仿人机器人的机械结构设计与控制系统构建

文章研发了一款适用于机器人教育教学的多功能、多用途、普适性的19自由度的小型仿人机器人,主要完成了该机器人的机械结构设计与控制系统构建工作[1]。所设计的机器人机械结构可靠性高、工艺性好、结构紧凑、样式新颖；所构建的机器人控制系统鲁棒性高、稳定性好、控制准确、反应迅速,圆满地实现了预期的设计任务。通过对优缺点的综合对比,得出组合式构型方案在功能性、实用性和稳定性等方面具有明显优势,有望通过后续软件系统的开发提高其运动效能,真正在青少年机器人教育中发挥重要作用[2]。     

Improved biogas yield from organic fraction of municipal solid waste as preliminary step for fuel cell technology and hydrogen generation

Biogas utilization in fuel cell technology and hydrogen generation is a modern and economically viable approach. A pretreatment step prior to anaerobic digestion (AD) is obligatory to increase the hydrolysis, solubilize the complex matter present in organic fraction of municipal solid waste (OFMSW) and to achieve higher yield of biogas. This study was intended to find out the effects of thermal, chemical and thermochemical pretreatments on the properties and structure of OFMSW and also on biogas production. There was an increase in chemical oxygen demand of 6.87, 1.61 and 11.60% for thermal, chemical and thermochemical pretreatments, respectively. Also, the content of volatile solids was reduced by 2.36% by thermochemical pretreatment. FTIR, XRD and SEM analysis revealed that these pretreatments also caused chemical and morphological changes on the substrate, as a result reduced its crystallinity and enhanced the rate of hydrolysis. A significant increase of 54% in biogas yield was achieved after thermochemical pretreatment in comparison to untreated OFMSW sample.     

pH-independent dissolution enhancement for multiple poorly water-soluble drugs by nano-sized solid dispersions based on hydrophobic–hydrophilic conjugates

The objective of this study was to achieve an optimal formulation of hydrophilic–hydrophobic conjugates for nano-sized solid dispersions (SDs) with enhanced dissolution of multiple drugs in different gastrointestinal (GI) tract environments. A new conjugate powder with an optimized process was used to fabricate SDs that contained three poorly water-soluble drugs that were also poorly soluble in different dissolution media. The self-assembled nanoparticle formation, drug crystallinity and SD molecular interactions were investigated by measuring the particle size during dissolution testing and physicochemical property analysis (powder X-ray diffraction and Fourier transform infrared spectroscopy). Drug release studies indicated that SD containing conjugated powder significantly improved the dissolution rates of these poorly water-soluble drugs in the GI tract. In addition, particle size analysis showed nano-sized particles in the dissolution media in the early stage with a tendency to reduce smaller particles over time. Physicochemical characterizations demonstrated almost amorphous drug states and hydrogen bonding interactions between the drugs and conjugates in the SD. This study optimized a promising material for SD, and the material was shown to have a promising performance under various pH medium conditions with poorly water-soluble drugs.     

气瓶内部淬火过程的流动换热特性

 大直径厚壁气瓶内部淬火时的流动换热过程极其复杂，受到多种因素的影响，而研究气瓶内部压强和温度的变化规律对改善流动换热效果、提高产品组织性能具有重要的理论指导意义。以914 mm厚壁气瓶和瓶内流体为研究对象，建立了二维等效流 固耦合模型；采用多喷嘴系统对气瓶内外进行喷水淬火，研究了气瓶总长、喷水流速及淬火时间对瓶内压强及内壁温度的影响，通过间歇淬火试验验证了数学模型的正确性。结果发现，气瓶长度对瓶内压强和瓶壁温度的影响显著，喷水流速次之，当喷水流速大于8 m/s后，水量对瓶壁的冷却效果大大降低；气瓶内壁长度方向的温度梯度分别随气瓶总长的增加和淬火时间的延长而减小，但基本不受喷水量的影响。     

