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1.
用MNDO-PM3方法对沙蚕毒系化合物二氢沙蚕毒,硫氰酸酯,巴丹,杀虫单及其异构件的几何构型进行了全自由度优化,并计算了其电子结构,讨论了生物活性与几何构型和电了结构的关系。  相似文献   
2.
将5种离子液体[Bmim]HCO3, [TMG]L, [MEA]L, [Bmim]Cl和[Bmim]BF4分别与N-甲基二乙醇胺(MDEA)水溶液混合, 得到新型复配脱硫剂, 考察了离子液体的消泡性能和复配脱硫剂在不同离子液体、 吸收温度以及复配比例下的脱硫性能, 并且对较优脱硫剂进行了再生性能的研究. 采用离子色谱仪对经臭氧深度处理的再生液进行了SO42-离子浓度测试, 并对脱硫剂进行了密度泛函理论研究, 从而进一步分析了吸收机理. 结果表明, 室温下复配脱硫剂脱硫能力大小顺序为[Bmim]Cl-MDEA-H2O>[Bmim]HCO3-MDEA-H2O>[Bmim]BF4-MDEA-H2O>MDEA-H2O>[TMG]L-MDEA-H2O>[MEA]L-MDEA-H2O. 离子液体与MDEA结合的稳定性为主要影响因素, [Bmim]HCO3的消泡能力最强, [Bmim]Cl-MDEA-H2O, [Bmim]BF4-MDEA-H2O和[Bmim]HCO3-MDEA-H2O脱硫剂可以通入空气获得基本再生, H2S与离子液体的结合越稳定, 脱硫效率越高, 但脱硫剂的再生程度会降低.  相似文献   
3.
褐煤蜡中树脂组分的化学研究:生物标志化合物   总被引:4,自引:3,他引:1  
用气相色谱-质谱联用仪对吉林舒兰褐煤蜡树脂和云南寻甸褐煤蜡树脂,进行了生物标志化合物的研究。结果指出,三萜类化合物中含有四环三萜、五环三萜、芳香五环三萜和含氧化合物,其中以C25A,B,C,D环-四芳鸟散烷和C25A,B,C,D环-四芳奥利烷含量最高,舒兰树脂中这两种化合物的含量高于寻甸树脂约10倍;无羁萜和3-氧代别桦木烷量亦以舒兰树脂占优势  相似文献   
4.
The challenges of nanoparticles, such as size‐dependent toxicity, nonbiocompatibility, or inability to undergo functionalization for drug conjugation, limit their biomedical application in more than one domain. Oval‐shaped iron@gold core–shell (oFe@Au) magnetic nanoparticles are engineered and their applications in magnetic resonance imaging (MRI), optical coherence tomography (OCT), and controlled drug release, are explored via photo stimulation‐generated hyperthermia. The oFe@Au nanoparticles have a size of 42.57 ± 5.99 nm and consist of 10.76 and 89.24 atomic % of Fe and Au, respectively. Upon photo‐stimulation for 10 and 15 minutes, the levels of cancer cell death induced by methotrexate‐conjugated oFe@Au nanoparticles are sixfold and fourfold higher, respectively, than oFe@Au nanoparticles alone. MRI and OCT confirm the application of these nanoparticles as a contrast agent. Finally, results of in vivo experiments reveal that the temperature is elevated by 13.2 °C, when oFe@Au nanoparticles are irradiated with a 167 mW cm?2 808 nm laser, which results in a significant reduction in tumor volume and scab formation after 7 days, followed by complete disappearance after 14 days. The ability of these nanoparticles to generate heat upon photo‐stimulation also opens new doors for studying hyperthermia‐mediated controlled drug release for cancer therapy. Applications include biomedical engineering, cancer therapy, and theranostics fields.  相似文献   
5.
以氯化1,7-二(2-苯并咪唑)-庚烷(SBHt)为客体,八元瓜环(Q[8])为主体,利用1H NMR技术、动态光散射实验、荧光发射光谱、紫外吸收光谱详细探索了其在溶液中的相互作用、超分子自组装过程及作用模式. 首先考察了八元瓜环对客体pKa的影响,确定了研究主客体相互作用的条件,并详细探索了主客体的超分子自组装过程及作用模式. 主体Q[8]与客体SBHt相互作用的1H NMR谱图表明,主客体相互作用自组装形成1:1超分子聚合物. 这一推断得到动态光散射实验、紫外吸收光谱、荧光发射光谱测定结果的证实,并通过紫外吸收光谱、荧光发射光谱确定其表观稳定常数分别为2.79×105 L/mol及2.48×105 L/mol. 而晶体结构测定表明主体Q[8]与客体SBHt自组装形成1:2的简单包结配合物. 导致Q[8]与SBHt在溶液中和固体状态下形成不同自组装结构可能源于瓜环的外壁作用与包结作用竞争所致.  相似文献   
6.
