叶绿体色素提取和分离实验中色素带扩散高度的探究

2002年10月份,我在完成"实验四叶绿体中色素的提取和分离"的学生实验后,将实验结果与同学的、自己高一时做过的实验进行了对照.发现胡萝卜素扩散的高度差异很大,这引起了我的疑惑和兴趣.在老师的指导下,对该问题进行实验研究.

宾汉姆流体柱-半球形渗透注浆形式扩散参数的研究

采用理论分析与试验研究等方法,以宾汉姆流体流变方程及渗流运动方程为基础,研究了宾汉姆流体柱—半球形渗透注浆形式的半球体部分扩散半径及柱体部分扩散高度的理论计算公式;分析了宾汉姆流体流变性、注浆压力、地下水压力及注浆管半径对柱-半球形渗透注浆形式的半球体部分扩散半径及柱体部分扩散高度的影响;并设计注浆试验对其进行验证。结果表明,由宾汉姆流体柱-半球形渗透注浆形式的半球体部分扩散半径及柱体部分扩散高度理论公式计算出的半球体部分扩散半径及柱体部分扩散高度理论值与注浆试验的实测值间有25%~30%范围内的差异,处于可接受误差的范围内。因此,研究成果可为实际注浆施工提供理论支撑与指导作用。

牛顿流体柱-半球面渗透注浆形式扩散参数的研究

文献检索表明:目前国内外还没有一个能较准确地计算牛顿流体柱-半球面渗透注浆形式扩散参数(如半球体部分扩散半径与柱体部分扩散高度等)的理论公式,导致理论远滞后于工程应用。以牛顿流体流变方程及渗流运动方程为基础,研究了牛顿流体柱-半球面渗透注浆形式半球体部分扩散半径与柱体部分扩散高度的理论计算公式;分析了牛顿流体的流变性、注浆压力、地下水压力及配置流体的水体温度对牛顿流体柱-半球面渗透注浆形式半球体部分扩散半径与柱体部分扩散高度的影响;并设计注浆试验对其进行验证。结果表明:由牛顿流体柱-半球面渗透注浆形式半球体部分扩散半径与柱体部分扩散高度的理论公式计算得到的半球体部分扩散半径和柱体部分扩散高度理论值与注浆试验实测值间虽有30%左右的差异,但它们都处于可接受误差范围内。因此,研究成果可为实际注浆施工提供理论支撑与指导作用。

黏性土中桩侧后注浆单桩抗压承载性能室内模型试验研究

后注浆技术的应用能有效减少桩周土体扰动和泥皮等造成的不利影响,从而提高钻孔灌注桩的承载力。目前有关后注浆技术的研究多集中于桩端后注浆,少有涉及桩侧后注浆,影响了桩侧后注浆技术进一步推广应用。根据桩侧后注浆工艺,开展单桩抗压室内试验,以研究桩侧后注浆量对单桩抗压承载性能的影响。结果表明:在荷载水平较大的工况下,相较于桩侧后注浆量为1 L的单桩,注浆量为2、3 L时单桩极限抗压承载力分别提高18.2%和66.0%,提高幅度与注浆量呈正相关,并且可以在很大程度上减小桩顶沉降量;桩侧后注浆桩桩身轴力在侧注浆点位附近减小较快,在整个加载过程中桩端附近处桩身轴力值均比较低,单桩受压表现为摩擦桩;水泥浆液同时存在上返和下劈扩散,在室内试验条件下,两者扩散高度均约为14倍桩径,在浆液扩散段桩侧摩阻力得到显著提高,且越靠近注浆点位提高程度越明显。

A modified method to estimate eddy diffusivity in the North Pacific using altimeter eddy statistics

The method proposed by Stammer (1998) is modified using eddy statistics from altimeter observation to obtain more realistic eddy diffusivity (K) for the North Pacific. Compared with original estimates, the modified K has remarkably reduced values in the Kuroshio Extension (KE) and North Equatorial Counter Current (NECC) regions, but slightly enhanced values in the Subtropical Counter Current (STCC) region. In strong eastward flow areas like the KE and NECC, owing to a large difference between mean flow velocity and propagation velocity of mesoscale eddies, tracers inside the mesoscale eddies are transported outside rapidly by advection, and mixing length L is hence strongly suppressed. The low eddy probability (P) is also responsible for the reduced K in the NECC area. In the STCC region, however, L is mildly suppressed and P is very high, so K there is enhanced. The zonally-averaged K has two peaks with comparable magnitudes, in the latitude bands of the STCC and KE. In the core of KE, because of the reduced values of P and L, the zonally-averaged K is a minimum. Zonally-integrated eddy heat transport in the KE band, calculated based on the modified K, is much closer to the results of previous independent research, indicating the robustness of our modified K. The map of modified K provides useful information for modeling studies in the North Pacific.

