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A comparative study of the land-atmosphere energy and water exchanges over the Tibetan Plateau and the Yangtze River Region
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作者 Nan Yao Yaoming Ma +3 位作者 Binbin Wang Jun Zou Jianning Sun Zhipeng Xie 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第2期52-59,共8页
正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8... 正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8个不同地表类型(包括高山荒漠,高山草地,(平原)城市和(平原)草地等)观测站点的地表辐射和能量通量数据.结果显示:(1)TP由于高原大气层稀薄且空气洁净,年平均入射短波辐射为251.3W m^(-2),是YRR的1.7倍.加之高原地表反照率高导致反射辐射(59.6 W m^(-2))是YRR的2.87倍.入射及出射的长波辐射为231.5和338.0 W m^(-2),分别为YRR的0.64和0.83.而两个区域的净辐射差异不大;(2)草地站更多的潜热释放使得地表总加热效率高于城市和高山荒漠,TP和YRR的草地站的年平均潜热分别为35.0和38.8 W m^(-2),而植被稀疏且土壤干燥的高山荒漠地区感热最大,年平均感热为42.1 W m^(-2);其次是城市下垫面,其年平均感热为37.7 W m^(-2).研究结果揭示了不同气候背景下典型下垫面地气相互作用特征,为地气相互作用过程深入分析奠定了基础. 展开更多
关键词 能量和水分交换 辐射分量 地表能量通量 青藏高原 长江流域 不同地表类型
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Response of soil water dynamics to precipitation years under different vegetation types on the northern Loess Plateau, China 被引量:13
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作者 LIU Bingxia SHAO Ming'an 《Journal of Arid Land》 SCIE CSCD 2016年第1期47-59,共13页
Implementation of the Grain-for-Green project has led to rapid land cover changes and resulted in a significantly increased vegetation cover on the Loess Plateau of China during the past few decades. The main objectiv... Implementation of the Grain-for-Green project has led to rapid land cover changes and resulted in a significantly increased vegetation cover on the Loess Plateau of China during the past few decades. The main objective of this study was to examine the responses of soil water dynamics under four typical vegetation types against precipitation years. Soil water contents (SWCs) were measured in 0–4.0 m profiles on a hillslope under the four vegetation types of shrub, pasture, natural fallow and crop in a re-vegetated catchment area from April to October in normal (2010), dry (2011), wet (2014) and extremely wet (2013) years. The results indicated that precipitation and vegetation types jointly controlled the soil water temporal dynamics and profile characteristics in the study region. SWCs in 0–4.0 m profiles of the four vegetation types were ranked from high to low as crop>fallow>pasture>shrub and this pattern displayed a temporal stability over the four years. In the extremely wet year, SWC changes occurred in the 0–2.0 m layer under shrub and pasture while the changes further extended to the depth of 4.0-m deep layers under fallow and crop. In the other three years, SWCs changes mainly occurred in the 0–1.0 m layer and kept relatively stable in the layers deeper than 1.0 m for all the four vegetation types. The interannual variation in soil depth of SWCs was about 0–2.0 m for shrub and pasture, about 0–3.4 m for fallow and about 0–4.0 m for crop, respectively. The dried soil layers formed at the depths of 1.0, 0.6, 1.6 and 0.7 m under shrub, and 1.0, 1.0, 2.0 and 0.9 m under pasture, respectively in 2010, 2011, 2013 and 2014. The infiltrated rainwater mostly stayed in the 0–1.0 m layer and hardly supplied to soil depth >1.0 m in normal, dry and wet years. Even in the extremely wet year of 2013, rainwater recharge depth did not exceed 2.0 m under shrub and pasture. This implied that soil desiccation was difficult to remove in normal, dry and wet years, and soil desiccation could be removed in 1.0–2.0 m soil layers even in the extremely wet year under shrub and pasture. The results indicated that the natural fallow was the best vegetation type for achieving sustainable utilization of soil water and preventing soil desiccation. 展开更多
关键词 precipitation pattern RESTORATION soil water dynamics soil desiccation vegetation type
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Influence of water potential and soil type on conventional japonica super rice yield and soil enzyme activities 被引量:5
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作者 ZHANG Jing WANG Hai-bin +6 位作者 LIU Juan CHEN Hao DU Yan-xiu LI Jun-zhou SUN Hong-zheng PENG Ting ZHAO Quan-zhi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第5期1044-1052,共9页
