Flow-induced shear stress and deformation of a core–shell-structured microcapsule in a microchannel

A numerical model was developed and validated to investigate the fluid–structure interactions between fully developed pipe flow and core–shell-structured microcapsule in a microchannel. Different flow rates and microcapsule shell thicknesses were considered. A sixth-order rotational symmetric distribution of von Mises stress over the microcapsule shell can be observed on the microcapsule with a thinner shell configuration, especially at higher flow rate conditions. It is also observed that when being carried along in a fully developed pipe flow, the microcapsule with a thinner shell tends to accumulate stress at a higher rate compared to that with a thicker shell. In general, for the same microcapsule configuration, higher flow velocity would induce a higher stress level over the microcapsule shell. The deformation gradient was used to capture the microcapsule's deformation in the present study. The effect of Young's modulus on the microcapsule shell on the microcapsule deformation was investigated as well. Our findings will shed light on the understanding of the stability of core–shell-structured microcapsule when subjected to flow-induced shear stress in a microfluidic system, enabling a more exquisite control over the breakup dynamics of drug-loaded microcapsule for biomedical applications.     

氯乙烯精馏过程模拟优化与节能降耗的研究

针对某聚氯乙烯厂精馏过程中氯乙烯产品纯度低、能耗高的问题,利用化工流程模拟软件Aspen Plus对氯乙烯精馏系统中的T-203塔进行模拟优化,选择适合氯乙烯体系的NRTL模型进行计算,确定理论板数为28块。根据灵敏度分析和正交试验得到最佳操作参数为:回流比为0.8,进料位置为第2块理论板,侧线采出位置为第18块理论板。产品中氯乙烯质量分数达到99.999%,低沸物质量分数小于1×10-6,高沸物质量分数小于5×10-6。同时对精馏系统提出两项节能降耗技术,其中循环水改造技术预计为企业带来经济效益1034.85万元/a,高效导向筛板技术可以有效提高分离效率和生产能力。     

Strategies for Improving the Catalytic Performance of 2D Covalent Organic Frameworks for Hydrogen Evolution and Oxygen Evolution Reactions

Hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have been deemed as clean and sustainable strategies to solve the energy crisis and environmental problems. Various catalysts have been developed to promote the process of HER and OER. Among them, two-dimensional covalent organic frameworks (2D COFs) have received great attention due to their diverse and designable structure. In this minireview, we mainly summarize the diverse linkages of 2D COFs and strategies for enhancing the catalytic performance of 2D COFs for HER and OER, such as introducing active building blocks, metal ions and tailored linkages. Furthermore, a brief outlook for the development directions of COFs in the field of HER and OER is provided, expecting to stimulate new opportunities in future research.     

《近思录》的“教学之道”与朱熹的教育思想

朱熹的教育思想与《近思录》"教学之道"的语录文字联结紧密,二者存在相当的一致性;《近思录》语录文字是朱熹辑录与发明,是有意张扬四子思想,并藉以表达自己教育思想之取向。程朱理学,注重人之禀赋的开掘,达成圣贤;强调早期教育,"以豫为先",养成"圣贤坯璞";对传统教学内容的继承与拓展,尤重洒扫应对;对教法阐释透彻,继承而推新。这些在当下对我们有很好的启示。     

Hierarchical motion planning at the acceleration level based on task priority matrix for space robot

Nonlinear Dynamics - A capacitive micromachined ultrasonic transducer (CMUT) due to many benefits is being considered as an imaging and therapeutic technology recently. The critical challenge is to...     

Detecting nonclassicality of light via Lieb's concavity

Nonclassical light states are important for both conceptual and practical reasons: they are basic ingredients in testing and exploring quantum foundations, and are crucial resources in quantum technologies. Various useful criteria have been developed to detect nonclassicality in the literature, and several meaningful measures of nonclassicality have been introduced and measured experimentally. In this work, by use of a non-Hermitian generalization of the Wigner-Yanase-Dyson skew information and playing with operator ordering in evaluating average photon number, we develop a novel family of criteria for detecting nonclassicality of light based on Lieb's concavity, which is a deep and powerful result concerning interaction between quantum states and observables. We elucidate the information-theoretic as well as the physical meaning of the criteria, and illustrate their effectiveness in capturing and quantifying nonclassicality of various important light states.     

Twining Poly(polyoxometalate) Chains into Nanoropes

Organic polymers and inorganic clusters belong to two different disciplines and have completely different properties and structures. When a cluster is attached to the backbone of a polymer as a pendant, the resultant hybrid polymers (polyclusters) exhibit unique behaviours totally different from those of conventional polymers owing to the nanoscale size of the cluster and its particular interactions. Herein, the aggregation of a poly(polyoxometalate)—a polynorbornene backbone with inorganic polyoxometalate cluster pendants—upon addition of a non-solvent to its dilute solution is reported. A three-dimensional network of tangled and snake-like nanothreads was observed. Direct visualisation of individual nanoscale clusters enabled identification of single chains within the nanothreads. These observations suggest that during the process of aggregation, the hybrid polymer forms curved or extended chains as a consequence of an armouring effect in which the collapsed cluster pendants wrap around the backbone. The collapse occurs because they become less soluble in the solvent/non-solvent mixture. The extended chains then become entwined and form nanoropes consisting of multiple chains wound around each other. This study provides a deeper understanding of the nature of polyclusters and should also prove useful for their future development and application.     

吸附法治理汞废气的机理研究

该文对载银活性炭吸附汞蒸气的机理进行了探讨 ,通过电子探针和扫描电镜对载银活性炭及被汞“饱和”的载银活性炭进行微观结构分析 ,结果显示 ,银在活性炭中主要分布于活性炭的凸面处 ,汞只在有银存在的地方出现 ,表明普通活性炭不具备吸附汞的能力 ,载银活性炭吸附汞属于以银为核心的多分子物理吸附 ,工业上的“饱和”载银活性炭仍具有一定的吸附汞蒸气的能力 ,为交替式吸附床的结构设计提供了技术依据 .     

金属薄膜制备及物性测量系列实验

介绍了由模拟真空实验和“金属薄膜的制备”、“金属薄膜厚度的测量”、“金属薄膜电阻率的测量”,以及“金属薄膜生长过程的动态监测”等4个实验组成的金属薄膜制备与物性测量系列实验.这组实验与现代科学技术发展联系紧密,仪器设备可靠,操作简单,适合于普通物理实验阶段的研究性教学.     

Three New Polyoxygenated Steroids from Two Species of the South China Sea Gorgonian Muricella flexuosa and Menella verrucosa Brundin

Three new polyoxygenated steroids, muricesteroid ( 1 ), and menellsteroids A ( 2 ) and B ( 3 ), were isolated from two species of the South China Sea gorgonian Muricella flexuosa and Menella verrucosa Brundin , respectively. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis, chemical methods and comparison with known related compounds.