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131.
2007年从云南省甘科所引进云引1号、3号、10号等几个甘蔗新品种,经过3年的观察、试验、示范表明:云引3号比较适宜保山市蔗区种植。该品种出苗快而整齐,出苗、分蘖率高,成茎率高。属中熟高产高糖、抗性强的品种,具有较好的推广应用价值。  相似文献   
132.
Background, aim, and scope  Sewage sludge use in agriculture should be limited by the presence of metals and other persistent environmental pollutants. The present study aims to contribute for the definition of a test battery of ecotoxicological assays that allows a proper ecotoxicological characterization of sludges, providing information on their potential hazard and identified “safe” application levels. Materials and methods  Three sludges from distinct sources (urban, olive-processing, and electroplating industries) were tested using avoidance and reproduction tests with earthworms (Eisenia andrei) and springtails (Folsomia candida) and plant growth tests with turnips (Brassica rapa) and oats (Avena sativa). Different soil–sludge mixture concentrations mimicking recommended/realistic field dosages were tested. Results  Only the sludge from the electroplating industry induced an avoidance response from the earthworms (EC50 = 0.4 t/ha) and collembolans (no observed effect concentration (NOEC) = 15 t/ha). This sludge was the only sludge responsible for any effect on the reproductive output of the earthworms (EC50 = 7.74 t/ha). Regarding collembolans, none of the sludges tested caused any significant decrease in reproduction. In higher plant tests, the two industrial sludges were toxic, causing a decrease growth in both species. The EC20 values determined for B. rapa were 20.3 and 24.2 t/ha and for A. sativa 14.7 and 16.2 t/ha for sludges from olive-processing and electroplating industries, respectively. Discussion  The metal loadings of the different test sludges could partially explain the results obtained. The toxicity of the test sludge from electroplating industry observed on the tested invertebrates and plants could be explained by the high amount of total chromium from which 22.3% was in the most toxic oxidation state—Cr(VI). However, the toxicity caused by the sludge from the olive-processing industry in the test plants could be attributed to the presence of other compounds (not measured in this study) since the metal content was not high enough to induce such an effect. The absence of toxicity showed by the urban test sludge was in agreement with its low levels of metals. Conclusions  The response of the different test organisms and end points varied according to the sludge type. The urban sludge was non-toxic whereas the sludge from the electroplating industry caused a toxic effect on almost all parameters measured (avoidance behavior of both test organisms, reproduction of earthworms, and growth of both plant species). Sludge from the olive-processing industry only caused a toxic effect on growth of both plant species. By analyzing the sensitivity of the different parameters for the most toxic sludge, it was found that avoidance and reproduction were more sensitive than plant growth, whereas plant seed germination was not sensitive at all. Recommendations and perspectives  The ecotoxicological evaluation of wastes can be used as an environmental safety control of sludge use in agriculture. A tiered approach could be adopted for this purpose, incorporating avoidance tests in the first tier (screening level) and reproduction and plant growth tests in a second tier. But more evidence aiming to define the most suitable ecotoxicological test battery for specific sludges with a different contamination profile is still needed.  相似文献   
133.
Abstract

This study was carried out to determine if ammonium bicarbonate‐DTPA soil test (AB‐DTPA) of Soltanpour and Schwab for simultaneous extraction of P, K, Zn, Fe, Cu and Mn can be used to determine the availability index for Se. Five Mollisols from North Dakota were treated with sodium selenate and were subjected to several wetting and drying cycles. These soils were extracted with hot water and with ammonium bicarbonate‐DTPA (AB‐DTPA) solution for Se analysis. Alfalfa plants were grown in these soils in a growth chamber to determine plant uptake of Se. In addition to the above experiment, coal mine soil and overburden materials from Western Colorado were extracted and analyzed as mentioned above.

It was found that hot water and AB‐DTPA extracted approximately equal amounts of Se from Mollisols. A high degree of correlation (r =0.96) was found between Se uptake by plants and AB‐DTPA extractable Se. Extractable level of Se in treated soils was decreased with time due to change of selenate to less soluble Se forms and plant uptake of Se. An AB‐DTPA extractable Se level of over 100 ppb produced alfalfa plants containing 5 ppm or higher levels of Se that can be considered toxic to animals. Soils with about 2000 ppb of extractable Se were highly toxic to alfalfa plants and resulted in plant concentrations of over 1000 ppm of Se. The high rate of selenate (4ppm Se) was less toxic to alfalfa plants in soils of high organic matter content. This lower toxicity was accompanied with lower extractable levels of Se.

The AB‐DTPA solution extracted on the average about 31% more Se than hot water from the mine and overburden samples and was highly correlated with the latter (r =0.92). The results indicated the presence of bicarbonate‐exchangeable Se in these materials.  相似文献   
134.
将等效负荷直接加到提升臂上,完成拖拉机在线提升试验。减少试验人员,提高试验效率,增加安全性。  相似文献   
135.
2002年进行了并番6号对番茄早疫病、病毒病的抗性比较试验,结果表明,并番6号对番茄早疫病、病毒病都有较高抗性,尤其对早疫病的抗性更为突出。  相似文献   
136.
田间小麦施用专用肥,小麦从经济性状、产量上都表现出一定的优越性,穗粒重增加0.1~1.9g,千粒重增加1.6~3.3g,不孕小穗减少0.2—1.6个。从产量和经济效益上看小麦专用肥施用量为750kg-hm^2。较为适宜。  相似文献   
137.
为筛选出优质的烤烟品种在生产上推广应用,解决黑龙江烟区品种单一的问题,以 NC89为对照,对7个新引进的美国和巴西品种进行了田间比较试验。结果表明:(1) PVH2310成熟早,抗病性强,综合经济性状、原烟外观质量最好,产量、产值、均价、上等烟比例最高,与对照品种 NC89相比,烟叶产量提高5.41%,产值提高25.08%,均价提高24.16%,上等烟比例提高13.25个百分点,是一个产量、品质、抗性、适应性等重要性状间较为谐调兼顾的优良品种。(2)NC-YATAS-2综合经济性状和外观质量与对照 NC89相当。  相似文献   
138.
不同行向麦棉套种初步研究   总被引:5,自引:0,他引:5  
郑国喜 《江西棉花》2007,29(4):10-13
麦套棉花的田间小气候影响着棉花的生长发育.本文通过东西行向与南北行向麦套棉的田间小气候对比试验,得出结论,东西套种行向有利于改善近地面的光照条件,提高温度等,有利于棉花生长发育和产量的提高.  相似文献   
139.
油莎豆属莎草科莎草属的一年生块茎草本植物,根系发达,收获难度大,直接收获易造成籽粒破碎,作业质量较难保证。本文研究设计一种油莎豆收获机,主要由机架、输送分离装置、脱粒分离装置、清选装置等部件组成,采用多重清选功能使该机具有良好的流动性和分离性,可实现油莎豆机械化收获过程中籽粒与杂质土、根茎的高效分离清选。本文以籽粒损失率和含杂率为评价指标,通过设置各部分不同转速,进行3因素3水平正交试验,最终确定油莎豆收获机的最佳参数组合,为各关键部件设计、改进及参数选择提供依据。  相似文献   
140.
试纸法作为一种简便、快速的现场定性半定量检测方法,在许多领域具备广泛的应用前景.就近几年试纸法在食品和水质快速检测方面的研究与应用进行概述,以利于这一方法的进一步研究与推广应用.  相似文献   
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