We carried out a pool culture experiment to determine the optimal water treatment depth in loam and clay soils during the late growth stage of super rice. Three controlled water depth treatments of 0-5, 0-10 and 0-15 ... We carried out a pool culture experiment to determine the optimal water treatment depth in loam and clay soils during the late growth stage of super rice. Three controlled water depth treatments of 0-5, 0-10 and 0-15 cm below the soil surface were established using alternate wetting and drying irrigation, and the soil water potential (0 to -25 kPa) was measured at 5, 10 and 15 cm. A 2-cm water layer was used as the control. We measured soil enzyme activities, root antioxidant enzyme activities, chlorophyll fluorescence parameters, and rice yield. The results showed that the 0-5-cm water depth treatment significantly increased root antioxidant enzyme activities in loam soil compared with the control, whereas soil enzyme activities, chlorophyll fluorescence parameters and yield did not differ from those of the control. The 0-10- and 0-15-cm water depth treatments also increased root antioxidant enzyme activities, whereas soil enzyme activities, chlorophyll fluorescence parameters and yield decreased. In clay soil, the soil enzyme activities, root antioxidant enzyme activities, chlorophyll fluorescence parameters, and yield did not change with the 0-5-cm water treatment, whereas the 0-10- and 0-15-cm water treatments improved these parameters. Therefore,the appropriate depths for soil water during the late growth period of rice with a 0 to -25 kPa water potential were 5 cm in loam and 15 cm in clay soil. 展开更多
关键词 RICE yield components soil type soil enzyme activity antioxidant enzyme activity chlorophyll fluorescence parameters water potential
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Effect of Pipe Diameter on Electrochemical Behavior of Stainless Steel Type 304 Pipes in Tap Water 被引量:1
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作者 Noriyuki Tanaka Shigeru Sato +4 位作者 Itaru Ikeda Tadahiko Uchida Motoki Kuratani Yutaka Yamada Osamu Sakurada 《Materials Sciences and Applications》 2019年第11期697-708,共12页
We investigated the effects of pipe diameter on the corrosion resistance of stainless steel type 304 pipes using electrochemical measurements. Compared to plate steel, pipes have harder physical properties and tend to... We investigated the effects of pipe diameter on the corrosion resistance of stainless steel type 304 pipes using electrochemical measurements. Compared to plate steel, pipes have harder physical properties and tend to be harder and showed greater permeability with decreasing inner diameter. We found that the maximum corrosion current density in the secondary active state, which is the starting point of secondary passivation, appeared in the polarization curve measurement in tap water. Similar to the Vickers hardness and the maximum current density in the secondary active state, the permeability tended to increase as the diameter decreased. This is thought to increase the amount of deformation-induced martensitic and increase corrosion susceptibility. The peak of the secondary active current density was clearly seen as the potential sweep speed was increased. In addition, potential sweep speed dependence was observed in the corrosion susceptibility evaluation of deformation-induced martensite. In comparison with acid treatment, the formation of deformation-induced martensite was considered to occur in the extreme surface layer. The maximum corrosion current density in the secondary active state is expected to be a new susceptibility evaluation method for evaluating the deformation-induced martensitic transformation. 展开更多
关键词 STAINLESS Steel type 304 ELECTROCHEMICAL CONSIDERATION Pipe Diameter ELECTROCHEMICAL Behavior TAP water
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Numerical Study of Steam-Water Separators with Wave-type Vanes 被引量:12
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作者 李嘉 黄素逸 王晓墨 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第4期492-498,共7页
Droplet behavior in the wave-type flow channel is discussed,especially with the secondary droplet gen- eration due to impingement of droplets on the wall considered.A numerical method is suggested to simulate the drop... Droplet behavior in the wave-type flow channel is discussed,especially with the secondary droplet gen- eration due to impingement of droplets on the wall considered.A numerical method is suggested to simulate the droplet behavior in the flow field.Calculations are compared with experimental data on the pressure drop and sepa- rating efficiency.Good agreement exists between the calculations and air-water experiments.The numerical method developed gives a reasonable description of the droplet deposition and secondary droplet generation,and it can be applied to predict the performance of wave-type vane separators. 展开更多
关键词 水蒸气隔离器 多相流动 波型羽片 数字方法
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Effects of Meat and Phosphate Level on Water-Holding Capacity and Texture of Emulsion-Type Sausage During Storage 被引量:24
