过碳酸钠在棉机织物漂白中的应用

采用过碳酸钠作漂白剂对棉织物漂白,通过实验确定过碳酸钠漂白棉机织物的最佳工艺为:过碳酸钠4g/L,双氧水稳定剂0.7g/L,温度90℃,时间60min,浴比1∶20。过碳酸钠漂白后棉机织物蓝光白度77.58%,较原布增加16.63%,接近双氧水漂白白度;降强率为11.67%,低于双氧水漂白强力损失。

Sintering preparation of porous sound-absorbing materials from steel slag

Porous sound-absorbing materials were prepared from steel slag using waste expanded polystyrene（EPS） particles as pore former.The influences of the experimental conditions such as fly ash content,sintering temperature,sintering time,and pore former addition on the performance of the porous sound-absorbing materials were investigated.The results show that the porosity of the specimens can reach above 50.0%;the compressive strength and average sound-adsorption coefficient of the sintered specimens are above 3.0 MPa and 0.47,respectively.The optimum preparation conditions for the steel slag porous sound-absorbing materials are as follows：mass fraction of fly ash 50%,waste EPS particles 3.6 g,sintering temperature 1100℃,and sintering time 7.5h,which are determined by considering the properties of the sound-absorbing materials,energy consumption and cost.

The increasing predominance of extreme precipitation in Southwest China since the late 1970s

Extreme precipitation events cause severe environmental and societal damage worldwide.Southwest China(SWC)is sensitive to such effects because of its overpopulation,underdevelopment,and fragile ecosystems.Using daily observations from 108 rain-gauge stations,the authors investigated the frequency of extreme precipitation events and their contribution to total precipitation in SWC since the late 1970 s.Results indicate that total precipitation is decreasing insignificantly,but rainfall-events frequency is decreasing significantly,whereas the region is experiencing more frequent and intense extreme precipitation events.Note that although fewer stations are statistically significant,about 60%of the rain-gauge stations show an increasing trend in the frequency and intensity of extreme precipitation.Furthermore,there is an increasing trend in the contribution of total extreme precipitation to total precipitation,with extreme precipitation becoming dominant in the increasingly arid SWC region.The results carry important implications for policymakers,who should place greater emphasis on extreme precipitation and associated floods and landslides when drafting water-resource management policies.

SPATIO-TEMPORAL VARIATION CHARACTERISTICS OF EXTREMELY HEAVY PRECIPITATION FREQUENCY OVER SOUTH CHINA IN THE LAST 50 YEARS

This paper comprehensively studies the spatio-temporal characteristics of the frequency of extremely heavy precipitation events over South China by using the daily precipitation data of 110 stations during 1961 to 2008 and the extremely heavy precipitation thresholds determined for different stations by REOF, trend coefficients, linear trend, Mann-Kendall test and variance analysis. The results are shown as follows. The frequency distribution of extremely heavy precipitation is high in the middle of South China and low in the Guangdong coast and western Guangxi. There are three spatial distribution types of extremely heavy precipitation in South China. The consistent anomaly distribution is the main type. Distribution reversed between the east and the west and between the south and the north is also an important type. Extremely heavy precipitation events in South China mainly occurred in the summer-half of the year. Their frequency during this time accounts for 83.7% of the total frequency. In the 1960 s and 1980 s, extremely heavy precipitation events were less frequent while having an increasing trend from the late 1980 s. Their climatological tendency rates decrease in the central and rise in the other areas of South China, and on average the mean series also shows an upward but insignificant trend at all of the stations. South China's frequency of extremely heavy precipitation events can be divided into six major areas and each of them shows a different inter-annual trend and three of the representative stations experience abrupt changes by showing remarkable increases in terms of Mann-Kendall tests.

Damage Pattern Recognition of Spatially Distributed Slope Damages and Rainfall Using Optimal GIS Mesh Dimensions

Damage assessment for slopes using geographical information system(GIS) has been actively carried out by researchers working on several government organizations and research institutes in Korea. In this study, 596 slope damages were examined to identify the types of damage associated with dip angles, dip directions, and heavy rainfall resulting from typhoons in South Korea. Heavy rainfall of 100 mm to 300 mm resulted in 80% at the investigated slope damages. A GIS database was developed for highways, rainfall, soil or rock geometry, and types of damage. A grid of rainfall intensity was generated from the records of maximum daily rainfall. Contours for slope damages and heavy rainfall using optimal GIS mesh dimensions were generated to visualize damage patterns and show substantially strong correlation of rainfall with slope damages. The combination of remote sensing with the GIS pattern recognition process described in this work are being expanded for a new generation of emergency response and rapid decision support systems.

防脆硫化黑应用试验小结

我厂生产的硫化黑灯芯绒销售全国各地,为广大工人和贫下中农所喜爱。长期以来,我们遵循伟大领袖毛主席关于“全心全意地为人民服务”的教导,抱着对人民负责的态度。在防止硫化黑脆损方面从染色工艺及处方上做了一些试验性工作。收到了一定效果。近年来,特别是在无产阶级文化大革命的凯歌声中,染料工业上的广大革命职工,高举毛泽东思想伟大红旗,突出无产阶级政治走自己工业发展道路。

Utilizing biodegradable alloys as guided bone regeneration(GBR)membrane:Feasibility and challenges

Guided bone regeneration(GBR)is a therapeutic procedure used to enhance alveolar bone volume before dental implants.Commercial non-absorbable membranes(i.e.,titanium membranes)typically require a second surgery to remove,whereas absorbable membranes(i.e.,collagen membranes)will fail when put over extensive bone lesions due to their low mechanical strength.The GBR membrane that has been sought is still being developed.Biodegradable metals(BMs),particularly Mg and Zn,have recently been postulated as promising barrier membrane candidates.Herein,the goal of this research is to evaluate the mechanical and biological feasibility of using BMs as GBR membranes.It shows that BMs have a wide range of potential applications as GBR membranes,owing to their benign biocompatibility,sufficient mechanical support,tunable degradation rate,good osteogenic capabilities,broad-spectrum antibacterial behavior,and improved wound healing ability.The rapid degradation rate,hydrogen evolution impact,and stress corrosion cracking behavior all pose obstacles to the use of Mg-based membranes,which can be improved by surface modifications,heat treatment,alloying,etc.Due to its acceptable degradation rate and lack of gas production,Zn appears to be a better candidate for usage as a GBR membrane.In general,advances in the development of BMs have paved the door for BMs to be used as GBR membranes in oral clinical trials.