Selective methylation of toluene using CO2 and H2 to para-xylene

二甲苯（PX）是石化工业的基本有机化工原料之一，主要用于生产三大合成材料—合成树脂、合成纤维和合成橡胶。随着我国下游产业的快速发展，PX的需求量迅猛增长，进口依存度大于50%。袁友珠教授课题组提出使用CO2和H2替代甲醇作为甲苯烷基化试剂，利用CO2和H2在相对较低温度下生成的甲氧基中间体（无需经甲醇）直接与甲苯烷基化。化学化工学院2018级博士生左佳昌为论文第一作者，博士生陈伟坤、硕士生刘佳以及醇醚酯化工清洁生产国家工程实验室（厦门大学）段新平博士和叶林敏博士等参与了论文的部分研究。该研究结果已分别申请了中国发明专利（申请号201911149539.2, 2019）和国际专利（申请号PCT/CN2020/077412, 2020）。【Abstract】Toluene methylation with methanol to produce xylene has been widely investigated. A simultaneous side reaction of methanol-to-olefin over zeolites is hard to avoid, resulting in an unsatisfactory methylation efficiency. Here, CO2 and H2 replace methanol in toluene methylation over a class of ZnZrOx–ZSM-5 (ZZO-Z5) dual-functional catalysts. Results demonstrate that the reactive methylation species (H3CO*; * represents a surface species) are generated more easily by CO2 hydrogenation than by methanol dehydrogenation. Catalytic performance tests on a fixed-bed reactor show that 92.4% xylene selectivity in CO-free products and 70.8% para-xylene selectivity in xylene are obtained on each optimized catalyst. Isotope effects of H2/D2 and CO2/13CO2 indicate that xylene product is substantially generated from toluene methylation rather than disproportionation. A mechanism involving generation of reactive methylation species on ZZO by CO2 hydrogenation and migration of the methylation species to Z5 pore for the toluene methylation to form xylene is proposed.This work was supported by the National Key Research and Development Program of China (2017YFA0206801), the National Natural Science Foundation of China (21972113), and the Program for Innovative Research Team in Chinese Universities (IRT_14R31).该工作得到了国家重点研发计划（2017YFA0206801）、国家自然科学基金（21972113、91545115）和教育部创新团队（IRT_14R31）的资助

面向城市可持续发展的自然解决途径(NBSs)研究进展

自然解决途径(NBSs)是近几年生态学应用研究的热点,其理念是综合考虑经济、环境和社会效益,引入自然生态系统服务功能用来修复、恢复甚至提升城市生态基础设施水平,进而解决城市面临的可持续发展挑战。自然解决途径的提出为生态设计注入了新鲜的血液,提供了新的视野和技术方法。基于VOSviewer文献计量分析软件对城市自然解决途径研究的热点关键词、主要研究国家、机构以及全球分布进行了综合分析。结果发现:(1)2015年至2018年有关城市NBSs的研究论文逐渐增多,覆盖6大洲(欧洲、北美洲、亚洲、南美洲、大洋洲、非洲),多数案例是对已有实施工程中采用的可以归纳为自然解决途径的某些方法或者经验的总结凝练;(2)与城市NBSs相关研究热点从高到低主要涉及生态系统服务、绿色基础设施、气候变化、人群健康与福祉;(3)城市自然解决途径研究的主要力量主要聚集在欧洲,目前中国对于NBSs研究仍处于初期起步阶段。将有助于促进自然解决途径研究及实践在中国的发展,同时为城市生态设计和可持续发展提供新视野和新技术。国家自然科学基金项目(41771573)国家重点研发计划(2016YFC0502702

Tissue engineered corneal epithelium derived from clinical-grade human embryonic stem cells

