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71.
Sponge gourd is a popular vegetable grown throughout India. Tomato leaf curl New Delhi virus, the causal virus of tomato leaf curl disease, has recently been reported to be associated with sponge gourd, causing up to 100% crop loss under epidemic conditions. We have collected 30 genotypically diverse genotypes of sponge gourd from different parts of India, screened these for resistance under natural epiphytotic conditions, and then confirmed the results through challenge inoculation with a purified strain of the virus under insect-proof greenhouse conditions. The minimum vulnerability index was recorded in genotype DSG-6 (3.33), followed by DSG 7 (6.0) under the challenge (whitefly-populated) inoculation conditions. Two susceptible genotypes (‘Pusa Sneha’ and NSG-1-11), both possessing desirable fruit characters, were crossed with the two most promising resistant lines (DSG-6 and DSG-7) and the disease reaction of segregating and backcross generations studied through challenge inoculation with a purified strain of virus under insect-proof greenhouse conditions. A chi-square (χ2) test of frequency distribution based on the vulnerability index of the F2 progenies of the two resistant × susceptible crosses revealed monogenic dominant Mendelian ratio 3(R):1(S) to be the best fit in all crosses. This monogenic dominant model was further confirmed by the 1(R):1(S) ratio found to be best fit for the test cross with the susceptible parent. These results reveal that resistance to Tomato leaf curl New Delhi virus associated with yellow mosaic disease of sponge gourd is controlled by a single dominant gene in the genetic background of the resistant parents (DSG-6 and DSG-7) and that these two lines can be effectively utilized for the development of high-yielding and yellow mosaic disease-resistant varieties/hybrids of sponge gourd. This is the first conclusive identification of a resistant source and the inheritance of resistance against Tomato leaf curl New Delhi virus in sponge gourd.  相似文献   
72.
The study was conducted to investigate the ameliorative roles of GA3 and CK on adverse effects of drought in maize. Drought stressed maize plants were applied with GA3 and CK at 50, 100, and 150 mg L?l as foliar spray at the vegetative and the reproductive stages. Plant height, internode length, stem diameter, leaf chlorophyll index, and dry matter production were significantly affected by drought. In most cases, GA3 and CK significantly improved the depressed plant traits, but in varying degrees depending on the growth stage encountering hormones, and their types and concentrations. Both GA3 and CK were found to be very effective in alleviating drought-imposed adverse effects on maize at the vegetative phase. Such alleviating effects varied depending on the concentration of the hormones. Application of CK at 150 mg L?l was excellent resulting in a 106% yield advantage compared to drought stress and 79.9% increase relative to well-watered controls. Conversely, GA3 at 50 mg L?l performed well showing 78.8% increase in grain yield. However, both GA3 and CK had very little effect on improving the depressed growth and yield attributes in maize at the reproductive phase. The relative yield advantages for the hormones were mainly attributed to improving the cob and seed-bearing capacity of drought-stressed maize plants.  相似文献   
73.
An exploratory survey was conducted among the Khasia living in Lawachara National Parkt (LNP) to investigate their depend- ency on the protected area (PA) for livelihoods, betel leaf hill farming, traditional forest conservation and perceptions of the PA, Field data were collected by interviewing 48 household heads from two villages (punjis) located inside the LNP and visiting their farms.: The economy of the Khasia was forest-based. They were largely dependent on betel leaf hill farming in LNP and nearly 71% of their mean annual income was de- rived from this irrespective of farmer category. On average, about 14% of the incomes of the poorer farmers came from forest produce followed by 10% and 6% for medium and rich farmers respectively. Hills and forests were the foundations of their lives and livelihoods, and LNP was the life-blood of Khasia survival. As a sustainable production system, this farming practice plays a vital role in conserving biodiversity in LNP and might be replicated elsewhere.  相似文献   
74.
Rice (Oryza sativa L.) is the most important economic activity on earth as it is second largest single use of the land for food production and also consumed by the half of the world's population. Salinity is the one of the most common abiotic problem in rice growing areas of the world. Millions of hectares in the tropics, arid and semi arid region could be potential rice growing areas but either left idle or cropped with very low yielding varieties due to the lack of suitable salt tolerant high yielding modem varieties.  相似文献   
75.
Globally, the prevalence of chronic, noncommunicable diseases is increasing at an alarming rate and diabetes is one of them. If diabetes is not controlled then a lot of complication like coronary artery disease, cerebrovascular disease, peripheral vascular disease, retinopathy, nephropathy and neuropathy arise in diabetic patients and causes morbidity and/or mortality. Diabetes is increasing at an epidemic form and in near future the largest increases will take place in the regions dominated by developing economies. So, it will be a great social and economical burden to developing countries as well as the developed. But if we be aware about our diet and lifestyle and take proper medication we may prevent and reduce the prevalence of diabetes. Oral medicine plays an important role in management of diabetes. But most of the oral drugs are costly and have a lot of side effects. For this it is also necessary to take medicines with fewer or no side effects. And antidiabetic medicinal plants may play an important role in this case. In this article we have tried to describe how diet and lifestyle with using medicinal plants may help to prevent or maintain diabetes and help to reduce the mortality and morbidity due to diabetes or complication related to it.  相似文献   
76.
