菊芋小孢根霉固态发酵纤溶酶的工艺优化

从酒曲中分离得到一株纤溶酶产生菌,经鉴定为菊芋小孢根霉.现对其固态发酵工艺的碳源、氮源、碳氮比、初始pH、含水量、无机盐、接种量、发酵时间、发酵温度和培养基厚度进行研究.结果表明,该菌株固态发酵工艺为:麸皮与豆粕比例2﹕1,初始pH,5.0,含水量(干基)1,mL/g,MgSO4,10,mmol/kg,(NH4)2,SO4200,mmol/kg,FeSO4,3,mmol/kg,接种量为6×106,g-1,培养基厚度为2,cm,29,℃恒温发酵72,h.最佳发酵条件下酶活力为684.39,U/g,是未优化时产酶量的8.2倍.通过对培养基的优化研究,使产酶量大幅提高,说明菊芋小孢根霉固态发酵纤溶酶具有工业潜力,也为工业化提供数据基础.     

A study of the suppression of the high-temperature helium embrittlement in an oxide-particle dispersion strengthened alloy

In this paper, an investigation on the micro-structure of an Fe-base oxide-dispersion-strengthened （ODS） alloy irradiated with high-energy ^20Ne ions to different doses at a temperature around 0.5Tin （Tin is the melting point of the alloy） is presented. Investigation with the transmission electron microscopy found that the accelerated growth of voids at grain-boundaries, which is usually a concern in conven- tional Fe-base alloys under conditions of inert-gas implantation, was not observed in the ODS alloy irradiated even to the highest dose （12000 at.ppm Ne）. The reason is ascribed to the enhanced recombination of point defects and strong trapping of Ne atoms at the interfaces of the nano-scale oxide particles in grains. The study showed that ODS alloys have good resistance to the high-temperature inter-granular embrittlement due to inert-gas accumulation, exhibiting prominence of application in harsh situations of considerable helium production at elevated temperatures like in a fusion reactor.     

白酒糟固态发酵生产蛋白饲料条件的优化

利用枯草芽孢杆菌和热带假丝酵母固态发酵白酒糟以提高白酒糟粗蛋白含量,优化了影响白酒糟固态发酵的单因子试验(接种量、发酵时间、菌种接种比例、尿素添加量)和多因子的正交试验[L9(34)]。结果表明,双菌株固态发酵白酒糟的最优条件为:接种量15%、发酵48 h、枯草芽孢杆菌与热带假丝酵母接种比例2∶1、尿素2 g。     

Detection and analysis of DNA recapture through a solid-state nanopore

Motion control of a single molecule through a solid-state nanopore offers a new perspective on detecting and analyzing single biomolecules. Repeat recapture of a single DNA molecule reveals the dynamics in DNA translocation through a nanopore and may significantly increase the signal-to-noise ratio for DNA base distin- guishing. However, the transient current at the moment of voltage reversal prevents the observation of instantly recaptured molecules and invalidates the continuous DNA ping-pong control. We performed and analyzed the DNA translocation and recapture experiment in a silicon nitride solid-state nanopore. Numerical calculation of molecular motion clearly shows the recapture dynamics with different delay times. The prohibited time when the data acquisition system is saturated by the transient current is derived by equivalent circuit analysis and finite element simulation. The COMSOL simulation reveals that the membrane capacitance plays an important role in determining the electric field distribution during the charging process. As a result of the transient charging process, a non-constant driving force pulls the DNA back to nanopores faster than theoretically predicted. The observed long time constant in the transient current trace is explained by the dielectric absorption of the membrane capacitor.     

以超高分子材料为载体研发新型固体缓释抑菌剂

利用超高分子材料载体制备一种固体缓释抑菌剂,对其进行表征,检验其缓释及抑菌效果.将挥发性中西药复配抑菌液吸附于特定的超高分子材料载体,对超高分子材料的力学性能进行考察,观察其微观结构,并对固体缓释抑菌剂的缓释效果和抑菌效果进行评价.结果表明:超高分子材料的拉伸断裂应力为28.79 MPa,抗冲击强度为78.85 kJ·m^-2,超高分子材料的孔隙率为69.17%,抑菌液吸附量为0.58 g·cm^<sup>-3,抑菌液吸附率为141.38%;固体缓释抑菌剂的有效释放时长为10 d,对多种致病菌的平均杀灭率均高于99%;超高分子材料具有高强度的力学性能和较高的抑菌液吸附率;固体缓释抑菌剂释放速率稳定,在空气中分布均匀,缓释效果和抑菌效果良好.     

VHF波段功率合成器的理论和设计

结合最新雷达研制工作的需要,介绍了VHF波段中集中参数Wilkinson功率合成器的设计理论和方法,并用微波仿真软件对其进行优化.通过制作并测试该功率合成器,验证了该设计方法的可行性.同时给出了实物照片和测试数据.该功率合成器适用于VHF波段的110MHz-140MHz,峰值功率可达到6KW,可作为独立的功率合成器,也可以用作功率合成的基本单元.     

DQ同步坐标系下非同步双电源固态开关切换控制研究

传统的双电源固态开关是以主备用电源同步为前提条件,无法保障两路独立电源供电.本文研究了一种基于dq变换和二阶广义积分器锁相技术的双电源固态切换开关切换控制方法,可实现主电源和备用电源非同步情况下快速和无冲击切换,可保证一类负荷的可靠稳定运行.通过二阶广义积分器提取非理想电网的基波正序分量,通过锁相和锁频得到精确的电网相...     

Biodegradation of Straw Stalk and Experiment of Ethanol Fermentation

Biological preprocessing of lignin degradation of straw stalk with white-rot fungi and ethanol fermentation experiment are carried out. The result shows that after biological preprocessing, lignin content in straw stalk reduces significantly. The higher the lignin degradation rate, the higher the ethanol productivity. When the technique of solid state culturing to degrade lignin is adopted to produce ethanol, the productivity is 15.8%, which is equal to 374.4% of that produced without preprocessing process.     

钠离子电池电解质的研究进展

相比锂离子电池来说,钠离子电池因高能量密度和低成本引起广泛关注。作为电池重要组成部分的电解质,对电池性能的发挥至关重要。简要介绍了液、固态电解质体系在钠离子电池中的研究进展,讨论这些电解质体系的电导率、电性能、电化学性能、热稳定性等特点。现今钠离子电池大多使用的是液体电解液,而液体电解液在具有高离子电导率的同时,安全性仍有待改善。而固态电解质还有许多基础科学需要探索,并且需要考虑电导率、成本等因素。基于以上评述,希望对钠离子电池电解质的研究发展提供帮助。     

固态溶剂法制备超薄混合基质膜用于分子筛分

分离过程在化工生产、国民经济和国防建设等方面具有重要意义,膜分离技术因高效、节能和环境友好的特点扮演着重要角色。混合基质膜结合了分子筛材料的高渗透分离性能和聚合物膜的良好加工性,近年来成为研究热点。本文主要介绍了混合基质膜的发展以及突破性工作。随着填料类型的丰富,混合基质膜在多种分离场景中表现良好。最近,南京工业大学膜研究团队提出了“固态溶剂法”制备混合基质膜,膜厚可控制在100 nm以下、掺杂量提高了2～4倍,实现了膜渗透性和选择性数量级的提升。该方法构建了一种以填料为主、聚合物为辅的新型混合基质膜结构,在保留良好加工性和放大制备前景的同时,将混合基质膜分离性能推向了类无机分子筛膜的新高度。