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作者 WANG Peng,XU Xing-lian and ZHOU Guang-hong Key Laboratory of Meat Processing and Quality Control,Ministry of Education/Nanjing Agricultural University,Nanjing 210095,P.R.China 《Agricultural Sciences in China》 CSCD 2009年第12期1475-1481,共7页
This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork ... This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork and frozen pork were pre-blended with five levels of phosphate and made into emulsion-type sausage. The yield, hardness and total expressible fluid (TEF) were measured with texture profile analysis machine and pressiometer when emulsion-type sausage was produced. Meanwhile, hardness and purge loss (PL) were measured during 30 d storage. As emusion-type sausage made by pre-rigor meat, higher yield and relatively stable hardness could be found. It indicated that increasing of phosphate level caused an alleviatable effects in increasing of hardness when emulsion-type sausage made by pre-rigor meat, but opposite effects made by ageing meat or frozen meat. The distribution of PL of emulsion-type sausage was found to be affected by phosphate addition. Significant decrease of PL could not be obtained by increasing of phosphate level during storage. Pre-rigor meat improved WHC and texture of emulsion-type sausage. Problem of WHC and texture of emulsiontype sausage during storage could not be resolved by single use of phosphate at relatively higher level (3%) of NaCl. 展开更多
关键词 MEAT emulsion-type sausage water-holding capacity TEXTURE
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Keggin type heteropolyacids-catalyzed synthesis of quinoxaline derivatives in water 被引量:4
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作者 Tai Kun Huang Lin Shi Rui Wang Xing Zhou Guo Xiao Xia Lu 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第2期161-164,共4页
Keggin 类型 heteropolyacids 被发现是为从有在水里的优秀收益的 1,2-dicarbonyl 混合物的 1,2 肼的冷凝作用的生物学上活跃的 quinoxaline 衍生物的合成的有效、可重用的催化剂。这个方法以催化剂,底层的一个宽范围,和简单病情的检... Keggin 类型 heteropolyacids 被发现是为从有在水里的优秀收益的 1,2-dicarbonyl 混合物的 1,2 肼的冷凝作用的生物学上活跃的 quinoxaline 衍生物的合成的有效、可重用的催化剂。这个方法以催化剂,底层的一个宽范围,和简单病情的检查过程的小数量提供一个新、有效的协议。 展开更多
关键词 KEGGIN型杂多酸 催化合成 衍生物 喹喔啉 二羰基化合物 可重复使用 生物活性
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Characteristics of Water Type Distribution and Seasonal Variations in the Southern East China Sea
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作者 Miao Yutian, Yu Honghua, He Dehua and Wang Chunsheng Second Institute of Oceanography, SOA , Hangzhou 310012 《Marine Science Bulletin》 CAS 1999年第1期11-24,共14页
By using the data of Summer and Winter 1987, Spring and Autumn 1988 obtained by the R/V " Shijian" during the China-Japan Joint Research Program on Kuroshio, the paper makes an analysis and research on the w... By using the data of Summer and Winter 1987, Spring and Autumn 1988 obtained by the R/V " Shijian" during the China-Japan Joint Research Program on Kuroshio, the paper makes an analysis and research on the water type distribution and its variations in the studied sea area. Trie results of which are mainly as follows: (1) The Class IV mixing water whose property is similar to that of the continental coastal water is located in the northeast sea area, along the coast of the continent in autumn and winter while extending to the open sea in spring and summer. (2) The boundary between the Kuroshio water and the shelf mixing water (called the left boundary of the Kroshio water) is approximately located in between the 100m and 200m isobaths in various seasons and various layers, and mostly near the 200m isobath. In the sea area northeast of Taiwan, the Kuroshio water is to the west most in spring and then in winter. In summer, it is to the east most while, in autumn, it is in between its positions in summer 展开更多
关键词 SOUTHERN East China Sea water type DISTRIBUTION SEASONAL variation
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The Influence of Lithostratigraphy on the Type and Quality of Stored Water in Mujib Reservoir-Jordan
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作者 Habes Mohammad Al-Mashakbeh 《Journal of Environmental Protection》 2017年第4期568-590,共23页
