混凝土在硫酸盐溶液中的腐蚀模型

混凝土在硫酸盐溶液中的腐蚀破坏是一种常见的混凝土破坏形式,研究混凝土抗硫酸盐腐蚀破坏对于混凝土工程具有重要意义。混凝土在硫酸盐溶液中受腐蚀的过程是一个循序渐进的过程,这个过程包括固液界面的表面吸附、硫酸盐溶液的扩散过程以及硫酸盐在混凝土试件内部的化学反应和物理结晶等物理化学过程。研究表明：可以采用Fick第二扩散定律来描述硫酸盐在混凝土中的扩散过程;硫酸盐溶液中,混凝土试件的固液相界面处发生物理吸附和化学吸附,并存在表面化学反应。     

Heat transfer calculation influence of pile geothermal ground exchanger ignoring the thermal property difference between grout and soil

桩基埋管换热器具有桩径大、埋深浅的特点,适用于桩基埋管特点的系列导热解析解模型被不断提出,但是该类模型均忽略了回填料与岩土热物性的差异。对于桩径较大的桩基埋管而言,较大的热物性差异将引起较大的计算误差。建立了区别回填料与岩土热物性差异的导热数值解模型,对比分析忽略热物性差异对桩基埋管换热计算的影响,研究表明：导热系数差异对桩基埋管长时间运行的换热热阻计算影响甚小;容积比热差异将引起桩基埋管较大的设计容量误差;桩径越大,热物性差异引起的计算误差越显著。     

甜杏仁粕蛋白的碱性蛋白酶酶解动力学研究

为了探究甜杏仁粕蛋白酶解动力学特性,实现对冷榨甜杏仁粕的广泛利用及其生物活性肽的推广,从酶解反应机理出发,应用数学推导的方法,于pH 8.0、温度50℃条件下,以碱性蛋白酶为工具酶,研究甜杏仁粕蛋白在不同初始底物浓度和初始蛋白酶浓度下的水解进程并建立动力学模型。结果表明:甜杏仁粕蛋白的水解度随着初始底物浓度的上升而减小,随着初始蛋白酶浓度的上升而增大,碱性蛋白酶水解甜杏仁粕蛋白的速率动力学模型为:R=(27.035 E_0+0.498 8 S_0)exp[-0.173 3(DH)],酶解反应速率常数K_2为27.035 min~(-1);水解度-水解时间的动力学模型为:DH=5.77 ln[1+(4.69 E_0/S_0+0.086)t],酶失活的动力学常数K_4为2.992 min~(-1)。与试验结果相比,模型值与试验值吻合较好,表明所建动力学模型对甜杏仁肽产业化具有一定的指导作用。     

河滨带土壤氮、磷自然渗透与迁移特征研究

为了探讨河滨带土壤特性,采用过硫酸盐消化法和M3法,对河滨带不同深度土壤N、P含量进行测定,分析其在河滨带纵向土壤中的自然渗透和横向迁移特征。研究结果表明：吸光度与氮和有效磷的校准曲线：y=-0.1308+0.2546x,R2=0.9173和y=0.0287+0.5617x,R2=0.9675,相关性非常好。该河滨带土壤N、P主要分布在0~10 cm土壤层,以5 cm土壤层为最高,表层土壤中N、P含量显著高于下层土壤,总体呈由上到下的迁移特征;河滨下游土壤表层含N量明显高于上游,而土壤含P量在上游主要集中在土壤表层,在下游主要集中在5 cm土层中。因此分析河滨带纵向土壤中的自然渗透和横向迁移特征必须从纵向和横向两方面来综合抑制土壤中氮、磷的不断升高的趋势。     

