The effect of dairy sewage sludge amendment on repellency and hydraulic conductivity of soil aggregates from two depths of Eutric Cambisol

Appropriate management of sewage sludge is an important worldwide issue due to the still growing amount of wastewaters. In the study we examined to what extent the addition of dairy sewage sludge compared with mineral fertilization affects porosity, repellency index, and hydraulic conductivity of variously sized aggregates from two soil depths of Eutric Cambisol derived from loess: 5–15 cm and 25–35 cm. The repellency index was calculated as a ratio of ethanol and water sorptivity. Data on water and ethanol sorptivities of initially air‐dry soil aggregate fractions were obtained from steady state flow measurements using an infiltration device. Hydraulic conductivity was determined by measuring water infiltration at five pressure heads: –8, –6, –4, –2, and 0 cm of water column with the same device as for sorptivity determination. Addition of sewage sludge to the soil decreased the soil repellency index by an average of 27% in topsoil and 32% in subsoil for both aggregate sizes, respectively, and increased hydraulic conductivity about four times in both layers. Smaller aggregates (15–20 mm diameter) from soil amended with sewage sludge, in comparison with larger ones (30–35 mm diameter), had a higher repellency index by 36 and 24% in topsoil and subsoil, respectively. As for aggregates from soil with mineral fertilization, those differences were smaller and equal to 15% in subsoil, in topsoil smaller aggregates even had slightly lower repellency index (by 5%). Aggregates taken from the upper soil layer were more water repellent and had smaller hydraulic conductivity than those taken from subsoil, regardless of soil treatment and aggregate size.     

9种园林植物的耐盐性比较

采用田间盆栽试验法,用衡水市区原土配制成含盐量分别为2.2g/kg、3.1g/kg、4.2g/kg、4.9g/kg、6.7g/kg、10.2g/kg的栽培土对9种供试植物进行了盐胁迫处理,测定了供试植物的存活率、相对生长量、叶绿素含量及相对含水量等指标,对9种植物的耐盐性进行研究。结果表明:在盐胁迫下,9种植物的存活率、相对生长量、叶绿素含量及相对含水量等指标均呈明显下降趋势,下降程度因种类而异。综合各指标的分析可知,9种植物的耐盐性差异较大,其耐盐性强弱的顺序为:白蜡国槐木槿栾树冬青卫茅紫叶李紫丁香金叶女贞楸树。     

Laboratory similar model test investigation of prestressed anchor rope strengthened slope fractured rock mass

Now in the highway construction of the mountain area, fractured rock mass slope always strengthened by the anchor rope. In order to investigate the strengthen effect of the slope fractured rock mass strengthened by the prestressed anchor rope, laboratory similar model test was designed and preceded. By the self-made facilities, a new method of modeling prestressed anchor rope was used in the test. Nylon ropes and the aluminum flakes were used to model the anchor rope and discrete rock mass joints. Gypsum based mix material was used to model rock. According to the real slope engineering site circumstances, six sorts of different disposed prestressed nylon rope strengthened model specimens and the specimens without prestressed nylon rope were made by the similar theory. With the test results, the strength and deformation properties of different model specimens were investigated. Comparison to different anchor effects of the different model specimens was made. The final analysis shows that in order to make full use of the anchor rope's strengthen ability, anchor rope should be disposed perpendicularly to the fracture structure rock mass's main joint direction and should be placed in the upper or top area of the fractured rock mass slope.     

Utility Analysis of Solid Waste Disposing Mechanism Under Market and Public Administration

Solid waste is one of the major pollution sources of environment.Currently,countries all over the world widely make use of market and public administration to solve the problem.Theories of environmental economics and legal science are fully applied to analyze the effects of these two measures,and conclusions can be made according to their respective traits: market has particular effect and function when dealing with problem of solid waste,but its imperfectness makes it necessary to introduce public administration.However, although it plays an important role in making up imperfectness of market,public administration still has inherent shortcomings and must be limited properly.     

