HYDROLOGICAL OBSERVATION IN AN EVERGREEN BROAD LEAVED FOREST IN THE WUYI MOUNTAINS

[中文文摘]对武夷山甜槠林成熟林水文学效应的研究结果表明：观测期间，年大气降水量2678.78ｍｍ，林内雨量2182.04ｍｍ，林冠截留量为496.74ｍｍ；林内雨中，穿透雨量2082.08ｍｍ，树干茎流99.96ｍｍ；到达甜槠林地作用面的林内雨量中，被地表枯枝落叶层截留的雨量为159.84ｍｍ，地表径流量11.6ｍｍ，地下渗流量109.32ｍｍ，其余林内雨量形成土壤含水量增量并由地表物理蒸发、根系吸收以及植物蒸腾所消耗；甜槠林地o~20０ｃｍ土层水分初渗率78.6ｍｍ·ｍｉｎ－１，稳渗率１５．５ｍｍ·ｍｉｎ－１，达到稳渗历时４５ｍｉｎ，地表枯枝落叶最大持水量5.2ｍｍ，土壤蓄水量154.0ｍｍ。与国内其它地区不同类型的森林相比较，武夷山甜槠林具有较强的水文学效能。[英文文摘]Hydrological observations were made in a 76 year old Castanopsis eyrei forest of the Wuyi Mountains.The results are as follows:(1)In the study period during 1993～1994,annual gross precipitation,net precipitation (throughfall was 208204mm and stemflow was 9996mm)and interception loss were 267878mm,218204mm and 49674mm respectively.Interception rate was 1845%.(2)Net precipitation,the part of gross precipitation appearing on the forest floor,was redistributed through different routes.The part absorbed by litter layer was an annual amount of 15984mm,and accounting for 733%.The parts as surface runoff and below ground drainage were annual amounts of 116mm and 10932mm respectively,and accounting for0.53% and 5.01%,respectively.The rest was kept in soil and then lost to the atmosphere by means of ground physical evaporation or plant transpiration as absorbed by the roots.Its amount was 190128mm,and accounting for 87.13%.(3) The initial infiltration rate and stable infiltration rate for the soil layer of 0～20cm were 786mm·min-1 and 155mm·min-1 respectively.The time needed to arrive at the stable state was 45min.Water storage capacity of soil was 15041t·hm-2.The maximum water holding capacity of litter layer was 52mm.福建省自然科学基金,武夷山自然保护区管理局资

聚乙二醇修饰牛胰核糖核酸酶

采用N 羟基珀酰亚胺活化酯法活化单甲氧基聚乙二醇 ,测定了聚乙二醇 (PEG)的活化度为86 2 %。以活化的PEG对牛胰核糖核酸酶进行化学修饰 ;分析了蛋白质被修饰程度。用毛细管电泳法给出了被修饰蛋白的修饰度与修饰蛋白分布的定量结果。比较了被修饰产物对大分子底物 (酵母RNA)与小分子底物 (2’ ,3’ 环磷酸胞嘧啶 )的降解活力 ,其表观酶活力分别保留了 5 2 8%和 66 3 %。结合毛细管电泳定量分析得到的修正酶活力略低于表观酶活

温度、光照、盐分和干旱胁迫对华北驼绒藜种子萌发的影响

通过测定温度、光照、盐分和干旱胁迫(Na Cl和PEG)对华北驼绒藜(Ceratoides arborescens)种子萌发的影响,探究该物种对荒漠生境的适应对策。结果表明,华北驼绒藜种皮具有透水性,吸水2 h后开始萌发,低温(5/15和5℃)条件下种子平均萌发时间(MGT)延长,萌发速率(GR)及发芽指数(GI)降低,但在不同光照和温度处理下,所有梯度均可达到较高最终萌发率(95%~100%),因此,该物种种子无休眠;种子初始萌发率随溶液渗透势降低而下降,渗透势高于-1.4 MPa的等渗溶液对种子初始萌发无显著影响,但是发芽指数(GI)显著降低;而在渗透势-2 MPa,种子仍保持10%~14%的萌发率,高渗透势溶液(0~-2.0 MPa)处理下的种子具有较高的萌发恢复率,而-2.7 MPa Na Cl处理下的种子死亡率高出与其等渗的PEG溶液处理的51%,高盐分胁迫会导致种子失去活力;华北驼绒藜种子具有快速的萌发特性及耐旱特性,有利于该物种在干旱荒漠环境的适应和种群维持

