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Search Results: 1 - 10 of 99923 matches for " 郭栋生 "
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植物代谢对荧蒽和()与DNA结合的影响
,袁小英,张芳
环境化学 , 2015,
Abstract: 利用紫外和荧光法测定了荧蒽和NB06D经绿豆幼苗代谢前后的光谱变化.结果表明,经植物代谢后,荧蒽的紫外和荧光光谱的精细结构没有发生变化,而NB06D的紫外和荧光光谱的精细结构以及荧光的最大发射波长均发生了改变利用荧光法测定荧蒽和NB06D经植物代谢前后与DNA结合的结果表明,在浓度约为2.5×10-6mol·l-1时,荧蒽及其植物代谢提取物与浓度为5.0×10-7—5.0×10-5mol·l-1范围内的DNA不发生结合,而NB06D及其植物代谢提取物都能与上述浓度的DNA结合,但经植物代谢后,提取物与DNA的结合能力稍有减弱,该结果表明,荧蒽和母体化合物与DNA的结合能力不同,在试验期内,植物代谢对这两种在动物体试验中表现不同致癌性的多环芳烃与DNA间的结合没有明显的活化或去活化作用.
脆性及准脆性开裂界面的剪胀内聚力模型
Cohesive zone model with dilation for brittle and quasi-brittle cracking interfaces

,杨应华
- , 2018, DOI: 10.13801/j.cnki.fhclxb.20171128.006
Abstract: 根据界面剪胀与Ⅱ型断裂能间的关系,给出构造含剪胀效应张力-位移关系的新途径,该方法先假定Ⅱ型张力-位移关系,再计算界面剪胀函数,从而更易于应用。通过定义基于能量和界面不连续位移的4个损伤变量,给出含剪胀效应的损伤张力-位移关系表示形式,使模型不仅能模拟单调加载问题,而且可模拟反复加载问题。对界面在受压状态下的切向粘结强度、法向位移和摩擦作用分别进行了讨论,给出了相应的计算方法或取值建议。最后通过一个张力-位移关系的实例讨论了界面压力作用、复合模式开裂、卸载-再加载行为和接触罚刚度对法向位移的影响等模型性质。 According to the relationship between interface dilation and mode Ⅱfracture energy, a new way of constructing traction-separation law with dilation was presented. The method, by first assuming the mode Ⅱ traction-separation relationship, and then deriving the interface dilation, was easier to apply. Defining four damage variables based on the interface separation and fracture energy, traction-separation laws with dilation considering damage effects were further given. This enables the model to simulate not only the monotonic loading problems but also reversed loading problems. In addition, interface tangential bonding strength, normal separation, and friction effect under interfacial pressure were discussed respectively, which led to corresponding computing methods or recommended value. Finally, an example of traction-separation law with dilation considering damage was proposed. Utilizing finite element method, interface pressure, mixed mode effect, unloading and reloading behavior, and effects of contact penalty stiffness on normal separation were investigated thoroughly. 陕西省建设科技计划(2016-K83)
含剪胀效应界面张力-位移关系的一种构造方法
A method for determining interfacial traction-separation law with dilatancy

杨应华,
- , 2017, DOI: 10.13801/j.cnki.fhclxb.20170412.002
Abstract: 为了研究异种材料界面的开裂过程,在S?rensen等人工作的基础上,给出一种含剪胀效应张力-位移关系的构造方法。在界面受拉状态下,通过预先给定的剪胀函数及法向张力-位移关系导出切向张力-位移关系;在界面受压状态下,将切向张力分解为粘结力和摩擦力,摩擦力的大小与法向压力和粘结界面的破坏程度相关。该方法的结果解释了S?rensen模型中切向张力-位移关系不连续及其不符合一致关联准则的原因。为便于进行数值计算,给出了用于三维有限元模型的界面刚度矩阵计算方法。选取了一种特定形式的剪胀函数,并将法向张力-位移关系假定为分段线性形式和指数形式,分别求得对应的切向张力-位移关系。最后给出了两个工程应用的例子,数值模拟结果与试验数据吻合较好。 Based on the work conducted by S?rensen etc., a method for determining interfacial traction-separation law with dilatancy was presented to investigate interfacial cracking processes of composites. The tangential traction-separation law was derived via a pre-defined shear dilation function and the normal traction-separation law while the interface was in tension. On the contrary, the tangential traction was decomposed into bond strength and friction strength while the interface was in compression. The friction strength is related to the normal pressure and the damage process on the cohesive interface. The results of the method explain why the tangential traction-separation law of S?rensen model is not continuous and violates the consistently coupled rule. In order to facilitate numerical simulation, expressions of interface stiffness matrix applying to three dimensional finite element models were also presented. Then a particular shear dilation function was adopted and the normal traction-separation law was assumed as multilinear form and exponential form, respectively. The corresponding tangential traction-separation law was derived applying the method presented in this paper to those functions. Finally, two examples of engineering application were given. These numerical simulation results are in good agreement with the experimental data. 陕西省建设科技计划(2016-K83)
鄱阳湖与长江干流洪水遭遇规律及风险分析
Flood Coincidence Risk Analysis for the Middle Yangtze River and Poyang Lake
 [PDF]