Correlation between α-amylase gene expression and seedling vigor in rice

Summary This report examines the relationship between seedling vigor, -amylase enzyme activity and -amylase mRNA accumulation in ten varieties of rice (Oryza sativa L.) grown at two temperatures (15°C and 30°C). A significant, positive correlation was observed between seedling vigor, -amylase enzyme activity, and the accumulation of mRNA from one rice -amylase gene (RAmy1A) at both temperature regimens. The results of this study support previous experiments which have correlated -amylase enzyme activity to seedling vigor. We have extended this correlation to the expression of one of ten genes that comprise the rice -amylase multigene family. These results suggest that the expression of -amylase gene RAmy1A is an important, and possibly rate-limiting factor in determining seedling vigor in rice.     

A male-sterile line with ‘virescent’ marker character in Upland cotton

Summary Inheritance of 81A genetic male-sterility with virescent marker character and its cytology in Upland cotton (Gossypium hirsutum L.) are presented. The chromosome number of 81A is normal, 2n = 52, and pollen abortion occurs mainly in the late uninuclear stage. Male-sterility and virescence in 81A are controlled by one pair of recessive gene. Because male sterility and virescence showed no recombination, pleiotropy is assumed. However, very close linkage could not be ruled out. Allelic tests indicated that virescence observed in 81A is non-allelic to all virescence genes identified earlier in Upland cotton and its male-sterility is non-allelic to msc₁, msc₂ and msc₃ discovered in P.R. China. It is proposed that 81A male-sterile gene symbol be tentatively named to msc₇. The development of 81A genetic male-sterile line associated with virescence trait could raise considerably the efficiency of the hybrid seed production in cotton.     

Transformation of lily by Agrobacterium

Summary Lily cv. Harmony was inoculated with several Agrobacterium strains to study its susceptibility to Agrobacterium infection and transformation. Tumorous tissue formation on inoculated stem internodes of sterile-grown plantlets, as well as expression of a -glucuronidase marker gene interrupted by an intron in cells of inoculated stem nodes, indicate that the monocotyledon Lilium is a host for Agrobacterium.     

Geology Problems in the Disposal of Radioactive Waste and Its Research Situation

The geological disposal of radioactive waste is a complicated system engineering that involves many disciplines,such as, radiochemistry, atom physics, geohydrology, hydrogeochemistry, tectonic geology and civil engineering. The geological work is very important in the geological disposal of radioactive waste because the main body engineering of the warehouse building is geological engineering. Based on literature survey and the author's experience ,this paper introduces the research content and the research scope and its situation of the geological disposal of low and intermediate-level waste and the high level waste,all of are significant, including geologic structure geohydrology ,hydrogeochemistry, earth physics ,mineral & rock ,engineering, and geology hazard .     

星体型人工鱼礁流场效应的数值模拟

人工鱼礁在海中不同的投放方式会产生不同的流场效应,为了研究不同摆放方式下星体型人工鱼礁周围的流场分布,该文利用FLUENT软件,采用RNGk-ε湍流模型,模拟了不同流速(0.3、0.5、0.8m/s)及摆设方式对星体型人工鱼礁流场的影响,并将数值模拟结果与其他研究方法的结果相比较。结果显示,FLUENT数值模拟结果与其他数值模拟方法的结果基本相符,表明该数值模拟方法能较好的反映人工鱼礁周围上升流和背涡流特征。其中,组合鱼礁横向摆放时,最大上升流速度、上升流面积及上升流高度均随布设间距的增大而增大,背涡流面积随布设间距的增大而减小;纵向摆放时,当两礁体间距为1.5倍礁体尺寸时,上升流高度、上升流面积和两礁体后背涡流面积达到最大值;两礁体间的背涡流面积随鱼礁间距的增大而增大。该研究可为人工鱼礁在海底的投放方式和投放间距提供理论参考。     

大型油罐环焊缝自动清根方法

目前，在大型油罐焊接施工过程中，对环焊缝初次焊接进行清根，主要有人工方法和自动化机械方法。介绍了自动碳弧气刨、自动砂轮磨削机构、电火花切削机构进行清根的方法；并指出了各种自动清根方法的特点和自动清根所必需的一些辅助装置。自动清根机的使用对大型油罐施工速度的提高起到一定作用。