Cr（Ⅵ）在合成沸石上的吸附/脱附行为研究

为深入研究沸石对水溶液中Cr(Ⅵ)吸附和脱附机理,利用合成沸石对水溶液中的Cr(Ⅵ)进行了吸附和脱附实验。实验结果表明：pH值对合成沸石吸附Cr(Ⅵ)影响较大,Cr(Ⅵ)的吸附率随pH值与初始浓度的增加而减小,但吸附量却随初始质量浓度的增加而增加;Freundlich比Langmuir模型更适合描述其吸附行为,且其属于易吸附。在最优条件下,合成沸石在25.0、50.0和100.0 mg?L-l三种质量浓度下对Cr(Ⅵ)的平衡吸附量分别为3.58mg?g-l,6.76 mg?g-l和8.08 mg?g-l;准二级反应动力学模型比准一级能更好地描述合成沸石对Cr(Ⅵ)的吸附行为,准二级动力学拟合得到的吸附量与实测吸附量相差小于5.8%,吸附传质过程主要受液膜扩散和颗粒内扩散的共同控制其吸附速率。在蒸馏水中Cr(Ⅵ)的E%仅为2.57%,而添加NaOH后脱附率明显增加,同时Cr(Ⅵ)在合成沸石上的脱附符合准二级反应动力学。, 为深入研究沸石对水溶液中Cr(Ⅵ)吸附和脱附机理,利用合成沸石对水溶液中的Cr(Ⅵ)进行了吸附和脱附实验。实验结果表明：pH值对合成沸石吸附Cr(Ⅵ)影响较大,Cr(Ⅵ)的吸附率随pH值与初始浓度的增加而减小,但吸附量却随初始质量浓度的增加而增加;Freundlich比Langmuir模型更适合描述其吸附行为,且其属于易吸附。在最优条件下,合成沸石在25.0、50.0和100.0 mg?L-l三种质量浓度下对Cr(Ⅵ)的平衡吸附量分别为3.58mg?g-l,6.76 mg?g-l和8.08 mg?g-l;准二级反应动力学模型比准一级能更好地描述合成沸石对Cr(Ⅵ)的吸附行为,准二级动力学拟合得到的吸附量与实测吸附量相差小于5.8%,吸附传质过程主要受液膜扩散和颗粒内扩散的共同控制其吸附速率。在蒸馏水中Cr(Ⅵ)的E%仅为2.57%,而添加NaOH后脱附率明显增加,同时Cr(Ⅵ)在合成沸石上的脱附符合准二级反应动力学。     

动力学光度法测定小麦过氧化氢酶活动度

过氧化氢酶与四甲基联苯胺和过氧化氢反应生成蓝色物质,通过分光光度法检测蓝色产物进而可测定小麦中过氧化氢酶活动度.结果表明,光度法测得的蓝色反应的初始速率与小麦中过氧化氢酶的活动度呈线性关系,线性方程为:y=110.26x +44.06,相关系数为R=0.993.采用此方法测定小麦中的过氧化氢酶活动度准确高,重复性好,简便快捷,是测定粮食中的过氧化氢酶活动度的一种较好的方法.     

辽北低山丘陵区坡耕地土壤侵蚀作用效果研究

本文研究不同坡度、降雨量、耕作方式对辽北低山丘陵区坡耕地土壤侵蚀作用的影响。研究结果表明：降雨量（x）与土壤流失量（y）之间遵守y=aebx的指数曲线变化规律,且有a〉0,b〉0的回归特征,说明土壤流失量随降雨量的增加而加剧;在相同降雨条件下,土壤流失量随坡度的增加而加剧,顺坡垄农田的侵蚀量＞等高垄农田的侵蚀量;流失量（y）和降雨量（x1）、坡度（x2）的回归方程为：Y=2.49-1.83 X1+ 2.13 X2+ 0.02 X1X1-0.162 X2X2 + 0.13 X1X2,降雨对流失量的影响要大于坡度对流失量的影响。     

模拟粮仓压力半衰期规律研究

研究气密性良好、存在刚性孔、存在柔性孔等3种情况下的模拟粮仓在不同初始压强下的压力半衰期变化情况。得出：①在相同孔径下,粮仓压力半衰期的时间随着初始压强的减小而减小;②对孔径、初始压强、压力半衰期进行回归分析,得出压力半衰期与初始压强、孔径二者均成二阶多项式的关系。500Pa-250Pa的半衰期与孔径关系可表达为：y=756．63x^2—1087．7x＋485．77,R^2=0．9864。     

虾蛏混养池底泥耗氧速率的初步研究

本研究探讨了不同水温和有机质含量对不同养殖模式底泥耗氧速率的影响。通过采集试验前后池塘不同位点的底泥沉积物,对单养对虾和虾蛏混养两种模式下底泥耗氧速率作了初步研究。结果表明：在两种模式下底泥耗氧速率y都随着温度t的升高而升高,且呈良好的幂指数相关（虾蛏混养池y和t的关系式为：y=0.1525e0.0717x,R2=0.968,P<0.01,对虾单养池y和t的关系式为：y=0.1591e0.0816x,R2=0.971,P<0.01）;底泥耗氧速率与有机质相关性显著(P<0.05);对不同养殖模式下虾塘底泥耗氧速率分析表明：虾蛏混养池与对虾单养池的底泥底泥耗氧速率差异极显著(P<0.01);在相同养殖模式下,试验初期底泥耗氧速率小于后期底泥耗氧速率。在相同时期,单养虾池塘底泥耗氧速率高于虾蛏混养池塘底泥耗氧速率。     