玉米秸秆衍生碳基固体酸的制备及其催化纤维素水解糖化

以玉米秸秆为原料，通过碳化-磺化法制备了碳基固体酸（CSA），采用XRD、FTIR、XPS、SEM、阳离子交换与返滴定法等手段对其结构形貌进行表征，并考察了制备条件对固体酸表面活性基团含量与催化活性的影响。以NaOH/尿素冻融预处理后的纤维素为底物，研究了CSA催化纤维素水解糖化的效果与条件。结果表明：NaOH/尿素冻融预处理能够有效辅助固体酸催化纤维素水解，在350℃碳化2h、100℃磺化5h条件下制备的CSA催化性能最好，其酸量达3.94mmol/g，其中磺酸基、羧基、酚羟基含量分别为1.09mmol/g、1.36mmol/g、1.49mmol/g。在m(CSA)∶m(纤维素)=3∶1、水解温度200℃、水解时间为0.5h的条件下，纤维素水解还原糖得率与转化率分别为47.1%和63%。CSA循环利用3次催化活性下降不大。本研究可为废弃生物质原料制备的固体酸催化纤维素水解转化利用提供科学参考。     

Chemical Stability of α‐Tocopherol in Colloidal Lipid Particles with Various Morphologies

Colloidal lipid particles (CLPs) are promising encapsulation systems for lipophilic bioactives, such as oil‐soluble antioxidants that are applied in food and pharmaceutical formulations. Currently, there is no clear consensus regarding the relation between particle structure and the chemical stability of such bioactives. Using α‐tocopherol as a model antioxidant, it is shown that emulsifier type (Tween 20 or 40, or sodium caseinate) and lipid composition (tripalmitin, tricaprylin, or combinations thereof) modulated particle morphology and antioxidant stability. The emulsifier affects particle shape, with the polysorbates facilitating tripalmitin crystallization into highly ordered lath‐like particles, and sodium caseinate resulting in less ordered spherical particles. The fastest degradation of α‐tocopherol is observed in tripalmitin‐based CLPs, which may be attributed to its expulsion to the particle surface induced by lipid crystallization. This effect is stronger in CLPs stabilized by Tween 40, which may act as a template for crystallization. This work not only shows how the architecture of CLPs can be controlled through the type of lipid and emulsifier used, but also gives evidence that lipid crystallization does not necessarily protect entrapped lipophilic bioactives, which is an important clue for encapsulation system design. Practical Applications: Interest in enriching food and pharmaceutical products with lipophilic bioactives such as antioxidants through encapsulation in lipid particles is growing rapidly. This research suggests that for efficient encapsulation, the particle architecture plays an important role; to tailor this, the contribution of both the lipid carrier and the emulsifier needs to be considered.     

激光立体成形TC4钛合金的热力场演化

激光立体成形能够实现高性能复杂零件的精确成形，但成形过程中的高温度梯度极易导致残余应力和变形，最终影响构件的几何精度和力学性能。通过搭建基板单边夹持原位热变形测量系统，探究了多道多层TC4钛合金成形件在激光立体成形过程中基板温度、变形的演化规律，分析了不同扫描策略对构件热应力场的影响。研究结果表明，构件的变形发展受其热历史驱使，扫描策略对成形件的热变形具有显著影响。     

固态法蒸馏酒与液态法蒸馏酒产品风味研究进展——以中国白酒与葡萄白兰地为例

酒产品的蒸馏技术主要为固态蒸馏技术和液态蒸馏技术，不同的蒸馏技术由于原理、设备和工艺的不同，所形成的产品风味各有特色。该文以两种蒸馏技术所形成的经典产品为例，对中国白酒与葡萄白兰地的主要风味区别进行概述，阐明其异同。并探讨原料、微生物和设备，以及相关生产工艺对产品风味及成分的影响。为开发出适合中国大部分消费者口感的白酒与葡萄蒸馏酒产品提供参考。