根据1992—1994 年的田间实际观测资料，提出用Logistic方程求算小麦累积光合量的方法，它不但具有明确的生物学意义和生态学意义，而且计算极其简便，结果较为精确，不失为一种简单、实用又准确的计算小麦累积光合量的好方法。

Currently available models of photosynthate partitioning in crops are poorly developed compared to carbon and water balance models. This paper presents a dynamic photosynthate partitioning model (PPModel) that simulates the partitioning of crop biomass to leaf, stem and root through the interaction between carbon gain (assimilation less respiration) and transpiration, in relation to environmental factors. The central concept is the theory of plant functional equilibrium, in which transpirational loss and water uptake are balanced, within acceptable limits, by a dynamic partitioning of assimilates between shoot and root growth. The model was shown to perform effectively against experimental data for growth and partitioning of biomass in winter wheat (collected over a 2-year period), when environmental factors varied daily and water supply was controlled over a wide range.

The stratospheric ozone depletion and enhanced solar ultraviolet-B (UV-B) irradiance may have adverse impacts on the productivity of agricultural crops. The effect of UV-B enhancements on agricultural crops includes reduction in yield, alteration in species competition, decrease in photosynthetic activity, susceptibility to disease, and changes in structure and pigmentation. Many studies have examined the influence of supplemental UV-B irradiance on different crops, but the effect of UV-B irradiance on cotton (Gossypium hirsutum L.) crops has received little attention. Cotton is one of the most versatile of all the crops. It is a major fiber crop of the world and a major source of trade and economy in many countries. In this study, we provide quantitative examination of the effects of elevated UV-B irradiance on cotton plant (Sukang 103). The tested cotton crop was grown under natural and four regimes of supplemental UV-B irradiance in the field. With UV-B irradiance increased 9.5% throughout the growing season, the negative impacts on cotton growth included reductions in height of 14%, in leaf area of 29%, and in total biomass of 34%. Fiber quality was reduced and economic yield dropped 72%; an economic coefficient was reduced 58%. A brief discussion is included on how the impacts on cotton contrast with impacts that have been observed in other studies on other plants, including trees.

This paper describes the development ofChina's power industry, present situation, environmental influences and potential benefits of regional power grid interconnections in China. Power plants in China are mainly thermal, burning fossil fuels especially coal which emit a great deal ofpollutants and greenhouse gases such as SO2, NOx and CO2. China leads all other countries in emissions of SO2, CO2, and the power industry is the largest contributor to these emissions. There are a number ofenvironmental benefits through regional power grid interconnection. That is, the construction ofsmall electricity generation capacity would be avoided; natural resources would be used to generate electricity on a regional scale; and generating sources can be separated from centers ofelectricity use, which will decrease emission of pollutants and greenhouse gases and help to reduce human exposure to elevated air pollutant concentrations. Therefore, gradually enlarged power grids, and power grid interconnection, should be part of the general pattern ofpower system development in China.

Stratospheric ozone depletion has caused an increase in the amount of ultraviolet-B (UV-B) radiation reaching the earth's surface. Numerous investigations have demonstrated that the effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species competition, susceptibility to disease and changes in plant structure and pigmentation. Many experiments examining UV-B radiation effects on plants have been conducted in growth chambers or greenhouses. It has been questioned whether the effect of UV-B radiation on plants can be extrapolated to field responses from indoor studies because of the unnaturally high ratios of UV-Bultraviolet-A radiation (320-400nm) and UV-Bphotosynthetically active radiation (PAR) in many indoor studies. Field studies on UV-B radiation effect on plants have been recommended to use the UV and PAR irradiance provided by natural light. This study reports the growth and yield responses of a maize crop exposed to enhanced UV-B radiation and the UV-B effects on maize seed qualities under field conditions. Enhanced UV-B radiation caused a significant reduction in the dry matter accumulation and the maize yield in turn was affected. With increased UV-B radiation the flavonoid accumulation in maize leaves increased and the contents of chlorophyll a, b and (a+b) of maize leaves were reduced. The levels of protein, sugar and starch of maize seed decreased with enhanced UV-B radiation, whereas the level of lysine increased with enhanced UV-B radiation.