苯乳酸抑制链格孢霉作用靶位的分析

以从自然腐败的樱桃上分离的链格孢霉（Alternaria sp.）LD3.0086为指示菌，研究苯乳酸对链格孢霉的主要抑制作用靶位。应用分光光度法测定苯乳酸对链格孢霉的最小抑菌浓度，通过卡尔科弗卢尔荧光增白剂染液（calcofluor white，CFW）染色观察苯乳酸对菌丝顶端生长的破坏作用，利用扫描电子显微镜和透射电子显微镜观察链格孢霉的超微结构变化，通过测定苯乳酸作用前后链格孢霉上清液中N-乙酰葡萄糖胺质量浓度变化研究苯乳酸对菌丝细胞壁的破坏作用，应用荧光双染色法观察苯乳酸对链格孢霉菌丝细胞膜的损伤作用。结果表明，12.5 mmol/L的苯乳酸能有效抑制链格孢霉的生长；与对照组（无菌水处理）相比，苯乳酸处理后链格孢霉顶端生长细胞无明显形变，经12.5 mmol/L苯乳酸处理的链格孢霉上清液中N-乙酰葡萄糖胺质量浓度基本不变；苯乳酸处理24 h，链格孢霉菌丝细胞壁表面无明显损伤，细胞内结构发生明显变化；苯乳酸短时间（4 h）处理链格孢霉，菌丝细胞膜仍较为完整，加入苯乳酸较长时间（8 h）后细胞膜发生破裂。综合分析可知，苯乳酸对链格孢霉的主要作用靶位应不是菌丝体的细胞壁和细胞膜，而是在菌丝体内部，通过破坏菌丝内部细胞器结构或引起细胞内的生化反应，从而抑制链格孢霉的生长和繁殖，发挥抑菌活性。     

Enhanced performance of Ni catalysts supported on ZrO2 nanosheets for CO2 methanation: Effects of support morphology and chelating ligands

A series of Ni/ZrO₂ catalysts was prepared by the impregnation method with modification of the morphology of ZrO₂ support as well as the impregnation procedure and tested for CO₂ methanation. The catalysts supported on the ZrO₂ nanosheets displayed superior catalytic performance as compared with that on ZrO₂ nanoparticles, which could be mainly attributed to the abundant oxygen vacancies promoting the adsorption and dissociation of CO₂ molecules as well as the high dispersion of Ni species. With the introduction of ethylenediamine (En) in the impregnation procedure, the resulting Ni-15En/ZrO₂-1.5 catalyst showed the optimal activity with CO₂ conversion of 86% significantly higher than Ni/ZrO₂-0 of 44% and Ni/ZrO₂-1.5 of 79% at 0.5 MPa and 300 °C. The excellent performance was attributed to increased moderately basic sites for CO₂ adsorption in ZrO₂ nanosheets, as well as the enhanced dispersion of nickel caused by the complexation of Ni ions with En, which inhibited the aggregation of nickel particles in the subsequent thermal treatments. In conclusion, the synergistic effects of the morphology of ZrO₂ nanosheets as well as the chelating behavior of En contributed to the enhanced performance of Ni-15En/ZrO₂-1.5 in the CO₂ methanation reaction. The strategy shows good prospects for controlling the size of active metals, especially those that were dispersed on the surface of the two-dimensional (2D) metal oxide materials.     

基于Pro/E二次开发参数化技术的研究与应用

介绍了参数化设计的基本原理，阐述了Pro／E参数化设计的特性及基于Pro／program二次开发实现参数化建库的方法，并给出了实例。     

具有输入低频电流纹波抑制功能的光伏高频链并网逆变器

光伏发电系统对光伏电池输出电流低频纹波有严格的要求,而普通光伏并网逆变器通常增加滤波器容量或复杂的控制策略实现输入低频电流纹波抑制。将LCL-T谐振网络引入光伏并网逆变器,在变换器开关频率等于谐振频率时,可由谐振网络特性有效抑制光伏电池输出电流中的低频纹波。分析了光伏并网系统中电流、电压与各元件参数之间的关系,提出了相关元件参数的设计规则,并提出了相应的控制策略。实验结果表明,所提逆变器能够很好地抑制光伏电池输出电流中的低频纹波,且具有较高的效率。     

A versatile strategy towards semi-interpenetrating polymer network for proton exchange membranes

