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101.
为了给高产栽培提供试验依据,以不同旱作类型的春小麦高产(≥350kg/667m~2,呼盟;≥200kg/667m~2,赤峰)为目标,通过四因素最优组合设计试验,以对春小麦生育影响较大的基本苗数、施磷量、施钾量、施氮量四项主要农艺栽培措施为决策变量,以产量为目标函数,建立了内蒙古不同旱作区春小麦主要农艺栽培措施与产量关系的二次多项式回归数学模型,通过频数寻优,定量化提出了不同旱作地区春小麦实现高产的综合农艺栽培措施优化方案。即施磷量、施钾量、施氮量和基本苗在呼盟地区分别为4.02~4.70 kg P_2O_5/667m~2、3.26~4.39 kg K_2O/667m~2、3.66~4.80 kg N/667m~2和45.3×10~4~47.8×10~4株/667m~2;赤峰地区则分别为5.13~5.74 kg P_2O_5/667m~2、3.50~4.02 kg K_2O/667m~2、7.49~8.86 kg N/667m~2和3.06×10~4~32.2×10~4株/667m~2。  相似文献   
102.
Providing food, energy and materials for the rising global population is a challenge which is compounded by increased pressure on natural resources such as land, water and fossil sources of raw materials. Greenhouse gas (GHG) emissions from human activities have increased with industrial development and population expansion, and it is anticipated that resulting climate change might further limit agricultural productivity, through changes to weather patterns and global availability/distribution of agriculturally productive land. Growing crops as feedstocks for industrial uses is seen as one way of reducing GHG emissions and dependency on fossil resources. However, determining the extent to which the development of crops for industrial use will effect GHG balances and provide for a more energy efficient manufacturing system requires the development and use of appropriate calculation methodologies.Research at the Porter Institute has identified over 250 different scenarios for bioenergy production systems using commodity crops. In order to rationalise this complexity and diversity, a modular approach to Life Cycle Assessment (LCA) and sustainability analysis has been taken. This allows characterisation of discrete sections of supply chains and enables comparisons to be made between different crop production systems, different process systems and different end product uses. The purposes of this paper are to introduce the concepts of biofuel GHG and sustainability metrics, to introduce the approach taken by our organization and to use the example of UK grown willow in a lignocellulosic ethanol production system to demonstrate how GHG emission outcomes can be reviewed for “new” crops and technologies.The results show a range of variation, in both growing and process systems and how outcomes such as energy and GHG balances can be affected by various activities.LCA methodologies provide data to inform governments and industry of the potential specific supply chains may have for energy and GHG saving. However, methodological approaches can also affect assessment outcomes. Unresolved issues in LCA methodology must also be evaluated e.g. impacts resulting from land use change. Sustainability assessments of crop growing systems, irrespective of the end use, also assist in the assessment of environmental impacts of supply chains. However, it is critical that data continue to be collected, analysed and reviewed, to ensure that the most appropriate crops are grown and processed for the most appropriate end use.  相似文献   
103.
高新技术在茶叶深加工生产中的应用分析   总被引:1,自引:1,他引:0  
阳秋华 《茶叶通讯》2005,32(1):21-23
本文从茶叶深加工的提取、外源酶、分离、浓缩、杀菌等方面,就可探索应用的主要高新技术进行了介绍分析。  相似文献   
104.
优质晚稻平衡施肥数学模型研究   总被引:5,自引:1,他引:4  
应用联合国粮农组织 (FAO)提出的氮、磷、钾 3因素 4水平 14个处理的田间试验设计 (即 3 414设计 ) ,研究了氮、磷、钾肥用量和配比对优质晚稻产量的影响 ,并获得了相应的数学模型。通过对模型的优化和解析 ,得出了优质晚稻获得最佳产量时的肥料用量是 :N 2 0 2 .5kg/hm2 ,P2 O50 .0kg/hm2 ,K2 O 3 0 3 .0kg/hm2 ,此时稻谷的产量为 5 491.5kg/hm2 。  相似文献   
105.
Temporary cardiac pacing is used in the emergency treatment of life-threatening bradyarrhythmias and for the support of heart rate and blood pressure of patients with sick sinus syndrome or high-grade atrioventricular (AV) block undergoing general anesthesia, typically for permanent pacemaker implantation. We retrospectively evaluated the safety and efficacy of a noninvasive transthoracic external cardiac pacing system in 42 dogs treated for bradyarrhythmias. Optimal placement of the patch electrodes on the skin of the thorax was initially established on 2 anesthetized normal dogs. The optimal electrode placement was determined to be on the right and left hemithoraces, directly over the heart. Afterward, by means of this electrode placement all 42 dogs treated for bradyarrhythmias in this study were successfully paced with the noninvasive transthoracic system. Dogs ranged in age from 1 to 15 years and weighed between 3.2 and 40 kg. Miniature Schnauzers, German Shepherds, and mixed breeds were most common in the study population. Indications for noninvasive transthoracic pacing included emergency treatment of hemodynamically unstable 3rd-degree AV block (2 dogs): support of heart rate during general anesthesia for permanent pacemaker implantation or lead-wire adjustment (38 dogs): and support of heart rate during general anesthesia for ophthalmologic surgery in dogs with sick sinus syndrome (2 dogs). Complications included pain and skeletal muscle stimulation, which required general anesthesia. We conclude that the noninvasive transthoracic pacing system evaluated is satisfactory for clinical veterinary use.  相似文献   
106.