水压力环境中混凝土经历循环荷载后的抗压强度

研究了水压力环境中混凝土在经历循环荷载后的动态压缩强度，分析了水压力和循环次数对混凝土强度的影响。试验应变速率为10^-5/s、10^-4/s、10^-3/s和10^-2/s，水压为0~10 MPa。试验结果表明，在不同水压力下饱和混凝土的强度都随应变速率提高而增加，也随水压力提高呈增加地趋势。在相同水压力下，应变速率越高，混凝土强度提高越显著。饱和混凝土经过循环荷载后，其强度随荷载循环次数的增加呈现出先提高后降低的现象。应变速率越高，混凝土强度最大时所对应的荷载循环次数也相应增加。还构建了饱和混凝土强度与应变速率、水压力的关系，其与试验数据吻合较好。进一步引入了管道孔隙模型，并基于汞压法的原理和孔隙分布特点，考虑混凝土孔隙的微观结构解释了孔隙水对混凝土强度的作用机理。     

Diffusion Behavior of Chloride Ions in Concrete Pipe Piles

Concrete pipe piles, whose internal surface is usually closed and external one is exposed to chloride environment, are widely used in marine environment. Based on Fick second law and the boundary condition of pipe pile, the analytical solution to chloride diffusion equation was deduced with the method of separation of variables. The solution comprises two parts: a stationary solution consisting of Bessel functions, and a transient solution. This is different from the traditional analytical solution that is based on semi-infinite boundary condition. Applying this result to a typical PHC pipe pile, the diffusion of chloride concentration was analyzed. Furthermore, the effects of the ratio of outer radius and inner radius, diffusion coefficient and protective concrete cover thickness on diffusion of chloride concentration were also discussed. When the ratio of outer radius and inner radius equals 1.5, the decay rate of secondary segment of transient solution is 4 times larger than that of the primary part. This example provides a computational basis for the corrosion of steel bar and some reference for durability design of pipe piles as well.     

Field Comparative Experimental Study on Bearing Capacity of Both Bored Pile with Branches and Plates and Column Bored Pile at the Same Site

Compared with column bored pile,the bored pile with branches and plates is a new type of piles with higher bearing capacity and lower settlement.Field comparative tests related to ultimate bearing capacity of both the bored piles with branches and plates and column bored piles at the same site in Huzhou city of province Zhejiang in China were studied through self-balanced method under static pressure.The results testify that,compared with column bored pile under the same geological conditions,the bored pile with branches and plates can obtain better economic benefit such as: increasing ultimate compressive bearing capacity and ultimate extraction bearing capacity used per cubic meter concrete over 75.3%and 118.9%respectively,while dropping consumption of reinforced concrete upwards of 41.9%and 44.1% respectively,reducing settlement and pile length under the same loading.The tests will present an objective reference to the new type of piles in both theoretic study and application to analogous engineering.     

同功酶电泳与田间种植方法鉴定大白菜杂交种纯度的相关研究

用垂直板和等电聚焦丙烯酰胺过氧化物同功酶电泳方法对14个大白菜杂交品种进行了纯度鉴定,并同时在田间进行重复检测。二者纯度结果相关系数r=0.87,表明电泳鉴定和田间检验结果间存在着显著的正相关关系。因此应用同功酶电泳技术鉴定大白菜杂交种纯度是可行的,可作为鉴定真伪杂种的一种新方法。     

Foundation pile test by self-balanced method of rock-socketed piles and friction piles in multilayer soil geological structure

结合检测工况对测试数据的影响,对自平衡“精确转换法”进行改进,提出摩擦桩位移协调转换法和嵌岩桩的荷载协调转换法,实际应用结果说明两种转换方法合理。所得测试结果表明湄公河大桥桩基承载力符合设计要求;分析湄公河大桥试桩的侧摩阻力和端承力分布,嵌岩桩和摩擦桩纵向承载均以侧阻力为主。     

