[en] With the trend of professional operation on the nuclear power engineering (thereafter using NPE for short) construction, the companies specialized on NPE whole-contracting are established one after the other, the mode of NPE whole-contracting has been wide adopted domestically. As people always concern for the safety of nuclear power, the risks exposed to NPE contractors are also concerned with the operator, the NPE corporations and the society. Therefore, it is very meaningful to analyze on the risks exposed to NPE contractors and the strategies they should take, for it not only determines whether the NPE construction will be finished on time, but also related to sustainable development of the NPE contracting corporations. The main content of this paper includes the analysis on the features and advantages of NPE whole contracting, the major NPE contracting risks, such as nuclear safety risks, strategic risks, market risks, legal risks, financial risks and operation risks, and the strategies to prevent or to control these risks. The paper focuses on identifying those business processes which risks may frequently take place, and how to manage them, illustrating practice cases to explain the theory, in order to make reference to NPE corporations. (author)

[en] A pot experiment was conducted to investigate the effects of ¹⁵N-urea and 4 kinds of plant materials (P₁, P₂, P₃ and P₄) as urease inhibitor on sorghum and rice nutrition and soil characters. The results indicated that the growth, above-ground parts and roots weight of rice and sorghum were respectively promoted by 4 plant urease inhibitors and P₁ with little change of chl.a/chl.b ratios in these treatments. The content of amino acid in rice leaf and utilization rate of nitrogen by rice were enhanced by 12.9%-25.1% and 5.2%-7.7% respectively, and the utilization rate of nitrogen by sorghum was improved by urease inhibitor treatments (except P₁). Plant urease inhibitor could obviously increase the apparent utilization rate of nitrogen by 4.3%-19.2% for two crops and improve phosphorus and potassium uptake by rice plant but decrease phosphorus and potassium uptake by sorghum plant. The contents of soil alkali-hydrolyzable nitrogen were increased by plant urease inhibitor under two cultivated condition. The inhibition time of plant urease inhibitor to soil urease was short and it disappeared as 36 days of rice growth under flooded condition, while the activities of soil urease were decreased by 10.6%-18.3% at 48 days of sorghum growth in upland soil