Synthesis of Cu-Based Nanomaterials and Their Catalytic Properties

Cu在地球上有着丰富的储量并且价格低廉，其在诸多领域都有着大规模的应用，尤其是催化领域，如：电催化、光催化和热催化等，因此Cu基纳米材料受到了人们的广泛关注，科研工作者也致力于开发新的合成策略用以制备各种性能优异的Cu基纳米材料。常见的Cu基纳米材料包括：Cu单质、Cu基合金、Cu基氧化物、Cu基多级结构和负载型Cu基纳米材料等。然而，由于Cu单质极易被氧化，因此合成稳定的单质Cu纳米材料依旧是一个很大的挑战，特别是具有超薄结构的Cu基纳米材料。本论文主要的研究内容就是使用不同的方法制备新型的Cu基纳米材料，并研究其各方面的催化性能，具体内容如下： 第一章：简要的总结了Cu基纳米材料的分类和...The applications of Cu-based nanomaterials, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis, like electrocatalysis, photocatalysis and thermocatalysis. The possible modification of the chemical and physical properties of these nanomaterials using different synthetic strategies to obtai...学位：理学硕士院系专业：化学化工学院_无机化学学号：2052014115150

液晶性树状高分子

对树状高分子进行功能化,使之成为具有特定性能的新型材料是目前很热门的课题,树状液晶就是其中之一。树状高分子长径比很小,似乎难以形成液晶态,但人们已发现多种树状液晶分子,几乎囊括了所有在其他高分子中出现过的液晶相。本文按液晶相分类,介绍树状液晶高分子的研究进展

嗜虫耶尔森氏菌HlyA及HasA外分泌表达系统的构建

【目的】构建一株具备外分泌蛋白功能的工程菌,解决杀虫毒素无法由胞内分泌至胞外,无法直接作用于虫体等问题,为松墨天牛防治提供新思路。【方法】本研究先测定从松墨天牛肠道及其生境中分离出的嗜虫耶尔森氏菌(CSLH88)的生长特性及抗性,进而对其进行分子改造。构建HlyA (pGHKW2)以及HasA (pGHKW4)外分泌表达载体,利用电穿孔法将其转入CSLH88菌株,获得能够表达绿色荧光蛋白的工程菌。利用稀释涂板及荧光体式镜检测技术对两个质粒进行遗传稳定性检测,并采用SDS-PAGE及Western blotting技术验证蛋白外分泌功能。【结果】CSLH88菌株培养2–4 h能够进入对数生长期,并对卡那霉素(Kan)敏感。成功构建了含有Kan抗性基因的pGHKW2(GenBank:MK562405)和pGHKW4(GenBank:MK562404)两个外分泌表达载体的CSLH88工程菌株。其中,发现pGHKW4质粒更加适合在嗜虫耶尔森氏菌中稳定遗传。SDS-PAGE及Western blotting检测结果表明HlyA系统无法在CSLH88菌株中将目的蛋白分泌到胞外,而HasA系统则可以有效地发挥外分泌表达功能。【结论】通过对HlyA及HasA两个外分泌表达系统进行研究,从中筛选出HasA型血红素转运系统作为CSLH88菌株的外分泌表达系统,为后续外分泌杀虫毒素蛋白菌株构建以及CSLH88菌株的致病性研究奠定基础。国家重点研发计划课题(2017YFD0600105);;\n国家自然科学基金(31601905);;\n福建省科技厅自然科学基金(2016J01097);;\n福建省科技计划项目(2018N5002);;\n福建农林大学科研基金(xjq201614);福建农林大学林学院林学高峰学科项目(71201800720,71201800753,71201800779);;\n福建省大学生创新创业训练计划项目(201810389102);;\n福建省林业科学研究项目[Minlinke(2017)03]~

Ultrastable Atomic Copper Nanosheets for Selective Electrochemical Reduction of Carbon Dioxide

