土工布环向约束球形鼓胀变形及破坏特性分析

对于库底采用复合土工膜水平防渗的平原水库,复合土工膜局部可能会出现气胀甚至胀破现象,从而引起库水渗漏问题。复合土工膜一般由土工膜和土工布组成,其中土工布发挥保护和加强作用,对复合材料的鼓胀变形有着重要影响。本文将土工布的气胀现象简化为环向约束球形鼓胀变形模型,采用土工布下放置薄膜垫层的方法进行土工布的球形鼓胀变形试验,文中分析了土工布变形特征,借助于显微镜着重研究了土工布鼓胀变形过程中纤维结构变化的过程和胀破机理,得出结论： ①土工布的鼓胀压力~鼓胀高度曲线表现为近似线性变形特征,而张应力~应变曲线近似表现为塑性变形特征,可分为线弹性、屈服、强化和胀破拉断阶段四个阶段;相应于土工膜而言,相同条件下土工布具有较小的鼓胀变形和较高鼓胀压力、张应力,说明土工布不仅对土工膜具有一定的保护、反滤作用,更能够提高膜布复合材料鼓胀变形的安全性。②土工布鼓胀变形形状为球形,一般在冠顶处出现破坏撕裂点,撕裂点进一步扩展形成纺锤形撕裂破坏;微观结构分析表明针刺短纤维形成的缠结点具有一定的缠结力,缠结点之间的纤维具有一定的拉伸强度,缠结点缠结力逐渐失效和纤维断裂是是土工布鼓胀变形破坏的主要原因。③土工布单位面积质量越大,纤维和缠结点的数量越大,土工布承受的鼓胀压力和张应力越大,抵抗变形的能力越强,胀破撕裂长度越小。研究成果对于分析膜上土工布对土工膜鼓胀变形强度的贡献具有一定的实际意义。     

湖区堤防滑坡治理及稳定分析研究

滑坡是湖区堤防的常见险情之一,具有发展迅速、滑裂面较深、治理难度大的特点。本文结合工程实例分析了滑坡产生的原因,采用静力触探技术和理论分析方法推算滑裂面的位置,提出了填塘控源、块石固脚、木桩阻滑的综合治理方案。采用理论分析方法分别对沿现有滑裂面的滑动、沿桩顶的浅层滑动及沿桩底的深层滑动的稳定性进行分析计算,以验证治理方案的可靠性,可为类似滑坡的综合治理提供一定的参考和借鉴。     

浅层反射多次覆盖技术在滑坡勘探中的应用

利用浅层反射法施工场地小，高分辨率，高信噪比具有不受速度倒转层影响的特点，对滑坡堆积层分层，探查划带及确定滑坡边界等有较好的效果。     

油气藏裂缝型储层预测方法——以济阳坳陷古潜山为例

济阳坳陷富台油田的潜山主要由下古生界寒武系和奥陶系碳酸盐岩地层组成。采用特征重构和属性反演技术，分析了碳酸盐岩储层发育机理，认为其储层裂缝的测井响应特征主要表现为深侧向电阻率（R_lld）变化不大，浅侧向电阻率（R_lls） 的值相对降低。通过重构反映储层裂缝发育程度的特征曲线，并选取相关的地震属性作为井间信息，用概率神经网络反演获得反映裂缝发育程度的特征属性数据体，预测裂缝发育带的空间展布。预测结果表明，所述方法具有良好效果。     

切削过程中高强合金钢浅表层性态强化研究

切削浅表层显微结构状态对机械构件力学性能和服役寿命有重要影响。为获得性能优良的切削表层,综合应用理论计算和测试分析的研究手段,对不同切削速度下高强合金钢浅表层微观结构演变和力学性能强化的内在关联展开研究。结果表明：中高切削速度能够相对最大程度实现高强钢切削表层梯度微观结构的形成,由表及里分别为致密纳米等轴晶所在的回复层,高密度亚结构聚集的流变层和晶粒残留畸变状态的畸变层。中高切速下平均晶粒尺寸相对最小（392.1 nm）,同时位错密度相对最高（1.072 5×10¹² cm^-2）,变形应变、位错和小角度晶界等亚结构均高度集中于流变层。经性能测试发现,中高切速实现了高强合金钢切削浅表层硬度、表面质量和韧性的同时提升,这是上述中高切速带来的微观结构变化所形成的细晶强化和位错强化综合作用的结果。     

大功率瞬变电磁法在铅锌矿勘探中的应用

瞬变电磁法是当前矿产勘查攻深找盲中的主流物探方法之一.本文结合瞬变电磁法原理及TEM异常特征分析,利用矿区实际地质及物探资料,推测异常体的形态、位置、产状、埋深等地质信息,为地质及钻探提供理论依据.     