中国科学院力学研究所非线性国家重点实验室;清华大学工程力学系;

采用直接数值模拟计算了雷诺数Re_&Upsilon;=205的槽道湍流。并在此流动条件下,对泰勒冻结假设的有效性进行了测试。由于输运方程包含了泰勒假设项(时间导数项、流向方向的对流项),所以当输运方程的各附加项(例如,动量输运方程中的附加对流项、压力梯度项以及黏性项)或其和的值很大时,泰勒假设的有效性会降低。通过分别对动量输运方程和涡量输运方程中各附加项的分析,考察了泰勒假设在速度场以及在涡量场中有效性降低的范围,有效性降低的程度,以及各附加项对泰勒假设有效性降低的贡献程度。</p

聚乙二醇修饰牛胰核糖核酸酶

采用N 羟基珀酰亚胺活化酯法活化单甲氧基聚乙二醇 ,测定了聚乙二醇 (PEG)的活化度为86 2 %。以活化的PEG对牛胰核糖核酸酶进行化学修饰 ;分析了蛋白质被修饰程度。用毛细管电泳法给出了被修饰蛋白的修饰度与修饰蛋白分布的定量结果。比较了被修饰产物对大分子底物 (酵母RNA)与小分子底物 (2&rsquo; ,3&rsquo; 环磷酸胞嘧啶 )的降解活力 ,其表观酶活力分别保留了 5 2 8%和 66 3 %。结合毛细管电泳定量分析得到的修正酶活力略低于表观酶活

Enhancing Mechanical Performance and Intelligent Response of Chitosan/mah PEGmah-N-Vinylpyrrolide Double Network Hydrogel

先以壳聚糖(CS)用戊二醛(gA)交联为刚性网络,后将聚乙二醇马来酸酐双酯(MAH PEgMAH)与n-乙烯基吡咯烷酮(VP)的共聚物交联成柔性网络,合成了一种高强度且具有P H值、电场敏感性的智能型双网络水凝胶。利用红外光谱、扫描电镜表征了凝胶的化学结构和内部形态;X射线衍射研究了凝胶的结晶性能;研究了凝胶的力学性能及其影响因素,探讨了凝胶的P H值、电场敏感性能。研究结果表明,当CS含量为20%,gA用量为0.2 g gA/g CS,PEg相对分子质量为1000,bIS用量为0.5%时,所制备凝胶的压缩强度可达9.3 MPA。随着PEg相对分子质量的增加,凝胶的P H值敏感性增强;随CS交联度的增加,凝胶的最大弯曲角和电场敏感性先增加后降低。A kind of high strength intelligent double network(DN) hydrogel was synthesized by two-step cross linked method.Firstly chitosan(CS) was cross linked with glutaraldehyde(GA),secondly polyethylene glycol and maleic anhydride esterified products(mah PEGmah) and N- vinylpyrrolidone(VP) copolymers were cross linked with N,N'-methylene double acrylamide(BIS).The DN hydrogel has good p H and electric field sensitivity.The structure of resultant hydrogel was characterized by Fourier transform infrared(FT-IR) spectroscopy,scanning electron microscopy(SEM),crystallization properties of composite hydrogels were investigated by X-ray diffraction(XRD).It's found that when the CS content is 20%,the GA used content is 0.2 g GA/g CS,the molecular weight of PEG is 1000,and the BIS used content is 0.5%,the hydrogel strength of the compression rises up to 9.3 MPa.With the molecular weight of PEG increasing,the p H stim-response sensitivity of hydrogel is improved.With the degree of crosslinking increasing,the maximum bending angle of the gel and the electric field sensitivity of the hydrogel are decreased