李天元, , 刘章君, 刘国强, 曾思
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.36062
Abstract:
本文引入von Mises分布及其混合形式拟合年最大洪水发生时间与间隔时间,应用Copula函数分别构造汉口、湖口两站年最大洪水发生时间二维联合分布和年最大洪水发生时间(间隔时间)与洪水量级的三维联合分布,分析了研究两站年最大洪水在时间、量级及过程三个方面的遭遇风险。结果表明:鄱阳湖和长江年最大洪水在7月16日遭遇的可能性最大,约为0.058%,鄱阳湖和长江年最大7d洪水过程发生遭遇的概率为7.31%。研究可为鄱阳湖流域防洪规划制定和生态经济区建设提供科学依据。
The von Mises distribution was used to fit the series of annual maximum flood occurrence and in-terval dates. The Copula functions were used to establish the bivariate joint distribution of annual maximum flood occurrence dates and the multivariate joint distribution of interval dates and flood magnitude. The flood coincidence risk of annual maximum flood occurrence date, flood magnitude and flood process were analyzed based on the data series of Hankou and Hukou hydrological stations. The results show that the highest flood coincidence risk of annual maximum flood occurrence date and 7-day flood process between the middle Yangtze River and Poyang Lake may reach to 0.058% (on July 16th) and 7.31% respectively during the flood season. The research can provide scientific basis for Poyang Lake basin on flood prevention planning and ecological- economic zone construction.
四种金属离子对CHBr3和小牛胸腺DNA间结合作用的影响
惠晓梅,,袁小英
环境科学学报 , 2010,
Abstract: 采用紫外光谱和荧光光谱法研究了CHBr3与离体小牛胸腺DNA(ctDNA)间的相互作用,以及Cu2+、Co2+、Cd2+、Mg2+4种金属离子单独或共存时对CHBr3与ctDNA结合的影响.结果表明:4种金属离子与CHBr3、ctDNA均能发生基态络合反应,络合物的生成导致体系的紫外吸收峰强度和形状改变,使ctDNA-溴化乙锭体系的荧光发生了不同程度的猝灭;向CHBr3-ctDNA-溴化乙锭体系中分别或同时加入4种金属离子后,Cu2+、Co2+、Cd2+可减弱两者之间的结合,减弱顺序为Cu2+>Co2+>Cd2+,Mg2+可加强两者之间的结合,4种金属离子同时加入后出现不同于4种金属离子单独加入时的中间类型.据此推断,CHBr3可能主要是通过嵌插作用与ctDNA碱基结合,金属离子对CHBr3与ctDNA结合的影响主要取决于金属离子与DNA的碱基和磷酸基团间结合的相对亲和比.
BSA体系中2,4-D和阿特拉津对性激素的干扰机理
李一菲,,袁小英
环境化学 , 2015,
Abstract: 在2,4-D和阿特拉津以及天然性激素(雌二醇、睾酮)中加入牛血清白蛋白(BSA),通过紫外吸收峰的变化、温度与体系荧光强度的关系、以及计算扩散碰撞猝灭常数Kq等方法确定2,4-D和阿特拉津均可以发生类似天然性激素和BSA间的基态络合.并通过双倒数公式计算出各自二元体系的结合常数.2,4-D、阿特拉津、雌二醇、睾酮与BSA的结合常数(K)均在104数量级,可以认为2,4-D和阿特拉津具有与天然性激素相近的对BSA结合能力,并可通过竞争占据结合位点的方式干扰正常性激素与BSA的结合.
新型钾分子筛的表征及其对K+的交换性能
袁俊,兆寿,张林
过程工程学报 , 2006,
Abstract: 通过扫描电镜、化学组成分析、X射线衍射和热重差热分析对自制的新型分子筛进行了表征,并测定了分子筛对纯钾溶液和海水中K+的交换容量及对K+的选择性系数.结果表明,新型分子筛由76.25%的Na6Al6Si10O32×12H2O和23.75%的K2Al2Si3O10×3H2O两种物质混合构成,其硅铝比(摩尔比)为5.22;分子筛在350℃以内是稳定的,温度过高,内部结构被破坏;分子筛对纯钾溶液和海水钾离子的交换容量分别为100.30和55.10mg/g,对海水中K+的选择性系数达到74.41,与改性天然沸石相比,对海水中K+的交换容量提高2倍,选择性系数提高3倍.说明新型分子筛对K+具有很高的选择性,可用于从海水及含钾卤水中高选择性分离钾盐.
取代苯化合物生物富集系数的估算
解静芳,,高越,范仁俊,
应用生态学报 , 2006,
Abstract: 为了用气相色谱保留时间(tr)估算取代苯类化合物在鱼体内的生物富集系数(bcf),测定了草鱼对氯苯、邻氯甲苯、对二氯苯、间二氯苯、邻二氯苯、硝基苯、对氯苯胺、对硝基氯苯、4-氯联苯9种取代苯类化合物的bcf和不同取代苯化合物在6种不同极性固定相上的tr,建立了tr与bcf的一元回归方程及tr一阶分子连接性指数(1xv)与bcf的二元回归估算方程.统计检验表明,两类估算方程在不同固定相上的平均相关系数分别为0.952和0.965,均呈极显著相关(p<0.01),可用于估算取代苯类化合物在草鱼体内的bcf,估算结果不受固定相极性的影响.
The effect of Cu2+,Co2+,Cd2+ and Mg2+ on the interactions between bromoform and calf thymus DNA
四种金属离子对CHBr3和小牛胸腺DNA间结合作用的影响

