种植业结构调整与节水型农业

本文在分析大量数据的基础上探讨鄂北区现行种植业结构中存在的问题 ,认为水资源不足是制约该区农业发展最主要的因素 ,而种植业结构不合理又进一步加剧了水资源的短缺 ;指出该区农业发展的前提是调整种植业结构 ,走节水型农业之路 ,只有这样才能实现该区农业经济、社会、生态效益的同步提高 ;通过分析鄂北区降水的时空分布及作物适水性 。

Applicability of Some Stomatal Models to Natural Conditions

Under natural conditions, the use of vapor pressure deficit between mesophyll cell surface and ambient air ( VPD s ) instead of atmospheric humidity factors in some stomatal models may markedly promote the applicability of stomatal models. It has been pointed out from theoretical analysis that the expression of the responses of stomatal conductance to VPD s is equivalent to the expression of responses of stomatal conductance to water loss of transpiration in stomatal models.

Study on the Floating Plant Climatic Adaptation of Undercurrent Constructed Wetland in North China

[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.

Differences in Ecological Fitness Between Bt Transgenic Rice and Conventional Rice Under Insect-infestation Pressures

[Objective] This study aimed to improve density and practicality of the ge- netic map of sunflower （Helianthus annuus L.） by adding some SSR markers. [Method] A total of 123 F8 RILs populations derived from a cross between PAC-2 and RHA-266 were selected as the materials, and a total of 300 pairs of SSR primers were used to screen polymorphic markers between the parents and some of their RILs, and finally 51 pairs of the primers producing polymorphic patterns were selected to construct the genetic map of the RILs populations. [Result] Nineteen pairs of SSR primers did not generate polymorphic patterns or any bands, and 32 SSR pairs showed polymorphism. Thirty-five alleles which distributed in the 15 link- age groups of the maps were detected. The new map covered a total length of 2 914.5 cM, 7.5 cM longer than that of the original map. The average marker interval is 8.1 cM replacing original 9.0 cM. [Conclusion] This study provided reference for genetic map integration and molecular marker assisted selection of sunflower.

Akebia ― a valuable wild fruit under domestication

Akebia is a wild fruit originating in the Yangtse river valley and the surrounding areas. It includes mainly three species （subspecies）： Akebia trifoliata, Akebia trifoliata subsp, australis, and Akebia quinata. It has many good traits, such as large fruit size, early fruit-setting and high yield, excellent eating quality, and good environmental adaptability. However, there are some shortcomings with the fruit, including thick skin, excessive number of seeds, and relatively small proportion of edible flesh. Akebia is also a traditional Chinese medicine, which has the functions of relieving internal heat and diuresis, dredging venation and improving blood circulation, cleansing facial chloasma, detoxication and anti-cancer activities. Akebia can be used as fresh fruit, for processing, and for pharmaceutical purposes. We have been undertaking a series of research on the domestication and utilization of Akebia, including cultivar selection, techniques for cultivation, storage and processing, and related basic studies. A Chinese trade name “Hehuanguo” and an English trade name “Joyfruit” have been registered for Akebia to facilitate its commercial development.

僧海豹

僧海豹喜欢热带温暖的海水,体型比海狮、海象更适宜在水中生活,后肢不能曲向前方,这在水中运动十分重要。僧海豹体表平滑,几乎成流线型,非常适合在水中快速游泳和潜水。敏锐的视觉和听觉再加上灵巧的适水性,使它更容易捕捉到各种鱼类。但到了陆地上,它的动作就显得十分笨拙,善于游泳的四肢只能起支撑作用,只好缓慢地匍匐爬行。

Rainwater harvesting in the challenge of droughts and climate change in semi-arid Brazil

Some successful experiences of rainwater harvesting in Brazil’s semi-arid region are shown how rural communities are living during the severe drought from 2011 to 2013 using technologies of rainwater harvesting for the household in agriculture livestock raising and the environment.Starting from the positive experiences principles of living in the challenge of droughts and climate change are elaborated and summarized into different guidelines for sustainable livelihood and production access to water and sufficient land area rainwater harvesting to provide water security to households and communities preservation recovering and management of drought-resistant vegetation emphases on raising of small and medium sized livestock and water and forage storage appropriate crop selection and sustainable extraction processing and marketing of crop products capacity building of the people. These principles contribute to preparing a national policy on living in harmony with the semi-arid climate. Rainwater harvesting is an important part of a package of measures which enables a sustainable livelihood in such a difficult environment.

