Chemical characteristics of cloudwater over Maoer Mountain district

Samples of cloudwater, rainwater and ambient aerosol were collected over Maoer Mountain in the northeast of Guangxi Province in March 1988. The pH value of cloudwater ranged from 3.37 to 6.20 with a mean value of 4.34. SO42- , NO3- , NH4+, Ca2+ and H+ were the principal ionic species of cloudwater. The advance of cold fronts into Maoer Mountain appeared to lead to higher major ionic concentration and acidity than that of warm fronts. The relative acidity and concentration of NO3- of cloudwater were much greater than that of aerosol samples. With the exception of. NO3- and H+, most of the concentration of SO42- and NH4+ in cloudwater came from the nucleation scavenging of aerosol. Gaseous nitric acid and organic acid from local may be one of the important source of cloudwater acidity. Compared with other sites, Maoer Mountain can be as a clean contrast station for studying acidic precipitation in Guangdong and Guangxi provinces.     

Effect of domestic sewage on growth of phytoplankton-mathematical model

A mathematical model relating to the change in phytoplankton biomass in the period of growth and nutrient concentration in the media was proposed on the basis of the Monod equation and was testified by simulation experiments. Analysis of the experiment data showed that: the half-saturation constants for growth Kp (μmol/L) for Skeletonema, Chaetoceros and Prorocentrum were 5.52, 1.90 and 0.46, respectively; the balance between stimulation of nutrients and the inhibition of some other materials was found in the effect of domestic sewage on algal growth and the stimulation played a leading role; domestic sewage was more stimulative on dinoflag-ellate than on diatom and chlorophyte when the assemblage of the algae was cultured. The experiment suggested that mathematical model reasonably explained the characteristics of phytoplankton growth in different nutrient conditions and was worthy to be further improved for eutrophication prediction in off-shore water.     

A study on Se application for improving the soil in the environment at lower Se level

A result that application of sodium selenite or fly ash to some of soilin loess plateau can increase Se content in wheat grain has been demonstrated by the pot and field experiments, and added Se in soil can last its availability for 3 years. So this is a good measure for improving the low Se soils and preventing the Kaschin-Beck disease.     

An evaluation of quality assurance to monitor acidprecipitation by using ion balancein Guizhou, China

ＡｎｅｖａｌｕａｔｉｏｎｏｆｑｕａｌｉｔｙａｓｓｕｒａｎｃｅｔｏｍｏｎｉｔｏｒａｃｉｄｐｒｅｃｉｐｉｔａｔｉｏｎｂｙｕｓｉｎｇｉｏｎｂａｌａｎｃｅｉｎＧｕｉｚｈｏｕ，ＣｈｉｎａＫａｎｇＤｅｍｅｎｇ（ＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏ－Ｅｎｖｉｒ...     

Seasonal changes of endogenous ABA and cytokininsin environmental adaptation of differentecotypes of reed plants

ＳｅａｓｏｎａｌｃｈａｎｇｅｓｏｆｅｎｄｏｇｅｎｏｕｓＡＢＡａｎｄｃｙｔｏｋｉｎｉｎｓｉｎｅｎｖｉｒｏｎｍｅｎｔａｌａｄａｐｔａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｅｃｏｔｙｐｅｓｏｆｒｅｅｄｐｌａｎｔｓＷａｎｇＨｏｎｇｌｉａｎｇ，ＺｈａｎｇＣｈｅｎｇｌｉ...     

Kinetic-spectrophotometric determination of free cyanide by stopped-flow reversed flow injection analysis

A stopped-flow reversed flow injection method for the determination of free cyanide is proposed. Pyridine-barbituric acid mixture is injected in the flow system as reagent to form the colour species with cyanide. The flow is stopped when the reagent zone comes in the flow cell, where absorbance-time data are collected at 580nm wavelength. The linear range of the determination is 0.1 -10μg/ml CN-. The sampling rate is 60h-1 and the relative standard deviation is 1.6% (n=16) at 5.0 μg/ml CN-1 level. With satisfactory results, the proposed method was applied to the determination of free cyanide in wastewater without sample pretreatment.     

The epidemic characteristics of Kaschin-Beck disease (KBD) in different eco-environments

Epidemiological survey of 573 families, clinical examination of 2593 persons, and X-ray examination of 1136 persons (in 16 typical endemic villages) were conducted, based on the classification of endemiology for KBD disease areas, i.e, mountain type, loess plateau type, plateau type, and flatlands type. It was revealed that the KBD disease areas exhibited the regular pattern of corming-into-being, development and passing-away and the characteristics of growth and decline. Further, it was found clinically that the disease areas may be divided into 4 types, i.e., recent onset, developing, stable, and historical. This division is simple and easy, practical, scientific, and reliable and can be applied by medical personnel at different levels.     

Analysis on reasons for the Yellow River''s dry-up and its  eco-environmental impacts

The Yellow River, or Huanghe, is one of the most important river in China. It is the major water resources for north and northwest China. Since 1972, the Yellow River's dry-up has occurred frequently and become even more year by year. Except the huge loss to social life and economic development, the Yellow River's dry-up brings about great impacts to eco-environment. This paper analyzed the reasons and impacts from multi-aspect: effects of climate change, influence of human activities and impacts to delta's eco-environment, aquatic life resources, agricultural eco- environment, water pollution and flood prevention as well.     

Protozoa of Lough Neagh,Northern Ireland,UK

ＰｒｏｔｏｚｏａｏｆＬｏｕｇｈＮｅａｇｈ，ＮｏｒｔｈｅｒｎＩｒｅｌａｎｄ，ＵＫ￥ＸｕＭｕｑｉ（ＩｎｓｔｉｔｕｔｅｏｆＺｏｏｌｏｇｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００８０，Ｃｈｉｎａ）ＢｒｉａｎＷｏｏｄ（Ｆｒｅｓ...     

Ecological-breaking zone originates and its ecosystems reconstruction in arid area

Ｅｃｏｌｏｇｉｃａｌ－ｂｒｅａｋｉｎｇｚｏｎｅｏｒｉｇｉｎａｔｅｓａｎｄｉｔｓｅｃｏｓｙｓｔｅｍｓｒｅｃｏｎｓｔｒｕｃｔｉｏｎｉｎａｒｉｄａｒｅａ￥ＨｕａｎｇＰｅｉｙｏｕ；ＬｕＺｉｌｉ（ＢｉｏｌｏｇｙＤｅｐａｒｔｍｅｎｔｏｆＸｉｎｊｉａｎｇＵｎｉｖｅ...