角膜上皮位于角膜最表层，对维持角膜的透明性发挥非常重要的作用。角膜上皮细胞处于不断更新之中，它们更新的源泉在于角膜缘处的上皮干细胞，即角膜缘干细胞。眼表面化学伤、热烧伤以及部分先天性遗传疾病可以引起角膜缘干细胞缺乏，或者使干细胞丧失向正常角膜上皮细胞分化的能力，导致经久不愈的角膜上皮缺损、角膜新生血管、角膜上皮结膜化、角膜溃疡等病理改变，严重影响患者视力，甚至导致失明。由于眼表面的严重破坏，这类患者的治疗具有很大的挑战性，目前比较理想的治疗方法是进行组织工程角膜上皮移植。 厦门大学眼科研究所和中国科学院动物研究所干细胞与生殖生物学国家重点实验室合作研究采用中科院动物研究所研发的我国第一个临床级胚胎干细胞系Q-CTS-hESC-1，体外诱导分化为角膜上皮祖细胞，在此基础上构建组织工程角膜上皮，移植于兔角膜缘干细胞缺乏动物模型，成功重建眼表面。 厦门大学眼科研究所博士研究生贺佳和欧尚坤为该论文的共同第一作者，厦门大学眼科研究所李炜教授、刘祖国教授以及中科院动物所郝捷副研究员为共同通讯作者。【Abstract】Purpose: To construct tissue engineered corneal epithelium from a clinical-grade human embryonic stem cells (hESCs) and investigate the dynamic gene profile and phenotypic transition in the process of differentiation.Methods: A stepwise protocol was applied to induce differentiation of clinical-grade hESCs Q-CTS-hESC-1 and construct tissue engineered corneal epithelium. Single cell RNA sequencing (scRNA-seq) analysis was performed to monitor gene expression and phenotypic changes at different differentiation stages. Immunostaining, realtime quantitative PCR and Western blot analysis were conducted to detect gene and protein expressions. After subcutaneous transplantation into nude mice to test the biosafety, the epithelial construct was transplanted in a rabbit corneal limbal stem cell deficiency (LSCD) model and followed up for eight weeks. Results: The hESCs were successfully induced into epithelial cells. scRNA-seq analysis revealed upregulation of ocular surface epithelial cell lineage related genes such as TP63, Pax6, KRT14, and activation of Wnt, Notch,Hippo, and Hedgehog signaling pathways during the differentiation process. Tissue engineered epithelial cell sheet derived from hESCs showed stratified structure and normal corneal epithelial phenotype with presence of clonogenic progenitor cells. Eight weeks after grafting the cell sheet onto the ocular surface of LSCD rabbit model, a full-thickness continuous corneal epithelium developed to fully cover the damaged areas with normal limbal and corneal epithelial phenotype. Conclusion: The tissue engineered corneal epithelium generated from a clinical-grade hESCs may be feasible in the treatment of limbal stem cell deficiency.This study was supported in part by the National Key R&D Program of China (2018YFA0107301 [to WL], 2018YFA0107304 [to ZL], 2013CB967003 [to WL]), the National Natural Science Foundation of China (NSFC, No.81770894, No.81470602 [to WL], and No.81330022 [to ZL]). 该论文获得了国家重点研发计划项目和国家自然科学基金项目的资助

Observation of Life Cycle and Control of Parasite Amyloodinium ocellatum at Cyst Stage

自发病的大黄鱼鳃上取得眼点淀粉卵涡鞭虫滋养体,置于凹玻片上连续观察其分裂过程。淀粉卵涡虫包囊的直径为61.3~112.7μM,平均(85.3±16.0)μM。以二分裂的方式分裂,每完成一次分裂细胞数量增加1倍。水温27~29℃时,大多数滋养体经8~12H后进入二细胞期,此后4~10H完成一次分裂。所观察的包囊中,最多的能完成8次分裂,最少的完成2次分裂。不同分裂次数的包囊均孵出涡孢子,滋养体脱落至涡孢子孵出需48~66H。硫酸铜硫酸亚铁合剂可以对大黄鱼苗鳃丝上的眼点淀粉卵涡鞭虫滋养体起到明显的驱除作用。The theronts of parasite Amyloodinium ocellatum were collected from infected large yellow croaker,Larimichthys crocea,and placed on the concave glass for observation of the continuously splitting process.It was found that the theronts had diameter of 61.3-112.7μm,and reproduction with two division ways,one time increase in cell quantity by each completed cell division.Most of the theronts developed into two cell phase in 8-12 h,then completed a division every 4-10 hat water temperature of 27-29℃,with the maximum 8times and the minimum 2times.The spores were hatched from all the theronts with different division frequency in 48-66 h.The obvious removal of the theronts were observed in the gill filaments of the large yellow croaker exposed to mixture of copper sulfate and ferrous sulfate.福建省2012年科学计划区域重大项目(2012N3013

