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1.
Laboratory evaluation of the insect growth regulator lufenuron againstHelicoverpa armigera on cotton
An insect growth regulator (IGR), lufenuron (Match 5EC), was tested for its toxicity toHelicoverpa armigera on cotton. Potency of the IGR against the larval stage of the pest was demonstrated with respect to larval instars; the LC90 values of 1st, 2nd, 3rd, 4th and 5th instar larvae were 5.63, 7.89, 8.03, 11.39 and 14.76 mg a.i.l
−1, respectively. However, different larval instars did not differ significantly with respect to LC50 and LC10. IGR-treated larvae had swollen heads and were significantly smaller (1.5–2.3 mm) than the untreated control (2.9 mm). Larval
weight was significantly reduced from 190 mg in the control to 50–70 mg in the lufenuron treatment. IGR treatment in the larval
stage significantly affected both pupal length and pupal weight. Pupal duration of the test insect was significantly extended
by IGR treatment. Pupal deformities, including an inability to shed the last larval skin and formation of larval-pupal intermediates,
occurred following treatment. A significant reduction in adult emergence was recorded. In addition, abnormalities in the form
of development of cavities in the forewings of adult were evident. A significant decline in fecundity was noted in the studies.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
2.
The annual reproductive cycle of the commercial sea cucumber Holothuria spinifera was studied in Tuticorin, Tamil Nadu, India, from September 2000 to October 2001, by macroscopic and microscopic examination
of gonad tubule, gonad index and histology of gametogenic stages, to determine the spawning pattern. The gonad consists of
long tubules with uniform development. It does not confirm the progressive tubule recruitment model described for other holothurians.
The maximum percentage of mature animals, gonad and fecundity indices, tubule length and diameter, with the observations on
gonad histology, ascertained that H. spinifera had the peak gametogenic activity during September and October 2001 followed by a prolonged spawning period from November
2000–March 2001. 相似文献
3.
The methanol extract of Butea monosperma seeds, tested in vitro, showed significant anthelmintic activity. 相似文献
4.
For large-scale seed production of sea cucumbers through a hatchery system, it is imperative to know the effects of environmental parameters on larval rearing. Auricularia larvae (48 h post-fertilization) were obtained from induced spawning of Holothuria spinifera and used in experiments to ascertain the effects of temperature, salinity and pH on the growth and survivorship of the larvae. The larvae were reared for 12 days at temperatures of 20, 25, 28 and 32 °C; salinities of 15, 20, 25, 30, 35 and 40 ppt; and pH of 6.5, 7.0, 7.5, 7.8, 8.0, 8.5 and 9.0. The highest survivorship and growth rate and fastest development of auricularia indicated that water temperature of 28–32 °C, salinity of 35 ppt and pH of 7.8 were the most suitable conditions for rearing larvae of H. spinifera. 相似文献
5.
Climate is a critical factor affecting forest ecosystems and their capacity to produce goods and services. Effects of climate change on forests depend on ecosystem-specific factors including dimensions of climate (temperature, precipitation, drought, wind etc.). Available information is not sufficient to support a quantitative assessment of the ecological, social and economic consequences. The present study assessed shifts in forest cover types of Western Himalayan Eco-region (700?4500 m). 100 randomly selected samples (75 for training and 25 for testing the model), genetic algorithm of rule set parameters and climatic envelopes were used to assess the distribution of five prominent forest cover types (Temperate evergreen, Tropical semi-evergreen, Temperate conifer, Subtropical conifer, and Tropical moist deciduous forests). Modelling was conducted for four different scenarios, current scenario, changed precipitation (8% increase), changed temperature (1.07°C increase), and both changed temperature and precipitation. On increasing precipitation a downward shift in the temperate evergreen and tropical semi-evergreen was observed, while sub-tropical conifer and tropical moist-deciduous forests showed a slight upward shift and temperate conifer showed no shift. On increasing temperature, an upward shift in all forest types was observed except sub-tropical conifer forests without significant changes. When both temperature and precipitation were changed, the actual distribution was maintained and slight upward shift was observed in all the forest types except sub-tropical conifer. It is important to understand the likely impacts of the projected climate change on the forest ecosystems, so that better management and conservation strategies can be adopted for the biodiversity and forest dependent community. Knowledge of impact mechanisms also enables identification and mitigation of some of the conditions that increase vulnerability to climate change in the forest sector. 相似文献
6.