金属铜表面很容易被空气氧化，因此铜纳米材料在空气中极不稳定，如何制备原子级厚度的二维铜纳米片一直是纳米材料领域的一个挑战性难题。厦门大学化学化工学院郑南峰教授课题组发展了一种制备稳定超薄二维铜基纳米材料的有效方法，并将这类材料应用于二氧化碳的选择性电催化还原。该项研究还发现所合成的复合纳米材料能够将二氧化碳和水选择性地电化学还原为组成可调的合成气（一氧化碳和氢气混合气），在较低的还原电位下可高选择性地将二氧化碳还原成一氧化碳(其法拉第效率高达92%)。铜基纳米材料在二氧化碳电化学还原中具有优异的性能，但产物异常多样，选择性控制的难度很大。该项工作利用简单的表面配位修饰大幅改善电催化选择性的策略为二氧化碳还原电催化剂的设计提供了新思路。 该工作是在郑南峰教授指导下，并与傅钢教授课题组、加拿大Dalhousie大学张鹏教授合作完成，第一作者为化学化工学院博士生代磊，硕士生钦青、博士生汪佩、赵小静等参与了该工作。【Abstract】The electrochemical conversion of CO2 and H2O into syngas using renewably generated electricity is an attractive approach to simultaneously achieve chemical fixation of CO2 and storage of renewable energy. Developing cost-effective catalysts for selective electroreduction of CO2 into CO is essential to the practical applications of the approach. We report a simple synthetic strategy for the preparation of ultrathin Cu/Ni(OH)2 nanosheets as an excellent cost-effective catalyst for the electrochemical conversion of CO2 and H2O into tunable syngas under low overpotentials. These hybrid nanosheets with Cu(0)-enriched surface behave like noble metal nanocatalysts in both air stability and catalysis. Uniquely, Cu(0) within the nanosheets is stable against air oxidation for months because of the presence of formate on their surface. With the presence of atomically thick ultrastable Cu nanosheets, the hybrid Cu/Ni(OH)2 nanosheets display both excellent activity and selectivity in the electroreduction of CO2 to CO. At a low overpotential of 0.39 V, the nanosheets provide a current density of 4.3 mA/cm2 with a CO faradaic efficiency of 92%. No decay in the current is observed for more than 22 hours. The catalysts developed in this work are promising for building low-cost CO2 electrolyzers to produce CO.We thank the beamline BL14W1 (Shanghai Synchrotron Radiation Facility) for providing the beam time. the Ministry of Science and Technology of China (2017YFA0207302 and 2015CB93230)and the National Natural Science Foundation of China (21731005, 21420102001, 21333008). 研究工作得到了科技部和国家自然科学基金委的资助，X-射线吸收光谱测试在上海光源BL14W1线站完成

DiFFerentiation of HL-60 cell induced by bromelain

目的：为获得对Hl-60细胞具有高效低毒作用的天然诱导分化剂而进行的研究。方法：以菠萝酶brOMElAIn为药物，对人前髓细胞性白血病细胞株Hl-60进行作用，通过不同浓度及不同作用时间的药物作用，统计Hl-60细胞的增殖率、生化变化及形态学的变化。结果：发现brOMElAIn在高浓度下（8μg/Ml）作用4天即可诱导Hl-60细胞发生显著的诱导分化，其nbT阳性率及形态学指标均达到60%以上，电镜下核异染色质浓聚，出现特异性颗粒。结论：brOMElAIn对Hl-60细胞具有明显的诱导分化作用，但其作用机理仍需进一步研究。Purpose: Is to select a diFFerentiation inducer with high eFFicacy and low toxicity For HL-60 cells, a human promyelocyte leukemina cell line.Method: Bromelain was selected For this purpose.HL-60 cell was incubated with bromelain in a certain range of concentrations.The HL-60 cell growth, biochemical changes and morphological changes were determined.Results: both the NBT positive rate and the morphological changes rate were above 60% aFter induction of the cell with high concentration of Bromelain (8 μg/ml).Conclusion: Bromelain can induce HL-60 cell diFFerentiation and reduce the malignant phenotypic characters of HL-60 cell.The mechanism of diFFerentiation induction needs to be studied Further.福建省自然科学基

神经调节素1β通过激活Sirt1信号通路抑制自噬改善大鼠脑缺血再灌注损伤研究 Neuregulin 1β Improves Cerebral Ischemia Reperfusion Injury by Inhibiting Autophagy via Sirt1 Signaling Pathway in Rats