This study was carried out to investigate the impact of drainage basin’s lithostratigraphy on the quality and type of stored water in the Mujib dam reservoir. The water samples were collected on a monthly basis from ... This study was carried out to investigate the impact of drainage basin’s lithostratigraphy on the quality and type of stored water in the Mujib dam reservoir. The water samples were collected on a monthly basis from surface water from January 2012 to December 2015. The classifications of collecting water samples for domestic and irrigation purposes were based on different physico- chemical parameters such as pH, EC, TDS, TSS, Na+, K+, Ca2+, Mg2+, Cl-, SO42-, HCO3- , NH4+, NO3- , NO2- , SAR, RSC, SSP, RSBC, PI, MAR, KR, and TH. All analyzed water samples were satisfied the Jordanian permissible limit and graded as “fresh water”. The hydrochemical indices (Mg/Ca and Cl/HCO3) and Cation Exchange values (CEV), indicating that the surface water chemistry is due to the rock weathering minerals with respect to their inland origin. The water samples have complied within the respective limits in respect of pH, EC, SAR, RSC, RSBC, MAR, KR, SSP and PI, and hard in respect of TH which may be due to the dissolution of the weathered rocks. Abundance of cations and anions is in the following order: Ca > Na > Mg > K and HCO3 > SO4 > Cl > NO3 during the period 2013-2015 and SO4 > HCO3 > Cl > NO3 through 2012. Thus, calcium and bicarbonate–sulfate are the dominant ions present in the surface water of this study. Piper diagram suggested that carbonate and gypsum weathering is the dominant process controlling reservoir water chemistry in the basin area. The quality and type of surface water can be modified by the lithology of the catchment area. The hydrogeochemical study of Mujib reservoir water indicated that the water quality is safe for drinking and agricultural purposes. 展开更多
关键词 water type water QUALITY Drinking-Irrigating water Hydrogeochemical In-dices LITHOSTRATIGRAPHY Mujib Dam RESERVOIR
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Type of major water hazards and study of countermeasures in Shennan Mining Area
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作者 WANG Hong-ke GUO Jiao SHI Ying-chun 《Journal of Groundwater Science and Engineering》 2015年第1期70-76,共7页
By analysing the hydrogeological conditions of this region and the coal mines hereof, together with the water hazards troubled Shennan mine area in recent years, this paper summarized six types of mine water hazards. ... By analysing the hydrogeological conditions of this region and the coal mines hereof, together with the water hazards troubled Shennan mine area in recent years, this paper summarized six types of mine water hazards. As per the basic characteristics, geological distribution, threat degree and difficulty of prevention of various water hazards, along with the practice of water prevention in the mining area, this article proposed effective technical measures for the prevention and control of different water hazards and laid a solid foundation for the safe production in the mining area. 展开更多
关键词 Shennan Mining Area Hydrogeological conditions type of water hazard Characteristics of water hazards COUNTERMEASURES
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Effectiveness of Alkali Water Consumption to Reduce Blood Sugar Levels in Diabetes Mellitus Type 2
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作者 Edy Siswantoro Nasrul Hadi Purwanto Sutomo   《Journal of Diabetes Mellitus》 2017年第4期249-264,共16页
Background: Non-Communicable Diseases (NCDs) have become a public health problem, globally, regionally, nationally and locally. Non-Communicable Diseases (NCDs) that took a lot of attention was diabetes mellitus. In I... Background: Non-Communicable Diseases (NCDs) have become a public health problem, globally, regionally, nationally and locally. Non-Communicable Diseases (NCDs) that took a lot of attention was diabetes mellitus. In Indonesia diabetes mellitus is a serious threat to health development. Efforts developed to overcome the problems of diabetes mellitus type 2 is to apply four pillars of therapy namely education, nutrition therapy, physical activity and pharmacology. However, these efforts have not been able to achieve optimal results due to many obstacles encountered. One of the non-pharmacological treatments that can be utilized is to consume alkaline water to reduce blood sugar levels in diabetes mellitus type 2. Methods: The research design used was quasy experiment with pre-post control group design approach. The variables observed in this study were random blood sugar changes in people with diabetes mellitus type 2 prior to intervention and after intervention. Intervention is given over a period of 14 days. To measure the demand of drinking water on the respondents, the measurement was done using Water Drink Reminder - Hydro application. The alkaline water used in this study is alkaline water produced from Kangen Water Type SD501 Platinum