水灌碾压法施工及试验

根据设计与当地实际情况,采用水灌碾压法填筑路基,简要阐述了砂土路基的施工工艺,对检测内容及方法、试验压实参数设计做了探讨,并就试验数据进行了分析,达到了指导施工的目的,对同类工程有积极的借鉴意义。

Performance of grouts for post-tensioned prestressed structures

New high performance grouts with high volume stability and good fluidity were prepared with Portland cement and a multifunctional admixture (MFA). The theological characteristics and mechanical performance of the grouts were investigated. The addition of MFA effectively improves the pseudo-plasticity of the grout. The Ma cone flow time decreases obviously, and the bleeding rate tends to be zero. The deformation behaviors of fresh mixture and hardened grout are systematically studied. Mercury injection method (MIP), scanning electron microscopy (SEM) and X-ray diffractory analysis experiments are used to analyze the microstructure evolution of the grouts, which manifests that the co-action of the early bubble reaction and the latter ettringite crystallization ensure the volume stability throughout the whole hydration process and result in refined pore structure of the grout.

淹没在黄河水下的石灰土基层未遭破坏的原因分析

一场突如其来的黄河水不但没有冲毁刚刚施工完成的填方路基和石灰土基层,而且这条路在承受了大数量、大吨位的行车载冲击后仍然保持了良好的状况。从这一令人费解的事件入手,进行分析得出的结论是黄河水的淹没使得路基更加稳定、密实并为石灰土基层养生提供了最为良好的外部条件。推而广之,对于广大粉性土地区而言,水灌法在工程上具有很大的应用价值,对于高标准、高质量要求的重点工程而言尤其有其研究价值和应用价值。

Effect of Limited Single Irrigation on Yield of Winter Wheat and Spring Maize Relay Intercropping

A field experiment was conducted during the 2002/2003 cropping season of winter wheat （Triticum aestivum） and spring maize （Zea mays） to evaluate the effect of limited single drip irrigation on the yield and water use of both crops under relay intercropping in a semi-arid area of northwestern China. A controlled 35 mm single irrigation, either early or late, was applied to each crop at a certain growth stage. Soil water, leaf area, final grain yield and yield components such as the thousand-grain weight, length of spike, fertile spikelet number, number of grains per spike, and grain weight per spike were measured, and water use efficiency and leaf area index were calculated for the irrigated and non-irrigated relay intercropping treatments and sole cropping controls. The results showed that yield, yield components, water use efficiency, and leaf area index in the relay intercropping treatments were affected by limited single drip irrigation during various growth stages of wheat and maize. The total yields in the relay intercropping treatment irrigated during the heading stage of wheat and the heading and anthesis stage of maize were the highest among all the treatments, followed by that irrigated during the anthesis stage of wheat and silking stage of maize; so was the water use efficiency. Significant differences occurred in most yield components between the irrigated and non-irrigated relay-intercropping treatments. The dynamics of the leaf area index in the relay-intercropped or solely cropped wheat and maize showed a type of single-peak pattern, whereas that of the relay intercropping treatments showed a type of double-peak pattern. Appropriately, limited single irrigation and controlled soil water content level could result in higher total yield, water use efficiency, and leaf area index, and improved yield components in relay intercropping. This practice saved the amount of water used for irrigation and also increased the yield. Therefore, heading stage of wheat and heading and anthesis stage of maize were suggested to be the optimum limited single irrigation time for relay-intercropped wheat and maize in the semi-arid area.

Comprehensive Evaluation on the Irrigation Water Quality in Turpan City Based on Matter Element Analysis Method

Matter-element analysis method was used to construct the comprehensive matter-element model for the evaluation of the quality of various kinds of irrigation water in Turpan City to evaluate the quality of irrigation water（such as river water,spring water, Karez well water, pumped well water） in Turpan City, Xinjiang. The results showed that the quality of the irrigation water was the best in October,which was in Grade I or Grade 2; in May, the quality of some of the irrigation water became poorer to Grade II, which was easy to soil salinization; in March, the detected qualities of the water samples water from the Meiyaogou basin were all in Grade IV, which was not suitable for farmland irrigation. The comparison on the evaluation results of matter-element analysis and fuzzy evaluation method showed that the results of the 2 methods were almost consistent with each other, and showed good uniformity.

Optimal Groundwater Irrigation Allocation of Al-Wajid Aquifer in the Kingdom of Saudi Arabia

Groundwater is the primary water source in the Kingdom of Saudi Arabia. As result of lack of basic knowledge on irrigation practices, massive abstractions of groundwater occurred in 1980＇s. A Decision Support Linear Goal Programming （LGP） model was developed to determine optimal groundwater irrigation levels, to assess the implications for water management policies, and to estimate welfare impact on producer surplus. Due to the reductions of groundwater in 1980＇s, the Al-Wajid aquifer water levels have dropped in agricultural areas by more than 200 m. Results from this study estimate that the total groundwater of the Al-Wajid aquifer that can be saved is equal to 66 MCM for the first scenario, 147 MCM for the second scenario, and 229 MCM for the third scenario. Regarding the welfare analysis impacts, it is clear that the total gross margin is decreasing up to 7.7% at the end of the year of scenario Ⅲ. Therefore, the third scenario with a water saving increase to 18.1% is recommended as a directive for agricultural policy formation in the future.

