发酵法生产D-乳酸的研究进展

从发酵菌种、发酵工艺等方面综述了发酵法生产D-乳酸的国内外研究现状,着重介绍了代谢工程在发酵产酸方面的应用,对今后的研究趋势进行了展望。     

煤层气井连通技术研究

由于我国煤层气储层具有渗透率低、压力低的特点,直井煤层控制面积小,产量低,钻单支水平井不利于后期的排水降压作业,所以现在煤层气开发多采用羽状水平井,羽状水平井需要工艺井与排采井之间的连通。两井连通需要对两井距离、方位偏差、新的靶点坐标、南北坐标、东西坐标等进行精确测量,找出新的靶点,然后对定向井进行定向指导,确保成功连通。     

Genetic Variation in ZmPAT7 Contributes to Tassel Branch Number in Maize

Tassel branch number (TBN) is one of the important agronomic traits that contribute to the efficiency of seed production and has been selected strongly during the modern maize breeding process. However, the genetic mechanisms of TBN in maize are not entirely clear. In this study, we used a B73 × CML247 recombination inbred lines (RILs) population to detect quantitative trait loci (QTLs) for TBN. A total of four QTLs (qTBN2a, qTBN2b, qTBN4, and qTBN6) and six candidate genes were identified through expression analysis. Further, one of the candidates (GRMZM2G010011, ZmPAT7) encoding an S-acyltransferase was selected to validate its function by CRISPR-Cas9 technology, and its loss-of-function lines showed a significant increase in TBN. A key SNP(−101) variation in the promoter of ZmPAT7 was significantly associated with TBN. A total of 17 distant eQTLs associated with the expression of ZmPAT7 were identified in expression quantitative trait loci (eQTL) analysis, and ZmNAC3 may be a major factor involved in regulating ZmPAT7. These findings of the present study promote our understanding of the genetic basis of tassel architecture and provide new gene resources for maize breeding improvement.     

高性能CHDI型聚醚聚氨酯弹性体

介绍了CHDI型PTMG聚氨酯的制备工艺和性能，并就其物理机械性能和其它二异氰酸酯聚氨酯作了比较。     

角色化访问控制在集中监管电子信息平台中的应用

随着电子政务建设迅速的发展,资源共享及业务协同方面的应用需求急剧增加,各部门对更广泛地实现“信息共享、业务协同、共同监督”均有迫切需求。基于吉林省政府性投资项目和财政专项资金集中监管电子信息平台（以下简称集中监管电子信息平台）中资源共享、互相监督、协同工作、公示公开、共同监督的业务需要,提出一种基于角色化访问控制的有效模式,用于推动地方政府信息资源共享及业务协同工作建设。     

Intracellular Delivery of mRNA for Cell-Selective CRISPR/Cas9 Genome Editing using Lipid Nanoparticles

Messenger RNA (mRNA) is being used as part of an emerging class of biotherapeutics with great promise for preventing and treating a wide range of diseases, as well as encoding programmable nucleases for genome editing. However, mRNA's low stability and immunogenicity, as well as the impermeability of the cell membrane to mRNA greatly limit mRNA's potential for therapeutic use. Lipid nanoparticles (LNPs) are currently one of the most extensively studied nanocarriers for mRNA delivery and have recently been clinically approved for developing mRNA-based vaccines to prevent COVID-19. In this review, we summarize the latest advances in designing ionizable lipids and formulating LNPs for intracellular and tissue-targeted mRNA delivery. Furthermore, we discuss the progress of intracellular mRNA delivery for spatiotemporally controlled CRISPR/Cas9 genome editing by using LNPs. Finally, we provide a perspective on the future of LNP-based mRNA delivery for CRISPR/Cas9 genome editing and the treatment of genetic disorders.     

Ni single-atom arrays as self-supported electrocatalysts for CO2RR

Developing highly active, selective, and stable electrocatalysts for the CO₂ reduction reaction (CO₂RR) is essential to relieve the greenhouse effect and the energy crisis. Traditional catalytic electrodes require ionomer binders, which inevitably impose undesired high CO₂ transport resistance and block the active sites. Herein, Ni single atoms anchored on nitrogen-doped carbon nanoarrays (denoted as Ni-SAC-NA) were developed as the electrode without additional ionomers for efficient CO₂RR. The unique nanoarray structure provided a higher specific surface area, more exposed active sites, and enhanced electron/mass transport due to its short diffusion pathway and ionomer-free nature. As a result, the Ni-SAC-NA electrode exhibited enhanced activity of CO₂RR and selectivity towards CO with Faradaic efficiency of 96.7%, turnover frequency of 27,504 h⁻¹, and cathodic energy efficiencies of 54.9% at −0.88 V (vs. RHE). Our findings provide a rational design strategy for CO₂RR electrocatalysts by constructing ionomer-free electrodes.     

掺水化油器的应用研究

介绍了掺水化油器的要点及用于自然吸气式汽油机和涡轮增压汽油机的台架试验结果,并对有关问题作了相应的讨论。     

乙烯聚合用树枝状过渡金属催化剂研究进展

树枝状过渡金属催化剂是在树枝状大分子上负载上过渡金属活性中心,因此,此类催化剂既具有树枝状大分子特有的艺术结构,同时还具有过渡金属配合物的功能化性能,使其两者能够协同发挥作用,兼具均相和非均相催化体系的特点,在催化烯烃聚合方面具有较高的催化活性和良好的催化稳定性,近年来备受关注,催化乙烯聚合就是其中的研究热点之一。本文按其过渡金属活性中心进行分类,综述了近年来国内外树枝状过渡金属催化剂在这乙烯聚合方面的进展,阐述了多种树枝状效应产生的原因,并且对乙烯聚合用树枝状过渡金属催化剂的发展前景进行了展望。     

化学气相沉积法制备碳化铬薄膜的研究

以三（2,2,6,6-四甲基-3,5-庚二酮）化铬为前驱体,采用化学气相沉积（CVD）法在氧化铝（Al₂O₃）陶瓷基板上制备碳化铬（Cr₃C₂）薄膜,其中沉积温度为723 K至923 K,沉积时间为1 200 s。研究了不同沉积温度对Cr₃C₂薄膜的相组成、择优取向、宏观表面、微观结构及电学性能的影响。结果表明,在723 K至923 K下制备得到具有高度（130）择优取向的Cr₃C₂薄膜。随着沉积温度的升高,Cr₃C₂薄膜表面先由光滑变粗糙,后逐渐变光滑;薄膜晶粒呈椭球型生长;薄膜的厚度先增加后减小,从而导致电阻先减小后增大。在798 K时制备得到厚度最大且电阻最小的（130）择优取向的最佳Cr₃C₂薄膜。同时,在实验条件下Cr₃C₂薄膜表面存在少量的碳和Cr₂O₃。