Respiratory system is the primary settlement place of opportunistic organisms and considered as chief carrier of common respiratory pathogens. The aim of the study was to know the opportunistic organisms present in the healthy subjects as well as subjects that were suffering from respiratory symptoms. The organisms were identified as per standard bacteriological protocol and pathogenicity tests of the identified organisms were performed in mouse model. Antibiotic sensitivity of the identified organisms was performed. The bacterial flora present in the throat swab of apparently healthy as well as subjects suffering from respiratory symptoms were: Staphylococcus spp. (39.44%) of which Coagulase positive Staphylococcus (21.13%) and Coagulase negative Staphylococcus (18.31%), Klebsiella spp. (19.72%), Pseudomonas spp. (15.49%), Proteus spp. (4.23%), E. coli (9.86%) and Bacillus spp. (11.27%). Among the isolates Staphylococcus, Klebsiella and Pseudomonas were the predominant species. Percentages of identified bacteria were higher in respiratory symptoms exhibiting individuals (53.52%) than apparently healthy individuals (46.48%). All coagulase positive Staphylococcus, Klebsiella spp. and Pseudomonas spp. isolated from respiratory symptoms' subjects were found to be pathogenic. The isolated bacteria were resistant to amoxicillin and ampicillin but sensitive to ciprofloxacin and norfloxacin. Isolated Pseudomonas spp. showed multidrugs resistant properties. The study provided information about the pathogenic organisms' present respiratory systems of apparently healthy as well as subjects suffering from respiratory symptoms. The pathogenic natures of the isolated organisms were determined to make aware of scientists as well as clinicians. Antibiotics sensitivity assays would provide information to the clinicians for the selection of appropriate antibiotics to treat their patients.  相似文献   
77.
Paddy and Water Environment - Japan has many concrete irrigation channels with total length of about 400,000 km. Most of these channels are now too old for continued use. It would be too...  相似文献   
78.
Jute fabric reinforced polypropylene composites were fabricated by compression molding technique. Fiber content in the composites was optimized at 45 % by weight of fiber by evaluating the mechanical parameters such as tensile strength, tensile modulus, bending strength, bending modulus. Surface treatment of jute fabrics was carried out by mercerizing jute fabrics with aqueous solutions of NaOH (5, 10 and 20 %) at different soaking times (30, 60 and 90 mins) and temperatures (0, 30 and 70 °C). The effect of mercerization on weight and dimension of jute fabrics was studied. Mechanical properties of mercerized jute-PP composites were measured and found highest at 20 % NaOH at 0 °C for 60 min soaking time. Thermal analytical data from thermogravimetric and differential thermal analysis showed that mercerized jute-PP composite achieved higher thermal stability compared to PP, jute fabrics and control composite. Degradation characteristics of the composites were studied in soil, water and simulated weathering conditions. Water uptake of the composites was also investigated.  相似文献   
79.
Abstract

Phytoremediation is a natural approach to use plants for decontaminating soil. A pot-culture factorial experiment in completely randomized design was conducted to evaluate the effects of four levels [0, 25, 50, and 100?mg/kg] of chromium (Cr) with three levels [0, 0.5, and 1-M solution) of plant defense inducer salicylic acid (SA) on growth, physiological processes, and biochemical responses of Malabar spinach (Basella alba). Results showed that Cr significantly decreased vine length (VL), leaf number (LN), leaf area (LA), fresh- (FBM), and dry-biomass (DBM), root length (RL), and dry-matter ratio (DMR). Cr also significantly decreased SPAD (chlorophyll contents), by 9% to 29% and net photosynthesis (Pn) rates, by 36% to 71%, but increased transpiration (E) rates, by 1.5 to 2.7 times and stomatal conductance (C), by 1.7 to 3.5 times, as compared with the control. Proline contents increased with an associated decrease in oxidative enzyme activities such as peroxidase, (POD) and catalase, (CAT) with increasing Cr levels. Cr significantly reduced the Dry Matter Ratio (DMR) (12% to 42%) and LA (10% to 35%), RL -stress (11% to 27%), and SPAD (10% to 28%) stress tolerance indices. The integrated stress tolerance index (ISTIndex) of Malabar spinach was reduced (by 6% to 23%) by Cr stress, as compared to the control. SA application, in contrast, partially alleviated the severity of Cr toxicity effects on VL, LN, LA, FBM, DBM, RL, and DMR and increased the SPAD (by 12%), Photosynthesis Net (Pn) (by 53% to 68%), and stomatal conductance (C) (by 35% to 50%), respectively. Furthermore, SA increased plant stress tolerance indices by increasing antioxidant enzymatic functions. SA application recovered the ISTIndex at all Cr levels, and the recovery effect on plants was more pronounced by 0.5-M SA than by other SA treatments. The mechanism of stress tolerance as induced by SA application may help plants to better survive and maintain growth in presence of higher Cr contents in soil. Results suggested that SA, as a plant defense inducer, can be exploited for improving Cr phytoremediation potential of Malabar spinach to decontaminate soil.  相似文献   
80.
A Compendium on Host Genes in Flax Conferring Resistance to Flax Rust   总被引:1,自引:0,他引:1  
A list with information about named host genes controlling resistance to rust in both cultivated and wild flax has been compiled. These will be useful for genetic, physiological and biochemical research as well as breeding for resistance. Information regarding mutation, temperature sensitivity and the effect of inhibitor/avirulence gene interaction on expression of certain host genes is included.  相似文献   
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