Machine. Test analysis used is paired t test to determine the effectiveness of alkaline water consumption to decrease random blood sugar level of diabetes mellitus type 2. To know the difference of effectiveness of alkaline water consumption to decrease of blood sugar level, it uses one way anova test with significance value α: 0.05. Results: From result of the one way anova test with significance value α: 0.05, we have got significance 0.039. Since the significance probability value is 0.039 0.05, the research hypothesis is accepted which means that there is a significant difference in the level of random blood sugar of diabetes mellitus type 2 performed by using four kinds of intervention of alkaline water treatment (Alkali Water PH 7.0, PH 8.0, PH 9.5 and PH 9.5 and PH 11.5) for a period of 14 days. Conclusion: Support from health personnel and adherence to diabetes mellitus is required to utilize alkaline water as nonpharmacologic therapy to control blood sugar levels in people with type 2 diabetes mellitus. To achieve maximum results from nonfarmakologi therapy performed, people with diabetes mellitus type 2 should routinely consume antidiabetic drugs provided by health personnel and always strive for a healthy life. 展开更多
关键词 Diabetes MELLITUS type 2 Nonpharmacology Therapy ALKALINE water
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Pore-Throat Combination Types and Gas-Water Relative Permeability Responses of Tight Gas Sandstone Reservoirs in the Zizhou Area of East Ordos Basin, China 被引量:5
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作者 LI Mi GUO Yinghai +2 位作者 LI Zhuangfu WANG Huaichang ZHANG Jingxia 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第3期622-636,共15页
With the aim of better understanding the tight gas reservoirs in the Zizhou area of east Ordos Basin,a total of 222 samples were collected from 50 wells for a series of experiments.In this study,three pore-throat comb... With the aim of better understanding the tight gas reservoirs in the Zizhou area of east Ordos Basin,a total of 222 samples were collected from 50 wells for a series of experiments.In this study,three pore-throat combination types in sandstones were revealed and confirmed to play a controlling role in the distribution of throat size and the characteristics of gas-water relative permeability.The type-I sandstones are dominated by intercrystalline micropores connected by cluster throats,of which the distribution curves of throat size are narrow and have a strong single peak(peak ratio>30%).The pores in the type-II sandstones dominantly consist of secondary dissolution pores and intercrystalline micropores,and throats mainly occur as slice-shaped throats along cleavages between rigid grain margins and cluster throats in clay cement.The distribution curves of throat size for the type-II sandstones show a bimodal distribution with a substantial low-value region between the peaks(peak ratio<15%).Primary intergranular pores and secondary intergranular pores are mainly found in type-III samples,which are connected by various throats.The throat size distribution curves of type-III sandstones show a nearly normal distribution with low kurtosis(peak ratio<10%),and the micro-scale throat radii(>0.5μm)constitute a large proportion.From type-I to type-III sandstones,the irreducible water saturation(Swo)decreased;furthermore,the slope of the curves of Krw/Krg in two-phase saturation zone decreased and the two-phase saturation zone increased,indicating that the gas relative flow ability increased.Variations of the permeability exist in sandstones with different porethroat combination types,which indicate the type-III sandstones are better reservoirs,followed by type-II sandstones and type-I sandstones.As an important factor affecting the reservoir quality,the pore-throat combination type in sandstones is the cumulative expression of lithology and diagenetic modifications with strong heterogeneity. 展开更多
关键词 tight gas sandstone pore-throat COMBINATION type THROAT characteristic GAS-water relative permeability Zizhou area ORDOS Basin
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A QUANTITATIVE STUDY ON ENHANCEMENT OF TYPE Ⅱ PHOTOSENSITIZED OXIDATION REACTION RATE BY HEAVY WATER
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作者 Xian Fu ZHANG Hui Jun XU Institute of Photographic Chemistry,Academia Sinica,Beijing,100101 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第8期715-718,共4页
A method for quantitative evaluating the enhancement of the rate of Type Ⅱ photosensitized oxidation by D_2O was suggested. The effect of substrate concentration on this process was also discussed.
