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1.
新疆国际客源市场时空发展变化分析研究   总被引:1,自引:0,他引:1  
利用集中度和亲景度、竞争态指标,对新疆国际客源市场13个主体客源国1997~2004年统计数据进行分析,揭示国际客源时空演替规律,指出新疆主要的3个国际客源市场是日本、俄罗斯和美国,并提出了拓展国际客源市场的建议。  相似文献   
2.
我国农村资金外流分析   总被引:1,自引:1,他引:0  
在中国,“二元经济结构”导致资本发生流动偏好,资本流动偏好又加快农村资金外流的规模与速度。因此,减缓叶:国农村资金外流必须依据资本流动偏好规律,改善农村投资环境,完善农村各种金融机构职能。从而改变资金流动方向,引导资金向农村回流。  相似文献   
3.
This study is part of an effort to improve the quality of dried shiitake mushrooms (Lentinula edodes) in accordance with consumer preference. Results are presented of a trend survey that examined the preferences of consumers using questionnaires combined with sensory evaluation. From the original preference (OP) survey, the distributions of OP divided by age class (AC) were statistically equal to the results obtained in 2000. The medians of OP for teenagers and twenties were “neutral” and “slightly like,” respectively. A firm preference change occurred between teenagers and those in their twenties. It is empirically realized that sensory intensity (SI) scores that were too high or too low led to a low hedonic preference (HP) score. The same tendency was seen for “neutralists” and “likers.” In addition, almost all distributions concerned with HP had no significant difference between 2000 and 2005; for example, that of SI divided by AC. These results showed that the preference for dried shiitake mushroom has been unaffected by the passage of the past 5 years. Dried shiitake mushrooms have been used from ancient times and for many dishes; therefore, the overall preference appears to have remained unchanged.  相似文献   
4.
We examined collembolan food preference for fungal mycelium grown on copper-contaminated medium, and the relationship between copper content, food selectivity and collembolan fitness when fed contaminated mycelium.To clarify whether collembolan food selectivity is related to fitness parameters, Folsomia candida were fed mycelium of the dark-pigmented fungus Alternaria alternata grown on medium with different copper concentrations. Copper-contaminated food (fungus grown on 50, 125, 250 and 500 μg Cu g−1 medium, fresh wt.) was offered together with untreated food for 4 weeks. F. candida fed selectively on the provided mycelium and discriminated clearly between mycelium grown on high and low levels of contamination, distinctly preferring fungus grown on medium with a total copper concentration of 50 and 125 μg g−1. In contrast, fungus grown on highly contaminated medium (250 and 500 μg g−1) was avoided. Collembolan food preference generally matched fitness parameters. Reproduction was significantly affected by the total copper concentration of the fungal growth medium. When fed their preferred mycelium, collembolan reproduction was enhanced, whereas a diet of highly contaminated mycelium (250 or 500 μg g−1) resulted in a strong decrease in reproduction. Adult survival was affected only marginally. Even though heavy metal contamination is a potential stress factor for many soil microarthropods, F. candida is able to discriminate between high and low quality food sources, and even benefits from moderately elevated copper concentrations.  相似文献   
5.
在把握江苏农村公共投资现状基础上,通过个案调查对农村居民公共物品需求进行考察并提出相应政策建议。笔者研究发现,农村居民公共物品需求明显表现出“生产第一、生活第二”规律,不同类型农村居民对公共投资的期望不存在显著差异;虽多数农村居民认识到“投资非农产业收益较高”,但多数农村居民仍非常重视农业生产,对农业生产公共物品的政府投资抱很大期望;农村居民对公共物品的期望排序与宏观层面农村公共投资收益率大小次序基本一致,农村居民急需的公共物品也是政府投资收益率较高的公共项目。  相似文献   
6.
研究了不同寄主植物与斜纹夜蛾喜食程度、生长发育及存活率的关系结果表明 ,斜纹夜蛾喜食植物依次为槟榔芋 >莲藕 >甘蓝 >青菜 >水蕹菜 >黄牙白 >棉花 >大豆 >萝卜 >豇豆 >木耳菜 ;较喜食植物依次为花生 >芝麻 >酸模叶蓼 >四叶萍 >甘薯 >绿豆 >黄瓜 ;其余为次要寄主植物。斜纹夜蛾幼虫取食不同寄主植物 ,其发育历期、蛹重、蛹羽化出成虫比率均有显著差异 ,取食芋头、水蕹菜、青菜、甘蓝、豇豆和莲藕等作物叶片的幼虫发育历期较短 ,蛹较重 ,蛹羽化率较高 ,而取食棉花、大豆和向日葵叶片的幼虫历期相对较长 ,蛹较小 ,蛹羽化率相对较低。  相似文献   
7.
