Integrated Biorefinery Design with Techno-Economic and Life Cycle Assessment Tools in Polyhydroxyalkanoates Processing

To support and move toward a sustainable bioeconomy, the production of polyhydroxyalkanoates (PHAs) using renewable biomass has acquired more attention. However, expensive biomass pretreatment and low yield of PHAs pose significant disadvantages in its large-scale production. To overcome such limitations, the most recent advances in metabolic engineering strategies used to develop high-performance strains that are leading to a new manufacturing concept converting biomass to PHAs with co-products such as amino acids, proteins, biohydrogen, biosurfactants, and various fine chemicals are critically summarized. This review article presents a comprehensive roadmap that highlights the integrated biorefinery strategies, lifecycle analysis, and techno-economic assessment for sustainable and economic PHAs production. Finally, current and future challenges that must be addressed to transfer this technology to real-world applications are reviewed.     

小角度空间交错轴变厚齿轮传动的啮合动态特性研究

为揭示小角度空间交错轴变厚齿轮副的时变啮合特性与非线性动态特性,在精确几何建模的基础上,建立了空间小角度交错轴变厚齿轮传动时变啮合模型,获取其时变啮合刚度与时变传动误差;考虑外部载荷与侧隙变化的影响,采用集中参数法建立了齿轮传动非线性动力学模型,对其系统非线性特征进行了仿真。结果表明外部载荷的增加直接导致了齿轮副啮合刚度、传动误差、动态传动误差和动态啮合力的增加,同时啮合刚度的增加使得系统共振频率增加;侧隙的增加使得系统在轻载下出现与单边、双边冲击耦合的突跳现象,在重载下双边冲击区域变大,动态啮合力增加。     

评委培训考核应与生产和市场紧密结合

自1952年全国第一届评酒会至1989年,评酒会已进行了5届。历届评酒会都推动了白酒生产和技术的发展。随着生活水平的提高,消费者对白酒酒度、香型、饮酒、消费市场、消费理性、产品的选择和评价标准均发生了新的变化。因此,白酒评委的培训考核应与生产和消费市场紧密结合,培养传承创新实用型的技术人才。（孙悟）     

Majority and minority influence in group negotiation: The moderating effects of social motivation and decision rules.

In organizational groups, often a majority has aligned preferences that oppose those of a minority. Although such situations may give rise to majority coalitions that exclude the minority or to minorities blocking unfavorable agreements, structural and motivational factors may stimulate groups to engage in integrative negotiation, leading to collectively beneficial agreements. An experiment with 97 3-person groups was designed to test hypotheses about the interactions among decision rule, the majority's social motivation, and the minority's social motivation. Results showed that under unanimity rule, minority members block decisions, thus harming the group, but only when the minority has proself motivation. Under majority rule, majority members coalesce at the minority's expense, but only when the majority has a proself motivation. Implications for negotiation research and group decision making are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new multi-purpose audio-visual UNMC-VIER database with multiple variabilities

Audio-visual recognition system is becoming popular because it overcomes certain problems of traditional audio-only recognition system. However, difficulties due to visual variations in video sequence can significantly degrade the recognition performance of the system. This problem can be further complicated when more than one visual variation happen at the same time. Although several databases have been created in this area, none of them includes realistic visual variations in video sequence. With the aim to facilitate the development of robust audio-visual recognition systems, the new audio-visual UNMC-VIER database is created. This database contains various visual variations including illumination, facial expression, head pose, and image resolution variations. The most unique aspect of this database is that it includes more than one visual variation in the same video recording. For the audio part, the utterances are spoken in slow and normal speech pace to improve the learning process of audio-visual speech recognition system. Hence, this database is useful for the development of robust audio-visual person, speech recognition and face recognition systems.     

Numerical calculations of the pressure spike in elastohydrodynamic lubrication

The application of advanced multilevel techniques to the solution of the EHL line contact problem has resulted in a multilevel solver of complexity O(n In n). The reduction in computing time thus obtained enables the use of large numbers of nodes and allows detailed study of the pressure spike. Both occurrence and height of the spike as a function of the governing parameters were studied. The parameter range where a pressure spike can be expected, and the results of spike height calculations, are presented.     

Phase-Change Perovskite Microlaser with Tunable Polarization Vortex

Metasurfaces supporting optical bound states in the continuum (BICs) are emerging as simple and compact optical cavities to realize polarization-vortex lasers. The winding of the polarization around the singularity defines topological charges which are generally set by the cavity design and cannot be altered without changing geometrical parameters. Here, a subwavelength-thin phase-change halide perovskite BIC metasurface functioning as a tunable polarization vortex microlaser is demonstrated. Upon the perovskite structural phase transitions, both its refractive index and gain vary substantially, inducing reversible and bistable switching between distinct polarization vortexes underpinned by opposite topological charges. Dynamic tuning and switching of the resulting vector beams may find use in microscopy imaging, particle trapping and manipulation, and optical data storage.     

变频调速在精矿回水再利用中的应用

本文介绍了永平铜矿精矿回水泵运用变频器进行调速改造的控制系统、原理、参数设置及应用效果。实践证明 ,变频调速在精矿回水利用中是可行的 ,具有一定的推广价值     

Indirect modelling of the scattering from two‐dimensional composite uniaxial bianisotropic cylinders of arbitrary cross‐sections

The indirect modelling of electromagnetic scattering from two‐dimensional composite uniaxial bianisotropic cylinders of arbitrary cross‐section is successfully performed according to the principle of equivolumetric model. The mathematical treatment here is based on the generalized boundary‐value method combined with the technique of separate variables. The solution is obtained from a system of linear equations of infinite order which is then truncated during numerical computations. Then, numerical investigation is carried out to demonstrate hybrid effects of geometrical and constitutive parameters of guest and host cylinders on the co‐ and cross‐polarized echo widths in the far‐field zone. It is shown that under certain circumstances, the indirect modelling technique is very efficient to study the scattering characteristics of many practical complex planar structures, and has some advantages over the direct numerical method. Copyright © 2001 John Wiley & Sons, Ltd.     

Joining composite pipes using hybrid prepreg welding and adhesive bonding

A critical technology for composite piping systems in offshore platforms is the joining technique. This paper discusses the development of a hybrid joining approach by using heat‐activated prepreg welding and adhesive bonding. The joining procedure was demonstrated via specimens' fabrication. Four adhesives, with varying mechanical properties, were used to seal the gap between the two pipes. A glass fiber reinforced prepreg was used to wrap the pipes. A total of forty‐five specimens were prepared and evaluated using standardized internal pressure tests. A finite element analysis was conducted to aid in the understanding of the mechanisms of the hybrid joining method. Recommendations for further studies were made based on the test and finite element analysis results.