水土保持科研与管理专家王万忠研究员

王万忠研究员 ,男 ,生于 1 95 2年 ,陕西省临潼县人。 1 976年毕业于陕西师范大学地理系 ,分配到中国科学院水利部水土保持研究所工作至今。 1 988年担任科研处处长 ,1 991年任中国科学院黄土项目办公室副主任 ,1 994年 9月 ,以高级访问学者身份赴日本东京大学、宫崎大学访问 ,1 995年任副所长 ,现任西北农林科技大学党委副书记 ,硕士研究生导师。王万忠研究员 ,长期从事土壤侵蚀与水土保持研究工作 ,曾主持国家“八五”攻关专题“黄土高原区域水土保持与农业发展综合研究”,国家“九五”攻关子专题“水土保持效益区域性评估及主体措施配置”,中国科学院知识创新项目子专题“高强度治理下黄土高原水土流失预测”以及“中国降雨侵蚀力研究”等项目。其中国家“八五”攻关专题“黄土高原区域水土保持与农业发展综合研究”获 1 998年中国科学院科技进步二等奖 ,他本人也被国家计委、国家科委及财政部授予“八五”国家科技攻关先进个人 ,受到江泽民总书记的接见。出版专著 2部 ,参编专著 2部 ,发表论文 2 0余篇 ,其中专著《黄土高原降雨侵蚀产沙与黄河输沙》、《黄土高原降雨侵蚀产沙数据图集》,以及论文“黄土地区...

水土保持专家介绍——我国著名土壤物理和水土保持专家邵明安研究员

邵明安 ,男 ,出生于 195 6年 ,湖南省常德县人。 1982年毕业于湖南师范大学物理系 ,获理学学士学位 ,1985年在中国科学院水利部水土保持研究所获理学硕士学位 (土壤学 ) ,1992起在美国留学 ,于 1996年在衣阿华州立大学获哲学博士学位(土壤学 )。现任中国科学院水利部水土保持研究所研究员 ,博士生导师 ,副所长 ,黄土高原土壤侵蚀与旱地农业国家重点实验室主任 ,中国土壤学会常务理事、土壤物理专业委员会主任 ,陕西省土壤学会理事长。兼任中国农业大学教授、湖南师范大学教授、西安理工大学教授 ,中国科学院水问题联合研究中心常委 ,陕西省决策咨询委员 ,中国农业专家咨询团首批专家。曾获首届中国科协青年科技奖、中国科学院方树泉青年科学家奖 ,陕西省有突出贡献的中青年专家 ,陕西省优秀留学回国人员等多项荣誉称号。邵明安研究员主持过中国科学院青年奖励基金项目 ,国家自然科学基金项目 ,中国科学院重大项目 ,国家“86 3”计划项目 ,国家“八五”科技攻关等国家和部委项目。在《Soil Science》、《Soil Sci.Soc.Am.J.》及《中国科学》、《科学通报》等国内外著名刊物发表论文 10 ...

土壤干湿交替对玉米耗水特性及水分利用的影响

旱地农业与灌溉农业中作物经常面临的土壤干旱与湿润交替变化是实际田间环境[1]。作物在生长发育的不同时期可能会遇上各不相同的土壤缺水胁迫 ,这些不同胁迫会对作物诱导出适应性的生理反应和伤害性影响[2 ,3],对此进行研究和认识 ,可以在节水灌溉中控制作物生长发育不同阶段土壤水分来调节作物生理过程 ,避免伤害性变化的发生 ,而促进适应性变化的产生 ,以改善作物发育后期籽粒形成阶段根系和叶片的功能来提高作物产量、品质和水分利用效率 ,达到高效、优质的目的。本文主要研究玉米在土壤干湿交替过程中的耗水特性和叶水分状况的关系 ,探讨提高水分利用效率的机制 ,为节水农业提供优化供水模式。1　材料与方法于 1 998年在香港浸会大学生物系温室进行 ,将陕单 9号玉米杂交种的种子播入口径 1 6ｃｍ ,高 1 8ｃｍ的生长钵内 ,内装 1 .8ｋｇ混合土 (蛭石、泥炭和沙子按体积 7∶3∶2 )混合 ,加入适量复合肥 ,在 2 6～ 30℃温室中生长 ,用高压钠灯做为光源 ,光合有效辐射 (ＰＡＲ)约为 40 0 μｍｏｌｍ- 2 ｓ- 1 。植株供水良好 ,每钵留两棵生长均匀一致的苗子 ,大约 1个月后 ,待玉米长至 3至 ...