关键词 A QUANTITATIVE STUDY ON ENHANCEMENT OF type PHOTOSENSITIZED OXIDATION REACTION RATE BY HEAVY water RATE
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Attenuation-type and failure-type curve models on accumulated pore water pressure in saturated normal consolidated clay 被引量:1
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作者 赵春彦 《Journal of Central South University》 SCIE EI CAS 2012年第7期2047-2053,共7页
Based on dynamic triaxial test results of saturated soft clay,similarities of variations between accumulated pore water pressure and accumulated deformation were analyzed.The Parr's equation on accumulated deforma... Based on dynamic triaxial test results of saturated soft clay,similarities of variations between accumulated pore water pressure and accumulated deformation were analyzed.The Parr's equation on accumulated deformation was modified to create an attenuation-type curve model on accumulated pore water pressure in saturated normal consolidation clay.In this model,dynamic strength was introduced and a new parameter called equivalent dynamic stress level was added.Besides,based on comparative analysis on variations between failure-type and attenuation-type curves,a failure-type curve model was created on accumulated pore water pressure in saturated normal consolidation clay.Two models can take cycle number,coupling of static and dynamic deviator stress,and consolidation way into consideration.The models are verified by test results.The correlation coefficients are more than 0.98 for optimization of test results based on the two models,and there is good agreement between the optimized and test curves,which shows that the two models are suitable to predict variations of accumulated pore water pressure under different loading cases and consolidation ways.In order to improve prediction accuracy,it is suggested that loading cases and consolidation ways should be consistent with in-situ conditions when dynamic triaxial tests are used to determine the constants in the models. 展开更多
关键词 孔隙水压力 饱和软粘土 正常固结土 曲线模型 故障类型 积累 衰减 动三轴试验
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Research and Application of Ecological Outdoor Ground Structure with Composite Water Storage and Drainage Function
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作者 Peng ZHONG Yuqi FAN Zhenggen FAN 《Asian Agricultural Research》 2023年第10期6-9,共4页
