Lipase-catalyzed Synthesis of Caffeic Acid Phenethyl Ester in Ionic Liquids： Effect of Specific Ions and Reaction Parameters

Caffeic acid phenethyl ester（CAPE） is a rare, naturally occurring phenolic food additive. This work systematically reported fundamental data on conversion of caffeic acid（CA）, yield of CAPE, and reactive selectivity during the lipase-catalyzed esterification process of CA and phenylethanol（PE） in ionic liquids（ILs）. Sixteen ILs were selected as the reaction media, and the relative lipase-catalyzed synthesis properties of CAPE were measured in an effort to enhance the yield of CAPE with high selectivity. The results indicated that ILs containing weakly coordinating anions and cations with adequate alkyl chain length improved the synthesis of CAPE. [Emim][Tf2 N] was selected as the optimal reaction media. The optimal parameters were as follows by response surface methodology（RSM）： reaction temperature, 84.0 °C; mass ratio of Novozym 435 to CA, 14︰1; and molar ratio of PE to CA, 16 ︰ 1. The highest reactive selectivity of CAPE catalyzed by Novozym 435 in [Emim][Tf2 N] reached 64.55%（CA conversion 98.76% and CAPE yield 63.75%, respectively）. Thus, lipase-catalyzed esterification in ILs is a promising method suitable for CAPE production.     

Ni(OH)2与不同碳质材料复合制备超级电容器电极材料研究进展

超级电容器具有功率密度大、寿命长、生产成本低等优点,被认为是最有发展前途的储能系统之一。然而,超级电容器的低能量密度阻碍了其实际应用。由于存储的能量与CV2成正比,可以通过增加材料的电容"C"或操作电压窗口"V"或两者同时增加来提高超级电容器的能量密度。然而具有宽电位窗口的有机电解质离子往往电导率差,成本高,容易引起环境问题。因此为改善能量密度,应采用高比电容的电极材料,故而设计出具有高比电容的适合电极材料就成为研究热点。Ni(OH)2作为超级电容器电极材料,具有理论容量大、成本低、天然丰富、易于合成等优点,近年来备受关注。但由于Ni(OH)2导电率低、比表面积小,其容量劣化严重。碳质材料作为双电层超级电容器的电极材料,其能量存储机制取决于电极表面的电解质离子吸附和解离,具有导电率好、原料丰富、成本较低、电化学稳定性高等优点而应用广泛。因此,有必要将高导电碳质材料引入Ni(OH)2组成复合材料以提高电容性能。笔者综述了Ni(OH)2基材料的合成方法,特别是与碳质材料复合来提高Ni(OH)2基材料的循环稳定性和倍率性能方面的研究新进展。     

中间相炭微球在锂离子电池负极材料的应用进展

中间相炭微球(MCMB)具有良好锂离子扩散性、导电性和机械稳定性等优势,是目前应用广泛、综合性能优异的锂离子电池负极材料,但较低理论比容量是制约其发展的关键因素。为了获得性能优良的MCMB基锂离子电池负极材料,改性修饰和复合材料已然成为目前研发重点。笔者论述了碳结构、表界面和复合材料等微观结构设计对MCMB负极材料电化学性能的影响。从碳堆积结构类型、有序性、层间距以及球体粒径大小等方面,论述了碳结构微观设计对MCMB电化学性能的影响。发现具有乱层结构的MCMB在充放电过程中内部产生应力较小,且碳结构较稳定,具有优异循环稳定性;内部具有大量微孔或碳层间距较大的MCMB,在充放电过程中可提高锂离子在电极中的迁移速率,并提供更多的储锂空间,一般具有优良的充放电比容量和倍率性能;小粒径MCMB具有较短的锂离子迁移路径和随之增加的比表面积,通常具有较好倍率性能,伴随着可逆比容量和充放电效率的衰减。从表界面碳层改性、包覆和掺杂改性等方面,论述了表界面改性对MCMB电化学性能的影响。表面碳层修饰可增加MCMB与电解液的相容性及其比表面积,提高了与电解液的接触面积及贮锂容量,改善了锂离子电池负极材料的电化学性能;另外,MCMB表面包覆一层无定型碳,可避免其表面与电解液直接接触,减少电化学副反应的产生,提升其可逆比容量。从碳活性物质复合材料、非碳活性物质复合材料等方面,论述了复合材料微观结构设计对MCMB电化学性能的影响。碳活性物质可降低MCMB内部碳层结构的有序性,减少锂离子嵌入过程中的内部应力,提升MCMB循环稳定性。非碳活性物质诱导MCMB生成更加有序的碳层结构,提高MCMB的比表面积,从而改善MCMB表面与电解液分子的接触能力及其嵌锂性能,有利于提升MCMB负极材料可逆比容量、循环性能和倍率性能。MCMB具有高碳层间距和多缺陷位点等结构特征,有利于钠离子自由脱嵌,应用于钠离子电池时具有良好的可逆比容量、循环稳定性和倍率性能。MCMB的不规则定向层状结构经活化等处理具有较高比表面积,可应用于超级电容器电极材料。最后提出在高性能锂离子电池电极材料快速发展的需求下,从微观结构角度设计MCMB纳米复合材料将是MCMB负极材料的研究重点。     

