高首效富镍正极材料LiNi0.6Co0.2Mn0.2O2的合成及电化学性能研究

采用共沉淀—高温固相烧结的方法合成了富镍正极材料LiNi0.6Co0.2Mn0.2O2（简称NCM622）,通过X射线粉末衍射（XRD）/Rietveld精修法、扫描电子显微镜（SEM）及电化学测试,对不同温度下合成材料的结构、形貌、电化学性能进行表征.结果表明,800℃下NCM622阳离子混排程度最低（1.97%）,首周库仑效率高达92.2%,100周容量保持率为81.4%.国家自然科学基金项目(No.21233004,No.21428303)资

Synthesis of Novel Thiazolo[3,2-a]pyrimidine Compounds

5-乙氧羰基-4-芳基-6-甲基-3,4-二氢嘧啶-2-酮与丁炔二酸二甲酯反应,合成了系列新的噻唑并[3,2-A]嘧啶类化合物,反应具有时间短、收率高、后处理简单等优点.采用nMr(1H,13C,COSy,HSQC和HMbC),Ir等多种谱学技术,结合元素分析对产物进行详细表征,通过对目标产物的1,3-偶极环加成的衍生化产物进行X射线单晶衍射而确定目标产物的结构.A new class of thiazolo[3,2-a]pyrimidine compounds were synthesized by the reaction of 5-carbethoxyl-4-aryl-6-methyl-1,2,3,4-tetrahydropyrimidin-2-ones with dimethyl acetylenedicarboxylate.The reaction has the advantages of excellent yields and simple workup procedures.The products were char-acterized thoroughly by IR and NMR(1H,13C,COSY,HSQC and HMBC) together with elemental analysis.The X-ray crystallographic analysis of the 1,3-dipolar cycloaddition derivative of the title product provided the direct information for the structure of the product.国家自然科学基金(Nos.20772027;20803020);中国博士后科学基金(No.20070410805);卫生部科学研究基金-福建省卫生教育联合攻关计划(No.WKJ2008-2-036);厦门市重大疾病攻关研究基金(No.3502Z20051027);湖南科技大学博士基金(No.E50839)资助项

NMR Studies on Interactions between Diperoxovanadate and 1-Ethyl-1H-Imidazole

为探讨过氧钒配合物中有机配体对反应平衡的影响,在模拟生理条件下(0.15MOl·l-1nACl溶液),应用多核(1H、13C和51V)多维(COSy和HSQC)核磁共振(nMr)以及变温技术等谱学方法研究双过氧钒配合物[OV(O2)2l]-(l=d2O或HOd,与之配位的过氧钒物种简写为bPV)和[OV(O2)2ll′]n{-n=1-2,ll′=3-羟基-皮考啉酸根(3-OH-PIC),2-(2′-吡啶)-咪唑(Py-IM),1,10-邻菲啰啉(PHEn),与它们配位的含钒物种分别简写为bPV(3-OH-PIC)、bPV(Py-IM)和bPV(PHEn)}与n-乙基咪唑(n-ET-IM)的相互作用.实验结果表明,n-ET-IM与4种双过氧钒配合物反应性从强到弱的顺序为bPV>bPV(3-OH-PIC)>bPV(Py-IM)>bPV(PHEn).研究表明,金属中心上配体的配位能力、空间位阻和分子量等因素都对反应平衡产生较大的影响,同时竞争配位的结果导致新的6配位过氧物种[OV(O2)2(n-ET-IM)]-的生成.利用上述谱学方法有助于揭示此类相互作用体系的反应过程和配位方式.To understand the effects of organic ligands on the reaction equilibrium, interactions between a series of diperoxovanadate complexes [OV(O2)2L]- (L=D2O or HOD, the corresponding peroxovanadate species (bpV)) and [OV (O2)2LL′]n-{n=1-2; LL′ =3-hydroxyl-picolinate (3-OH-pic), 2-(2′-pyridine)-imidazole (py-im), 1,10-phenanthroline (phen), the corresponding peroxovanadate species bpV(3-OH-pic), bpV(py-im), and bpV(phen)}and 1-ethyl-1H-imidazole (N- Et-im) in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, COSY (correlated spectroscopy), HSQC (heteronuclear single quantum coherence) and variable temperature nuclear magnetic responance (NMR) using 0.15 mol·L-1 NaCl ionic medium to mimic physiological conditions.Experimental results indicated that the reactivity of these four complexes with 1-ethyl-1H-imidazole decreased as follows: bpV>bpV(3-OH-pic)>bpV(py-im)> bpV(phen).The coordinating ability, the steric effect, and the molecular weight of these organic ligands affected the reaction equilibrium.A new six-coordinated peroxovanadate species [OV(O2)2(N-Et-im)]- was formed because of competitive coordination.国家自然科学基金(20772027;20803020);中国博士后科学基金(20070410805);卫生部科学研究基金-福建省卫生教育联合攻关计划(WKJ2008-2-036);厦门市重大疾病攻关研究基金(3502Z20051027)资助项目---

