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101.
利用X射线微区分析,对共价法得到的固定化L—天门冬酰胺酶的活性进行了分析。L—天门冬酰胺作为底物,MgCl2作为捕捉剂,底物经L-天门冬酰胺酶催化分解产生氨,后者和捕捉剂反应产生沉淀,可以确定固定化L-天门冬酰胺酶的催化活性部位。结果表明:大孔树脂载体,酶活较高,活性L-天门冬酰胺酶分布较均匀。并得到了固定化L-天门冬酰胺酶的活性定位的最佳条件。并对不同结构载体固定化酶活性进行了研究。 相似文献
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LI Li SHI Ke-ying . Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education . Laboratory of Physical Chemistry School of Chemistry Materials Science Heilongjiang University Harbin P. R. China 《高等学校化学研究》2009,25(5):595-599
Fe(II) was deposited into the bottom of the mesopores of highly ordered large caged cubic mesoporous silica by electrodeposition. And the deposited Fe mesoporous silica thin film was treated by 1%―4% HF to remove the SiO2 template and then calcined. It was found that nanowire bundles, dendritic plates of porous iron oxide, dense parallel backbones of porous iron oxide were obtained at 1.4―-1.6 V and 0.08―0.1 mol/L electrolyte concentration after calcinations; the dendritic pattern of porous iron oxide film ... 相似文献
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文章根据医院临床需要,利用PE公司的Spectrum GX傅里叶变换红外光谱仪研究了多组恶性多形性腺瘤及其周围正常组织结构的FTIR光谱.结果发现:恶性多形性腺瘤与其周围正常组织的红外傅里叶光谱在若干波段处有所不同:相对于正常组织,癌变后核酸分子中的磷酸二脂基团的对称伸缩振动谱带、蛋白质的酰胺Ⅰ带的红外光谱都向高波数移动且吸收都得到增强,说明癌变多形性腺瘤的核酸和蛋白质的氢键化程度普遍增高,吸收普遍增强;而膜脂分子中亚甲基的无序性增加,吸收随之增强.就此可将多形性腺瘤癌区通过红外光谱从正常组织中区分出来. 相似文献
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HUANG Lin LIN Zhi-cao LIN Qing LUO Lian-zhong HUANG He-qing . Key Laboratory of the MOD for Cell Biology Tumor Cell Engineering School of Life Sciences . State Key Laboratory of Physical Chemistry of Solid Surface . Key Laboratory of Chemical Biology of Fujian Province College Chemistry & Chemical Engineering Xiamen University Xiamen P. R. China 《高等学校化学研究》2008,24(5):550-556
Pig pancreas ferritin(PPF) was purified by ultra-centrifugation, ion-exchange chromatography, and native gradient polyacrylamide gel electrophoresis(PAGENG). Sodium dodecyl sulfate(SDS)-PAGE indicates that PPF consists of two subunit types, namely, H(21000) and L(19000) subunits, and its core shows an average element composition of 1698 Fe3+ and 179 phosphate molecules within the hollow shell, giving a 9.5:1 ratio of Fe3+ to phosphate. An off line approach combining reversed-phase high-performance liquid chromatography(RP-HPLC) with matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS) made the decomposition of PPF shell into H and L subunits for the analysis of mass spectrometry(MS), giving molecular weights of both H(21014.4) and L(18319.9) subunits. Both subunit types were further identified by an approach combining peptide mass fingerprint(PMF) with database search. A ratio of 1H to 2L subunits in PPF was determined by SDS-PAGE, RP-HPLC, and MALDI-TOF MS, respectively. It is well known that the non-covalent interaction of L-L or H-L subunits is stronger than that of H-H subunits in PPF, which may be further used to explain the unclear physiological function between H and L subunits in PPF. 相似文献
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研究了退火条件和 In 组份对分子束外延生长的 In Ga As 量子点(分别以 Ga As或 Al Ga As 为基体)光学特性的影响。表明:量子点中 In 含量的增加将导致载流子的定域能增加和基态与激发态之间的能量间隔增大。采用垂直耦合的量子点及宽能带的 Al Ga As 基体可增强材料的热稳定性。以 Al Ga As 为基体的 In Ga As 量子点,高温后退火工艺 ( T= 830℃)可改善低温生长的 Al Ga As 层的质量,从而改善量子点激光器材料的质量。 相似文献
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The mirror nuclei 12N and 12B are separated by the Radioactive Ion Beam Line in Lanzhou(RIBLL) at HIRFL from the breakup of 78.6 MeV/u 14N on a Be target.The total reaction cross-sections of 12N at 34.9 MeV/u and 12B at 54.4 MeV/u on a Si target have been measured by using the transmission method.Assuming 12N consists of a 11C core plus one halo proton,the excitation function of 12N and 12B on a Si target and a C target were calculated with the Glauber model.It can fit the experimental data very well.The ch... 相似文献
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稀土Eu掺杂PtRu/C催化剂及其对甲醇电氧化的性能 总被引:1,自引:0,他引:1
采用化学还原和热处理方法对商业PtRu/C催化剂进行稀土Eu掺杂,制备了不同Eu含量的PtRuEux/C催化剂.透射电子显微镜(TEM)、X射线能量色散光谱(EDX)、X射线衍射(XRD)和X射线光电子能谱(XPS)等方法表征催化剂的结果表明,Eu的掺杂未改变PtRu/C催化剂的平均粒径(约为3nm),并且Eu以金属和氧化物两种形态修饰PtRu表面.循环伏安和计时电流法测试显示,PtRuEux/C催化剂较商业PtRu/C对甲醇氧化具有更高的活性,其中PtRuEu0.3/C的活性最高.运用原位傅里叶变换红外(FTIR)光谱从分子水平研究了该催化剂对甲醇电催化氧化的反应过程,检测到甲醇在催化剂上解离吸附的吸附态产物是线型吸附态CO(COL),Eu的掺杂使COL的氧化电位降低,明显提高了催化剂的活性和抗CO毒化的能力. 相似文献
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研究了以GaAs和Al0.15Ga0.85As为基体,当铟的摩尔分数(x)不同时,后退火对InxGa1-xAs单层量子点光致荧光(PL)谱特性的影响。后退火将导致铟含量不同的样品(x=0.23,0.37,0.50,1.0)的PL谱线宽度变窄和蓝移。对于GaAs基体,在700℃退火90分钟所造成的PL谱蓝移与退火30分钟相似;(仅当x=0.23时,退火90分钟所造成的PL谱蓝移小于30分钟)。对于Al0.15Ga0.85As基体,在700℃退火30分钟和90分钟,其PL谱蓝移是不同的。 相似文献