In order to solve the problems of surface runoff increase,water accumulation in rainy days and urban heat island effect,an ecological outdoor ground structure with composite water storage and drainage functions was st... In order to solve the problems of surface runoff increase,water accumulation in rainy days and urban heat island effect,an ecological outdoor ground structure with composite water storage and drainage functions was studied and applied in this paper:Through the comprehensive design of road ground,road inspection well,garden inspection well and drainage pipe network,it can quickly store and drain ground water,alleviate the urban heat island effect,realize plant infiltration irrigation,and achieve the purpose of saving water and energy. 展开更多
关键词 Composite water storage and drainage waterlogging prevention Ecological type Outdoor ground
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The construction types of inner river wharf with huge water fluctuation and their development
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作者 ZHU Yunfei 《International English Education Research》 2016年第4期1-1,共1页
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宁南黄土区不同人工植被类型深层土壤水分亏缺评价
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作者 王月玲 许浩 +4 位作者 安钰 万海霞 董立国 韩新生 袁心 《甘肃农业大学学报》 CAS CSCD 北大核心 2024年第2期215-223,共9页
【目的】开展评估不同人工植被类型深层土壤水分亏缺程度,能为区域科学合理实施植被恢复策略提供理论依据。【方法】以宁夏彭阳中庄小流域5种不同植被类型(山桃林、沙棘林、柠条林、苜蓿地,农田为对照)为研究对象,采用土壤水分相对亏缺... 【目的】开展评估不同人工植被类型深层土壤水分亏缺程度,能为区域科学合理实施植被恢复策略提供理论依据。【方法】以宁夏彭阳中庄小流域5种不同植被类型(山桃林、沙棘林、柠条林、苜蓿地,农田为对照)为研究对象,采用土壤水分相对亏缺指数(CSWDI)和干燥化指数(SDI)定量评价模型,对不同植被类型下0~1 000 cm土壤水分亏缺及干燥化程度进行定量化分析与评价。【结果】不同植被类型深层土壤水分变化特征差异明显,0~1 000 cm平均土壤水分含量呈现出农地(16.29%)>山桃林(13.06%)>沙棘林(12.22%)>柠条林(9.12%)>苜蓿地(8.08%)。在垂直剖面上,土壤水分随土层深度增加总体呈现先减小后增加再逐渐稳定的趋势。在0~1 000 cm农地基本没有水分亏缺和干层发生,山桃林、柠条林、沙棘林和苜蓿地均呈现不同程度的土壤水分亏缺现象,平均土壤水分相对亏缺指数分别为0、0.22、0.62、0.35、0.79,平均土壤干燥化指数分别为185.5%、67.45%、51.55%、87.35%、36.10%,5种植被类型中苜蓿地土壤水分亏缺最严重,其次为柠条林、沙棘林、山桃林、农地。山桃林、柠条林、沙棘林、苜蓿地均有不同程度的干层分布,分别呈现中度、轻度和严重干燥化,干层厚度(DSLT)分别为890、860、800、920 cm,DSL-SWC分别为12.42%、8.14%、11.56%、7.76%。【结论】宁南黄土区不同人工植被类型对深层土壤水分亏缺具有明显影响,导致不同程度土壤干层发生,其中苜蓿地土壤水分亏缺最严重,应采取相应措施恢复土壤水分,促进区域水土资源可持续利用和生态健康发展。 展开更多
关键词 植被类型 土壤水分 水分亏缺 宁南黄土区
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氨型碱性水化学对690TT腐蚀特性的影响
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作者 赵永福 唐敏 +5 位作者 姜峨 银朝晖 陈子瑞 张根 吴宗佩 李杨 《材料导报》 EI CAS CSCD 北大核心 2024年第7期167-172,共6页