Causes for the Unimodal Pattern of Leaf Carbon Isotope Composition in Abies faxoniana Trees Growing in a Natural Forest along an Altitudinal Gradient

Leaf morphological and physiological traits of Abies faxoniana growing in a natural forest along an altitudinal gradient were measured with the aim to identify the central mechanism for the marked variation in foliar δ13C determined by an isotope ratio mass spectrometer. There is a unimodal pattern of plant functional traits in these temperate and semi- humid areas. Stomatal parameters, specific leaf area, and C/N ratio increased, whereas C, N and δ13C values decreased with increasing altitude below 3000 m a.s.1. In contrast, they exhibited opposite trends above 3000 m a.s.l.. Our results demonstrated that high-altitude plants achieve higher water use efficiency （WUE） at the expense of decreasing nitrogen use efficiency （NUE）, whereas plants at 3000 m can maintain a relatively higher NUE but a lower WUE. Such intra-specific differences in the trade-off between NUE and WUE may partially explain the altitudinal distribution of the plants in relation to moisture and nutrient availability. Our results clearly indicate that the functional relations between nutritional status and the structure of leaves are responsible for the altitudinal variations associated with δ13C. The pivotal role of specific leaf area in regulating plant adaptive responses provides a potential physiological mechanism for the observed growth advantage of populations occupying the medium altitude. These adaptive responses altitudinal gradients showed that an altitude to of approximately 3000 m a.s.1, is the optimum distribution zone for A. faxoniana, allowing the most vigorous growth and metabolism. These results improve our understanding of the various roles of environmental and biotic variables upon δ13C dynamics and provide useful information for subalpine coniferous forest management.

New Challenges and Opportunities for Flood Control in the Huai River: Addressing a Changing River-Lake Relationship

This paper addresses the change of the river-lake relationship in the Huai River and its causes due to environmental change and human activities. A preliminary analysis is made from three aspects: (1) the natural geographical change particularly captured by the Yellow River, (2) water conservancy project construction, and (3) socioeconomic development in the Huai River Basin. Key problems of changes in this river-lake relationship and the Huai River flood control are tackled, involving flood control and disaster alleviation ability of the Basin, engineering and non-engineering measurements applied to flood control and disaster mitigation, and water governance for adaptive management. Research shows that the Huai River is a rather complex one due to its complex geography with a hybrid wet and dry climate zoon, and higher population density. With the alternation of the river-lake relationship and socioeconomic development in the region, new problems keep arising, imposing new requirements on its sustainable water management. Thus, understanding the Huai River is a long and gradually improving process. Its future planning should keep absorbing new achievements of science and technology development, employing new technologies and methods, and gradually deepening our understanding of its fundamental principles. Water governance and adaptive water management will be new challenges and opportunities for the Basin in its river system change and flood control.

Applicability of Waterside Corrosion Models in Range of IFPE Database

Fuel rod cladding waterside corrosion is one of the phenomena that limit the life time of nuclear fuel. Corrosion performance depends on the cladding material properties as well as operating conditions during the irradiation of the fuel. As a function of temperature, power history, water chemistry, time, etc., waterside corrosion is of great concern in fuel performance evaluation, especially for high burnup fuels. This paper is dedicated to the study of the waterside corrosion phenomenon using the IFPE database by COPERNIC, which is developed for the analysis of fuel rod behaviors in normal operation and transient conditions. Different models, MATPRO, FRAMATOME and EPRI models, for example, are adopted in the simulations. The results derived from the models are compared and the unconformities are analyzed. Based on the comparative analysis, reasonable models are chosen to simulate certain irradiated fuel rods. Our analyses indicate that potential affecting factors which are not considered in COPERNIC code, such as water chemistry and alloy composition, should be responsible for discrepancies of certain rod predictions.

Gray Synthetic Evaluation on Moisture Comfort of Sportswear Fabrics under the Condition of Heavy Sweating

Moisture and water transfer under the condition of heavy sweating are analyzed. Four different experiments are made to test moisture resistance, water-keep, wicking effect and drying ability of samples. Then gray analysis method is introduced to evaluate the comprehensive comfort of these fabrics. Result shows chemical fiber with high moisture transfer performance has advantage in water transfer and diffusion, which is suitable for human under the condition of heavy sweating. Though natural fiber can absorb moisture well, it cannot transfer fluid sweat. Therefore natural fiber fabrics such as cotton, wool are unsuitable to make functional sportswear.

