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41.
用紫外分光光度法,找出介孔碳材料对蛋白质的最佳吸附条件,并测定出该介孔碳材料对溶菌酶的最大吸附量。主要从3方面研究介孔碳材料对蛋白质吸附行为的影响。分别是介孔碳材料对蛋白质吸附行为随接触时间的变化产生的影响,pH值的改变对介孔碳材料吸附蛋白质行为的影响,以及介孔碳材料的量的改变对蛋白质吸附行为随接触时间的变化产生的影响。结果表明,当溶菌酶溶液的初始浓度为210μm ol/L,pH值为11.0,接触时间为96h时介孔碳材料对蛋白质即可达到吸附饱和。该介孔碳材料在最佳条件下对溶菌酶的最大吸附量为27.32μm ol/g,表现出优越的溶菌酶吸附性能。  相似文献   
42.

We propose a single-photon router that is made of three coupled-resonator forming a Π-type waveguide. The two atoms embedded in the two junctions, which have the distance of 2d, are used as quantum switch to control single photons routing. We find that the scattered rate depend on the incident single photons come from either infinite CRWs or semi-infinite CRWs, and the boundary can enhance the transfer rate.

  相似文献   
43.
用一种新合成的套索冠醚N,N′-双(乙酰苄胺)-二氮杂-18-冠-6作为固定相,涂渍在弹性石英毛细管内,测其柱效、惰性、热稳定性、平均极性及选择性等性质。实验表明,它具有良好的色谱性能,中等极性,分离选择性高,适用于对醇、卤代烃、芳香烃等各类异构体的分离,并从分子结构和热力学参数等探讨了保留机理。  相似文献   
44.
Water-gas shift reaction catalyst at lower temperature (200—400℃) may improve the conversion of carbon monoxide. But carbonyl sulfide was found to be present over the sulfided cobalt-molybdenum/alumina catalyst for water-gas shift reaction. The influences of temperature, space velocity, and gas components on the formation of carbonyl sulfide over sulfided cobalt-molybdenum/alumina catalyst B303Q at 200—400℃were studied in a tubular fixed-bed quartz-glass reactor under simulated water-gas shift conditions. The experimental results showed that the yield of carbonyl sulfide over B303Q catalyst reached a maximum at 220℃with the increase in temperature, sharply decreased with the increase in space velocity and the content of water vapor, increased with the increase in the content of carbon monoxide and carbon dioxide, and its yield increased and then reached a stable value with the increase in the content of hydrogen and hydrogen sulfide. The formation mechanism of carbonyl sulfide over B303Q catalyst at 200—400℃was discussed on the basis of how these factors influence the formation of COS. The yield of carbonyl sulfide over B303Q catalyst at 200-400℃was the combined result of two reactions, that is, COS was first produced by the reaction of carbon monoxide with hydrogen sulfide, and then the as-produced COS was converted to hydrogen sulfide and carbon dioxide by hydrolysis. The mechanism of COS formation is assumed as follows: sulfur atoms in the Co9S8-MOS2/Al2O3 crystal lattice were easily removed and formed carbonyl sulfide with CO, and then hydrogen sulfide in the water-gas shift gas reacted with the crystal lattice oxygen atoms in CoO-MoO3/Al2O3 to form Co9S8-MoS2/Al2O3. This mechanism for the formation of COS over water-gas shift catalyst B303Q is in accordance with the Mars-Van Krevelen's redox mechanism over metal sulfide.  相似文献   
45.
Uniform-sized molecularly imprinted polymer (MIP) beads for metsulfuron-methyl (MSM) were firstly prepared by one-step swelling and polymerization method using 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA) as functional monomer and cross-linker, respectively. The preparation was optimized by varying the ratio of MSM to 4-VPY. The chromatographic behaviors of MSM and other structurally related sulfonylureas (SUs) on the resultant MIP column were evaluated. The imprinted polymer revealed specific affinity to the template and the fair resolution of SUs was also obtained. Furthermore, the uniform-sized MSM-MIP was used as the solid phase extraction (SPE) material to enrich MSM in real water samples before reversed-phase HPLC (RP-HPLC) analysis. The recovery of MSM from 100 mL of drinking water at a 50 ng/L spike level was 99.59% with R.S.D. of 1.13%. The detection limit was about 6.0 ng/L of MSM when enriching a 100 mL water sample.  相似文献   
46.
β-羧基乙基锗倍半氧化物(即Ge-132)是一种无毒和具较强抗癌活性的有机锗化合物。为了进一步提高其抗癌活性。已对Ge-132进行了化学结构修饰。本文介绍8种未见报导的Ge-132衍生物,β-酚酯基乙基锗倍半氧化物的合成和体外培养细胞实验结果。  相似文献   
47.
An optimal temperature is crucial for a broad range of applications, from chemical transformations, electronics, and human comfort, to energy production and our whole planet. Photochemical molecular thermal energy storage systems coupled with phase change behavior (MOST-PCMs) offer unique opportunities to capture energy and regulate temperature. Here, we demonstrate how a series of visible-light-responsive azopyrazoles couple MOST and PCMs to provide energy capture and release below 0 °C. The system is charged by blue light at −1 °C, and discharges energy in the form of heat under green light irradiation. High energy density (0.25 MJ kg−1) is realized through co-harvesting visible-light energy and thermal energy from the environment through phase transitions. Coatings on glass with photo-controlled transparency are prepared as a demonstration of thermal regulation. The temperature difference between the coatings and the ice cold surroundings is up to 22.7 °C during the discharging process. This study illustrates molecular design principles that pave the way for MOST-PCMs that can store natural sunlight energy and ambient heat over a wide temperature range.

