小麦地保护性耕作措施和压实对水分保护的影响

在模拟降雨条件下研究小麦地的传统、免耕和深松3种耕作措施和0，25％，50％和75％4种覆盖度以及拖拉机轮胎压实与非压实对土壤水分保护效果的影响。试验结果表明：在耕作措施、覆盖度和压实3种因素中，压实对土壤水分保护效果的影响最大，可以使具有25％～75％残茬覆盖的保护性耕作地的平均径流强度增大3倍之多。传统耕作加覆盖的保水效果好于免耕加覆盖和深松加覆盖。

Leaf Senescence Characteristics and Responses to Water Shortage of Different Hybrid Rice Cultivars during Grain Filling Stage

[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivated under limited and conventional irrigation managements; after the heading of rice, the root activities, nitrogen content in leaves, chlorophyll content （SPAD value）, net photosynthetic rate and the activities of superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT） were determined. [Result] The rhythms in attenuation of xylem sap flow rate, leaf nitrogen content, chlorophyll content （SPAD value） and net photosynthetic rate of different rice cultivars were significantly different in attenuation starting time, attenuation frequency and attenuation range. Physiological indexes of different cultivars responded inconsistently to water shortage. Extremely significantly positive correlations were found between the decline rates of chlorophyll content and leaf nitrogen content and xylem sap flow rate of roots, the photosynthetic rate and chlorophyll content. The changes in activities of SOD, CAT and POD were different, and responded to water shortage differently in different cultivars. The change dynamic of leaf nitrogen content and chlorophyll content was positively related with the activity dynamic of SOD and CAT. The change dynamic of leaf nitrogen content and chlorophyll content was negatively related with the malondialdehyde （MDA） content. The difference in the attenuation rhythm of physiological indexes of leaves and response to water shortage of different hybrid rice cultivars were related to genotype difference. Increasing roots activities and protecting enzyme activities of leaves benefit to defer attenuation of chlorophyll content and nitrogen content of leaves and to keep stronger photosynthetic function. [Conclusion] The senescence resistance of rice is a combined result of genotype differences and physiological response to environment.

Policy and Practice Progress of Watershed Eco-compensation in China

The ecological protection of the watersheds in China is being confronted with a lot of problems such as soil and water erosion, water pollution at present. Therefore watershed eco-compensation is becoming a question of common interest. Based on the analyses of the major problems and their origins in the watershed protection in China, the paper discusses the concerned policies including relative rules and laws, financial policies and water right transaction policies. Simultaneously the paper reviews the practices carried out in China, including the ecological construction project in the western China, the trans-provincial eco-compensation practice and the small watershed eco-compensation practice. According to the present situation of eco-compensation practices and the future policy requirement, this paper finally puts forward four key problems to be solved in the watershed eco-compensation of China in the future.

Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams

Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine. We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method. From our calculations and analyses of variance, we used factors such as the overlying strata strength, mining disturbing factors and rock integrity as related factors of the composite index. We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock, the thickness of the weathered zone and the size of safety coal-rock pillars. As a result, we propose the preliminary classification system of aquifer-protective mining in shallow coal seams. It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.

Change in Activities of Protective Enzymes in New Strains of Cichorium intybus L. Mutated in Outer Space under Water Stress