Practice and adaptable conditions classification of aquifer-protective mining in longwall coalface for shallow seam with thin bedrock

A set of adaptable conditions classification of aquifer-protective mining in the Iongwall coalface for shallow coal seams with thin bedrock was put forward to deal with the conflict between water protection and high efficiency for the mining field in west China. This classification was suitable for shallow coal seams with different thickness and was beneficial to the local environmental protection. Using the 3-Universal Distinct Element Code （3DEC） numerical software, the height of the fractured zones for shallow coal seams with thin bedrock was calculated and analyzed, and its predicting formula was achieved. Meanwhile, according to the lithology and the weathering degree of the shallow coal seam the thickness of the protective layer was determined as 10 m and the overlying water body of loose water-bearing sand for shallow coal seams with thin bedrock was divided into three types, namely, weak, medium and strong. Based on these, the necessary bedrock thickness of the Iongwall coalface for shallow coal seams with thin bedrock was confined according to the different mining height and water yield nature of the overlying loose water-bearing sand. Combined with the present mining status, a set of new methods of adaptable conditions classification of aquifer-protective mining technology in the Iongwall coalface for shallow coal seams with thin bedrock was put forward.

Response of Germination Physiology of Cajanus cajan Seeds to Drought Stress: Comparison between Karst Water and Allogenic Water Treatments

In this paper, responses of germination physiology of pigeon pea （Cajanus cajan） seeds to drought stress in karst water environment and non-karst （allogenic） water environment were studied to explore the adaptability of pigeon pea to karst environment. The results showed that： （i） Under drought stress of 20% PEG- 6000, the germination rate, vigor index, germination index and biomass of pigeon pea seeds on day 7 cultivated with karst water were all greater than that of the allogenic water treatment group, while the seed germination stress index was significantly smaller than that of the allogenic water treatment group, suggesting that karst water environment was more favorable to pigeon pea seed germination. （ii） Without drought stress, the malondialdehyde （MDA） and superoxide dismutase （SOD） activities of pigeon pea seeds cultivated with karst water were all smaller than that of the allogenic water group. However, under drought stress, the SOD activity was significantly higher than that of allogenic water group, suggesting pigeon pea SOD in karst water was able to more rapidly respond to external drought stress, and increase its own activity to reduce the damage to the plants. And （iii） with and without drought stress, the soluble protein level of the karst water group was higher than that of the allogenic water group, while the free amino acid level was lower than that of the allogenic water group. This difference was more significant with the presence of drought stress, suggesting that the karst water environment was more favorable to the accumulation of soluble proteins and thus produced larger biomass. Hence, pigeon pea is a tree species that is adapted to high-calcium, alkaline environments in karst areas, and is of great significance for the revegetation and rocky desertification control in mountainous karst areas.

Impacts of Climate Change and Human Activities on Water Suitability in the Upper and Middle Reaches of the Tao'er River Area

Due to the impact of climate change and human activities, the upper and middle reaches of the Tao＇er River have become an ecologically sensitive area in Northeast China. It is important to evaluate the contributions of climate change and human activities to water suitability in the Tao＇er River area. From the perspective of water and heat balance, the water suitability index （Cr） was used to analyze the water suitability of the upper and middle reaches of the river. The nonparametric Mann-Kendall, moving t-test and cumulative anomaly methods were used to detect abrupt changes in Taonan station runoff from 1961 to 2012. Three inflexion years were detected. Thus, the entire time period was divided into four periods： 1961-1974, 1975-1983, 1984-1998, and 1999-2012. In order to estimate the impacts of climate change and human activities on runoff, the slope change ratio of cumulative quan- tity （SCRCQ） was adopted. Finally, the contribution of climate change and human activity to Cr was transformed from the contribution of climate change and human activity to runoff by the sensitivity coefficient method and SCIRCQ method. The results showed that the water suitability index （cr） had a decreasing trend 1961-2012. Fac- tors influencing cr, such as net radiation and runoff, also exhibited a decreasing trend, while precipitation exhibited an increasing trend over the past 52 years. The trends of Cr, net radiation and runoff were obvious, which passed the Mann-kendall test of significance at a=0.05. Human activities were the main factors that affected runoff, al- though the degree of impact was different at different times. During the past 52 years, the biggest contributor to the change in Cr was precipitation.

Applicability of cement-based grout for ground heat exchanger considering heating-cooling cycles

The applicability of cement grout （or cement-based grout） has been considered as an alternative to bentonite grout commonly used to backfill closed-loop vertical ground heat exchangers. In a geothermal heat pump system, repeated heating-cooling cycles may cause adverse effects on the integrity of cement grout in the ground heat exchanger. To account for the temperature cycling effect, the strength degradation of cement grout due to temperature cycling has been examined by measuring the unconfined compression strength of cured specimens in a humidity-temperature controlling chamber with applying temperature cycles between -5℃ and 50℃. There is a tendency that the unconfined compression strength decreases with an increase in the number of temperature cycles. On the other hand, an equivalent hydraulic conductivity of a pipe-embedded cement grout specimen was evaluated by carrying out a modified flexible wall permeameter test equipped with a water circulating system to control temperature inside the pipe section. The applied operating temperature range was from 5 to 35℃. After three cycles of heating-cooling circulation, the equivalent hydraulic conductivity becomes asymptotic to a constant value, which implies there is no severe detachment of the pipe from the cement grout.

