Dehydrogenative reagent-free annulation of alkenes with diols for the synthesis of saturated O-heterocycles

氧化反应虽然在实验室合成中有着广泛的应用，但在工业领域却由于常用氧化试剂在安全和环境友好等方面存在的诸多问题而限制其应用。开发更为高效、安全和环保的氧化方法是解决氧化反应在有机合成中应用受限的关键。近年来，徐海超教授课题组利用电化学技术实现了系列无需氧化试剂的氧化偶联新反应，为多种重要杂环化合物体系的合成提供了高效、绿色的新方法。他们通过电氧化形成高反应活性的碳、氮自由基中间体，实现了通过其它方法不易实现的化学转化。【Abstract】Dehydrogenative annulation reactions are among the most straightforward and efficient approach for the preparation of cyclic structures. However, the applications of this strategy for the synthesis of saturated heterocycles have been rare. In addition, reported dehydrogenative bond-forming reactions commonly employ stoichiometric chemical oxidants, the use of which reduces the sustainability of the synthesis and brings safety and environmental issues. Herein, we report an organocatalyzed electrochemical dehydrogenative annulation reaction of alkenes with 1,2- and 1,3-diols for the synthesis of 1,4-dioxane and 1,4-dioxepane derivatives. The combination of electrochemistry and redox catalysis using an organic catalyst allows the electrosynthesis to proceed under transition metal- and oxidizing reagent-free conditions. In addition, the electrolytic method has a broad substrate scope and is compatible with many common functional groups, providing an efficient and straightforward access to functionalized 1,4-dioxane and 1,4-dioxepane products with diverse substitution patterns.We acknowledge the financial support of this research from MOST (2016YFA0204100), NSFC (No. 21672178), the “Thousand Youth Talents Plan”, and Fundamental Research Funds for the Central Universities. 研究工作得到国家重点研发计划纳米科技重点专项（项目批准号：2016YFA0204100）、国家自然科学基金（项目批准号：21672178）、中组部青年千人计划和中央高校基本科研业务费专项资金的资助

非标准岩样岩石力学参数试验研究

通过对非标准岩样的室内试验来获取岩石力学参数是试验研究中必须处理的技术问题。对某矿4种不同岩石的非标准岩样进行单轴抗压实验和巴西劈裂实验,分析了岩样的强度分布特点,考虑尺寸效应和形状效应,对岩石强度试验结果进行了修正,获得了岩石的单轴抗压、抗拉强度、弹性模量、帕松比、粘聚力和内摩擦角等力学参数,并对所得参数进行了分析。所得力学参数为该矿山的岩石力学和地压研究提供了基础资料

债权融资结构与公司业绩实证研究

文章以沪深两市2004年--2007年4 154家A股上市公司的数据对债权融资结构与公司业绩的关系进行了实证研究,将债权融资结构细分为债权融资水平结构、债权融资期限结构和债权融资类型结构,分别与其公司业绩的关系进行实证研究,同时以市净率和净资产收益率两个指标作为公司业绩的替代变量分别对债权融资结构进行研究,得到了不同的结论,说明我国的债权市场还不完善,希望通过研究能够对我国的资本市场提供一些参考意义

实验室建设与运行管理的探索与实践

文章阐述了高校实验室建设在\"双一流\"建设中的重要支撑作用。结合厦门大学化学化工学院物理化学实验室建设和管理的探索与实践,从物理化学实验室建设特点出发,探讨了如何统筹管理、规划、设计、整合、优化实验室布局结构等,并分享了实验室装修、改造过程中的思路和举措。建一流实验室促进实验教学的长远发展,充分发挥物理化学实验室在培养一流人才中的作用,以期推动\"双一流\"工程良好快速发展。2017年厦门大学教学改革研究项目(JG20170222);;\n国家基础科学人才培养基金项目(J1310024);;\n2016年度教育部“基础学科拔尖学生培养试验计划”研究课题资