黄土高原森林植被水土保持机理研究

土壤侵蚀是造成环境退化的一个主要因素。长期以来因不合理的利用自然资源 ,日积月累的结果使得植被生存的环境受到极大的破坏 ,导致植被衰退 ,引发了严重的水土流失 ;水土流失的不断加剧 ,破坏了土地的生产力 ,土壤肥力降低 ,土壤蓄水能力减弱 ,植被生存的环境进一步恶化 ,如此以往使生态环境陷入恶性循环状态。黄土高原严重的水土流失与该区植被覆被率低有密切的关系。据“七五”统计 ,主要水土流失区现有森林面积约 2 5× 1 0 6ｈｍ2 ,其中人工林占 40 %左右 ,有林地森林覆盖率仅为 9 3% ,而且能发挥水土保持功能的森林覆被率仅为 7 0 % ,这些覆被率高的地区 ,地处六盘山、乔山、黄龙山等地 ,该区域人口密度较低 ,人为活动轻微 ,水土流失小 ;在黄土高原水土流失严重的地区 ,森林覆被率更低 ,仅 5 9% ,即使发挥水土保持功能 ,在宏观范围内仍然难以体现出保持水土的效益 (中共陕西省委研究室等 ,1 999;吴钦孝等 ,1 998)。森林植被有强大的水土保持功能 ,体现在下列几个方面 :植被冠层及地被物的截留作用 ,使大气降水的损失量较大 ,减小了产生径流的净雨量 ;地被物层对汇流的延长作用 ...

温度对Ti_(45)Zr_(35)Ni_(20)合金电化学贮氢性能的影响

采用真空熔炼法制备了Ti45Zr35Ni20合金,研究了合金在不同温度下的电化学贮氢性能。结果表明,Ti45Zr35-Ni20电极的电化学性能随着温度而变化,温度从323 K升高到343 K时,电极的活化次数从22次减少到8次,放电容量从86.1 mAh/g增到135.0 mAh/g,快速放电能力也有所提高,然而,高温使电极的循环稳定性显著下降,自放电率增大。

毛细管电泳电化学法对苯丙胺的检测

建立了毛细管电泳电化学法检测尿样中苯丙胺的方法。以直径33μm的碳纤维电极为工作电极,在最佳检测条件即检测电位1.30 V,15 kV下电动进样3 s,选择电泳分离高压为15 kV,电泳缓冲液为pH10.0的20 mmol/L的磷酸盐,实验发现,在1.0×10-8~1.0×10-5mol/L范围内,响应电流与苯丙胺浓度呈良好的线性关系,线性相关系数为0.998 4,检出限达3.3×10-9mol/L。对于浓度为1.0×10-5mol/L的苯丙胺,峰电流及迁移时间的RSD分别为2.4%和2.5%(n=7)。对于尿样中2.0×10-5mol/L的苯丙胺,回收率为75%。

Ambipolar permeable metal-base transistor based on NPB/C-60 heterojunction

In this paper, we report the fabrication of permeable metal-base organic transistors based on N,N'-diphenyl-N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPB)/C-60 heterojunction as both emitter and collector. By applying different polarities of voltage bias to the collector and the base, and input current to the emitter, the ambipolar behavior can be observed. The device demonstrates excellent common-base characteristics both in P-type and N-type modes with common-base current gains of 0.998 and 0.999, respectively.

Electrochemiluminescence detection with integrated indium tin oxide electrode on electrophoretic microchip for direct bioanalysis of lincomycin in the urine

In this article, an antibiotic, lincomycin was determined in the urine sample by microchip capillary electrophoresis (CE) with integrated indium tin oxide (ITO) working electrode based on electrochemiluminescence (ECL) detection. This microchip CE-ECL system can be used for the rapid analysis of lincomycin within 40 s. Under the optimized conditions, the linear range was obtained from 5 to 100 muM with correlation coefficient of 0.998. The limit of detection (LOD) of 3.1 muM was obtained for lincomycin in the standard solution. We also applied this method to analyzing lincomycin in the urine matrix. The limit of detection of 9.0 muM was obtained. This method can determine lincomycin in the urine sample without pretreatment, which demonstrated that it is a promising method of detection of lincomycin in clinical and pharmaceutical area.

Simultaneous determination of dopamine and ascorbic acid at an in-site functionalized self-assembled monolayer on gold electrode

The in-site functionalization of 4-aminothiophenol (4-ATP) self-assembled monolayer on gold electrode at physiological pH yields a redox active monolayer of 4'-mercapto-N-phenylquinone diimine (MNPD). The functionalized electrode exhibits excellent electrocatalytic responses towards dopamine (DA) and ascorbic acid (AA), reducing the overpotentials by about 0.22 V and 0.34 V, respectively, with greatly enhanced current responses. Due to its different catalytic activities toward DA and AA, the modified electrode resolves the overlapping voltammetric responses of DA and AA into two well-defined voltammetric peaks by differential pulse voltammetry (DPV), which can be used for the simultaneous determination of these species in a mixture. The catalytic peak current obtained from DPV was linearly related to DA and AA concentration in the ranges of 5.0 x 10-6 - 1.25 x 10-4 M and 8.0 x 10-6 - 1.3 x 10-4 M with correlation coefficient of 0.999 and 0.998, respectively. The detective limits (3sigma) for DA and AA were found to be 1.2 x 10-6 M and 2.4 x 10-6 M, respectively.