3D-printed integrative probeheads for magnetic resonance

射频探头前端作为核磁共振设备的核心部件之一，极大程度的决定着系统实验性能的优劣。探头前端通常由射频线圈、射频电路及样品检测管道等部分组成。现有的射频线圈制作技术主要是通过手工或机械手段按照所需的线圈形状进行绕制。但是，当线圈结构较为复杂、不规则，或体积尺寸较小时，常规绕制方法便难以满足结构设计和制造的精度需求，因此造成线圈性能的劣化，增大检测区域的射频场不均匀性，对核磁共振检测产生负面影响。本研究中，利用3D打印熔融沉积制造或光敏树脂选择性固化技术精确加工出一体化磁共振探头前端，使用常温液态金属填充线圈模型管路形成射频线圈，搭建出稳定的一体化磁共振射频探头。利用高精度3D打印和液态金属灌注技术制备出包含有射频线圈和定制化样品管道结构在内的一体化磁共振射频探头前端，克服了传统磁共振三维微型线圈成型困难、与样品腔匹配程度差等问题，提高了探头的信噪比，为定制化的磁共振检测提供了新思路。 该工作由厦门大学电子科学与技术学院陈忠教授、游学秋副研究员和孙惠军高级工程师共同指导完成，博士研究生谢君尧为论文第一作者。厦门大学电子科学与技术学院黄玉清高级工程师、王忻昌副教授、倪祖荣助理教授、硕士研究生张德超，化学化工学院杨朝勇教授、博士研究生李星锐，萨本栋微米纳米科学技术研究院陈宏教授为合作作者。【Abstract】Magnetic resonance (MR) technology has been widely employed in scientific research, clinical diagnosis and geological survey. However, the fabrication of MR radio frequency probeheads still face difficulties in integration, customization and miniaturization. Here, we utilized 3D printing and liquid metal filling techniques to fabricate integrative radio frequency probeheads for MR experiments. The 3D-printed probehead with micrometer precision generally consists of liquid metal coils, customized sample chambers and radio frequency circuit interfaces. We screened different 3D printing materials and optimized the liquid metals by incorporating metal microparticles. The 3D-printed probeheads are capable of performing both routine and nonconventional MR experiments, including in situ electrochemical analysis, in situ reaction monitoring with continues-flow paramagnetic particles and ions separation, and small-sample MR imaging. Due to the flexibility and accuracy of 3D printing techniques, we can accurately obtain complicated coil geometries at the micrometer scale, shortening the fabrication timescale and extending the application scenarios.The work is supported by the National Natural Science Foundation of China (Grants U1632274, 11761141010, U1805261, 11475142, 22073078, and 61801411), and China Postdoctoral Science Foundation (2017M622075).研究工作得到国家自然科学基金、中国博士后科学基金等项目支持