A study was conducted in corn-peanut and sweet potato-peanut fields on the flying behavior of the white grub parasitoid Tiphia popitliavora Rohwer wasps. Observation on the first three times of flying,after the wasps being released, revealed that the first flying was an escape style and not showed preference to land on any special crops. 81.82 % wasps landed on corn leaves at the second flying but stayed for just about 3min. In the sweet potato-peanut field, 51.43 % wasps landed on sweet potato in contrast with 48.57 % landed on peanuts and in the afternoon 33.53 % on sweet potato compared with 76.4 % landed on peanut field. Majority preferred landing on peanut field on the third flying in both type fields of inter-cropping. Behavior of flying was different between morning and afternoon. The time length between two flies showed that wasps were more active in the morning than in the afternoon.  相似文献   
8.
Classifying and ranking the huge amounts of landscape planning works of urban wetland park is always difficult due to the multi-functions (ecological, leisure, educational and disaster prevention) of t...  相似文献   
9.

Now that group housing is replacing individual crates, so that calves can lie, stand and walk on the pen floor, the quality of the floor for group-housed calves has become the focus of attention. The reaction of two groups of four calves to a double area of floor made from two materials (wooden slats and synthetic slats with a rubber coating) was examined round the clock for 5 days. The calves were switched between pens twice, and in each case the 5 day observation period was repeated. In all three phases all calves spent significantly more time ( P <0.01) lying on the wooden floor: on average 656 min day -1 compared with 294 min day -1 on the synthetic floor. The time spent in the standing/walking position on both floors, occurrence of slip incidents and self-maintenance behaviour did not differ significantly between floors. The observations on use of the pen floor for lying and for standing/walking in combination with feeding, plus observations on fouling of the floors with excreta suggest that future pen design could be functionally divided into lying and walking/eating areas.  相似文献   
10.
Seventy-three villages randomly selected in 29 ethnic areas and three regions or agro-ecological zones of Benin were investigated by a participatory rural appraisal survey to assess the diversity of the species used as traditional leafy vegetables (TLVs). In total, 187 plant species belonging to 141 genera and 52 families were recorded. Among these, 47 (25.13%) were cultivated and 140 (74.87%) were gathered from the wild. Herbs (64.78%) were the most numerous followed by shrubs (19.78%) and trees (15.50%). The Shannon–Weaver diversity index calculated was 3.232. The total number of TLVs used highly varies, across ethnic groups, from 15 (Toli tribe) to 58 (people Mahi) with, on average, 36 species per ethnic group. The relative proportions of the wild and cultivated species used also vary with the tribes but on average appeared almost the same. Of the species inventoried, 18 of national importance were found among which Solanum macrocarpon, Corchorus olitorius, Amaranthus cruentus and Gymnanthemum amygdalinum ranked first. The matrix scoring technique yielded 12 criteria of different natures used to define preference. Among these, four (taste, ease of preparation, availability and quantity of required condiments) were the most important and represent, all together, more than 72% of responses. Despite the diversity of species used as leafy vegetables, they were all basically consumed in the same way. Sauces were the main type of preparation and involved all the species. The perceived nutritional and medicinal (curative, regulative and stimulative) properties of the species as well as their cultural significance were documented. Some TLVs are known and consumed by all or many ethnic groups while many others were simply ethnospecific or used by only a few peoples. However, no correlation was found between the distribution of the utilisation of the species and their degree of consumption which all depend on the eating habits of the peoples. Cluster analysis revealed that peoples sharing a common geographical space and/or cultural identity or origin seem to consume almost the same types of TLVs and cluster together. Given the large quantity of evidence of the importance of the TLVs, there should be a systematic effort to improve their understanding and their uses to reduce if not alleviate rural poverty and malnutrition in Benin.  相似文献   
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