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永平县自然保护地整合优化探析

黑龙江生态工程职业学院学报 2024年第5期37卷 7-12,34页

作者：张加宝李金亮云南省林业调查规划院大理分院云南大理671000

以永平县范围内的4个自然保护地为例,通过对自然保护地的调查、评估,梳理自然保护地的现状,分析其存在的问题,按照自然保护地整合优化相关政策规定,提出永平县自然保护地整合优化预案,以期在深入推进永平县自然保护地体系建设中提供一... 详细信息

以永平县范围内的4个自然保护地为例,通过对自然保护地的调查、评估,梳理自然保护地的现状,分析其存在的问题,按照自然保护地整合优化相关政策规定,提出永平县自然保护地整合优化预案,以期在深入推进永平县自然保护地体系建设中提供一种方法和路径,同时为全国自然保护地建设提供参考。

关键词：自然保护地整合优化永平县问题预案

模式切换结合模糊PWM的气动容腔压力控制方法

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液压与气动 2024年第2期48卷 78-84页

作者：孙国鑫李帅鹏虞启辉张家宝内蒙古科技大学机械工程学院内蒙古包头014000

容腔压力是管路系统的主要控制对象,用高速开关阀代替普遍使用的比例阀进行压力调控,可大幅降低系统成本。针对单腔双阀压力跟踪系统,提出了一种模式切换结合模糊PWM的气动容腔压力控制方法。该方法的目的是减小超调,降低调节时间,提高... 详细信息

容腔压力是管路系统的主要控制对象,用高速开关阀代替普遍使用的比例阀进行压力调控,可大幅降低系统成本。针对单腔双阀压力跟踪系统,提出了一种模式切换结合模糊PWM的气动容腔压力控制方法。该方法的目的是减小超调,降低调节时间,提高压力跟踪性能。首先由模糊控制器根据偏差给出占空比指令,然后通过引入PWM将开关量转换为连续量调节,进而通过快速切换开关阀的工作模式实现容腔内压力的精细化调节。仿真结果表明:阶跃响应的超调量小于0.6%,峰值时间0.15 s,调节时间0.16 s,同时能够很好的跟踪上0.5 Hz的谐波信号,与当前控制策略相比,超调量和调节时间均有明显的降低。

关键词：模式切换模糊PWM 压力控制高速开关阀

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Acid and Alkali Buffer Capacity of Typical Fluvor-Aquic Soil in Huang-Huai-Hai Plain

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Agricultural Sciences in China 2009年第11期8卷 1378-1383页

作者： HUANG Ping zhang jia-bao ZHU An-ning zhang Cong-zhi State Environmental Station ofAgro-Ecosystem of Fengqiu State Key Laboratory of Soil Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 P.R.China Graduate School Chinese Academy of Sciences Beijing 100049 P.R. China

Soil acid and alkali buffer capacity, as a major indicator for evaluating its vulnerability and resistibility to acidification and alkalization, is an important factor affecting the sustainable agriculture, through knowledge on which soil acidification process can be predicted and modified. In this study, titration curve method was adopted to investigate the pH buffer capacity （pHBC） of fluvor-aquic soil, and separate titration curves were established by adding incremental amounts of either standardized hydrochloric acid （HC1）（0.12 mol L^-1） or sodium hydroxide （NaOH）（0.10 mol L^-1） to soil suspended in deionized water （soil：solution = 1：5）. Soil pH was measured after 7 d resuspension and isothermal equilibrium （T = 25℃）. Linear regressions were fitted to the linear portion of each titration curve and the slopes of these lines were derived as the soil pHBC. The results showed that significant correlations between the amounts of adding acid or alkali and each pH change were presented, and titration curve method was feasible for measurement of pHBC on typical fluvor-aquic soil in Huang-Huai-Hai Plain, and the coefficients of determination were higher than the similar researches on acid soil （R^2 = 0.96）. The slope-derived pHBC of acid and alkali were 158.71 and 25.02 mmol kg^-1, respectively. According to the classification of soil buffer systems, the soil tested belongs to the calcium carbonate buffer system, carbonates contribute the most to pHBC, and the contribution of soil organic matter relatively less than it.

关键词： fluvor-aquic soil Huang-Huai-Hai Plain pH buffer capacity (pHBC)

Stable Isotope Studies of Crop Carbon and Water Relations:A Review

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Agricultural Sciences in China 2009年第5期8卷 578-590页

作者： zhang Cong-zhi zhang jia-bao ZHAO Bing-zi zhang Hui HUANG Ping State Experimental Station of Agro-Ecosystem in Fengqiu/State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 P.R.China Graduate School of the Chinese Academy of Sciences Beijing 100049 P.R.China

Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper is to review the current state of knowledge on stable isotopes of carbon, oxygen, and hydrogen in the research of crop carbon and water relations, such as carbon isotope discrimination （△^13C） during carbon fixation process by photosynthesis, application of △^13C in crop water use efficiency （WUE） and breeding programs, oxygen isotope enrichment during leaf water transpiration, CO2 fixation by photosynthesis and release by respiration, application of hydrogen isotope composition （619） and oxygen isotope composition （6180） for determination of water source used by a crop, stable isotope coupling Keeling plot for investigating the carbon and water flux in ecosystem, energy and material cycle in SPAC and correlative integrative models on stable isotope. These aspects contain most of the stable isotope researches on crop carbon and water relations which have been widely explored internationally while less referred in China. Based on the reviewed literatures, some needs for future research are suggested.