通用链条预拉拆节装置设计及研究

针对链条制造过程中的预拉拆节环节，设计了一种链条预拉拆节的通用装置。该装置在实现链条预拉拆节连续加工的前提下，通过设置驱动链轮移动模块、带T型槽的油缸连接件及冲钉安装模块、带直槽口的链条限位板及链条挡板等零部件来提高装置的通用性和互换性。整台装置具备更换较少零部件以加工多款链条的功能，加工产品质量高，使用寿命长

双排链条预拉拆节装置设计及研究

针对双排链条制造过程中的预拉拆节环节，设计了一种新型的双排链条预拉拆节装置，该装置包含预拉拆节两大模块：预拉模块采用液压油缸加载，以移动关联链轮进而预拉链轮组间的链条；拆节模块采用气动滑台驱动链条插板稳固链条，气液增压缸驱动冲钉拆除销轴，气缸驱动链条推板推去链板。该预拉拆节机结构合理，标准化程度高，易损件互换性好，能够高效地实现双排链条的动态预拉与拆节

Research and implementation of OPC UA Publish /Subscribe mode based on message broker

针对目前OPC UA客户端/服务器通信模式中存在的紧耦合、服务器性能瓶颈等问题,进行了OPC UA发布/订阅通信模式总体架构的研究。首先具体分析了UA的核心功能,包括地址空间技术和数据编码技术,并在两者的基础上,利用消息代理机制,完成了发布者和订阅者的功能开发。还通过实验进一步验证了功能的稳定性和对数据的传输能力,结果表明,此模式可以满足大多数工业需求。</p

基于末端牵引式康复机器人的定量化上肢运动功能评估研究

目的为在现有基于末端牵引式康复机器人训练系统基础上建立定量化上肢运动功能评估系统,本文设计了基于画圆和直线两类运动任务的定量化上肢运动功能评估参数并通过不同运动方向的人机交互试验验证评估参数的有效性。方法在已有康复机器人的软硬件系统基础上,通过交互软件设计了用户控制摇杆末端进行画圆与画直线两类人机交互任务。8位志愿者参与了试验。通过对于电机运动参数采集与分析设计用于定量化评估上肢运动能力的评估参量,进一步使用统计学t检验结合对画圆的顺、逆时针组和画直线的外围线组与倾斜线组之间进行对比研究,利用统计学方法验证所设计的评估参数的有效性。结果针对8名志愿者的逆时针画圆运动圆度偏移量分值(91. 64±3. 45)均明显高于顺时针运动圆度偏移量分值(87. 84±3. 98)。针对志愿者的点到点直线运动试验中轨迹长度差与最大法向偏移量在外围线组的数值明显低于倾斜线组,平均速度与平均加速度在外围线组的数值明显高于倾斜线组,平均法向偏移量、末端精准定位能力与完成时间在不同方向直线组之间没有明显的数值差异。结论本文设计的圆度偏移量可有效表征健康成人在操作康复机器人进行画圆运动时的上肢运动功能,轨迹长度差、最大法向偏移量、平均速度与平均加速度可有效评估点到点画直线运动时的上肢运动功能。对比已有相关研究发现人体上肢在相对身体不同位置时对于运动控制的能力会有区别,可能与上肢功能位相关

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel