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Determination of a Reasonable Percentage for Ecological Water-Use in the Haihe River Basin, China

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Pedosphere 2006年第1期16卷 33-42页

作者： XIA jun feng Hua-Li ZHAN Che-sheng NIU Cun-Wen Key Laboratory of Water Cycle ＆ Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Science Beijing 100101 （China）. State Key Laboratory of Water Resources ＆ Hydropower Engineering Sciences Wuhan University Wuhan 430072（China） Nanjing Hydraulic Research Institute Nanjing 210029 （China）

An investigation was conducted to study problems of determining a reasonable percentage for ecological water-use in the Haihe River Basin of China. Three key aspects for the ecological water requirement （EWR） were analyzed, involving i） the EWR for river system, ii） the EWR for wetlands and lakes, and iii） the EWR for discharge into the sea to maintain the estuary ecological balance of the Haihe River. The Montana method and related water level-flow relationships, and the statistic approach based on hydrological records were applied to estimate different components of EWR. The results showed that the total ecological water demand in the region, was about 3.47-14.56 billion m^3. Considering flow regime change and uncertainty, the ecological water demand could be estimated by the hydrological frequency approach. Preliminary analysis showed that for different annual runoff under the frequencies of 20%, 50%, 75% and 95%, the ecological water demand approached 12%-50%, 18%-74%, 24%-103%, 35%-148% and 16%-66%, respectively. By further analysis to balance ecological water-use and socioeconomic water-use, the rational percentage of ecological water-use was estimated as 35%-74%, that provides useful information to judge whether the allocation of water resources is reasonable, and was proved to be satisfactory by comparing with the practical condition.

关键词： ecological water requirement ecological water-use Haihe River Basin

An integrated optimization design of a fishing ship hullform at different speeds

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Journal of Hydrodynamics 2018年第6期30卷 1174-1181页

作者： Lei Yang sheng-zhong Li feng Zhao Qi-jun Ni China Ship Scientific Research Center Wuxi 217082China

This paper shows how to improve the hydrodynamics performance of a ship by solving a shape optimization design problem at different speeds using the simulation-based design(SBD) technique. The SBD technique is implemented by integrating the advanced CFD codes, the global optimization algorithms and the geometry modification methods, which offers a new way for the hullform optimization design and the configuration innovation. The multiple speed integrated optimization for the hullform design is a challenge. In this paper, an example of the technique application for a fishing ship hullform optimization at different speeds is demonstrated. In this optimization process, the free-form deformation method is applied to automatically modify the geometry of the ship, and the multi-objective particle swarm optimization(MOPSO) algorithm is adopted for exploring the design space. Two objective functions, the total resistances at two different speeds(12 kn and 14 kn) are assessed by the RANS solvers. The optimization results show that the decrease of the total resistance is significant after the optimization at the two speeds, with a reduction of 5.0% and 11.2%, respectively. Finally, dedicated experimental validations for the design model and the optimized model are carried out for the computation and the optimization processes. At the two speeds, the reduction of the total resistance in the model scale is about 6.0% and 11.8% after the optimization. It is a valuable result in view of the small modifications allowed and the good initial performances of the original model. The given practical example demonstrates the feasibility and the superiority of the proposed SBD technique for the multiple speed integrated optimization.

关键词： Hullform design optimization simulation-based design (SBD) techniques multiple speeds optimization CFD techniques total resistance

Photoelectrochemical performance of TiO_(2) nanotube arrays by in situ decoration with different initial states

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Rare Metals 2021年第3期40卷 720-727页

作者： Fan Li Chun-Lai Wang sheng Ding Kun Yang Chang-jun Liu feng Tian Institute of Medical Support Technology Academy of Military SciencesTianjin 300161China

Here,carbon dots(CDs) only or nanocomposites of CDs and TiO_(2)(CDs-TiO_(2)) were used to decorate titanium dioxide nanotube arrays(TiO_(2)NTs) in situ by solvothermal *** initial states of TiO_(2)NTs were prepared for contrast,including the amorphous TiO_(2)NTs(TiO_(2)NTs-0) just experienced anodic oxidation process and that further calcined TiO_(2)NTs(TiO_(2)NTs-450).It was found that the newborn CDs or CDs-TiO_(2)were more likely to anchor on TiO_(2)NTs-0 than the calcined TiO_(2)NTs-450,and more Ti-C bonds were found in the composites which were derived from TiO_(2)NTs-0 after the solvothermal *** evident photocurrent could be demonstrated for either CDs or CDs-TiO_(2)decorated TiO_(2)NTs once exposed to visible *** CDs-TiO_(2)NTs-0 showed the highest photocurrent density(4.51 μA·cm^(-2)).However,the results of photodegradation measurements revealed that CDs-TiO_(2)decorated TiO_(2)NTs with different initial states(especially CDs-TiO_(2)-TiO_(2)NTs-0) showed more excellent photocatalytic activity under both ultraviolet(UV) and visible light illumination.