[Objective] This study aimed to investigate the effects of space mutation on the activities of protective enzymes in different strains of Cichorium intybus L. and provide theoretical basis for screening drought-tolerant plants in southern karst area. [Method] C. intybus seeds were sent into outer space by ＇Shijian No.8＇ seed- breeding satellite. The new strains and original variety of C. intybus L. were used as experimental materials to determine the activities of catalase （CAT）, peroxidase （POD）, superoxide dismutase （SOD）, and malondialdehyde （MDA） content. [Result] The results showed that MDA content in PA-82, Puna chicory and PA-43 increased gradually with the increase of water stress duration, which was enhanced by 0.575, 0.72 and 0.844 μmol/g respectively at 12 days. In addition, the activities of SOD, POD and CAT increased rapidly; at 9 days, the activities of SOD in PA-82, Puna chicory and PA-43 were enhanced by 878.9, 809.2 and 711.1 U/g, with the increas- ing range of 139.1%, 136.7% and 121.1%, respectively; the activities of POD were enhanced by 4 397, 3 754 and 2 767 U/（g ·min）, with the increasing range of 265.84%, 257.65% and 204.06%, respectively; the activities of CAT were enhanced by 402.1, 277.1 and 170.9 KU/L, with the increasing range of 73.08%, 39.69% and 26.20%, respectively; subsequently, the activities of these three protective enzymes were reduced significantly; at 12 days, the activities of SOD in PA-82, Puna chicory and PA-43 were reduced to 1206.5, 1144.7 and 1108.6 U/g, respectively; the activi- ties of POD were reduced to 3 145, 2 876 and 2 753 U/（g·min） , respectively; the activities of CAT were reduced to 587.2, 698.1 and 584.1 KU/L, respectively. [Con- clusion] According to the results of comprehensive evaluation, drought resistance in three C. intybus varieties exhibited a descending order of PA-82 〉 Puna chicory 〉 PA-43.

Design of an Index System for Deep Groundwater Management Efficiency Evaluation: A Case Study in Tianjin City, China

An effective evaluation system can provide specific and practical suggestions to the deep groundwater management. But such kind of evaluation system has not been proposed in China. In this study, an evaluation index system is specifically developed to evaluate deep groundwater management efficiency. It is composed of three first-level indicators(law enforcement capability, management ability, and management effectiveness) and eleven second-level indicators. The second-level indicators include seven mandatory indicators and four optional indicators. Piecewise linear function is used to normalize the quantitative indicators, and expert scoring method and questionnaire survey method are used to normalize the qualitative indicators. Then a comprehensive indicator weighting evaluation method is used to evaluate the first-level indicators and the target topic. A case study is carried out to evaluate deep groundwater management efficiency in Tianjin City. According to the evaluation score in each period, the management efficiency of every district in Tianjin City gradually improved. The overall evaluation score in the early deep groundwater extraction period is 0.12. After a series of deep groundwater protection efforts, this score reached to 0.61 in 2007, and met the regulation criteria. The evaluation results also showed that the further groundwater management efforts in Tianjin City should be focused on building a dynamic database to collect comprehensive deep well-log data; and on a reasonable design and distribution of the groundwater monitoring network. It demonstrated that the index system is suitable to locate the deficiencies of current groundwater management systems and to guide further improvements. It can then be used to protect deep groundwater.

Quantitative Simulation on Soil Moisture Contents of Two Typical Vegetation Communities in Sanjiang Plain,China

Different types of vegetation occupy different geomorphology and water gradient environments in the San- jiang Plain, indicating that the soil moisture dynamics and water balance patterns of the different vegetation communi- ties might differ from each other. In this paper, a lowland system, perpendicular to the Nongjiang River in the Honghe National Nature Reserve （HNNR）, was selected as the study area. The area was occupied by the non-wetland plant forest and the typical wetland plant meadow. The Microsoft Windows-based finite element analysis software package for simulating water, heat, and solute transport in variably saturated porous media （HYDRUS）, which can quantita- tively simulate water, heat, and/or solute movement in variably-saturated porous media, was used to simulate soil moisture dynamics in the root zone （20-40 cm） of those two plant communities during the growing season in 2005. The simulation results for soil moisture were in a good agreement with measured data, with the coefficient of determi- nation （R2） of 0.44-0.69 and root mean square error （RMSE） ranging between 0.0291 cm3/cm3 and 0.0457 cm3/cm3, and index of agreement （d） being from I）.612 to 0.968. During the study period, the volumetric soil moisture content of meadow increased with the depth and its coefficient of variation decreased with the depth （from 20 cm to 40 cm）, while under the forest the soil moisture content at different depths varied irregularly. The calculated result of water budget showed that the water budget deficit of the meadow was higher than that of the forest, suggesting that the meadow is more likely to suffer from water stress than the forest. The quantitative simulation by HYDRUS in this study did not take surface runoff and plant growth processes into account. Improved root water uptake and surface runoff models will be needed for higher accuracy in further researches.