Air Pollution Concentration Approach to Potential Area Selection of the Air Quality Monitoring Station in Nakhon Ratchasima Municipality, Thailand

The purpose of the study is to generate traffic air information system） to determine a proper zone of AQMS （air analyzed were carbon monoxide （CO）, and nitrogen oxides （NOx） pollution map using mathematical model and GIS （geographic quality monitoring station） in municipality area. The pollutants which can be harmful to people living in the area. The three steps of mapping process were performed under the GIS environment using the existing vehicle emission rates and pollutant dispersion model. First, traffic volume, road network, and the emission rates of road segments varying with types of vehicle were collected from existing data. Second, the pollutant concentrations were calculated by use of CALINE4, a tool with Gaussian dispersion model. The model parameters include emission rate, wind directions and speeds, ambient temperature and observed pollutant concentration, and atmospheric stability during all seasons from the January 1, 2010 to May 31,2011 with regardless the rainy season. This resulted in concentrations at many receptor points along links of the road network. Third, distributions of pollution concentrations were generated by means of the spatial interpolation of those from receptors. The results of pollution raster-based maps are used for determining frequency of violence and combined pollution map. The resulting frequency of violence and intensity concentration will be further integrated to determine a potential area of AQMS. Finally, achieving pollution potential area of AQMS can be located as helpful basic data for efficient traffic and transportation planning.

Enhanced mechanical properties in oxide-dispersion-strengthened alloys achieved via interface segregation of cation dopants

With significantly enhanced irradiation resistance,high-temperature strength,and creep resistance,oxide-dispersion-strengthened tungsten(ODS-W)alloys present tremendous potential for high-temperature applications.However,the oxide particles tend to segregate at W grain boundary and grow up(even to micron),greatly suppressing their strengthening effect.It is always a great challenge to effectively refine and disperse the oxide particles at W grain boundary.Here,we successfully developed a new type of cation-doped W-Y2O3 alloy via a wet chemical method and subsequent low-temperature sintering.It was found that proper cation doping could not only significantly refine the intergranular Y2O3 second phase particles but also dramatically improve the sinterability of W matrix.These doping effects,as a result,simultaneously enhance the strength and ductility of the W-Y2O3 alloy.It was confirmed that the segregation of cation dopants at the W/Y2O3 interface is the origin of these doping effects.Furthermore,X-ray photoemission spectra(XPS)analyses confirmed that cation dopant segregation also obviously affects the chemical bonding(i.e.,W–O bond)along the W/Y2O3 interface.As a result,the ratelimiting mechanism for W grain growth is influenced remarkably,explaining well the difference of W grain size in various cation-doped W-Y2O3 alloys.For the refinement of intergranular Y2O3 particles,it can be understood well from both thermodynamic and kinetic views.Detailedly,W/Y2O3 interfacial energy and atom mobility for Y2O3 coarsening are all limited by cation dopant segregation.More importantly,this cation-doping approach can also be applicable to other ODS alloys for enhancing their comprehensive mechanical properties.

Diffusion process for efficiency improvement with high sheet resistance on traditional production lines of solar cell

By optimizing the diffusion temperature and time,four groups of samples with different sheet resistances are achieved.The front screen printing pattern and firing temperature are fine-tuned according to the needs.The performance of the low-and-plateau-temperature doping recipe(as recipe A)is better than that of the low-and-multiple-temperature doping recipe(as recipe B).And the 19.24%efficiency of volume production of monocrystalline solar cells with 238.95 mm2 and 80?/sq sheet resistance is obtained in the traditional process line.0.48%more efficiency is achieved than 60?/sq due to the reduction of the phosphorus surface doping and shallow junction by the low-and-plateau-temperature diffusion recipe.The module test shows that by using two drive-in zones,not only do we have a higher efficiency,but also have a stabler and lower power loss in encapsulation manufacture.It is showed that power of a large improvement will be gotten by statistical analysis and PC1D simulation.