关键词： Titanium dioxide nanotube arrays Carbon dots Solvothermal technique Photocatalysis

L^(p)Solution of Reflected BSDEs with One Continuous Barrier and Quasi-linear Growth Generators

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Acta Mathematicae Applicatae Sinica 2024年第4期40卷 943-953页

作者： sheng-jun FAN School of Mathematics China University of Mining and TechnologyXuzhou 221116China

This paper is devoted to solving a reflected backward stochastic differential equation(BSDE in short)with one continuous barrier and a quasi-linear growth generator g,which has a linear growth in(y,z),except the upper direction in case of y1)solutions for the reflected *** also prove that the minimal Lpsolution can be approximated by a sequence of Lpsolutions of certain reflected BSDEs with Lipschitz generators.

关键词： Reflected BSDEs Quasi-linear growth L^(p)solution Existence Comparison theorem

Al(III) speciation distribution and transformation in high concentration PACl solutions

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Journal of Environmental Sciences 2006年第5期18卷 872-879页

作者： HUANG Li TANG Hong-xiao WANG Dong-sheng WANG Shui-feng DENG Zai-jun State Key Lab of Environmental Aqueous Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Analytical and Testing Center Beijing Normal University Beijing 100875 China

Effects of Al（Ⅲ） concentration and pH on the speciation of Al（Ⅲ） in polyaluminum chloride （PACl） solutions especially on the Al13 fraction were investigated. A series of PACl samples were prepared over the range of Al（Ⅲ） concentration from 0.01 to 2.0 mol/L with the B （OH/Al ratio） value from 1.0 to 2.5 by forced hydrolysis of AICl3. The samples were characterized by ferron assay, pH and 27^Al NMR. It was shown that the Al（Ⅲ） concentration had a dramatic effect on the hydrolysis processes and the species distribution of PACl was in relate to the decrease of pH. The fraction of Al species, Alb （or Al13） decreased and Al0 increased with increase of total Al（Ⅲ） concentration. Under the condition of Al（Ⅲ） 2.0 reel/L, B = 2.5, the pH value was 2.73 and no Al13 could be detected. During diluting and aging, the species distribution evoIved. The Al13 could then be detected again and the amounts increased with time. If the diluted samples were concentrated by freeze dry at -35℃ or heating at 80℃, the pH value and Al13 content would decrease with the increased concentration. It demonstrated that the key factor for formation of Al13 in concentrated PACl was pH value.

关键词： PACl Al13 B value pH speciation

Effects of Si Addition and Long-Term Thermal Exposure on the Tensile Properties of a Ni–Mo–Cr Superalloy

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Acta Metallurgica Sinica(English Letters) 2015年第8期28卷 951-957页

作者： Zhou-feng Xu Jia-sheng Dong Li Jiang Zhi-jun Li Xing-Tai Zhou Thorium Molten Salts Reactor Center Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Metal Research Chinese Academy of Sciences

The effect of long-term thermal exposure on the grain boundary carbides and the tensile behavior of two kinds of Ni–Mo–Cr superalloys with different silicon contents（0 and 0.46 wt%） was investigated. Experimental results showed granular M2C carbides formed at the grain boundaries after exposure for 100 h for the non-silicon alloy. Furthermore, these fine granular M2C carbides will transform into plate-like M6C carbides as exposure time increases. For the Si-containing alloys,only the granular M6C carbides formed at the grain boundaries during the whole exposure time. The coarsening of the grain boundary carbides occurred in both alloys with increasing exposure time. In addition, the coarsening kinetics of the grain boundary carbides for the non-silicon alloy is faster than that of the standard alloy. The tensile properties of both alloys are improved after exposure for 100 h due to the formation of nano-sized grain boundary carbides. The grain boundary carbides are coarsened more seriously for non-silicon alloys than that of Si-containing alloys, resulting in a more significant decrease in the tensile strength and elongation for the former case. Silicon additions can effectively inhibit the severe coarsening of the grain boundary carbides and thus avoid the obvious deterioration of the tensile properties after a long-term thermal exposure.

