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Relationship between sand-dust weather and water dynamics of desert areas in the middle reaches of Heihe River

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Research in Cold and Arid Regions 2016年第6期8卷 516-523页

作者： Yun Niu XianDe Liu Xin Li YanQiang Wei Hu Zhang XiaoYan Li Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China Academy of Ecology Science of Zhangye Gansu Science and Technology Innovation Service Platform of Ecology in Qilian Mountains Gansu Province Zhangye Gansu 734000 China Academy of water Resource Conservation Forests of Qilian Mountains in Gansu Province Test Station of Desertification Control in Hongshawo Zhangye Gansu 734000 China

Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert sand and dust to the dynamics of water in desertification, we extracted long-term monitoring data related to precipitation, soil water, groundwater, and sand-dust weather. These data originated from the test stations for desertification control in desert areas of the middle reaches of the Heihe River. We used an algorithm of characteristic parameters, correlations, and multiple regression analysis to establish a regression model for the duration of sand-dust weather. The response char-acteristics of the natural desert sand and dust and changes of the water inter-annual and annual variance were also examined. Our results showed：（1） From 2006 to 2014 the frequency, duration, and volatility trends of sand-dust weather obviously increased, but the change amplitudes of precipitation, soil water, and groundwater level grew smaller. （2） In the vegetative growth seasons from March to November, the annual variance rates of the soil moisture content in each of four studied layers of soil samples were similar, and the changes in the frequency and duration of sand-dust weather were similar. （3） Our new regression equation for the duration of sand-dust weather passed the R test, F test, and t test. By this regression model we could predict the duration of sand-dust weather with an accuracy of 42.9%. This study can thus provide technological support and reference data for water resource management and re-search regarding sand-dust weather mechanisms.

关键词： sand-dust weather water dynamics regression model middle reaches of the Heihe River

The Linkage between Natural Vegetation, water dynamics and Pyrite （FeS2） Oxidation in Tidal Lowlands

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Journal of Environmental Science and Engineering(A) 2013年第4期2卷 243-249页

作者： Adzemi Mat Arshad Mustika Edi Armanto Elisa Wildayana Adipati Napoleon Dwi Probowati Ahmad Fadhli Adzemi Department of Agrotechnology Faculty of Agrotechnology and Food Science Uiversiti Malaysia Terengganu Terengganu 21030 Malaysia Department of Soil Science Faculty of Agriculture Sriwijaya University South Sumatra 30662 Indonesia Department of Agricultural Socio-Economics Faculty of Agriculture Sriwijaya University South Sumatra 30662 Indonesia Department of Biological Science Faculty of Science and Technology Uiversiti Malaysia Terengganu Terengganu 21030 Malaysia

The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite （FeS2） oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from February to December 2010. The field observations are done by exploring several transect on land units. The field description refers to Soil Survey Staff. water and soil samples were taken from selected key areas for laboratory analyses. The vegetation data were collected by making sample plots placed on each vegetation type with plot sizes 10 m × 10 m for secondary forests and 5 m × 5 m for shrubs and grass. The observations of surface water level were done during the river receding with units of meter above sea level （***）. The results shows that pyrite formation is largely determined by the availability of natural vegetation as S （sulfur） donors, climate and uncontrolled water balance and supporting faunas such as crabs and mud shrimp. Climate and water balance as well as supporting faunas is the main supporting factors to accelerate the process of formation pyrite. Oxidized pyrite increases soil pH thus toxic to fish, arable soils, plant growth, disturbing the water quality and soil nutrient availability. Oxidized pyrite is predominantly accelerated by the dynamics of river water and disturbed natural vegetation by human activities, and the pyrite oxidation management approach is divided into three main components of technologies, namely water management, land management and commodity management.

关键词： Linkage natural vegetation water dynamics pyrite tidal lowlands.

Terahertz spectroscopy of water in nonionic reverse micelles

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Chinese Optics Letters 2024年第1期22卷 128-134页

作者：张佳琦闫玉岳刘立媛张伟力 Centre for Terahertz Waves and College of Precision Instrument and Optoeletronics Engineering Tianjin UniversityTianjin 300072China School of Electrical and Computer Engineering Oklahoma State UniversityStillwaterOklahoma 74078United States

The dynamics of water within a nanopool of a reverse micelle is heavily affected by the amphiphilic *** this work,the terahertz(THz)spectra of cyclohexane/Igepal/water nonionic reverse micelle mixture are measured by THz timedomain spectroscopy and analyzed with two Debye models and complex permittivity of background with volume *** on the fitted parameters of bulk and fast water,the molar concentration of all kinds of water molecules and hydration water molecule number per Igepal molecule are *** find that slow hydration water has the highest proportion in water when the radius parameterω_(0)water becomes the main component whenω_(0)≥*** feature radius ratio of nonhydrated and hydrated water to total water nanopool is roughly obtained from 0.39 to 0.85 with increasingω_(0).

关键词： reverse micelle water dynamics THz spectroscopy

Salting-in/Salting-out Mechanism of Carbon Dioxide in Aqueous Electrolyte Solutions

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Chinese Journal of Chemical Physics 2017年第6期30卷 811-816,I0003页

作者：张霞张璐金坦潘志君陈浙宁张强庄巍渤海大学化学化工学院学院锦州121013 中国科学院福建物质结均研究所结构化学国家重点实验室福州350002

The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO2 in electrolyte solutions still remains elusive at molecule level. The ability of ion salting-out/salting-in CO2 in electrolyte solution follows Hofmeister Series and the change of water mobility induced by salts can be predicted by the viscosity B-coefficients. In this work, the chemical potential of carbon dioxide and the dynamic properties of water in aqueous NaCl, KF and NaClO4 solutions are calculated and analyzed. According to the viscosity B-coefficients, NaClO4 （0.012） should salt out the carbon dioxide relative to in pure water, but the opposite effect is observed for it. Our simulation results suggest that the salting-in effect of NaClO4 is due to the strongly direct anion-CO2 interaction. The inconsistency between＂ Hofmeister Series and the viscosity B-coefficient suggests that it is not always right to indicate whether a salt belongs to salting-in or salting-out just from these properties of the salt solution in the absence of solute.

关键词： Salting effect Viscosity B-coefficient Hofmeister Series water dynamics

Vibrating Carbon Nanotubes as water Pumps

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Nano Research 2011年第3期4卷 284-289页

作者： Hu Qiu Rong Shen Wanlin Guo Institute of Nano Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Nanopumps conducting fluids directionally through nanopores and nanochannels have attracted considerable interest for their potential applications in nanofiltration, water purification, and hydroelectric power generation Here, we demonstrate by molecular dynamics simulations that an excited vibrating carbon nanotube （CNT） cantilever can act as an efficient and simple nanopump. water molecules inside the vibrating cantilever are driven by centrifugal forces and can undergo a continuous flow from the fixed to free ends of the CNT. Further extensive simulations show that the pumping function holds good not only for a single-file water chain in a narrow （6,6） CNT, but also for bulk-like water columns inside wider CNTs, and that the water flux increases monotonically with increasing diameter of the nanotube.

关键词： Nanopump carbon nanotube nanofluidics centrifugal forces water dynamics