Analysis of Coupling between Soil and Water Conservation and Economic-social Development

The coupling relation exists in water and soil conser-vation and economic-social development. The article analyses the relation of soil and water conservation and economic-social development stages as well as the coupling analytical method. Then calculates the expecting income by dispersing Markov decision and calculates the correlation coefficient and the re-lationship degree. The article obtains the relationship of soil and water conservation investments and all kinds of incomes. Finally, it analyzes the important meaning in socio-economic development of water and soil conservation.

Annual Discharge and Sediment Load Variation in Jialing River During the Past 50 Years

Annual discharge and annual suspended sediment loads of Beipei Hydrological Station of the Jialing River catchment were analyzed to describe the trend of Jialing River over the last five decades (1956-2006). These loads were also analyzed to ascertain the influential factors associated with its variation with the help of Kendall's Tau-b correlation analysis and regression analysis. The results indicated that the Jialing River annual discharge showed no significant trend at >95% confidence level while the annual sediment load appeared to have a significant decrease trend over the last 50 years. A decrease in the annual sediment load was particularly apparent after the year 1985, at which a substantial shift in the sediment level occurred. This shift is attributed to the construction of numerous dams in 1980s. However, after the year of 1985, two periodical stages (1986-1991 and 1992-2006) with distinct sediment load and sediment-runoff ratio were identified. The period 1992-2006 is characterised by low sediment load, which is most probably due to the impact of large scale of soil and water conservation, which took place at the end of the 1980s. Last, models describing the relationship between the discharge and the sediment load, discharge and sediment-runoff ratio as well as between the sediment load and sediment-runoff ratio were constructed.

The Utilization of Real-Time High Resolution Monitoring Techniques in Karst Carbon Sequestration:A Case Study of the Station in Banzhai Subterranean Stream Catchment

The karst process acts as carbon sequestration for atmospheric CO_2.The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body.Based on the data from the monitoring station on Banzhai subterranean stream located in Maolan National Nature Reserve of Guizhou province,the process and influence factors of KCS have been analyzed.It shows that the amount of KCS is about 353 t C per year in the catchment of Banzhai subterranean stream,and there is good linear relationship between the strength of KCS and discharge of the stream at various time scales.Therefore,how to monitor the discharge accurately is the key to the estimation of KCS.And stations with real-time monitoring function are very important for KCS calculation because of strong seasonal variability of the karst water cycle.

如何去除油漆味

◇装满凉水的盆内加入适量的食醋,放在通风房间内,并打开家具门。这样既可适量蒸发水分保护墙面涂料,又可吸收消除残留异味;

A robust intelligent audio watermarking scheme using support vector machine

Rapid growth in information technology and computer networks has resulted in the universal use of data transmission in the digital domain. However, the major challenge faced by digital data owners is protection of data against unauthorized copying and distribution. Digital watermark technology is starting to be considered a credible protection method to mitigate the potential challenges that undermine the efficiency of the system. Digital audio watermarking should retain the quality of the host signal in a way that remains inaudible to the human hearing system. It should be sufficiently robust to be resistant against potential attacks, One of the major deficiencies of conventional audio watermarking techniques is the use of non-intelligent decoders in which some sets of specific rules are used for watermark extraction. This paper presents a new robust intelligent audio water- marking scheme using a synergistic combination of singular value decomposition （SVD） and support vector machine （SVM）. The methodology involves embedding a watermark data by modulating the singular values in the SVD transform domain. In the extraction process, an intelligent detector using SVM is suggested for extracting the watermark data. By learning the destructive effects of noise, the detector in question can effectively retrieve the watermark. Diverse experiments under various conditions have been carried out to verify the performance of the proposed scheme. Experimental results showed better imperceptibility, higher robustness, lower payload, and higher operational efficiency, for the proposed method than for conventional techniques.