关键词： Ni–Cr–Mo Silicon Carbides Mechanical properties

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接枝型PUA乳液合成及聚合动力学研究

应用化工 2010年第12期39卷 1830-1834,1842页

作者：陈广美陈炜盛俊峰张明月黄毅萍安徽建工学院材料与化学工程学院安徽合肥230601 安徽大学化学化工学院安徽合肥230039

甲基丙烯酸羟丙酯与水性聚氨酯预聚体反应,得到双烯封端的水性聚氨酯乳液。在乳化剂、引发剂存在下,将丙烯酸酯单体与水性聚氨酯乳液充分混合,并引发聚合,制备了接枝型PUA乳液。TEM观察了PUA乳液的形貌,PUA乳液的粒径在60～120 nm之间;F... 详细信息

甲基丙烯酸羟丙酯与水性聚氨酯预聚体反应,得到双烯封端的水性聚氨酯乳液。在乳化剂、引发剂存在下,将丙烯酸酯单体与水性聚氨酯乳液充分混合,并引发聚合,制备了接枝型PUA乳液。TEM观察了PUA乳液的形貌,PUA乳液的粒径在60～120 nm之间;FTIR和NMR表征了合成的PUA结构,显示丙烯酸酯的加入改变了PU本身的氢键相互作用;转化率测试表明,甲基丙烯酸羟丙酯与PU预聚体的反应具有二级动力学特征,而乳化剂的用量影响丙烯酸酯单体与双烯封端聚氨酯乳液的反应速率,反应速率与乳化剂用量符合Rp∝[SDS]0.28。

关键词：水性聚氨酯预聚体双烯封端氢键相互作用聚合动力学

Analysis on Shear Deformation for High Manganese Austenite Steel during Hot Asymmetrical Rolling Process Using Finite Element Method

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Journal of Iron and Steel Research International 2015年第11期22卷 990-995页

作者： feng-li SUI Xin WANG jun ZHAO Biao MA Chang-sheng LI School of Metallurgical Engineering Anhui University of Technology The 4th Steel Rolling Plant Ma’anshan Iron & Steel Group State Key Laboratory of Rolling and Automation Northeastern University

Based on the rigid-plastic finite element method（FEM）, the shear stress field of deformation region for high manganese austenite steel during hot asymmetrical rolling process was analyzed. The influences of rolling parameters, such as the velocity ratio of upper to lower rolls, the initial temperature of workpiece and the reduction rate, on the shear deformation of three nodes in the upper, center and lower layers were discussed. As the rolling parameters change, distinct shear deformation appears in the upper and lower layers, but the shear deformation in the center layer appears only when the velocity ratio is more than 1.00, and the absolute value of the shear stress in this layer is changed with rolling parameters. A mathematical model which reflected the change of the maximal absolute shear stress for the center layer was established, by which the maximal absolute shear stress for the center layer can be easily calculated and the appropriate rolling technology can be designed.

关键词： high manganese austenite steel hot asymmetrical rolling shear deformation finite element method

New Members of High-Energy-Density Compounds: YN5 and YN8

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Chinese Physics Letters 2021年第6期38卷 49-53页

作者： jun-Yi Miao Zhan-sheng Lu feng Peng Cheng Lu School of Physics Henan Normal UniversityXinxiang 453007China College of Physics and Electronic Information Luoyang Normal UniversityLuoyang 471022China School of Mathematics and Physics China University of Geosciences(Wuhan)Wuhan 430074China

Polymeric nitrogen is a promising candidate for a high-energy-density material. Synthesis of energetic compounds with high chemical stability under ambient conditions is still a challenging problem. Here we report a theoretical study on yttrium nitrides by first principles calculations combined with an effective crystal structure search method. It is found that many yttrium nitrides with high nitrogen content can be formed under relatively moderate pressures. The results indicate that the nitrogen-rich YN_(5) and YN_(8) compounds are recoverable as metastable high-energy materials under ambient conditions, and can release enormous energies(2.51 kJ·g^(-1) and 3.18 kJ·g^(-1)) while decomposing to molecular nitrogen and YN. Our findings enrich the family of transition metal nitrides, and open avenues for design and synthesis of novel high-energy-density materials.

关键词： material ambient yttrium