A universal method to prepare proton exchange membrane (PEM) with semi-interpenetrating polymer network (semi-IPN) via a versatile crosslinker 1,3-benzenedisulfonyl azide (1,3-BDSA) is proposed. Sulfonyl azide groups can react with any polymer with carbon-hydrogen bonds via hydrogen abstraction. Polyvinylidene fluoride (PVDF) and perfluorosulfonic acid (PFSA) polymer are selected as two precursors for semi-IPN. When 1,3-BDSA is heated to a sufficiently high temperature it can form the nitrene and connect with PVDF via hydrogen abstraction reaction, recombination, or CH-bond insertion. The crosslinking structure of PVDF is formed, and semi-IPN is constructed in the presence of PFSA at the same time. The mechanical properties, degree of crosslinking, water uptake, and proton conductivity of semi-IPN membranes are investigated. Compared with pure PFSA membrane, the mechanical properties and the dimensional stability of the semi-IPN membranes are improved significantly. The tensile strength of the composite membrane (27.2 MPa) is much higher than that of PFSA membrane (10.1 MPa). The maximum power density of the composite membrane can reach 382 mW cm⁻² at 940 mA cm⁻². Sulfonyl azide based crosslinkers can be used to prepare semi-IPN or IPN PEMs from any paired polymers with carbon–hydrogen bonds.     

Characteristic of filamentous fungal diversity and dynamics associated with wheat Qu and the traditional fermentation of Chinese rice wine

Chinese rice wine, a traditional alcoholic beverage, is fermented from steamed rice with a starter culture of wheat Qu which is either inoculated spontaneously with various microorganisms in natural environment or inoculated artificially with certain microorganisms. The diversity of filamentous fungi in wheat Qu and the fermentation mashes of Chinese rice wine was studied by high‐throughput sequencing. The results indicated that filamentous fungi varied in wheat Qu and fermentation periods. Moreover, Aspergillus was the dominant filamentous fungi at genus levels. On that basis, quantitative real‐time PCR was used to quantify some dominant Aspergillus species. It was found that Aspergillus species in wheat Qu were more abundant than that in various fermentation mashes and continually decreased until the end of rice wine fermentation. Furthermore, it was found that different organic acids were produced by microorganisms at different fermentation stages might due to the changes of oxygen and nutrient content.     

钴元素对SUS304不锈钢耐点腐蚀性能的影响

开发红土镍矿是解决镍资源危机的重点,由于红土镍矿中钴和镍伴生,导致不锈钢中钴元素的存在。本文以SUS304不锈钢钢板和电解钴为原料,采用真空感应冶炼炉和三高石墨铸模浇铸不同钴含量试样,利用线切割机加工腐蚀试样,进行三氯化铁点腐蚀试验。试验结果表明：钴元素的加入增大了铸态SUS304不锈钢点腐蚀敏感性,降低了铸态SUS304不锈钢耐点腐蚀性能,当钴含量小于0．3％时,点腐蚀速率没有增加,当钴含量为0．4％和0．5％时,点腐蚀速率明显增大。     

徐家围子断陷深层不整合结构及其与天然气运移的关系

为了深入了解徐家围子断陷深层不整合结构及其与天然气运移的关系,利用地震、钻井资料对徐家围子断陷深层不整合结构和岩石物性进行了统计分析;结合已有勘探成果划分了不整合运移通道类型,对与不整合相关的天然气运移方式进行了总结.结果表明:火山岩是徐家围子断陷深层不整合的重要组成部分,火山岩半风化岩石的孔渗性远优于顶板岩石;徐家围子断陷深层不整合运移通道可以划分为2大类9亚类,火山岩作为半风化岩石时可以形成多种类型运移通道.与不整合相关的天然气运移模式可归纳为不整合直接运移、不整合与连通砂体组合运移、不整合与断裂组合运移及不整合与断裂、连通砂体组合运移4种类型,不整合与断裂组合运移是沙河子组排出烃类运移至营城组火山岩圈闭的主要输导方式.     

Electrochemical impedance spectroscopy for analytical determination of paraquat in meconium samples using an immunosensor modified with fullerene, ferrocene and ionic liquid

The paper reports a highly sensitive electrochemical immunosensor for the detection of paraquat. The immunosensor bases on glassy carbon electrode modified with a composite made from fullerene, ferrocene and the ionic liquid. The components were immobilized on the electrode surface by chitosan. The antibody of paraquat was covalently conjugated to the surface which was then blocked with bovine serum albumin. Analytical characteristics of the immunosensor were investigated by electrochemical impedance spectroscopy. It offers good repeatability (RSD = 1.5%), a stability of more than 150 days, an impedimetric response to paraquat in the range from 3.89 × 10⁻¹¹ to 4.0 × 10⁻⁸ mol L⁻¹, and a detection limit (S/N = 3) of 9.0 × 10⁻¹² mol L⁻¹. The effects of omitting fullerene and the ionic liquid were well tested. The results indicated that sensitivity of the immunosensor is 3.7-fold better if fullerene and ionic liquid are used. This demonstrates that fullerene facilitates electron transfer on surface of the electrode due to unique electrochemical properties, while the ionic liquid provides biocompatible microenvironment for the antibody, which results in the enhanced sensitivity and stability. Moreover, surface morphology feature and electrochemical properties of the electrode were also examined. The method was satisfactorily applied to the determination of paraquat in meconium.