in each village were positively correlated, indicating that the farmers tended to discriminate
genotypes in similar fashion, although the genotypes actually selected by farmers were different in the two villages. In recent
years, a greater number of farmers in western Iran preferred the improved variety (Sararood-1) over the local barley (Mahali),
while in this project the farmers preferred the new genotypes over the two checks. This was also verified by the quantitative
data showing that the checks were outyielded by the new genotypes. Farmers were efficient in identifying the best genotypes
for their specific environment, as shown by biplot analysis, indicating their competence in selection. The genotypes selected
by the breeder and farmers were almost similar but some differences existed. In conclusion, PVS is a powerful way to involve
farmers for selecting and testing new cultivars that are adapted to their needs, systems and environments. 相似文献
49.
Mohamadi Yalsuyi Ahmad Forouhar Vajargah Mohammad Hajimoradloo Abdolmajid Mohammadi Galangash Mohsen Prokić Marko D. Faggio Caterina 《Veterinary research communications》2022,46(2):389-396
Veterinary Research Communications - Industrial chemical solutions are widely used as a method to disinfection of aquaculture water and environments. The aim of the present study was to evaluate... 相似文献
50.
An investigation on the dimensional properties of plain knitted fabric produced from cotton yarn and subjected to different
relaxation treatments is presented in this paper. The main aim of this research is to characterize the internal energy of
fabric by using yarn-pullout test method in ultrasonic relaxation state and compare it with other common mechanical relaxation
treatments. A comprehensive experimental analysis showed that, by using ultrasonic waves, the area geometry constant value
(k
s) achieved was higher than the conventional relaxation methods. Then, we introduced residual-energy forming and loss-energy
uniforming. The former appeared due to fabric shrinkage and the later one appeared due to release of fabric loops from extra
forces which imposed during knitting process. The results also indicated that ultrasonic waves energy causes more uniformity
on loop and consequently, the fabric reaches to a less internal energy than washing treatment. 相似文献