关键词： carbon fixation crop review stable isotopes water relations

Nitrate-Nitrogen Dynamics and Nitrogen Budgets in Rice-Wheat Rotations in Taihu Lake Region, China

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Pedosphere 2013年第1期23卷 59-69页

作者： zhang Jun-Hua LIU jian-Li zhang jia-bao CHENG Ya-Nan WANG Wei-Peng Institute of Soil Science Chinese Academy of Sciences State Key Laboratory of Rice Biology China National Rice Research Institute University of Chinese Academy of Sciences

Nitrate-nitrogen （NO3-N） dynamics and nitrogen （N） budgets in rice （0ryza sativa L.）-wheat （Triticum aestivum L.） rotations in the Taihu Lake region of China were studied to compare the effects of N fertilizer management over a two-year period. The experiment included four N rates for rice and wheat, respectively： N1 （125 and 94 kg N ha-1）, N2 （225 and 169 kg N ha-1）, N3 （325 and 244 kg N ha-1）, and NO （0 kg N ha-1）. The results showed that an overlying water layer during the rice growing seasons contributed to moderate concentrations of NO3-N in sampled waters and the concentrations of NO3-N only showed a rising trend during the field drying stage. The NO3-N concentrations in leachates during the wheat seasons were much higher than those during the rice seasons, particularly in the wheat seedling stage. In the wheat seedling stage, the NO3-N concentrations of leachates were significantly higher in N treatments than in NO treatment and increased with increasing N rates. As the NO3-N content （below 2 mg N L-1） at a depth of 80 cm during the rice-wheat rotations did not respond to the applied N rates, the high levels of NO3-N in the groundwater of paddy fields might not be directly related to NO3-N leaching. Crop growth trends were closely related to variations of NO3-N in leachates. A reduction in N application rate, especially in the earlier stages of crop growth, and synchronization of the peak of N uptake by the crop with N fertilizer application are key measures to reduce N loss. Above-ground biomass for rice and wheat increased significantly with increasing N rate, but there was no significant difference between N2 and N3. Increasing N rates to the levels greater than N2 not only decreased N use efficiency, but Mso significantly increased N loss. After two cycles of rice-wheat rotations, the apparent N losses of N1, N2 and N3 amounted to 234, 366 and 579 kg N ha-1, respectively. With an increase of N rate from NO to N3, the percentage of N uptake in total N inpu

关键词： above-ground biomass crop uptake nitrate-nitrogen leaching nitrogen mineralization nitrogen transport

Changes in soil organic carbon and aggregate stability after conversion to conservation tillage for seven years in the Huang-Huai-Hai Plain of China

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Journal of Integrative Agriculture 2015年第6期14卷 1202-1211页

作者： SHU Xin ZHU An-ning zhang jia-bao YANG Wen-liang XIN Xiu-li zhang Xian-feng State Experimental Station of Agro-Ecosystem in Fengqiu State Key Laboratory of Soil and Sustainable Agriculture/Institute of Soil Science Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

Soil aggregate stability and organic carbon（OC） are regarded as effective indicators of soil structure and quality. A longterm field experiment was established in 2006 to examine the influence of tillage systems on soil aggregation and OC in a sandy loam soil in the Huang-Huai-Hai Plain of China. The study involved eight treatments： plowing every year with（TS） and without residue（T）, plowing every 2 years with（2TS） and without residue（2T）, plowing every 4 years with（4TS） and without residue（4T）, and no plowing with（NTS） and without residue（NT）. In 2013, soil samples were collected at depths of 0–5, 5–10 and 10–20 cm, and separated into three aggregate-size classes： macroaggregates（〉250 μm）, microaggregates（53–250 μm） and the silt＋clay fraction（〈53 μm） using wet sieving method. Soil parameters measured were water-stable aggregates, geometric mean diameter（GMD）, mean weight diameter（MWD） and OC concentrations in different aggregate-size fractions and in bulk soil. The tillage treatments significantly（P〈0.05） influenced soil aggregate stability and OC distribution. Higher MWD and GMD were observed in 2TS, 4TS and NTS as compared to T. With increasing soil depth, the amount of macroaggregates and MWD and GMD values were increased, while the proportions of microaggregates and the silt＋clay fraction were declined. The OC concentrations in different aggregate fractions at all soil depths followed the order of macroaggregates〉microaggregates〉silt＋clay fraction. In the 0–5 cm soil layer, concentrations of macroaggregateassociated OC in 2TS, 4TS and NTS were 14, 56 and 83% higher than for T, whereas T had the greatest concentration of OC associated with the silt＋clay fraction in the 10–20 cm layer. Soil OC concentrations under 4TS and NTS were significantly higher（P〈0.05） than that of T in the 0–10 cm layer. Residue retention promoted formation of macroaggregates, increased macroaggregate-associated OC concentrations and thus increased total soil OC stock. The macroaggregate-