Assessment of Resource-Use Efficiency in Irrigated Rice Production in Dadinkowa, Gombe State, Nigeria

The study examined the levels of resource-use efficiency of rice farmers unde,r irrigation method in Dadinkowa, Gombe state of Nigeria. Using questionnaire, data were collected during the year 2010 irrigation season from 120 randomly sampled rice irrigators and the data were analyzed using multiple regression and marginal analyses. Results showed that significant factors influencing irrigated rice production were labour （P 〈 0.001）, land and fertilizer （P 〈 0.01）. In addition, the coefficient of determination （R2）, the F-ratio and the standard error of the mean （S） were found to be 0.471, 16.37＊＊＊ and 8.908, respectively. The results also indicated that efficiency values of land, seeds, fertilizer and labour were 1.234, 0.498, 2.352 and 1.620, respectively. Finally, it was found that resource-use among the farmers were not efficient thus equipment, land, fertilizer and labour inputs shall be increased by 78.3%, 18.9%, 57.5% and 38.3%, respectively, while seed input shall be reduced by 50.2% for the farmers to attain optimal resource utilization.

The Role of Traditional Irrigation Canals in a Long Term Environmental Perspective A Case Study in Southern France： The Durance Basin

The agricultural sector is often considered to be the largest water consumer and the policy aimed at saving irrigation water exists across Europe. The flip-side of such policy, however, is the disappearance of traditional irrigation canals since farmers are encouraged to turn to drip irrigation and overhead irrigation gradually. Given this, we would like to argue that traditional irrigation canals need to be reexamined. Such canals are not only built aquatic infrastructure, they are also the product of a culture and social relationship with water in the Mediterranean region. Canals form a complex system which is driven by environmental, economic and social factors. Our sociological and environmental research in Provence （and around the Durance basin more specifically） points up how the very dense territorial network of gravity-fed canals is useful in water management, as well as in other shared uses over the long-term. The findings underscore the positive environmental role played by these historical and anthropogenic constructions. They contribute to refilling the aquifer and also act as a valuable environmental good and service （e.g., run-off regulation, biodiversity, landscape, recreation, etc.）. Further, several local actors have underscored their role as part of an intangible cultural heritage and as important for the area＇s economic and social development. Such canals play a central role in sustainable development since beyond their productive role in agriculture, they play a social role （new uses） and an ecological role （as reservoirs for biodiversity and ecological corridors）.

Improvement of Plant Growing Techniques in Drying up and Water Scarcity Conditions

Due to its specificity, seasonality and location of large areas, the crops are exposed to the greatest degree of risks posed by climate change. To maintain stability and increase yields, it is imperative to implement an innovative approach by which to optimize certain processes such as tillage, sowing and irrigation. The main tasks of innovative solutions are proposed to increase the soil water holding capacities in the root layer over a prolonged period of time, and improve the accuracy of the drilling process for row crops and vegetables by using biodegradable materials, and on this basis to optimize the irrigation by use of specialized software products to determine irrigation scheduling and irrigation requirements.

Analysis of Factors Determining the Demand for Water： A Case Study of Sabie Administrative Post, Moamba District, Mozambique

Water is an important resource for human being. However, it has been increasingly becoming the limited resource. Therefore, the debate of water issues has been centered in mechanisms to implement sustainable water management. Hence, understanding the determinants of water demand might help design appropriate water management policies, however, they are not known in Mozambique. Due to the lack of knowledge about the determinants of water demand in Mozambique in general and in Sabi6 in particular, the present study was conducted to analyse the factors determining the water demand for irrigation and domestic use using a linear regression model and travel cost method, respectively. The results show that an increase in 1 h of irrigation time increases the quantity demanded of irrigation water by 362.04 m3 and an increase in one irrigation per week increases the quantity demanded of irrigation water by 1,065.61 m3. Additionally, the results show that an increase in 1% of time spent in water collection decreases the number of trips by 0.3% and an increase in 1% in the number of household members involved in water collection decreases the number of the water collection trips by 0.23%. Household having private taps have less number of trips collecting water compared to those collecting water from public taps and boreholes as well as rivers. Therefore, the water demand for irrigation is determined by time spent for irrigation per day and the number of irrigations per week, and water demand for domestic use is determined by time spent for water collection, number of household members involved in water collection, the volumes of the containers used to collect water, the number of containers used to collect water, the quantity of water consumed by the household as well as the main source of water （river, boreholes and public tap）.

运脾柔肝方对便秘型肠易激综合征大鼠SCF/c-kit信号通路的影响

目的通过观察运脾柔肝方对便秘型肠易激综合征(IBS-C)大鼠SCF/c-kit信号通路的影响。方法 80只Wistar大鼠用随机数字表法选取12只大鼠为正常组,其余大鼠采用冰水灌胃法建立IBS-C模型。建模成功后,将大鼠按照随机数字表法分为IBS-C模型组,莫沙必利组和中药低、中、高剂量组,每组12只。正常组和IBS-C模型组给予等容积的蒸馏水,莫沙必利组给予1.35mg/(kg·d)混悬液灌胃,中药低、中、高剂量组分别12.2,24.4,48.8g/(kg·d)药剂灌胃。采用墨汁推进实验测定肠道推进率,采用免疫组化法和RT-qPCR检测结肠组织SCF、c-kit蛋白和mRNA表达水平。结果与正常组比较,IBS-C模型组粪便颗粒数减少,粪便含水量以及肠道推进率明显降低,结肠组织SCF、c-kit蛋白和mRNA表达水平显著降低(P<0.01)。与IBS-C模型组比较,给药组大鼠粪便颗粒数及含水量,肠道推进率明显升高,结肠组织中SCF、c-kit蛋白和mRNA表达水平升高,其中除中药低剂量组SCF蛋白表达水平无统计学意义外,其他均有统计学意义(P<0.01或P<0.05)。结论运脾柔肝方可能是通过调节SCF/c-kit信号通路来改善大鼠肠道推进率和排便的。