Dynamic optimization for gas blending in pipeline networks with gas interchangeability control

The increasing penetration of unconventional gas and liquefied natural gas poses an operational challenge on existing regional gas networks for gas quality problems. A new dynamic model for natural gas pipeline network with multiple supplies is presented with a special emphasis on gas interchangeability control. Wobbe index serves as gas interchangeability indicator and is calculated by equations derived from rigorous composition-based partial differential equations. Disjunctive formulation is applied to represent different modes of gas blending due to gas reversal, and the disjunctive model is then reformulated as a nonsmooth model with min/max and absolute value functions, which is solved by a gradient-based nonlinear program solver after smooth approximation. Moreover, a heuristic algorithm is proposed to tune the penalty parameters in order to focus on different penalty terms while keeping the model well-conditioned. The developed model and strategy are first tested with a small pipeline network model and then extended to a large model. The results show that the model can effectively manage gas interchangeability issues in pipeline networks within reasonable CPU time.     

大兴安岭额尔古纳成矿带特征及金成矿条件探讨

额尔古纳成矿带处于西伯利亚板块东南缘蒙古-兴安造山带内,蒙古-鄂霍茨克断裂与得尔布于断裂之间,包括北部上黑龙江成矿亚区、中部额尔古纳成矿亚区和南部克鲁伦成矿亚区。区内13处岩金矿床(点)均与中生代岩浆活动有关,金矿形成于中生代(晚侏罗世-早白垩世),金矿床具有北东成带,北西成行的分布特征。成矿物质来源以深源为主,有部分地壳物质的加入;成矿溶液是岩浆热液和大气降水的混合流体;成矿温度为200-300℃,矿床属中低温热液型金矿床。     

稠油潜山底水运动规律及配套堵水工艺

结合稠油裂缝潜山油藏储层岩性发育特征,分析了曙一区古潜山底水运动规律。研究了堵剂颗粒粒径与储层裂缝开度的配伍,运用颗粒与凝胶堵剂复合应用的方法,现场采用单一、双段塞和大剂量三段塞复合堵水工艺对油藏底水进行封堵,2002年以来,共实施堵水工艺135井次,区块年度原油产量逐年上升,综合含水逐年下降,连续三年实现了综合负递减。室内实验和应用效果证明,该配套堵水工艺能够满足底水发育、稠油裂缝油藏堵水要求,值得进一步推广。     

Entangled Azobenzene‐Containing Polymers with Photoinduced Reversible Solid‐to‐Liquid Transitions for Healable and Reprocessable Photoactuators

Photoactuators based on liquid crystal elastomers or networks are smart materials that show photoinduced motions. However, their crosslinked networks make their repair or reprocessing difficult. Here, a healable and reprocessable photoactuator is fabricated using entangled high‐molecular‐weight azobenzene‐containing polymers (azopolymers) that are non‐crosslinked. A series of linear liquid crystal azopolymers with different molecular weights are synthesized. The low‐molecular‐weight azopolymers (5–53 kg mol^?1) cannot form freestanding photoactuators because their polymer chains lack entanglements, which makes them hard and brittle. In contrast, flexible and stretchable actuators are fabricated using high‐molecular‐weight azopolymers (80–100 kg mol^?1) that exhibit good processability because of the polymer chain entanglements. The azopolymer photoactuators show photoinduced bending based on photoinduced trans–cis isomerization of the azopolymers on the irradiated side. The experiments show not only photoinduced phase transitions or changes in the order parameters but also photoinduced solid‐to‐liquid transition of the azopolymers resulting in shape changes and mechanical responses. Thus, photoinduced solid‐to‐liquid transition is a new mechanism for the design of photoactuators. Moreover, the azopolymer photoactuators are healable and reprocessable via solution processing or light irradiation. Healability and reprocessability prolong lifetimes of photoactuators are important for materials reusage and recycling, and represent a new strategy for the preparation of smart materials.     

骨料种类对糯米灰浆性能的影响

采用灰浆性能表征并辅以扫描电镜（SEM）和X射线衍射（XRD）等技术手段,测定了制备的糯米灰浆的表面强度、抗压强度、抗冻性等性能,探讨了骨料的种类、粒径以及掺量对糯米灰浆性能的影响。结果表明：砖颗粒、河砂、石英砂3种骨料的掺入,使糯米灰浆的收缩性和抗冻性均得到较大改善。其中,砖颗粒骨料的加入使糯米灰浆的抗冻性较空白样品提高了125%;但随着骨料粒径和骨灰比的增大,掺入骨料糯米灰浆的抗压强度、抗冻性和收缩率呈下降趋势。因此,在砖石质文物的保护中,建议使用砖颗粒作为糯米灰浆的骨料,并将骨料粒径控制在3 mm以下,骨料/灰的比值控制在2∶1以下,对改善糯米灰浆的性能效果最佳。     

轩、榭、舫、厅、馆

中国古典园林的特征之一是以建筑为主。园林中的建筑有厅、堂、楼、阁、亭、廊、轩、榭、舫等。厅与堂常作为庭园中的主体建筑，建筑形式多采用歇山、硬山或组合形式。楼、阁为二层或二层以上的建筑，位于建筑群体的后部或作为建筑群的主体，建筑形式多采用歇山式、硬山式、攒尖式或组合式。轩是一种有特殊含义的建筑，园林建筑冠以轩的美称，典雅而别有情趣，它四面空透。榭与舫是中国园林中别具特色的建筑，榭多临水而建，造型多轻盈活泼，四面透空，建筑形式常采用歇山式。舫是仿船形的一种特殊的园林建筑，整体深入水中，这种建筑常采用组合形式，前部高起，中部较低，后部建成为二层楼房，供人登楼远眺。本文从四个方面探讨有关园林建筑构造技术方面的问题。     

六角亭构造技术（二）

亭是我国古典园林建筑中应用最广泛的一种建筑。亭本是供人休息的建筑，还是一种重要的点景建筑。亭的种类很多，以造型分，可分为三角、四角、五角、六角、八角、圆亭、扇面、卷书、天圆地方等。各种形式中又有单檐、重檐之分，还有各种组合式亭。仅以北方现存亭子形式粗略统计，就有四五十种之多。本文对各种六角亭的基本构造和技术要点进行简述。     

石材的清洗与翻新技术

本文简要叙述了装饰石材常见的病症，分析了各种污斑迹产生的原因和机理，介绍了有关清洗与翻新的方法，最后阐述了石材防护的作用。     

清粉系统设置及其流程形式的优化设计

阐述了不同粉路生产不同小麦粉时清粉系统的设置,尤其是对不同粉路的清粉范围、进机物料的组合、清粉系统的设置、清后物料的流向及清粉流程的优化设计进行了较为详细的论述,提出了清粉系统的设置及流程形式应遵循"同品质合并"的原则.