关键词： aggregate conservation residue sequestration aggregation depths proportions declined wheat concluded

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封丘县典型农田土壤质量与时空变化特征

生态与农村环境学报 2024年第3期40卷 408-417页

作者：谢越马东豪王擎运赵炳梓朱安宁张丛志张佳宝李晓鹏安徽农业大学资源与环境学院安徽合肥230036 土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所) 江苏南京210008

黄淮海平原作为我国重要的粮食产区,系统全面地评价该区域典型潮土的质量变化,对指导农业生产具有重要意义。以典型潮土分布的封丘县作为研究区,选取1984、2003和2011年的17项土壤指标,基于土壤参与生态过程中作物生产、碳固存、持水净... 详细信息

黄淮海平原作为我国重要的粮食产区,系统全面地评价该区域典型潮土的质量变化,对指导农业生产具有重要意义。以典型潮土分布的封丘县作为研究区,选取1984、2003和2011年的17项土壤指标,基于土壤参与生态过程中作物生产、碳固存、持水净化和养分运移等功能,构建土壤综合质量评价系统,采用主成分分析结合逼近理想点排序法(TOPSIS)计算各功能得分及土壤质量综合指数,通过GIS空间插值描述封丘县27年内潮土耕作区土壤质量和功能的时空变化特征。结果表明:(1)封丘县土壤全氮、全磷、碱解氮、有效磷、速效钾和有机质含量及阳离子交换量、饱和导水率和孔隙度均呈现不同程度的提升趋势;全钾含量、pH、容重、田间持水量和有效含水量则呈逐年降低趋势;(2)封丘县土壤作物生产、碳固存和养分运移功能得分均有所提升,增长率分别为9.29%、9.68%和7.36%,持水净化功能得分则降低4.17%;(3)封丘县土壤质量综合指数提升较为明显,1984年全县耕地土壤质量综合指数均≤2.0,2003年综合指数>2.0的耕地面积占全县总面积的8.44%,2011年提升至24.05%。整体而言,封丘县该时期的耕地保护和利用模式基本是有效的,封丘县耕地整体质量不断向好的方向发展,相关结果可以为黄淮海地区耕地资源可持续利用提供参考。

关键词：土壤质量评价体系土壤功能黄淮海平原 TOPSIS法 GIS

Density-Functional Theories for Polyelectrolyte Systems

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Chinese Journal of Polymer Science 2024年第9期42卷 1302-1312,I0006页

作者： jia-Wei zhang Yu-Hang zhang bao-Hui Li Qiang Wang School of Physics Nankai UniversityTianjin90001China Department of Chemical and Biological Engineering Colorado State University1370 Campus DeliveryFort CollinsCO80523-1370USA

Polymer density-functional theories(PDFTs)have distinct advantages in the study of polyelectrolyte(PE)systems over experiments and molecular *** we give an introductory review of some PDFTs recently developed for PE *** start with a general formalism of PDFTs and its relation to the widely used polymer self-consistent field theory(SCFT),then explain the various correlations that are neglected in SCFT but can be accounted for in PDFTs,including those due to the excluded-volume interaction and chain connectivity of uncharged polymers,the electrostatic correlations of small ions,and the chain correlations in *** also list some applications of PDFTs for PE systems,and finally give some perspectives on future *** hope that our review can attract more researchers to apply and further develop PDFTs as a promising class of theoretical and computational tools.

关键词： Polymer density-functional theories Polyelectrolytes Correlations

Enhanced preparation of dendritic metallic vanadium in recyclable NaCl-KCl-VCl_(2) molten salt by V_(2)CO electrolysis

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Rare Metals 2024年第8期43卷 3961-3973页

作者： jia-Liang An Ming-Yong Wang Yong-Zheng jia Jin-Tao zhang bao-Yan Feng Shu-Qiang jiao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China College of Material Science and Engineering Hebei Province Laboratory of Inorganic Nonmetallic MaterialsNorth China University of Science and TechnologyTangshan 063210China

A promising method for the preparation of pure metallic vanadium via V_(2)CO anode electrolysis was proposed and *** simple and controllable synthesis of a molten chloride salt containing VCl_(2) by an insitu reaction between VCl_(3) and metallic vanadium was verified through thermodynamic analysis and ***-KCl-VCl_(2) molten salt exhibited excellent recycling performance and could be repetitively used to prepare metallic vanadium by V_(2)CO *** V^(2+) ions remained in the molten salt after *** electrolysis conditions,such as the cathode diameter,current density,V^(2+) ion concentration,and temperature,were optimised to maximise the current *** was also simulated to reveal the regulatory *** highest current efficiency was 85%.The purity of metallic vanadium was up to 99.8%.In this study,an easy and efficient preparation of pure metallic vanadium was achieved.

关键词： V_(2)CO Metallic vanadium Current efficiency Molten salt electrolysis