Ultrathin oxide nanofibers are widely used in an array of catalytic applications toward energy conversion and environmental protection. Remarkable progress has been made with regard to the development of engineering oxide nanofibers into unique structures to suit or enable various functions. We aim to provide a comprehensive overview of oxide nanofibers, including the structure engineering, derivates, assemblies and their applications. We begin with a brief introduction to the production of nanofibers with diversified compositions, structures and properties, followed by discussions of the wet-chemistry derivates. Afterward, we discuss the applications of catalytic oxide nanofibers, including electrocata-lysis, photocatalysis and thermal-catalysis. Then we highlight the most significant role of oxide nanofibers as catalyst support for the immobilization of metal nanoparticles. Moreover, we showcase the advanced assemblies based on oxide nanofibers, including their use as multi-functional membranes and foams. In the end, we offer perspectives on the challenges, opportunities and new directions for future development.  相似文献   
7.
In the manipulation of nanoparticles, different behaviors are typically observed including sliding, rolling and rotation. Most of investigations in this field have so far focused on describing the interaction forces under vacuum (dry air) environmental condition, while the effect of the relative humidity has been poorly considered. In this work we developed a model for simulating the dynamic nanoparticle motion (rolling and sliding) in an AFM-based manipulation of nanoparticles in a humid environment. In our method, the interaction forces include the adhesion force, mainly consisting of the capillary force and van der Waals force, the normal force and friction forces. We calculated the adhesion force by considering the contributions from the wet and dry portions of the particle. Our stimulations show that nanoparticles smaller than the AFM tip tend to slide before rolling, while in large nanoparticles the rolling occurs first. The particle motion is achieved if the applied force exceeds a critical value and the direction of the rolling movement depends on the applied force angle. Furthermore, small nanoparticles are more easily manipulated by the tip in low-humidity conditions while the manipulations with large nanoparticles need high-humidity conditions. Preliminary results can be used to adjust proper handling force for the accurate and successful assembly of particles.  相似文献   
8.
将典型的光热等离激元石墨烯和纳米金简便地负载在钛酸钠(Na2Ti3O7)载体上, 构建出具有较窄禁带宽度和较高光催化活性的Au/RGO/Na2Ti3O7光热辅助光催化体系. 研究发现, 石墨烯片层与金纳米颗粒在光照下, 通过局域表面等离激元共振效应诱导产生大量的热电子, 以活化反应物并降低反应活化能, 其引发的光热效应还可精准提升光催化体系中反应位点附近的温度, 从而大幅提升光催化反应速率. 通过构建特殊微支结构, 进一步增强了Au/RGO/Na2Ti3O7催化剂对光的捕获, 并限域锚定高表面能催化剂以增强体系的稳定性. 在光热、 光催化的高效协同增强下, Au/RGO/Na2Ti3O7催化剂体系对对硝基苯酚和肉桂醛的加氢反应均表现出增强的光催化活性. 光热辅助下的Au/RGO/Na2Ti3O7光催化剂在对硝基苯酚反应中的转换频率(TOF)值高达54.4 min-1, 反应活化能显著降低至15.78 kJ/mol, 且其在长效测试中表现出良好的稳定性(4次循环催化后, 转化率的保持率近90%).  相似文献   
9.
10.
Epoxypropyl dodecyl dimethyl ammonium chloride (EPDDMAC) was synthesized with N,N-dimethyl dodecyl amine (DMDA) and epichlorohydrin (EPIC). Diethyl-2,3-epoxypropyl-[3-methyldimethoxyl)] silpropyl ammonium chloride (DEEPSAC) was synthesized with N,N-diethyl-aminopropyl-methyldimethoxysilane (DEAPMDES) and epichlorohydrin (EPIC). The products were characterized by infrared and elemental analysis and 1H NMR spectroscopy. The surface tension, conductivity, and antibacterial activities of EPDDMAC and DEEPSAC were studied.  相似文献   
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