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91.
In this communication, TiO2 nanocrystalline thin films synthesized by a room temperature (27 degrees C) chemical dip process. To our knowledge, this is first report of the preparation of nanoscale rutile TiO2 particles from common inorganic salt at such low temperature. Interestingly, unprecedented dynamic color change accompanies with titanium dioxide grain size, which can be seen with the naked eye that generated curiosity in our mind to check UV-vis absorption, where significant changes were observed. The room temperature synthesized thin films of rutile titanium dioxide make it a potential candidate for high-compatibility material, which can be used in artificial heart valves.  相似文献   
92.
Di  Lu  Dong  Hao  Chen  Dan Ni  Wang  Hai Ying  Liu  Hui Yan 《Transition Metal Chemistry》2021,46(1):57-63
Transition Metal Chemistry - A Cu(II) coordination polymer, [Cu2(pztrz)2(μ-CH3COO)(CH3COO)]·3H2O (1), derived from mono-substituted 1,2,4-triazole derivative 3-(pyrazinyl)-1,2,4-triazole...  相似文献   
93.
The reaction of Co(ClO4)2·6H2O with 2-hydroxy-3-methoxy-benzaldehyde and an aqueous solution of methylamine in acetonitrile/MeOH under microwave irradiation and controlled temperature/pressure leads to formation of heptanuclear cobalt cluster [Co7(mmp)6(CH3O)6]·(ClO4)2 (1) (mmp is 2-methoxy-6-methyliminomethyl-phenol anion) in only 20 min and also results in higher yields in contrast to other synthesis methods. Complex 1 displays dominant ferromagnetic interactions through μ 3-O and μ 2-O (oxidophenyl) binding modes.  相似文献   
94.
Fluorescence emission of wild‐type green fluorescent protein (GFP) is lost in the S65T mutant, but partly recovered in the S65T/H148D double mutant. These experimental findings are rationalized by a combined quantum mechanics/molecular mechanics (QM/MM) study at the QM(CASPT2//CASSCF)/AMBER level. A barrierless excited‐state proton transfer, which is exclusively driven by the Asp148 residue introduced in the double mutant, is responsible for the ultrafast formation of the anionic fluorescent state, which can be deactivated through a concerted asynchronous hula‐twist photoisomerization. This causes the lower fluorescence quantum yield in S65T/H148D compared to wild‐type GFP. Hydrogen out‐of‐plane motion plays an important role in the deactivation of the S65T/H148D fluorescent state.  相似文献   
95.
选择市售α-Al2O3粉体作为比表面积标准物质候选材料,采用交叉缩分方法对标准物质样品进行分装。检验结果表明α-Al2O3标准物质样品具有良好的均匀性和稳定性(18个月)。采用国际公认的氮气物理吸附BET方法,联合测量能力经过确认的8家实验室对α-Al2O3标准物质样品进行定值,标准值比表面积为5.47 m2/g,不确定度为0.22 m2/g(k=2)。  相似文献   
96.
Exosomes hold great potential in therapeutic development. However, native exosomes usually induce insufficient effects in vivo and simply act as drug delivery vehicles. Herein, we synthesize responsive exosome nano‐bioconjugates for cancer therapy. Azide‐modified exosomes derived from M1 macrophages are conjugated with dibenzocyclooctyne‐modified antibodies of CD47 and SIRPα (aCD47 and aSIRPα) through pH‐sensitive linkers. After systemic administration, the nano‐bioconjugates can actively target tumors through the specific recognition between aCD47 and CD47 on the tumor cell surface. In the acidic tumor microenvironment, the benzoic‐imine bonds of the nano‐bioconjugates are cleaved to release aSIRPα and aCD47 that can, respectively, block SIRPα on macrophages and CD47, leading to abolished “don't eat me” signaling and improved phagocytosis of macrophages. Meanwhile, the native M1 exosomes effectively reprogram the macrophages from pro‐tumoral M2 to anti‐tumoral M1.  相似文献   
97.
Design of stable adsorbents for selective gold recovery with large capacity and fast adsorption kinetics is of great challenge, but significant for the economy and the environment. Herein, we show the design and preparation of an irreversible amide‐linked covalent organic framework (COF) JNU‐1 via a building block exchange strategy for efficient recovery of gold. JNU‐1 was synthesized through the exchange of 4,4′‐biphenyldicarboxaldehyde (BA) in mother COF TzBA consisting of 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline (Tz) and BA with terephthaloyl chloride. The irreversible amide linked JNU‐1 gave good stability, unprecedented fast kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery. X‐ray photoelectron spectroscopy along with thermodynamic study and quantum mechanics calculation reveals that the excellent performance of JNU‐1 for gold recovery results from the formation of hydrogen bonds C(N)?H???Cl and coordinate interaction of O and Au. The rational design of irreversible bonds as both inherent linkage and functional groups in COFs is a promising way to prepare stable COFs for diverse applications.  相似文献   
98.
朱镇波  黄海 《电讯技术》2006,46(4):50-53
研究了基于固定电话网(PSTN)的采用中文信息终端服务接口通信协议(CTSI)的短消息终(CPE)的软硬件开发。介绍了短信编辑接收系统与信息终端之间数据交换的协议,并以电子订货系统中发送订单为例,描述了信息终端与CTSI服务器之间链路建立、信息交互的整个过程。  相似文献   
99.
计算机辅助立体全像技术研究进展   总被引:2,自引:0,他引:2  
介绍了计算机辅助立体全像技术的基本原理与发展历程,叙述了该技术的应用实例和最新进展,并讨论了显示系统的性能指标、参数选择和改进方案。  相似文献   
100.
Sm3+掺杂稀土硼酸盐玻璃的光谱参数计算和荧光光谱分析   总被引:2,自引:1,他引:1  
制备了具有高效可见荧光发射的Sm3 掺杂稀土硼酸盐(LBLB)玻璃,对玻璃的吸收和荧光光谱展开了测试与分析.根据Judd-Ofelt理论对吸收光谱进行了拟合,求得Sm3 离子的晶场调节参数Ωt=(2,4,6)分别为6.81×10-20,4.43×10-20和2.58×10-20 cm2,并进一步计算出各能级跃迁的谱线强度、自发辐射跃迁概率、辐射寿命和荧光分支比等光谱参数.紫外光激发下,Sm3 掺杂LBLB玻璃发出明亮的橙红色光.激发光谱表明,氩离子激光器是Sm3 掺杂LBLB玻璃有效的激发光源.  相似文献   
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