播期和密度对茎瘤芥主要经济性状的影响   总被引:3,自引:0,他引:3  
为给茎瘤芥的标准化栽培技术提供依据,研究了播期和密度对茎瘤芥主要经济性状的影响。结果表明:(1)播期和密度对茎瘤芥瘤茎主要经济性状的综合效应明显。(2)播期对瘤茎的小区产量、横径有显著的正效应,对瘤茎的纵径、菜形指数有显著的负效应,对单株瘤茎产量有不明显负效应;密度对单株瘤茎重有显著的负效应,对瘤茎纵径有显著的正效应;对瘤茎小区产量、横径有不明显的负效应,对菜形指数有不明显的正效应。(3)播期和密度的交互作用显著地影响瘤茎的小区产量、单株瘤茎重、瘤茎纵径,对横径和菜形指数影响也明显。据此,建立了相应的数学模型。  相似文献   
107.
AIM: To investigate the effect of advanced oxidation protein product-human serum albumin (AOPP-HSA) at different concentrations on the permeability of human umbilical vein endothelial cell (HUVEC) monolayer and the protective effect of NADPH oxidase inhibitor diphenyleneiodonium (DPI) against AOPP-HSA exposure. METHODS: Cultured HUVECs were exposed to 200 mg/L HSA (control) or AOPP-HSA (50, 100 and 200 mg/L). The permeability of the endothelial monolayer was assessed by measuring CMFDA-labeled THP-1 cells across the endothelial cells. The cultured HUVECs were treated with HSA (200 mg/L), AOPP-HSA (200 mg/L), or AOPP-HSA (200 mg/L) + DPI (100 μmol/L), and the activation of NADPH oxidase, endothelial monolayer permeability and cytoskeleton rearrangement were evaluated. RESULTS: AOPP-HSA increased the permeability of the endothelial cell monolayer, and AOPP-HSA at 200 mg/L significantly increased the phosphorylation level of NADPH oxidase in the cells. Treatment with 100 μmol/L DPI obviously attenuated AOPP-HSA-induced NADPH oxidase activation, the increase in the permeability of the cell monolayer and the cytoskeleton rearrangement. CONCLUSION: AOPP-HSA increases the hyperpermeability of HUVEC monolayer via the phosphorylation of NADPH oxidase, and the NADPH oxidase inhibitor DPI reverses such effects.  相似文献   
108.
汽车智能前照灯系统可以根据转向盘转角等各种车载传感器,判断驾驶员的操纵意图,并直接控制前照灯的转动、补偿角度及光照类型,为驾驶员提供了更为有效的照射区域。从前照灯灯光分布特性出发,结合现有的智能前照灯发展现状,介绍了目前国际主流的基于汽车行驶状态信息和基于道路几何信息的智能前照灯控制策略。  相似文献   
109.
郑单958的穴播效应研究   总被引:1,自引:1,他引:0  
比较了郑单958不同穴播密度条件下的生长特性、群体结构、光合指标以及产量变化。结果表明:增加穴播密度抑制了植株个体发育,使株高降低、茎粗变小、单株叶面积减少,群体结构变差,气孔导度、光合速率和蒸腾速率等指标也有所降低。在穴播密度增幅小于30%的范围内,这种负面作用效果基本不显著;当穴播密度达到12万株/hm2时,穴播群体的生长指标、群体结构及光合指标显著降低。郑单958的单位面积产量随密度增加先增后减,当穴播密度为10万株/hm2时,鲜物质产量最高,为69.61 t/hm2。  相似文献   
110.
Harvesting wheat (Triticium aestivum L.) for forage or leaving it for grain is the main decision uncertainty growers face in semi-arid regions during mid-season. To facilitate decision-making, a decision support system (DSS) has recently been proposed that requires information about crop water and nutritional status during spike emergence. Though remote sensing has been used to provide site-specific crop status information, a spectral vegetation index is needed to ensure that the information has been acquired during spike emergence. The objective of this study was to propose a spectral index sensitive to spike emergence and validate its suitability across different commercial farm fields by using ground spectral measurements and multispectral satellite imagery. To develop the index, controlled experiments with commonly grown wheat varieties were conducted during the 2004/2005 and 2005/2006 growing season in the agricultural area of the northern Negev desert of Israel. The experiments showed that spike emergence correlated most strongly (r = 0.7, p < 0.05) with spectral changes near the 1.2 μm water absorption feature in contrast to the band at 1.1 μm which appeared to be only weakly correlated. Thus, the spike emergence sensitive band at 1.2 μm has been combined with the insensitive band at 1.1 μm as reference to form the ratio-based normalized heading index (NHI). Experimental data were then used to establish an index threshold that helps separate data acquired before and after spike emergence. The proposed NHI was able to identify spike emergence with a classification accuracy varying between 53 and 83%. Accuracy was influenced by season, and whether narrow or broad spectral bands were used. Validation of the index in commercial farm fields in Israel and the United States showed that the classification accuracy was similar for ground spectral measurements and the advanced land imager (ALI) satellite imagery. These results suggest that the NHI is suited for identifying the onset of heading throughout wheat-growing areas without the need for characterizing seasonal trends.  相似文献   
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