为探索氨型碱性水化学对传热管材料690TT腐蚀行为的影响,开展传热管材料690TT合金在B-Li-NH_4OH和NH_4OH两种水质下的腐蚀特性研究,分析690TT腐蚀产物释放特性,综合评价氨型碱性水质对690TT腐蚀特性的影响。研究结果表明,690TT材料与两... 为探索氨型碱性水化学对传热管材料690TT腐蚀行为的影响,开展传热管材料690TT合金在B-Li-NH_4OH和NH_4OH两种水质下的腐蚀特性研究,分析690TT腐蚀产物释放特性,综合评价氨型碱性水质对690TT腐蚀特性的影响。研究结果表明,690TT材料与两种氨型碱性水质均具有较好的相容性。690TT在两种水质中均形成了致密的氧化膜,氧化膜由NiFe_(2)O_(4)尖晶石氧化物和少量的铁氧化物Fe_(2)O_(3)组成,相对而言690TT在NH_(4)OH型水质条件下的总腐蚀失重量、总腐蚀产物释放量略低于在B-Li-NH_(4)OH水质下,但690TT向水质释放的Ni元素总量与上述规律相反,这可能与Ni元素和氨形成络合物[Ni(NH_(3))_(m)]^(2+)有关,Ni元素释放量增加对反应堆一回路辐照场控制有不利影响。本研究结果可为氨型碱性水化学技术的设计和应用提供数据支撑。 展开更多
关键词 氨型碱性水化学 镍基合金690TT 腐蚀
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鲁中南典型地热区地热水氟分布特征及其驱动机制
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作者 李曼 张薇 +3 位作者 廖煜钟 刘峰 魏帅超 何雨江 《地质科技通报》 CAS CSCD 北大核心 2024年第3期36-47,共12页
山东省鲁中南典型地热区主要包括沂沭断裂带地热区和鲁中隆起地热区,为了探明研究区地热水氟分布特征及其富集规律,综合运用水化学图解、地球化学模拟和主成分分析等方法,分析沂沭断裂带地热区和鲁中隆起地热区地热水水化学数据。结果表... 山东省鲁中南典型地热区主要包括沂沭断裂带地热区和鲁中隆起地热区,为了探明研究区地热水氟分布特征及其富集规律,综合运用水化学图解、地球化学模拟和主成分分析等方法,分析沂沭断裂带地热区和鲁中隆起地热区地热水水化学数据。结果表明:研究区地热水以Na-Ca-Cl型、Na-Ca-SO_(4)-Cl型和Na-Cl^(-)SO 4型为主,基本为弱碱性水,优势阳离子为Na^(+),氟质量浓度在0.38~4.5 mg/L之间,富钠弱碱性环境有利于地热水中氟的富集。地热水中F-质量浓度与Na^(+)、Cl^(-)和总溶解固体(TDS)质量浓度呈显著正相关,而沂沭断裂带地热水样中F-质量浓度还与K^(+)、SO_(4)^(2-)质量浓度呈显著正相关,与Mg^(2+)和HCO_(3)质量浓度呈显著负相关;鲁中隆起地热区地热水中阳离子交换作用较沂沭断裂带地热区更为强烈,Na^(+)反应强度明显强于Mg^(2+)。鲁中隆起地热区和沂沭断裂带地热区均为裂隙型热储,热储岩性分别为石灰岩、灰岩热蚀变带和安山岩破碎带,水岩作用强烈。研究区地热水中氟离子的物质来源主要为萤石等含氟矿物的溶解沉淀,受控于阳离子交换等水岩相互作用影响,最终形成高氟地热水,其中高温和富钠对研究区地热水中氟离子富集影响较大。研究成果为地热资源开发利用提供了参考。 展开更多
关键词 鲁中隆起地热区 沂沭断裂带地热区 地热水 水岩作用 驱动机制 裂隙型热储
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滇中地区主要森林凋落物有效截留量及其影响因素
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作者 王平 李璐杉 +1 位作者 丁智强 李玉辉 《水土保持研究》 CSCD 北大核心 2024年第3期213-221,229,共10页
[目的]研究滇中地区主要森林类型凋落物有效截留量差异及其影响因素,为该地未来植被恢复和森林管理提供科学支撑。[方法]利用样方调查法、烘干法和浸泡法分析了昆明市双河—磨南德水源林自然保护区内的地带性次生常绿阔叶林(SF)、针阔... [目的]研究滇中地区主要森林类型凋落物有效截留量差异及其影响因素,为该地未来植被恢复和森林管理提供科学支撑。[方法]利用样方调查法、烘干法和浸泡法分析了昆明市双河—磨南德水源林自然保护区内的地带性次生常绿阔叶林(SF)、针阔混交林(TF)、旱冬瓜林(ACF)、华山松林(PA)、成熟云南松林(OPY)、幼龄云南松林(YPY)、银荆林(AD)7种主要森林类型凋落物未分解层(OL)和半分解层(OF)的有效截留量及其影响因素。[结果](1) 7种森林类型凋落物厚度为2.06~7.57 cm,其中OL层1.10~4.30 cm, OF层0.83~3.93 cm,凋落物层厚度排序为TF>ACF>PA>OPY>SF>AD>YPY,凋落物蓄积量为4.75~17.45 t/hm^(2),其中OL层占比为32.02%~62.48%,OF层占比为37.52%~67.98%,凋落物层蓄积量排序为TF>PA>SF>OPY>ACF>AD>YPY。(2)凋落物最大持水率为115.3%~170.7%,初始吸水速率为3.65~5.62 g/(g·h),凋落物持水率和浸水时间的关系可用对数函数y=aln(x)+b表示,吸水速率与浸水时间可用幂函数y=kt~n表示。(3)凋落物最大持水量为7.05~32.19 t/hm^(2),排序为PA>TF>SF>OPY>ACF>AD>YPY,有效截留量为5.45~25.34 t/hm^(2),以TF最高(25.34t/hm^(2)),PA(24.99 t/hm^(2))和SF(24.62 t/hm^(2))次之,YPY最低(5.45t/hm^(2)),影响有效截留量的场地特征主要为蓄积量、自然含水率、分解强度以及厚度,影响有效截留量的水动力过程主要是最大失水量、前6.0 h平均吸水速率和前2.0 h平均吸水速率。[结论]滇中地区未来植树造林应以针阔混交林为主,注重对地带性次生常绿阔叶林的保育,采取辅助自然更新的措施促进人工纯林向混交林演化,同时减少踩踏、收集凋落物等人类活动的干扰,从而增加森林生态系统凋落物的水源涵养能力。 展开更多
关键词 凋落物 主要森林类型 持水特性 有效截留量 滇中地区
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