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1.
利用改进的Hummers法氧化鳞片石墨,获得富含羟基和羧基的氧化石墨烯量子点(GOQDs)。通过透射电子显微镜、X射线衍射、红外光谱及拉曼光谱测试表征其理化性质。此外,利用鸡卵清蛋白(OVA)作为模式抗原,构筑GOQDs/OVA纳米疫苗并评估其载量、安全性、免疫效力等。结果显示,GOQDs/OVA纳米疫苗直径在5nm左右,具有高度的水分散性和稳定性。其对OVA的最大负载量约为 500mg·g-1,在pH=5.5和7.4环境下24 h的释放率分别为74.65%和56.93%,表现出pH刺激响应释放性能。当GOQDs浓度在500μg·mL-1以下时,不会引起溶血、细胞损伤、重要组织发生病变等现象。免疫后,与 OVA单独免疫对照组相比,GOQDs/OVA纳米疫苗可以诱导产生高水平的免疫球蛋白G(IgG)、免疫球蛋白G1(IgG1)及免疫球蛋白G2a(IgG2a)抗体,提高白细胞介素(IL)-1β、IL-2、IL-4和IL-6、肿瘤坏死因子-α(TNF-α)和γ干扰素(IFN-γ)的分泌,同时促进脾中辅助性(CD4+)和细胞毒性(CD8+)T淋巴细胞百分比的增加。  相似文献   

2.
采用简单的煅烧工艺合成了纳米硼化钴(CoB)晶体,并首次研究了纳米CoB晶体在氨硼烷溶液水解制氢过程中的催化活性。研究发现,纳米CoB晶体具有较高的催化活性,在室温条件下其转换频率(TOF)为35.3molH2·molcat-1·min-1,优于同等条件下贵金属Pt催化剂(TOF=29.3molH2·molcat-1·min-1)。此外,循环测试8次后纳米硼化物晶体的催化制氢性能没有发生衰减。进一步研究发现CoB表面的Co0物种是催化制氢的活性位点,而表面的B物种位点能够有效辅助Co0位点实现协同催化氨硼烷制氢。  相似文献   

3.
李丹  薛佳丹  郑旭明 《物理化学学报》2015,30(12):2216-2223
通过共振拉曼光谱实验和量子化学计算的方法研究了4-硝基咪唑(4NI)A-带激发态衰变动力学. 对4NI的振动光谱、紫外电子吸收光谱、荧光光谱和共振拉曼光谱进行了指认. 在全活化空间自洽场法(CASSCF)/6-31G(d)计算水平下获得了单重激发态S1(nOπ*)和S2(ππ*)和势能面交叉点S1(nOπ*)/S2(ππ*)的优化几何结构和能量, 分析了A-带共振拉曼光谱的强度模式特征, 获得了短时结构动力学, 并结合全活化空间自洽场法(CASSCF)理论计算结果确定了4NI 在S2(ππ*)态衰变通道主要是S2, FC→S2, min(ππ*)→S0辐射弛豫.  相似文献   

4.
以2种配体去甲基斑蝥酸钠(Na2DCA=7-氧杂二环[2.2.1]庚烷-2,3-二甲酸钠)和咪唑(IM),分别与镍(Ⅱ)和镉(Ⅱ)的醋酸盐通过溶液法合成了2种配合物[Ni(IM)(DCA)(H2O)2]·2H2O(1),[Cd2(IM)4(DCA)2]·2H2O(2)。应用元素分析、热重分析、红外光谱及X-射线单晶衍射法对配合物的组成和结构进行了表征。配合物12的中心离子分别与咪唑的亚胺氮原子、去甲基斑蝥酸根的羧基氧原子和醚键氧原子配位,配位数均为6,分别为单核(1)和双核(2)配合物。通过紫外光谱法、荧光光谱法和粘度法研究了配合物与DNA的相互作用。结果表明,配合物能通过部分插入模式与DNA发生较强的结合作用(Kb:5.51×103(1)、1.01×103(2)L·mol-1)。同时,利用荧光光谱法研究了配合物与牛血清白蛋白(BSA)的相互作用。配合物能与BSA发生强烈的相互作用(KAM:1.91×105(1)和6.17×105(2)L·mol-1),结合位点数均为1。测试了配合物对人肝癌细胞(SMMC7721)和人乳腺癌(MCF-7)的体外抗增殖活性。结果显示,配合物对不同癌细胞具有选择性抑制作用。镍配合物(1)对SMMC7721的抗癌活性较去甲基斑蝥酸钠有明显提高。  相似文献   

5.
利用γ-环糊精(γ-CD)、氢氧化钾、甲醇和水,制备了γ-CD-MOFs,并使用X射线粉末衍射、热重分析和扫描电镜对其结构、稳定性和形貌进行表征。由于γ-CD-MOFs的结构中含有一维孔道,在其孔道中引入黄光发射的罗丹明6G (R6G)染料,获得了荧光复合材料R6G@γ-CD-MOFs,并探索了其对不同金属离子的荧光响应情况。实验结果表明,R6G@γ-CD-MOFs能够从12种金属离子中选择性传感Fe3+离子,在2×10-4~2.0×10-2 mol·L-1范围内其荧光猝灭常数(Ksv)为1.03×104 L·mol-1。  相似文献   