Development of Electrospun Composite Fibers in Multiscale Structure and Investigating the Performance on Proliferation and Osteogenic Differentiation of ADSCs

Electrospun composite membranes in multiscale structures are developed for bone tissue engineering. Aligned polycaprolactone (PCL) fibers entrapping CA‐HAp microparticles (containing CaCO₃, hydroxyapatite, and casein in a hierarchical organization) are electrospun to find whether synergistic effects of fiber alignment and CA‐HAp microparticles on improving osteogenic differentiation can be obtained. CA‐HAp microparticles are in a spherical morphology of 1.42 ± 0.26 µm. Their presence increases fiber diameter and does not significantly affect fiber alignment. On all membranes, adipose derived stem cells (ADSCs) from humans spread very well. On a random group, cells distribute randomly and the presence of CA‐HAp microparticles facilitates cell proliferation, especially for the one at CA‐HAp/PCL 50 wt%; the one at CA‐HAp/PCL 20 wt% shows significantly much higher alkaline phosphatase (ALP) activity (112.0% higher) than the pure PCL membrane. On aligned samples, cells align along fibers and expression of ALP is enhanced. However, at the same composition (CA‐HAp/PCL 20 wt%), the random sample has much higher ALP activity than the aligned sample. The expressions of osteogenic marker genes are also evaluated. Combining the results and the applicability of membranes together, the random membrane at CA‐HAp/PCL 20 wt% is the best candidate for bone tissue engineering.     

基于红外透过滤光片的P-GMAW熔池图像传感

被动视觉熔池传感技术常采用窄带滤光片使熔池辐射较强而弧光较弱的某波长范围内的光进入摄像机,以抑制弧光干扰获得较清晰的熔池图像.在分析熔池辐射光谱分布、电弧光谱分布和摄像机光谱敏感曲线等影响熔池成像因素基础上,文中提出采用红外透过滤光片拍摄熔池图像,最大程度利用近红外波段熔池辐射能量高而电弧辐射弱的特点,同时透光波长范围的增加也避免了摄像机敏感性不足而导致的成像质量下降问题.P-GMAW熔池传感试验结果表明,红外透过滤光片能够较好的抑制弧光,在脉冲电流峰值和脉冲电流基值期间均可获得清晰和细节丰富的熔池图像.     

Partial Deficiency of Zfp217 Resists High-Fat Diet-Induced Obesity by Increasing Energy Metabolism in Mice

Obesity-induced adipose tissue dysfunction and disorders of glycolipid metabolism have become a worldwide research priority. Zfp217 plays a crucial role in adipogenesis of 3T3-L1 preadipocytes, but about its functions in animal models are not yet clear. To explore the role of Zfp217 in high-fat diet (HFD)-induced obese mice, global Zfp217 heterozygous knockout (Zfp217^+/−) mice were constructed. Zfp217^+/− mice and Zfp217^+/+ mice fed a normal chow diet (NC) did not differ significantly in weight gain, percent body fat mass, glucose tolerance, or insulin sensitivity. When challenged with HFD, Zfp217^+/− mice had less weight gain than Zfp217^+/+ mice. Histological observations revealed that Zfp217^+/− mice fed a high-fat diet had much smaller white adipocytes in inguinal white adipose tissue (iWAT). Zfp217^+/− mice had improved metabolic profiles, including improved glucose tolerance, enhanced insulin sensitivity, and increased energy expenditure compared to the Zfp217^+/+ mice under HFD. We found that adipogenesis-related genes were increased and metabolic thermogenesis-related genes were decreased in the iWAT of HFD-fed Zfp217^+/+ mice compared to Zfp217^+/− mice. In addition, adipogenesis was markedly reduced in mouse embryonic fibroblasts (MEFs) from Zfp217-deleted mice. Together, these data indicate that Zfp217 is a regulator of energy metabolism and it is likely to provide novel insight into treatment for obesity.     