流动注射分析法和传统方法测定土壤中N的比较研究

采用FIAstar 5000流动注射分析仪和传统方法（氧化镁浸提-扩散法、酚二磺酸比色法和镀铜镉还原-重氮化耦合比色法）分别测定了同一流域内不同利用类型土壤中铵态氮、硝态氮和亚硝态氮的含量,通过样品均值、测试误差、回收率和标准偏差等指标对两种方法进行比较研究。结果表明,流动注射分析仪在测定土壤中铵态氮和硝态氮时,分析速度快且仪器具有较好的稳定性（5次平行次数内结果RSD＜5％）。从分析结果的准确性看,采用流动注射分析仪分析土壤中铵态氮、硝态氮时,与传统方法也具有可比性,样品回收率分别为98.5~102.0%和96.7~98.3%。在测定土壤亚硝态氮时,流动注射分析法仪器稳定较差（5次平行次数内结果RSD＞6％）,且分析结果普遍偏低,需要进行必要的校正。因此,在大批量测定土壤样品铵态氮、硝态氮时,用流动注射分析法是可行的,但测定亚硝态氮含量时,存在较大的误差,需要进行校正。     

FEM Analysis of Differential Settlement of Gravel Pile Foundation Under Large scale Oil Tank

In order to reduce the differential settlement of gravel pile foundation under large scale oil tank, axisymmetric numerical simulation method and finite element method was employed to study the pile length, the exchange rate of length, the length of the cushion course to the influence of differential settlement and the relationship of negative lateral displacement and the settlement. It is found that: differential settlement has a minimum range of pile length. For the oil tank foundation center, by keeping the pile diameter, increasing pile spacing can increase the rate of exchange and obtain smaller differential settlement in relatively smaller displacement rate conditions. And by keeping replacement rate unchanged, the larger the pile diameter(namely the looser pile spacing) is, the smaller the differences settlement of the gravel pile foundation is. Moreover, pile length adjustment and the exchange rate have obvious effects on different subsidence and not obvious effects on the length of the cushion course. The appearance of oil tank foundation negative lateral displacement is one of the most important features of differential settlement adjustment.     

二次正交旋转组合设计优化雷公藤继代增殖培养基

摘 要：为获得雷公藤试管苗高频继带增殖的最佳条件,采用二次正交旋转组合设计对其继代增殖培养基进行优化研究。结果表明：雷公藤继带苗增殖倍数(y)对MS浓度(x1)、6-BA浓度(x2)及NAA浓度(x3)3个试验因子的正交回归模型为y=6.98483-0.25481x12-0.51998x22-0.37856x32-0.35x1x2-0.325x2x3。对模型的进一步解析表明,3个因素在试验设定范围内对增殖倍数的影响存在低浓度促进高浓度抑制的现象。MS在0.398~0.602倍常规浓度下,6-BA和NAA的浓度分别在0.919~1.092 mg/L和0.167~0.233 mg/L时,其增殖倍数大于6.3的可靠性为95%。通过实际接种验证,30 d平均增殖倍数为6.53,证明本研究优化出的培养基是雷公藤试管苗增殖的最佳培养基。     

Finite Difference "m-k" Method of Calculation of Anchor-stabilizing Piles

Based on the principle of the foundation coefficient " m-k " method,the ginite difference method is presented to analyze the internal forces of a whole prestressed anchor stabilizing pile. The calculation and figure treatments are programmed. An example shows that the high precise solution can be obtained if the segments are small enough, though more computing time may be consumed. Obviously,the calculation precision is better than that of traditional method. The results of figure treatments by the program can optimize the construction design of stabilizing piles. Three kinds of support condition are taken into account.The foundation coefficient "m-k " method applies to the situation that above the slide-surface is soil layer or efflorescence layer,while below the slide-surface is terrane.     

Analysis of Differential Shrinkage Deflection for PC Box girder Bridges

The long term deflection behavior of long span continuous rigid frame bridges has often attracted the attentions in engineering field. Based on the moisture diffusion theory, the calculation method of differential shrinkage deflection was proposed for PC box girder bridges. Finite Element Method(FEM) model of 2 D moisture field were established for typical cross sections of a case bridge. And the distribution law and the time variation characteristics of moisture field were analyzed. Through the deformation coupling condition of moisture field, the drying shrinkage deflection of the bridge was calculated and analyzed. It was found that the differential shrinkage deformation was significant and great error would be with the conventional method. When considering the effect of differential shrinkage, the deflection in mid span was 3.1cm larger than that of the conventional method. Thus, the differential shrinkage was the main reason for long term deflection of long span continuous rigid frame bridges.