有机磷农药混合标准溶液配制不确定度评价（英文）

标准溶液的不确定度对农药残留检测起着非常重要的作用,影响着检测结果的准确性。笔者以实际应用的14种有机磷农药混合标准溶液为例,采用配制混合标准溶液过程单元操作的不确定度计算方法(top down),分析了在配制混合标准溶液过程中的所有影响因素,得到了最终的扩展不确定度。最终结果显示使用精准的移液器将储备液配置为混合标液,得到最终的扩展不确定度相对小。     

Tomato productivity and the associated composition of the hydroponic or soil solution

The concentration and balance of nutrients in both the hydroponic or soil solution has been evaluated with relevance to tomato productivity. Yields of 200 mt/ha have been produced in greenhouse, hydroponic culture in a 9 to 10 month period. Yields of more than 100 mt/ha of field grown tomatoes have been produced in Florida in a 4 to 5 month period. Within the limitations of either culture, it is possible per unit of time to provide the nutrients required to produce equivalent yields. It is most significant that field grown tomatoes in Florida can be grown with minimal management and at a fraction of the cost of those grown hydroponically. The validity of the Florida fresh market tomato industry is based on the production efficiency of the field culture. There are annually 16,000 ha of tomatoes grown in Florida, perhaps less than 40 ha grown in hydroponic cultures.     

非算子型泛函微分方程概周期解的稳定性

利用指数型二分性理论及相关分析技巧，研究了一类具有有限时滞的非算子型的中立型泛函微分方程的概周期解问题，得到了方程存在唯一稳定的概周期解的新结果．     

向日葵栽培中存在的植保问题及解决对策

近几年,随着向日葵面积的不断扩大,在生产中普遍存在连作重茬造成耕层土壤环境破坏、产出力下降、除草剂残留药害以及病虫草害发生严重等几个突出问题,对向日葵的产量和品质造成较大的影响。根据多年的研究及实践经验特对向日葵选茬及病虫草害防治等相关问题提出相应的解决对策,以便为向日葵生产提供理论依据和实用技术指导。     

具时滞能源价格模型的动力学性质

以滞量τ为分支参数,研究了具时滞的能源价格模型的动力学行为,这些行为包括：系统在平衡点附近的稳定性，局部Hopf分支的存在性，发生条件Hopf分支的方向，分支周期解的稳定性以及分支随参数变化其周期解的周期变化.最后通过数值模拟验证了理论分析结果，并用分支理论解释了能源价格模型产生且维持周期振荡的原因.     

Calcium nutrition of the sugarbeet

Abstract

When sugarbeet seedlings are transferred from a complete nutrient solution to one from which Ca has been withheld, the rootlets and tops fail to develop. The same transfer at the eight‐leaf stage causes the rootlets to become stubby and swollen at the tips and blade expansion becomes modified; particularly the upper portions of the blades attaining nearly full development, which pucker and often develop a cupping or hooding effect; a unique symptom characteristic of Ca deficiency. As each new leaf develops, the blade area becomes smaller until only a black tip remains at the apex of the petiole, which is the symptom referred to as tip‐burn for this petiole and the successively . shorter petioles formed as Ca deficiency increases in severity. Strangely, these symptoms also appear during periods of rapid growth when the nutrient solution contains as much as 10 to 28 milliequivalents per liter of Ca or when soils are high in Ca. This implies that Ca absorption and possibly translocation limits the Ca supply at the growing point. Increasing Mg in the nutrient solution decreases Ca uptake and increases Ca deficiency. Potassium deficiency, unexpectedly, induces Ca deficiency apparently by decreasing the translocation of Ca to the growing point.

These phenomena suggest the hypothesis that when ion absorption takes place from the root exchange site that has the affinity for H > Ca > Mg > K > Na, then the H generated internally replaces, and the roots absorb, Na, K and Mg preferentially. Externally, Ca would be adsorbed preferentially from the nutrient solution by the exchange complex, and with the addition of Mg, it would compete for the common adsorption site of Ca and limit Ca absorption internally. Under these conditions potassium‐deficient nutrient solutions would not induce Ca deficiency by decreasing Ca absorption but rather by decreasing Ca translocation. Theoretically, Ba would replace H more readily than Ca on the exchange complex, and therefore, Ba would be adsorbed preferentially and Ca uptake would increase. This effect of Ba was verified experimentally.

Since the translocation of ⁴⁵Ca to the growing point was found to be unrestricted under Ca‐sufficient and Ca‐deficient conditions and since the formation of insoluble Ca compounds such as phosphate or oxalate did not account for the Ca deficiency at the growing point, the cause of the Ca deficiency at the growing point is most likely the higher priority of the storage root for Ca over tops when leaf blades and storage root are both expanding rapidly. However, Ca retransport from older to younger parts of the sugarbeet plant may be restricted by the formation of Ca phosphate under Ca‐deficient conditions and Ca oxalate under Ca‐sufficient conditions.

Calcium deficiency increases net photosynthesis per unit blade area initially, probably because of blade puckering, but not on a per unit chlorophyll basis.     

东阳义乌水权交易的第三方效应及对策研究

运用系统分析方法、比较分析方法和典型案例法,结合东阳义乌地区水权交易的经典案例,着重阐释了水权交易过程中产生的第三方正效应和第三方负效应,提出对水权交易第三方正效应进行多样化补偿和对第三方负效应采取预防、保障、补偿三结合的治理措施,以解决水权交易过程中的公平和效率问题。     

电气工程及其自动化专业生产实习模式研究

从生产实习的现状入手,以石河子大学电气工程及其自动化专业为例,分析了生产实习的重要性,并就存在的问题提出了解决方案。     

公共图书馆员职业倦怠的成因及对策探析——以广州图书馆为例

公共图书馆员职业倦怠是中国图书馆行业中普遍存在的问题,分析图书馆员职业倦怠的成因,以广州图书馆为例,探析解决公共图书馆员职业倦怠的对策。     

西部欠发达地区农村图书馆建设对策研究

面对建设社会主义新农村的重大历史任务，本文通过对西部欠发达地区农村图书馆建设现状及发展滞后的原因分析．提出了适合西部农村图书馆发展的对策和建议。