Correction to: Bismuth Yttrium Oxide (Bi3YO6), A New Electrode Material For Asymmetric Aqueous Supercapacitors

Journal of Inorganic and Organometallic Polymers and Materials - The original version of this article unfortunately contained mistakes. In line 9 of the abstract, 5% should read as 2%. The...     

脂肪伯胺的合成及工业化研究进展

有机胺在化工、医药、生命科学等领域有着广泛的应用,可作为染料、日用品原料以及抗生素、生物碱、临床医学药物等。在众多胺类化合物中,伯胺是最基础的结构单元,其应用在胺类化合物中也最为广泛。随着经济社会的快速发展与人们生活质量的提高,伯胺,尤其是脂肪伯胺的市场需求量与日俱增,脂肪伯胺的合成及工业化制备已成为一个重要领域。经过了数十年的发展,脂肪伯胺的生产技术已经取得了巨大的成果,但仍然存在一些问题,例如苛刻的反应条件、催化剂性能不足、污染严重、工艺复杂等。本文以脂肪伯胺的工业生产以及热点制备方法为研究对象,针对工业上制备脂肪伯胺的工艺进行了汇总归纳(包括卤代烃胺化法、醇还原胺化法,腈加氢还原法、烯烃直接胺化法、羧酸胺化法等),并举例说明各制备方法在工业生产中的实际应用,分析比较各工艺方案的优劣,并对当前的研究热点——通过羰基还原胺化制备脂肪伯胺的方法进行了研究进展的阐述,指出该制备方法在未来工业应用的潜力与挑战。     

工程教育专业认证背景下课程思政的审视

工程教育专业认证的核心理念得到了广泛认同,目前我国高校正在有序开展并大力推进工程教育专业认证工作。然而,高校在推行以价值引领为目标的课程思政改革的过程中存在认识上的误区。文章从课程思政和专业认证的接受度、课程思政德育目标设置和专业认证的毕业要求、课程思政和专业认证的教学文件、课程思政和专业认证的育人格局设计四个角度论述了两者的关系及认识上存在的误区,指出了课程思政教育与工程教育专业认证的重合点、相似性和相容性,并提出将课程思政与专业认证相融合,在践行“价值引领”和“以学生为中心”理念的同时,实现专业和课程的同步提升。     

Control of anthracnose rot and quality deterioration in loquat fruit with methyl jasmonate

BACKGROUND: Loquat (Eriobotrya japonica Lindl.) fruit has a short shelf‐life, mainly due to fungal decay. Current control of postharvest disease of the fruit is mainly dependent on fungicides. However, because of the increasing consumer concern over food safety, there is an urgent need to search for effective alternatives to control disease. The objective of this work was to determine the efficacy of methyl jasmonate (MeJA) in controlling anthracnose rot caused by Colletotrichum acutatum and maintaining quality of loquat fruit. RESULTS: Loquat fruit were treated with 10 µmol L^?1 MeJA and wound inoculated with C. acutatum spore suspension of 1.0 × 10⁵ spores mL^?1 24 h after treatment, and then stored at 20 °C for 6 days. The percentage of infected wounds showing decay symptom was reduced from 54.4% to 16.7% and the lesion diameter was reduced from 7.26 mm to 4.00 mm by MeJA treatment on the 4th day after inoculation. MeJA treatment induced higher activities of two defense‐related enzymes—chitinase and β‐1,3‐glucanase—during 6 days storage. Meanwhile, the treatment inhibited increases in fruit firmness and internal browning index, and maintained higher extractable juice rate and total soluble solids and titratable acidity contents, thereby delaying the development of flesh leatheriness. CONCLUSION: MeJA treatment effectively inhibited anthracnose rot and maintained quality in loquat fruit. Inhibition of the disease was mainly because of resistance induced in loquat fruit by MeJA. A postharvest application of MeJA could be an alternative to chemical fungicides for control of postharvest disease in loquat fruit. Copyright © 2008 Society of Chemical Industry