Synthesis of Novel Thiazolo[3,2-a]pyrimidine Compounds

A new class of thiazolo[3,2-a]pyrimidine compounds were synthesized by the reaction of 5-carbethoxyl-4-aryl-6-methyl-1,2,3,4-tetrahydropyrimidin-2-ones with dimethyl acetylenedicarboxylate. The reaction has the advantages of excellent yields and simple workup procedures. The products were characterized thoroughly by IR and NMR (H-1, C-13, COSY, HSQC and HMBC) together with elemental analysis. The X-ray crystallographic analysis of the 1,3-dipolar cycloaddition derivative of the title product provided the direct information for the structure of the product

NMR Studies on Interactions between Diperoxovanadate and 1-Ethyl-1H-Imidazole

To understand the effects of organic ligands on the reaction equilibrium, interactions between a series of diperoxovanadate complexes [OV(O-2)(2)L](-) (L=D2O or HOD, the corresponding peroxovanadate species (bpV)) and [OV (O-2)(2)LL'](n-) {n=1-2; LL' =3-hydroxyl-picolinate (3-OH-pic), 2-(2'-pyridine)-imidazole (py-im), 1,10-phenanthroline (phen), the corresponding peroxovanadate species bpV(3-OH-pic), bpV(py-im), and bpV(phen)} and 1-ethyl-1H-imidazole (N-Et-im) in solution were explored using multinuclear (H-1, C-13, and V-51) magnetic resonance, COSY (con-elated spectroscopy), HSQC (heteronuclear single quantum coherence) and variable temperature nuclear magnetic responance (NMR) using 0.15 mol.L-1 NaCl ionic medium to mimic physiological conditions. Experimental results indicated that the reactivity of these four complexes with 1-ethyl-1H-imidazole decreased as follows: bpV > bpV(3-OH-pic)> bpV(py-im)> bpV(phen). The coordinating ability, the steric effect, and the molecular weight of these organic ligands affected the reaction equilibrium. A new six-coordinated peroxovanadate species [OV(O-2)(2)(N-Et-im)](-) was formed because of competitive coordination.National Natural Science Foundation of China [20772027, 20803020]; China Postdoctoral Science Foundation [20070410805]; Science Research Foundation of Ministry of Health & United Fujian Provincial Health ; Education Project for Tackling the Key Research [WKJ2008-2-036]; Health and Science and Technology of Xiamen, China [3502Z20051027

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报道了利用LBO晶体对Nd:YAG纳秒激光器进行腔外倍频实验的研究结果，实验中LBO晶体采用I类非临界相位匹配（NCPM），温度调谐。实验证明，采用LBO温度调谐方式具有倍频效率高、稳定性好、易于调节等优点，当匹配温度为8.4 ℃、基频光功率为1.3J时，获得了855mJ的660nm倍频光输出，最高转换效率达到66%，倍频光能量稳定度小于±3%

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单排链驱动的自动扶梯经过多年的服役，磨损和老化严重，存在很大的安全隐患，也已经不符合最新的国家强制检验标准，将单排链驱动改为双排链是一种既经济又有效的改造手段。以济南贵和购物中心8台扶梯改造为例，详细阐述了自动扶梯的双排链传动设计方法与改造施工工艺。根据扶梯工况与性能要求，对双排链传动系统进行了设计计算，尤其是大、小链轮尺寸的计算与校核，并对链轮进行了结构设计。现场应用证明了所提出的双排链设计方法和施工工艺的正确性和可行性，可为其他类似的自动扶梯改造工程提供借鉴

LBO晶体非临界相位匹配倍频研究

利用LBO晶体对Nd:YAG ns激光器进行了腔外倍频实验研究,实验中LBO晶体采用I类非临界相位匹配(NCPM),温度调谐,将倍频转换效率和温度调谐的理论值与实验数据进行了对比,实验结果基本与理论值相符,当基频光的单脉冲能量为1.3J时,获得了840mJ的532nm倍频绿光输出,最高转换效率达到65%,倍频光能量不稳定度小于±3