Suitability mapping of global wetland areas and validation with remotely sensed data

With increasing urbanization and agricultural expansion, large tracts of wetlands have been either disturbed or converted to other uses. To protect wetlands, accurate distribution maps are needed. However, because of the dramatic diversity of wetlands and difficulties in field work, wetland mapping on a large spatial scale is very difficult to do. Until recently there were only a few high resolution global wetland distribution datasets developed for wetland protection and restoration. In this paper, we used hydrologic and climatic variables in combination with Compound Topographic Index （CTI） data in modeling the average annual water table depth at 30 arc-second grids over the continental areas of the world except for Antarctica. The water table depth data were modeled without considering influences of anthropogenic activities. We adopted a relationship between poten- tial wetland distribution and water table depth to develop the global wetland suitability distribution dataset. The modeling re- suits showed that the total area of global wetland reached 3.316× 10^7 km^2. Remote-sensing-based validation based on a compi- lation of wetland areas from multiple sources indicates that the overall accuracy of our product is 83.7%. This result can be used as the basis for mapping the actual global wetland distribution. Because the modeling process did not account for the im- pact of anthropogenic water management such as irrigation and reservoir construction over suitable wetland areas, our result represents the upper bound of wetland areas when compared with some other global wetland datasets. Our method requires relatively fewer datasets and has a higher accuracy than a recently developed global wetland dataset.

Suitability Evaluation for the Construction of Decentralized Wastewater Reclamation Facilities in Beijing

水资源的缺乏使越来越多的城市和城区开始使用中水作为额外的经济合理的供水水源,并为此制定相应政策。然而,不适宜的中水利用政策往往对用水户使用再生水产生不利影响。本研究目的在于评价中水设施建设适宜性并分析不同行业的中水利用适宜情况,为制定或修订中水利用政策提供参考。本研究以北京市为研究区,在中水生产成本影响因素分析基础上,得到了中水设施建设限制因素和中水设施建设适宜条件,并对北京市机关、高校、饭店的用水户进行了适宜性评价。本研究结果表明,运行水量对中水生产成本有决定性影响。有效原水量对应的给水量、有效中水需求量、建筑面积适合作为中水设施建设影响因素,它们的下限可作为中水设施建设适宜条件。本研究通过分析北京市部分机关、高校、饭店用水户的用水情况,得到这些行业的中水设施建设适宜条件,并用于适宜性评价。评价结果表明,大部分机关用水户和大部分一、二星级饭店不适宜建设中水设施,而大部分高校和大部分三星级以上饭店适宜建设中水设施。

Drought adaptability of phreatophytes:insight from vertical root distribution in drylands of China

Aims The vertical distribution of plant roots is a comprehensive result of plant adaptation to the environment.Limited knowledge on fine vertical root distributions and complex interactions between roots and environmental variables hinders our ability to reliably predict climatic impacts on vegetation dynamics.This study attempts to understand the drought adaptability of plants in arid areas from the perspective of the relationship between vertical root distribution and surroundings.Methods By analyzing root profiles compiled from published studies,the root vertical profiles of two typical phreatophytes,Tamarix ramosissima and Populus euphratica,and their relationships with environmental factors were investigated.A conceptual model was adopted to link the parameter distribution frequency with plant drought adaptability.Important Findings The strong hydrotropism(groundwater-dependent)and flexible water-use strategy of T.ramosissima and P.euphratica help both species survive in hyperarid climates.The differences in the developmental environments between T.ramosissima and P.euphratica can be explained well by the different distribution characteristics of root profiles.That is,higher root plasticity helps T.ramosissima develop a more efficient water-use strategy and therefore survive in more diverse climatic and soil conditions than P.euphratica.We conclude that the higher variation in root profile characteristics of phreatophytes can have greater root adaptability to the surroundings and thus wider hydrological niches and stronger ecological resilience.The inadequacy of models in describing root plasticity limits the accuracy of predicting the future response of vegetation to climate change,which calls for developing process-based dynamic root schemes in Earth system models.

Optical Properties of Laterally Aligned Si Nanowires for Transparent Electronics Applications

We have investigated the optical properties of laterally aligned Si nanowire （SiNW） arrays in order to explore their potential applicability in transparent electronics. The SiNW array exhibited good optical transparency in the visible spectral range with a transmittance of -90% for a NW density of -20-25 per 10 μm. In addition, polarization-dependent measurements revealed a variation in transmittance in the range of 80%-95% depending on the angle between the polarization of incident light and the NW axis. Using the SiNWs, we demonstrated that transparent transistors exhibit good optical transparency （greater than 80%） and showed typical p-type SiNW transistor characteristics.