Composite film of carbon nanotubes and chitosan for preparation of amperometric hydrogen peroxide biosensor

A new amperometric biosensor for hydrogen peroxide was developed based on cross-linking horseradish peroxidase (HRP) by glutaraldehyde with multiwall carbon nanotubes/chitosan (MWNTs/chitosan) composite film coated on a glassy carbon electrode. MWNTs were firstly dissolved in a chitosan solution. Then the morphology of MWNTs/chitosan composite film was characterized by field-emission scanning electron microscopy. The results showed that MWNTs were well soluble in chitosan and robust films could be formed on the surface. HRP was cross-linked by glutaraldehyde with MWNTs/chitosan film to prepare a hydrogen peroxide biosensor. The enzyme electrode exhibited excellent electrocatalytic activity and rapid response for H2O2 in the absence of a mediator. The linear range of detection towards H2O2 (applied potential: -0.2 V) was from 1.67 x 10(-5) to 7.40 x 10(-4) M with correction coefficient of 0.998. The biosensor had good repeatability and stability for the determination of H2O2. There were no interferences from ascorbic acid, glucose, citrate acid and lactic acid.

Manipulation, dissection, and lithography using modified tapping mode atomic force microscope

A modified tapping mode of the atomic force microscope (AFM) was introduced for manipulation, dissection, and lithography. By sufficiently decreasing the amplitude of AFM tip in the normal tapping mode and adjusting the setpoint, the tip-sample interaction can be efficiently controlled. This modified tapping mode has some characteristics of the AFM contact mode and can be used to manipulate nanoparticles, dissect biomolecules, and make lithographs on various surfaces. This method did not need any additional equipment and it can be applied to any AFM system.

A new hydrometallurgical process for extracting rare earths from apatite using solvent extraction with P-350

In this paper, a new process is proposed to recover rare earths from nitric acid leaching of apatite without interfering with the normal route for fertilizer production using solvent extraction with dimethyl heptyl methyl phosphonate CH3P(O)(OC8H17)(2) (P-350, B). In the present work, the leaching conditions are studied. In selected condition, apatite was dissolved in 20% (v/v) nitric acid solution at 60-70 degrees C while agitating. The most suitable acidity for extraction is 0.4 M HNO3. More than 98% of rare earths in apatite can be recovered using countercurrent extraction process with six stages when phase ratio = 0.5, and defluorination is unnecessary. The influences of phase ratio, stage number, acidity and salting-out agent on extractabilities Of P-350 are studied. The results show that rare earths can be separated with P-350 from Ca, P, Fe and other impurities. Mixed rare earth oxides (REO) of which purity is more than 95% with yield over 98% can be obtained.

KMgF_3及KMgF_3∶Eu~(2+)晶体的射线辐照效应

KMgF3∶Eu晶体中Eu3+→Eu2+的转换率在低浓度掺杂时接近100%,完全转换的饱和掺杂摩尔分数为0.29%.实验条件下,KMgF3晶体的X射线1 h辐照损伤可在约100 h后恢复;KMgF3∶Eu2+晶体经X射线辐照后,360 nm锐峰发射强度略有降低.不同剂量的γ射线辐照,KMgF3晶体热释光曲线的各个温度峰强度变化明显不同,即使小剂量辐照,造成的损伤也较难恢复,如γ射线辐照剂量为103Gy时,辐照损伤的恢复时间约需30 d.KMgF3∶Eu2+晶体360 nm锐峰发射强度随γ射线辐照剂量增大而呈线性降低.

Simultaneous determination of tramadol and lidocaine in urine by end-column capillary electrophoresis with electrochemiluminescence detection

Tramadol and lidocaine, used as analgesic and local anesthetic in surgery, are partly excreted by kidney. For the first time, we developed a simple and sensitive method, based on capillary electrophoresis with electrochemiluminescence (ECL) detection by end column mode without joint to monitor tramadol and lidocaine in urine. To eliminate the influence of ionic strength of urine sample, analytes were extracted by ether. Tripropylamine (TPA) was used as internal standard. ne recoveries of tramadol and lidocaine were between 94% and 97% at different levels. The method exhibited the linear range for the tramadol and lidocaine from 1.0 X 10(-7) to 1.0 X 10(-4) mol/L with correlation efficient of 0.998. The relative standard deviation (RSD) was 2.9% and 2.7% (n = 8) for tramadol and lidocaine, respectively. The limit of detection (LOD) was 6.0 x 10(-8) mol/L and 4.5 x 10(-8), mol/L (S/N = 3) for tramadol and lidocaine, respectively. The application for detecting tramadol and lidocaine in urine of patients showed that the method was valuable in clinical and biochemical laboratories for detecting tramadol, lidocaine and other tertiary amine pharmaceuticals for various purpose, such as metabolism investigation.