Preparation and Accelerator Mass Spectrometry Determination of --(53)Mn/--(55)Mn Standard Reference Material

宇宙成因核素53 Mn是一种非常理想的地质定年工具。近年来,随着加速器质谱(AMS)技术的不断发展,53 Mn的高灵敏测量成为可能。本工作介绍了53 Mn/55 Mn的系列实验室标准样品的制备以及AMS测量,结果表明:53 Mn/55 Mn的测量值与标称值在误差范围内比较吻合且呈现良好的线性关系,中国原子能科学研究院的AMS系统对53 Mn的测量灵敏度可以达到10-14。The cosmogenic isotope 53Mn is a very useful tool for geochronological dating.In recent years,with the development of AMS method,the high sensitivity mearsurment for 53Mn becomes advisable.High energy is required to remove the interference of 53Cr in the AMS measurement of 53Mn,only few AMS laboratories with high terminal voltage satisfy the condition in the world by now.In this paper,the preparation of 53Mn/55Mn laboratory standard's series and the measurement with AMS method are introduced.In order to reduce the interference of 53Cr efficiently,ΔE-Q3D method was used in AMS measurement of 53Mn at China Institute of Atomic Energy(CIAE) based on the HI-13 Tandem Accelerator and the large Q3D magnetic mass spectrometer.The results show that the measured values are in good agreement with their nominal values and the linear relationship between them is excellent.The mearsurment sensitivity of 10-14 for 53Mn/55Mn ratio can be achieved by the AMS system at China Institute of Atomic Energy(CIAE).国家自然科学基金项目(11075221)资

Accelerator Mass Spectrometry Measurement of --(53)Mn and Its Applications in Earth Sciences

宇宙成因核素53Mn是一种非常理想的地貌演变研究工具。近年来,随着加速器质谱(AMS)技术的不断发展,人们已能够进行53Mn的高灵敏测量。介绍了53Mn在地球科学中的应用前景、国际研究现状及中国原子能科学研究院目前正在开展的53Mn高灵敏AMS测量方法的研究。The determination of cosmogenic 53Mn concentrations found in terrestrial formations has many interesting applications for Earth Sciences.With Accelerator Mass Spectrometry(AMS) it should be possible to detect minute amounts of 53Mn.The situation of international research of 53Mn AMS measurement and applications are presented.The AMS measurement method of 53Mn at China Institute of Atomic Energy and its applications prospect are to be explored.国家自然科学基金资助项目(11075221);国家青年基金资助项目(10705054)---

AMS Measurement Technology for (182)Hf

为实现对182 Hf岩石样品的AMS精确测量,基于HI-13串列加速器对测量技术和方法等进行了系统的改进,主要包括:182 Hf空白样品的制备、偏置束流的同时监测技术、加速器系统稳定性检验、交替测量方案的实施、182 W扣除方法的改进、模拟样品测量检验、岩石样品测量检验及测量结果可信度检验等。实验结果表明,对于1x10-10(182 Hf/180 Hf)水平的模拟样品,测量结果的相对不确定度约为12%,基本达到岩石样品的测量要求。岩石样品的测量不确定度较大,主要原因是岩石样品中W的含量较高。In order to improve the accuracy of AMS measurement for 182Hf/180Hf,a series of improvement and innovations of measurement technique and method were taken,such as chemical synthesis of 182Hf free samples,technique of monitoring off-axis current simultaneously,testing the stability of accelerator system,performing the alternate measurement,modified deduction method of 182W,testing the measurement method with simulated samples and real rock samples,and testing the reliability of measurement results.The experimental results show that the relative uncertainty is about 12% for the simulated samples to the order of 1×10-10(182Hf/180Hf),which satisfies the requirement of measurements for real rock samples.The reason of big uncertainty with the rock sample mainly lies in the high content of W in the rock sample