目的 探讨神经调节素1β（neuregulin 1β，NRG1β）是否通过抑制自噬减轻大鼠大脑中动脉缺血再灌注（middle cerebral artery occlusion reperfusion，MCAO/R）损伤，以及对沉默信息调节因子1（silent information regulator protein 1，Sirt1）信号通路的影响。 方法 将210只健康雄性SD大鼠随机分为假手术组（Sham组）、模型组（MCAO/R组）、治疗组（NRG1β组）、激动剂组（SRT501组）、激动剂+治疗组（SRT501+NRG1β组）、抑制剂组（EX527组）和抑制剂+治疗组（EX527+NRG1β组），每组30只。采用改良线栓法建立MCAO/R模型，线栓由颈外动脉插入颈内动脉18～22 mm，堵塞左侧大脑中动脉起始部。缺血2 h后，缓慢拔出线栓，恢复脑血流22 h。EX527（5 mg/kg）、SRT501（100 mg/kg）于术前30 min腹腔注射，NRG1β（2 μg/kg）于拔出线栓后由微量注射器注入颈内动脉。脑缺血2 h、再灌注22 h后采用改良神经损伤严重程度评分（modified neurological severity score，mNSS）法评价各组大鼠的神经行为功能，采用2，3，5-氯化三苯基四氮唑（2，3，5-triphenyltetrazolium chloride，TTC）染色法计算大鼠脑梗死体积比例，苏木精-伊红染色观察神经元形态变化，免疫印迹（western blot，WB）和免疫荧光（immunofluorescence，IF）法分别检测额叶皮质缺血半暗带（ischemic penumbra，IP）区Sirt1、LC3、P62蛋白的表达和阳性细胞指数（positive cell index，PCI）。 结果 NRG1β组大鼠的mNSS[（10.0±0.8）分 vs.（12.8±0.6）分，P<0.001]和脑梗死体积比例[（23.78%±3.52%）vs.（40.24%±1.55%），P<0.001]均优于MCAO/R组，差异具有统计学意义；与MCAO/R组比较，NRG1β组、SRT501组、SRT501+NRG1β组mNSS均有不同程度下降、脑梗死体积比例缩小；各组中SRT501+NRG1β组mNSS最低、脑梗死体积比例最小，EX527组mNSS最高、脑梗死体积比例最大。苏木精-伊红染色显示，NRG1β组大鼠的神经元形态结构损伤较MCAO/R组、EX527组有所改善。WB结果显示，NRG1β组Sirt1表达[（0.81±0.01）vs.（0.67±0.02），P<0.001]和P62表达[（0.92±0.01）vs.（0.78±0.02），P<0.001]均高于MCAO/R组，LC3表达[（0.49±0.02）vs.（0.94±0.03），P<0.001]低于MCAO/R组。IF结果显示，NRG1β组Sirt1 PCI[（0.67±0.01）vs.（0.52±0.02），P<0.001]和P62 PCI[（0.52±0.02）vs.（0.37±0.01），P<0.001]均高于MCAO/R组，LC3 PCI[（0.38±0.01）vs.（0.50±0.01），P<0.001]低于MCAO/R组。WB和IF检测显示，Sirt1与P62表达趋势一致，NRG1β组、SRT501组与SRT501+NRG1β组表达高于MCAO/R组，各组中SRT501+NRG1β组表达最高、EX527组表达最低；LC3蛋白表达趋势与Sirt1、P62相反，在NRG1β组、SRT501组与SRT501+NRG1β组表达较MCAO/R组低；各组中SRT501+NRG1β组表达最低、EX527组表达最高。 结论 NRG1β可通过激活MCAO/R损伤大鼠Sirt1信号通路抑制自噬发挥神经保护作用。 Abstract: Objective To investigate whether neuregulin 1β (NRG1β) can alleviate middle cerebral artery occlusion reperfusion (MCAO/R) injury in rats by inhibiting autophagy, and whether this effect is mediated by the silent information regulator protein 1 (Sirt1) signaling pathway. Methods A total of 210 healthy male SD rats were randomly divided into sham group (sham group), model group (MCAO/R group), treatment group (NRG1β group), agonist group (SRT501 group) and agonist combined with treatment group (SRT501+NRG1β group), inhibitor group (EX527 group) and inhibitor combined with treatment group (EX527+NRG1β group), with 30 rats in each group. The MCAO/R model was established by the modified thread occlusion method to occlude the initial part of middle cerebral artery. After 2 hours of ischemia, cerebral blood flow was restored for 22 hours. EX527 (5 mg/kg) and SRT501 (100 mg/kg) were injected intraperitoneally 30 minutes before surgery, and NRG1β (2 μg/kg) was injected into the internal carotid artery with a microsyringe after restoration of reperfusion. Neurological behavioral function was evaluated by modified neurological severity score (mNSS) at 2 hours after cerebral ischemia and 22 hours after reperfusion. The proportion of cerebral infarction volume in rats was calculated by TTC staining. Morphological changes of neurons were observed by hematoxylin-eosin (HE) staining. The western blot (WB) and immunofluorescence (IF) were used to detect the expression of Sirt1, LC3 and P62 proteins in ischemic penumbra of the frontal cortex. Results The mNSS [(10.0±0.8) vs. (12.8±0.6), P<0.001] and TTC staining results [(23.78%±3.52%) vs. (40.24%±1.55%), P<0.001] in NRG1β group were better than those in MCAO/R group. Compared with MCAO/R group, mNSS in NRG1β group, SRT501 group, SRT501+NRG1β group all decreased in different degree, and the proportion of TTC-stained infarct volume reduced. The mNSS and the proportion of infarct volume were the lowest in SRT501+NRG1β group, while they were the highest in EX527 group among these groups. HE staining showed that the morphological and structural damage of neurons in NRG1β group improved compared with that in MCAO/R group and EX527 group. The WB results showed that the expression of Sirt1 [(0.81±0.01)vs. (0.67±0.02), P<0.001] and P62 [(0.92±0.01) vs. (0.78±0.02), P<0.001] in NRG1β group were higher than those in MCAO/R group, and the LC3 expression [(0.49±0.02) vs. (0.94±0.03), P<0.001] was lower than that in MCAO/R group. The IF results showed that Sirt1 positive cell index (PCI) [(0.67±0.01) vs. (0.52±0.02), P<0.001] and P62 PCI [(0.52±0.02) vs. (0.37±0.01), P<0.001] in NRG1β group were higher than those in MCAO/R group, and LC3 PCI [(0.38±0.01)vs. (0.50±0.01), P<0.001] was lower than that in MCAO/R group. The WB and IF results showed that the expression trend of Sirt1 and P62 was consistent as follows, their expression in NRG1β, SRT501 and SRT501+NRG1β groups were higher than that in MCAO/R group, with the highest expression in SRT501+NRG1β group and the lowest expression in EX527 group; the expression trend of LC3 protein was contrary to that of Sirt1 and P62, and the expression of LC3 protein in NRG1β, SRT501 and SRT501+ NRG1β groups were lower than that in MCAO/R group, with the lowest expression in SRT501+NRG1β group and the highest expression in EX527 group. Conclusions NRG1β plays a neuroprotective role in MCAO/R rats by activating Sirt1 signaling pathway to inhibit autophagy