HUI Xiaomei,GUO Dongsheng,YUAN Xiaoying,
惠晓梅
,,袁小英

环境科学学报 , 2010,
Abstract: Using the technique of ultraviolet absorption spectrometry and fluorescence spectrometry, this study examined the interactions between bromoform(CHBr3) and calf thymus DNA(ctDNA) with or without Cu2+, Co2+, Cd2+ and Mg2+individually or concurrently. The results show complex ground-state reactions among the metal ions, CHBr3and ctDNA, as evidenced by the variations in the peak of UV absorption intensity and shape in the ctDNA-ethidium bromide system. The interactions cause fluorescence quenching to various extents. The presence of Cu2+, Co2+, Cd2+ (ranked by decreasing strength) weakened the binding between CHBr3 and ctDNA, while Mg2+enhanced such binding. In addition, the simultaneous presence of the four metal ions resulted in intermediate impact, varying from the effect of the individual metal ions. The results suggest that CHBr3 is likely to intercalate into ctDNA and such intercalations mainly depend on the relative binding affinity of a metal ion to the bases and to the phosphate groups in DNA.
基于遥感解译的比如盆地油气潜力分析与有利区预测
建华,崔金,邓吉秋,刘辰
遥感技术与研究 , 2012,
Abstract: 为对国内最具潜力但自然条件恶劣的西藏地区进行油气勘测,用基于遥感解译的技术对比如盆地进行了研究。首先通过对野外踏勘路线上岩性、地层和线性构造的观察,归纳出不同岩性、地层和线性构造在遥感影像图上的特征,建立了岩性、地层、线性和环形构造解译标志,完成了比如盆地岩性、地层、线性构造和环形构造解译。其次应用比值法(油气点微渗漏)、融合法(遥感波段融合色调异常)、主成分分析法(羟基/铁质信息异常)对已知油气出漏点和异常信息进行叠加,发现烃类微渗漏信息异常区与已知油气出漏点存在正相关性,用烃类微渗漏异常信息和已知伦坡拉盆地油藏区叠加,发现烃类微渗漏信息异常区和地下已知油气藏负相关,从而确定了烃类微渗漏非异常区可能为含油气区。通过3种方法得出油气烃类渗漏异常区,进而圈定重点一级烃类微渗漏非异常区一处,并结合盆地的生、储、盖条件,指出了比如—伯列蝉—边坝所圈定的区域为油气勘探有利区域,是未来油气勘探的目标。
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