Sangappa B. Lakshmeesha Rao S. Asha S. Ganesh R. Somashekar Timma Reddy 《Fibers and Polymers》2013,14(6):1032-1039
Tassar silk fiber (Antheraea mylitta) was irradiated with the available maximum dose range upto 100 kGy using 8 MeV electron beam at room temperature. Irradiation effect in these fibers is quantified in terms of the changes in microstructural parameters studied using wide-angle X-ray scattering data (WAXS). The crystal imperfection parameters such as crystallite size (〈N〉), lattice strain (g in %), and surface weighted crystallite size (Ds in Å) have been determined by line profile analysis (LPA) using Fourier method of Warren. For this purpose, exponential, lognormal, and Reinhold functions for column length distribution have been used for the determination of these parameters. These parameters were compared with tensile properties of the fibers. The increasing trend of crystallite size values (〈N〉 as well as Ds in Å) and tenacity (gf/den) with increasing dosage of radiation clearly indicates the cross linking polymer network in fiber. Comparison of SEM photographs also confirms the X-ray results. 相似文献
7.
Downy mildew (DM) caused by Peronospora arborescens is the most destructive disease of opium poppy which assumes considerable importance in India and other poppy growing countries.
The present study was aimed at identification and evaluation of stable resistance sources of DM in opium poppy. Furthermore,
genetic variability and inheritance pattern of DM resistance has also been studied which can help in making strategy for crop
improvement. Evaluation of 35 selected germplasm accessions of opium poppy under glasshouse and field conditions during the
three consecutive years (2004–2005 to 2006–2007) resulted in identification of two genotypes (I-14 and Pps-1) as highly resistant
and stable sources for DM resistance. Genetic studies of DM resistance revealed polygenic control with the dominance of susceptibility
over resistance. Significant reciprocal differences were found largely due to maternal transmission of DM resistance indicating
the involvement of cytoplasmic genes in addition to nuclear control. Analysis of genetic variability and selection parameters
indicated predominance of additive effects for DM resistance and other yield contributing traits. Multivariate analysis resulted
in classification of 35 selected accessions into 11 different clusters revealing very high level of diversity among the genotypes.
Cluster analysis suggested that hybridization program involving genotypes from cluster V (which included highly resistant
genotypes Pps-1 and I-14) and cluster IX (which included highly susceptible Jawahar-16 having good economically important
traits like seed yield) could be expected to give best recombinants for improvement in terms of DM resistance and high seed
and straw yield in opium poppy. Analysis of selection parameters like heritability and genetic advance also suggested that
simple selection methods will be effective in stabilizing resistance traits following hybridization with high yielding genotypes. 相似文献
8.
NB7 silk fiber (Bombyx mori) was irradiated with the maximum dose range of 100 kGy using 8 MeV electron beam at room temperature. Irradiation effect
in these fibers is quantified in terms of the changes in microstructural parameters employing X-ray diffraction line profile
analysis technique. For this purpose we have used three asymmetric distribution functions for column lengths in a crystal.
The decreasing trend of crystallite size values (〈N〉 as well as D
s
) and crystallinity with increasing dosage of radiation clearly indicates the degradation of fiber. Of the several factors
responsible for such a behavior, we presume that the chain scission of polymer network is a significant one over others and
it is well pronounced here, leading to low molecular weight of the samples. This degradation is attributed to many changes
in tensile properties of the polymer. Comparison of SEM photographs also confirms the X-ray results. 相似文献
9.
Asha Kawatra C. M. Bhat Asha Arora 《Plant foods for human nutrition (Dordrecht, Netherlands)》1992,42(3):225-230
The study was conducted on eleven healthy non-anaemic adolescent girls of 16 to 18 years of age. Balance studies were conducted in two trials of three weeks each on low and high fibre diets. High fibre diet contained 25 g Isabgol husk in addition to low fibre diet. The mean diet and nutrient intakes of the subjects were approximately the same during both trials. Addition of Isabgol husk to low fibre diet significantly (P0.05) increased faecal excretion of zinc, copper and manganese and lowered their apparent retention. The serum levels of these trace minerals decreased significantly (P0.05). Thus the high level of Isabgol has undesirable effect on trace minerals. 相似文献
10.
Douglas J. Weiss P. Jane Armstrong Asha Mruthyunjaya 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1995,9(4):267-271
Serum from 21 dogs with chronic hepatitis was evaluated for anti-liver membrane protein (anti-LMP) antibodies by an enzyme-linked immunosorbent assay. Ten of the 21 dogs had anti-LMP antibody concentrations greater than 2 SD above the mean value for the 10 healthy control dogs; titers ranged from 1:40 to greater than 1:1,600. Anti-LMP—positive dogs were not restricted by breed, had higher alanine amino transferase activity and total bilirubin concentration, and more severe liver lesions when compared with anti-LMP—negative dogs. This study provided evidence of humoral autoantibodies in dogs with chronic hepatitis, but it did not determine if the autoantibodies were primary or secondary. 相似文献