6.
采用浸渍还原法制备了MgO负载纳米CuPd合金的复合催化剂(CuPd/MgO)。该催化剂在室温催化甲醛溶液重整产氢过程中表现出优异的催化性能,转换频率(TOF)高达812.6h-1,分别是相同条件下Cu/MgO(TOF=356.7h-1)和Pd/MgO(TOF=34.8h-1)的2.3倍和23倍。基于实验测试和表征结果,发现CuPd/MgO催化剂中纳米CuPd合金与表面富集缺陷的MgO载体之间存在金属-载体强相互作用。这种相互作用能够促进氧气在催化剂表面吸附活化并生成活性氧物种(超氧阴离子自由基,·O2-),·O2-先后促进甲醛中的C—H键断裂和水分子的解离,随后与反应体系中生成的质子及氢自由基(·H)依次结合,最终实现氢气的析出与氧气的再生。  相似文献   

7.
采用微乳液法制备NaLu(WO4)2-x(MoO4)x:8%Eu3+(x=0, 0.5, 1.0, 1.5, 2.0)/y%Eu3+,5%Tb3+(y=1, 3, 5, 7, 9)系列荧光粉.通过X射线衍射(XRD)表征,所制样品的X射线衍射峰与标准卡片PDF#27-0729基本吻合,表明所制的样品为白钨矿结构,属于四方晶系.扫描电镜SEM显示制备的纳米粒子是梭子状的,粒径大约是110 nm.激发发射光谱显示,在Eu3+离子掺杂浓度为8%时,NaLu(WO4)(MoO4):Eu3+发光强度最大.NaLu(WO4)2-x(MoO)x :8%Eu3+(x=0, 0.5, 1.0, 1.5, 2.0)荧光粉在Mo/W比达到1:1(x=1)时发光强度最大,强烈的红光发射表明该材料可用于白光LED材料.该荧光粉在268、394和466 nm波长光激发下分别发出橙红色、黄色和淡黄色光,可以满足不同光色需要.NaLu(WO)(MoO):y%Eu3+,5%Tb3+(y=1, 3, 5, 7, 9)荧光粉,随着y值增大,从绿光区(x=0.278, y=0.514)进入白光区(x=0.356, y=0.373), (x=0.278, y=0.313),同时观察到Tb3+到Eu3+有效能量传递.  相似文献   

8.
以结晶氯化铝(AlCl3·6H2O)作为铝源,十二烷基苯磺酸钠(SDBS)为模板剂,采用水热法在硅藻土盘上制备了束状纳米结构γ-AlOOH/Al2O3复合吸附剂。采用XRD、SEM、TEM、TG/DSC、N2吸脱附等对样品进行了表征。研究了样品对133Cs+及Pb2+的吸附能力。研究表明,样品γ-AlOOH/硅藻土、γ-Al2O3/硅藻土对Cs+及Pb2+均具有良好的吸附性能,两者对Cs+的去除率分别为98.9%和99.6%;对Pb2+的最大吸附量分别为357.1、416.7mg·g-1。两种样品对Pb2+的吸附均符合Langmuir吸附模型。  相似文献   

9.
利用柔性酚胺类配体N,N'-二甲基-N,N'-(2-羟基-4,5-二甲基苄基)乙二胺(H2L)与Cu(Ⅱ)反应,合成了2个新的酚氧桥联多核Cu(Ⅱ)配合物[Cu3II(L)2(CH3OH)2](ClO4)2(1),[Cu3II(L)2(CuICl2)2](2)。配合物1~2中,3个Cu2+之间通过2个酚氧桥连接,形成线性三核结构。两边的铜离子分别被配体L2-上的N2O2螯合配位,轴向与甲醇分子的氧(配合物1)或[CuCl2]-的氯(配合物2)配位,形成四方锥配位构型。中间铜离子与两侧L2-上的4个酚氧原子以平面四边形配位。CuII-O-CuII键角为100.14°~101.79°。对配合物1~2进行变温磁化率测量表明,铜离子之间通过酚氧桥存在强的反铁磁耦合,磁耦合常数J分别为-277(9)cm-1(配合物1)和-299(3)cm-1(配合物2)(基于自旋哈密顿算符Ĥ=-2J(Ŝ1·Ŝ2+Ŝ2·Ŝ3)。J值与酚氧桥桥联键角有一定相关性,即Cu-O-Cu桥联键角越大,反铁磁耦合越强。  相似文献   

10.
以价廉、易得的石墨片为原料,采用改进的Hummers法,简单、快速、高效地制备了具有良好生物相容性的橙色荧光氧化石墨烯量子点(GOQDs)。所制备的GOQDs尺寸约7.2 nm,具有尺寸均匀、晶格间距为0.20 nm的高度结晶的核心和氧化的外围结构。与大多数报道的碳点(CDs)、包裹掺杂碳点(掺杂 CDs)、石墨烯量子点(GQDS)和 GOQDs不同,我们的方法制备的 GOQDs显示出橙红色并具有激发波长独立的荧光发射。此外,GOQDs具有pH依赖性荧光发射、强的光漂白抗性、低细胞毒性、良好的水溶性(ρ=10 mg·mL-1)和优异的生物相容性。这些特性使其成功应用于细胞pH成像。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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