Practical and stereoselective electrocatalytic 1,2-diamination of alkenes

1,2-二胺结构广泛存在于天然产物、药物和不对称合成中使用的催化剂中。烯烃双胺化，即在烯烃两端同时引入两个氨基，是合成1,2-二胺最为简便和高效的方法之一。但该方法面临着诸多挑战，是有机合成中有待解决的难题。其难点主要是源于二胺产物对过渡金属催化剂的抑制作用以及难以控制反应非对映选择性和区域选择性。徐海超课题组对电化学促进的烯烃双官能团化反应进行了深入研究，通过进一步脱除磺酰基成功实现了高非对映选择性和区域选择性的烯烃双胺化反应，为1,2-二胺类化合物提供高效、简便的合成方法。该工作通过有机电子转移催化剂与电的结合避免了过渡金属催化剂和氧化剂的使用，且增强了底物和官能团的兼容性。 该项研究实验部分主要由博士生蔡晨燕完成，研究助理束晓敏参与了部分化合物的合成。The 1,2-diamine motif is widely present in natural products, pharmaceutical compounds, and catalysts used in asymmetric synthesis. The simultaneous introduction of two amino groups across an alkene feedstock is an appealing yet challenging approach for the synthesis of 1,2-diamines, primarily due to the inhibitory effect of the diamine products to transition metal catalysts and the difficulty in controlling reaction diastereoselectivity and regioselectivity. Herein we report a scalable electrocatalytic 1,2-diamination reaction that can be used to convert stable, easily available aryl alkenes and sulfamides to 1,2-diamines with excellent diastereoselectivity. Monosubstituted sulfamides react in a regioselective manner to afford 1,2-diamines bearing different substituents on the two amino groups. The combination of an organic redox catalyst and electricity not only obviates the use of any transition metal catalyst and oxidizing reagent, but also ensures broad reaction compatibility with a variety of electronically and sterically diverse substrates.We acknowledge the financial support of this research from MOST (2016YFA0204100), NSFC (No. 21672178), Program for Changjiang Scholars and Innovative Research Team in University and Fundamental Research Funds for the Central Universities. 研究工作得到国家重点研发计划纳米科技重点专项、国家自然科学基金、长江学者和创新团队发展计划、中央高校基本科研业务费专项资金的资助

Applied research on RA codes in underwater acoustic ofDM communication system

正交频分复用(OrTHOgOnAl frEQuEnCy dIVISIOn MulTIPlEXIng,OfdM)技术由于具有频谱利用率高、抗多径能力强等优点,成为当前水声通信的研究重点和热点,但较高的峰均功率比(PEAk-TO-AVErAgE POWEr rATIO,PAPr)严重影响了水声OfdM通信系统的性能。采用重复累积码(rEPEAT ACCuMulATE,rA)作为信道编码方案,并用线性反馈移位寄存器(lInEAr fEEdbACk SHIfT rEgISTErS,lfSr)代替原rA码结构中的累加器,再通过选择映射(SElECTIVE MAPPIng,SlM)方法降低系统的峰均功率比。计算机仿真和水池实验结果表明,采用改进结构的rA码结合SlM技术能有效降低水声OfdM系统的PAPr,提高系统的性能,具有很好的应用前景。Orthogonal frequency division multiplexing(ofDM) technology has become the research focus and hotspot of underwater acoustic communications owing to its advantages such as high spectrum efficiency and robustness to multipath fading,but it possesses high peak-to-average power ratio(PAPR) which severely degrades the performance of Underwater Acoustic ofDM Communication System.In this paper,repeat accumulate(RA) code is adopted as the channel coding scheme,and linear feedback shift registers(LFSR) is used to replace the accumulator of original RA code structure,then selective mapping(SLM) method is also adopted to reduce the PAPR of system.Computer simulation and experimental results show that modified RA code and SLM can effectively reduce the PAPR and improve the per-formance of underwater acoustic ofDM communication system,which have a very good application prospect.研究基金访问学者项目(2011631504); 中央高校基础研究基金项目(201112G020和201212G012); 国家自然科学基金项目(41176032

Preparation and determination of polyclonal antibody to thymosin α1

目的 :制备用于检测转胸腺素基因蓝藻表达产物的特异性抗体。方法 :用提纯的小肽 (2 8个氨基酸 )胸腺素α1与牛血清白蛋白偶联后作为抗原 ,采用皮下多点注射免疫的方法免疫大鼠。经过 3个月的免疫 ,获得抗Tα的多克隆抗体。结果 :用间接酶联免疫吸附 (ELISA)方法 ,测得抗体效价超过 40 96。蛋白印迹 (Westernblot)检测结果显示 ,该抗体能特异性地与胸腺素α1抗原产生明显免疫亲和反应。结论 :所制备的抗体具有很好的灵敏性和特异Objective:To prepare specific antibody against Thymosin α1 Methods:Thymosin α1(Tα1,28 peptide) was conjuncted with BSA as immune antigen,rats were immunized and the polycolonal antibody to Tα1 was obtained.Results:With ELISA detection,the titer of antibody was more than 1:4 096;Western blot analysis showed that the antibody can bind with Tα1 specifically.Conclusion:The prepared antibody against Tα1 has good specificity and reactivity and can be used to detect the expression products of transgenic cyanobacteria which expressed Tα1 gene.国家“863”课题资助!(No 819 0 4 0 3