微型定容燃烧腔内丙烷/空气火焰传播特性

利用高速摄像的方法,在狭缝间距为2,mm的圆盘状微型定容燃烧装置中考察了常温常压、当量比φ为1.0~ 1.6静止丙烷/空气预混气中心点火后向外传播的火焰传播特性.结果表明:微型定容燃烧腔内形成的火焰面有光滑、褶皱和断裂3种形态;光滑火焰面的火焰传播速度低于常规尺度下的火焰传播速度;火焰传播速度随着当量比的增加先增大后减小;在点火能量影响范围外,火焰传播速度随半径增大而减小;随当量比的增加火焰锋面容易出现褶皱和断裂现象

微型定容燃烧腔内C2～C4烷烃/空气火焰传播

在直径35 mm、高度2 mm光学可视的定容燃烧腔内,实验研究了常温常压静止乙烷/空气、丙烷/空气和正丁烷/空气预混气在燃烧腔中心由电火花点燃后向外传播的火焰传播特性。结果表明：3种燃料空气混合气可形成火焰传播的当量比范围不同,范围由大到小排序为乙烷〉丙烷〉正丁烷;3种燃料均存在由光滑火焰面向褶皱火焰面转变的传播形态;在微型定容燃烧腔内,3种燃料的火焰传播速度均低于常规尺度下定容燃烧弹内火焰传播速度,且火焰传播速度随半径增加而减小;随着当量比增加,火焰锋面容易出现褶皱和断裂现象,在高当量比情况下,火焰传播会出现短暂停滞

微型定容燃烧腔内C_2~C_4烷烃/空气火焰传播

在直径35 mm、高度2 mm光学可视的定容燃烧腔内,实验研究了常温常压静止乙烷/空气、丙烷/空气和正丁烷/空气预混气在燃烧腔中心由电火花点燃后向外传播的火焰传播特性。结果表明：3种燃料空气混合气可形成火焰传播的当量比范围不同,范围由大到小排序为乙烷〉丙烷〉正丁烷;3种燃料均存在由光滑火焰面向褶皱火焰面转变的传播形态;在微型定容燃烧腔内,3种燃料的火焰传播速度均低于常规尺度下定容燃烧弹内火焰传播速度,且火焰传播速度随半径增加而减小;随着当量比增加,火焰锋面容易出现褶皱和断裂现象,在高当量比情况下,火焰传播会出现短暂停滞