鄂尔多斯盆地奥陶纪层序岩相古地理

通过大量露头与钻井沉积相观察,系统编制了三级层序地层格架下的鄂尔多斯盆地奥陶纪岩相古地理图。研究认为,早奥陶世发育近SN走向的伊盟-中央古陆将盆地分为东、西2部分碳酸盐台地沉积区,其沉积古地理分别受控于华北海及祁连海;由早奥陶世至中奥陶世盆地总体呈现出逐渐海侵及伊盟-中央古陆逐渐缩小的过程,伊盟-中央古陆在中奥陶世大部分被海水侵没并已分化为南、北相隔的2个古陆即庆阳古陆和伊盟古陆,至中奥陶世晚期即达瑞威尔期（马家沟组六段沉积期）海侵达到最大范围;晚奥陶世发生海退,造成现今鄂尔多斯盆地范围内大部分表现为古陆剥蚀区,仅在盆地西缘及南缘发育了较窄的开阔镶边台地及其斜坡相沉积,至晚奥陶世中晚期（凯特期-赫南特期）几乎全部隆升为陆。自早奥陶世晚期（弗洛期）至中奥陶世中期（达瑞威尔初期）即马家沟组一段至五段沉积期,盆地中东部发育大面积的局限蒸发环境,形成局限潟湖甚至膏盐潟湖。盆地西部与南部受贺兰拗拉槽与秦祁海槽发展演化控制,主要发育大陆边缘沉积体系,由早奥陶世-中奥陶世早期的被动陆缘碳酸盐缓坡台地向中奥陶世晚期-晚奥陶世的主动陆缘弱镶边碳酸盐台地演化。     

Recent development of polyfluorene-based RGB materials for light emitting diodes

As a continuation of our presentation at IUMRS-2000 in Hong Kong, we report the latest development of polyfluorene-based Red, Green and Blue (RGB) materials for light emitting diodes at The Dow Chemical Company. A modified Suzuki coupling process is used to synthesize RGB fluorene-based homopolymers and copolymers. Optimization of reaction conditions has led to a highly efficient procedure to generate polymers with controlled molecular weight (Mw), ranging from 10,000 to above 500,000 depending on the requirements of the desired applications. The optical and electronic properties of the polymers are tailored through selective incorporation of different aromatic units into the fluorene copolymer systems. By using this methodology, a portfolio of fluorene-based polymers has been designed and synthesized, achieving emissive colors that cover the entire visible spectrum.The performance of fluorene-based polymers in light emitting devices has been optimized by modifying the polymer compositions so as to increase charge mobilities and to improve the carrier injection balance. As a result of these compositional changes, devices based on Dow's green emitters, using bi-layer structures on indium tin oxide substrates and evaporated metal cathodes, have demonstrated unprecedented high efficiencies at high brightness levels and long lifetime performance. A device comprised of a Dow green emitting polymer has a low turn-on voltage of 2.25 V and exhibits a peak efficiency of 10.5 Cd/A at 6600 Cd/m² at 4.85 V. These devices maintain an efficiency of greater than 10.0 Cd/A up to 50,000 Cd/m²and demonstrate very good stability as exemplified by a device half-life of greater than 1500-h starting from 1100 Cd/m². Similar outstanding progress with red and blue emitters has also been made and will be discussed.     

First-Principles Study of the Influence of Lattice Misfit on the Behavior and the Ductility Effect of Hafnium in Ni-Ni_3Al System

Two Ni/Ni_3Al-interface-contained cluster models with/without lattice misfit are studied by first-principles method to clarify the debates about the segregation behaviors of Hafnium(Hf) and explore the influence of lattice misfit on the ductility effect of Hf.It is found that though Hf prefers to substitute Al rather than Ni in Ni_3Al phase within most of the investigated misfit range,its stronger preferring to Ni phase than Ni_3Al phase makes it impossible to go into Ni_3Al phase to occupy Al site in Ni-Ni_3Al alloys.Bond order analysis in Hf-free case shows that lattice misfit has different effects on the Griffith work of interfacial cleavage 2_(γint)/E and the maximum theoretical shear stress τ_(max) of Ni and Ni_3Al,contributing to the existence of anomalous strength-temperature phenomena in Ni_3Al alloys.However,the addition of Hf will make the2_(γint)/E(or τ_(max)) of both Ni_3Al and Ni decrease(or increase) with lattice misfit,indicating that the addition of Hf may make the anomalous strength-temperature relationship in Ni_3Al region disappear locally.     

当归总黄酮提取方法比较及工艺条件优化

对当归总黄酮进行提取,比较其提取方法,优化其最适提取方法的工艺条件.试验分别采用水煎煮法、乙醇回流法、超声波提取法对当归总黄酮进行提取,采用亚硝酸钠-硝酸铝-氢氧化钠法测定总黄酮含量,采用正交试验优化提取工艺条件.试验结果表明：乙醇回流法为当归总黄酮的最适提取方法,当提取温度85℃、提取时间2.0h、料液比1∶30、乙醇浓度80％时,得当归总黄酮含量为10-066 mg·g-1,比优化前提高了59.52％.试验较为完整地对当归总黄酮的提取方法和提取条件进行了研究,可为开发和利用当归总黄酮提供理论依据.