Evaluation of chemiluminescence immunoassays kits for detection of influenza A virus

目的考核甲型流感化学发光检测试剂的灵敏度和特异性。方法分别利用病毒分离培养液和入境人群的鼻咽拭子标本考查甲型流感试剂盒的检测灵敏度和特异性。结果化学发光法对H1、H3、H5、H7、H9等亚型的甲型流感病毒株均有很好的检出率,灵敏度明显优于flu A-dOT和dIrECTIgEn Ez flu A;对102份入境人群鼻咽拭子标本的检测灵敏度为97.62%。结论甲型流感化学发光检测试剂具有很好的灵敏度和特异性,适用于口岸现场的甲型流感快速筛查。Objective To evaluate the sensitivity and specificity of chemiluminescence immunoassays kit for detection of influenza A virus.Methods To analyze the sensitivity and specificity of three different assay kits for detection of influenza A virus by using the viral culture liquid and nasopharyngeal swabs from entry-exit travelers.Results The chemiluminescence immunoassays kit had a good detection rate when it was tested against a panel of influenza A virus strains(H1/H3/H5/H7/H9),and its sensitivity was much better than Flu A-DOT kit`s and Directigen EZ Flu A kit' chemiluminescence immunoassays kit used for the detection of 102 nasopharyngeal swabs from entryexit travelers had a detection sensitivity of 97.62%.Conclusion Chemiluminescence immunoassays kit had good sensitivity and specificity, which was fit for the rapid detection of influenza A virus at frontier ports.国家质检总局科技计划项目(2014IK045); 厦门市科技惠民项目(3502Z20144083

Analysis on epidemiological charateristics of chlamydia trachomatis infection in Jiangsu Province,2006-2011

目的了解江苏省2006-2011年生殖道沙眼衣原体感染的流行病学特征,为制定防治生殖道沙眼衣原体感染的策略提供科学依据。方法收集2006-2011年江苏省通过中国疾病预防控制信息系统报告的生殖道沙眼衣原体感染病例资料,并对资料进行流行病学分析。结果 2006-2011年,江苏省生殖道沙眼衣原体感染发病率呈快速上升的趋势,2006年为0.12/10万,2011年为3.15/10万,发病率年均增长速度为92.23%;在报告的5 859例病例中,男女性别比为0.3∶1,各年生殖道沙眼衣原体感染男女性别差异有统计学意义;发病年龄主要集中在20~29岁年龄组,占50.96%;江苏省生殖道沙眼衣原体感染报告病例主要集中在苏南和苏中的较发达城市;主要以家庭及待业者和工人为主。结论江苏省生殖道沙眼衣原体感染发病率快速增长,应加强对生殖道沙眼衣原体的防治,以控制其感染的快速流行。江苏省医学重点人才(RC2011086);江苏省医学重点人才(RC2011087); 江苏省科技项目(Y201029

The Morphology of the Primary Dental Arch of Chinese Children in Shijiazhuang-City Part-I: Research concerning the size of the primary tooth crown, primary dental arch and the condition of primary occlusion

The purpose of this study was to investigate the size of the primary tooth crowns, primary dental arches, standard values and frequency distribution of primary occlusion in Chinese children. With the cooperation of a kindergarten in Shijiazhuang-city, China, the dental plasters from 55 children (36 boys and 19 girls, age range from 3-6 years old) with normal primary occlusion were collected. Because of different growth rates of the children, these children were divided into two groups, one comprising children less than 5 years old and the other of 5 years old or older. According to the method that the Japanese Society of Pediatric Dentistry reported, the data were statistically analyzed and compared to Japanese children. The results were summarized as follows: 1. Except lower primary lateral incisors, the values of the mesio-distal width of primary crowns of each tooth were significantly larger for boys than for girls in all tooth types. Also the Chinese children were inclined to show smaller mesio-distal tooth crown width than those of the Japanese children in all types of teeth. 2. Compared with the Japanese children, the Chinese children were inclined to show smaller primary dental arch length both in the maxilla and the mandible. But in the senior group, the Chinese girls were inclined to show smaller primary dental arch width than their Japanese female counterparts. On the contrary, the Chinese children tended to show larger dimensioned primary dental arch height than those of the Japanese children. 3. Though spaces between teeth (primate and growth spaces) were found in the Chinese children, the frequency was lower than that of the Japanese children. 4. The frequency of terminal plans in the Chinese children was 41.8% in the vertical type, 6.4% in the distal-step type and 51.8% in the mesial step type. 5. The primary canines occlusal relationship in the Chinese children was 63.1% in type I, 13.6% in type II and 23.7 in type III