We demonstrate rationally designed arylazopyrazoles as MOST-PCM that can be circularly charged and discharged below 0 °C with visible light.  相似文献   
48.
For the first time site-specific doping of silver into a spherical Au25 nanocluster has been achieved in [Au19Ag6(MeOPhS)17(PPh3)6] (BF4)2 (Au19Ag6) through a dual-ligand coordination strategy. Single crystal X-ray structural analysis shows that the cluster has a distorted centered icosahedral Au@Au6Ag6 core of D3 symmetry, in contrast to the Ih Au@Au12 kernel in the well-known [Au25(SR)18] (R = CH2CH2Ph). An interesting feature is the coexistence of [Au2(SPhOMe)3] dimeric staples and [P–Au–SPhOMe] semi-staples in the title cluster, due to the incorporation of PPh3. The observation of only one double-charged peak in ESI-TOF-MS confirms the ordered doping of silver atoms. Au19Ag6 is a 6e system showing a distinct absorption spectrum from [Au25(SR)18], that is, the HOMO–LUMO transition of Au19Ag6 is optically forbidden due to the P character of the superatomic frontier orbitals.

For the first time site-specific doping of silver into a spherical Au25 nanocluster has been achieved in [Au19Ag6(MeOPhS)17(PPh3)6] (BF4)2. It is a 6e system showing quite a different absorption spectrum from [Au25(SR)18].  相似文献   
49.
In this paper, we investigate some new interesting solution structures of the(2+1)-dimensional bidirectional Sawada–Kotera(bSK) equation. We obtain soliton molecules by introducing velocity resonance. On the basis of soliton molecules, asymmetric solitons are obtained by changing the distance between two solitons of molecules. Based on the N-soliton solutions,several novel types of mixed solutions are generated, which include the mixed breather-soliton molecule solution by the module resonance of the wave number and partial velocity resonance,the mixed lump-soliton molecule solution obtained by partial velocity resonance and partial long wave limits, and the mixed solutions composed of soliton molecules(asymmetric solitons), lump waves, and breather waves. Some plots are presented to clearly illustrate the dynamic features of these solutions.  相似文献   
50.
Direct electron transfer of myoglobin (Mb) was achieved by its direct immobilization on carbon ionic liquid electrode (CILE) with a conductive hydrophobic ionic liquid, 1‐butyl pyridinium hexaflourophosphate ([BuPy][PF6]) as binder for the first time. A pair of well‐defined, quasi‐reversible redox peaks was observed for Mb/CILE resulting from Mb redox of heme Fe(III)/Fe(II) redox couple in 0.1 M phosphate buffer solution (pH 7.0) with oxidation potential of ?0.277 V, reduction potential of ?0.388 V, the formal potential E°′ (E°′=(Epa+Epc)/2) at ?0.332 V and the peak‐to‐peak potential separation of 0.111 V at 0.5 V/s. The average surface coverage of the electroactive Mb immobilized on the electrode surface was calculated as 1.06±0.03×10?9 mol cm?2. Mb retained its bioactivity on modified electrode and showed excellent electrocatalytic activity towards the reduction of H2O2. The cathodic peak current of Mb was linear to H2O2 concentration in the range from 6.0 μM to 160 μM with a detection limit of 2.0 μM (S/N=3). The apparent Michaelis–Menten constant (K and the electron transfer rate constant (ks) were estimated to be 140±1 μM and 2.8±0.1 s?1, respectively. The biosensor achieved the direct electrochemistry of Mb on CILE without the help of any supporting film or any electron mediator.  相似文献   
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