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排序方式: 共有155条查询结果,搜索用时 15 毫秒
41.
AbstractDevelopment of novel supported catalysts with high activity and stability is still a challenge. In this study, the Au-polydopamine (Au-PDA) hollow microcapsules with Au nanoparticles embedded into the PDA microcapsule shell have been synthesized through a simple template-induced covalent assembly method, where polystyrene (PS) nanospheres were used as templates to form core/shell structured PS/Au-PDA composites, followed by core removal through tetrahydrofuran etching. Their morphology and composition were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), UV-Vis spectrophotometer and X-ray diffraction (XRD), respectively. Results showed that the Au-PDA microcapsules possessed well-fined hollow structure and uniform sizes with inner diameter of about 385?nm, shell thickness of about 30?nm, and Au nanoparticles with diameter of about 17?nm incorporated. The catalytic performance of Au-PDA hollow microcapsules was evaluated through the reduction of methylene blue (MB) dye with NaBH4 as a reducing agent. Compared to PDA/Au composites with Au nanoparticles loaded on the surface of PDA microspheres, as-prepared Au-PDA hollow microcapsules show good stability and recyclability in the catalytic experiments as the Au nanoparticles were firmly wrapped in PDA matrix, which makes the Au-PDA hollow microcapsules a practicable catalyst candidate for advanced catalytic systems. 相似文献
42.
设计并合成了 Cd 基金属有机骨架(MOF)[Cd(BDC)(BPZ)(H2O)]n (1),其中 BPZ=3,3'',5,5''-四甲基-1H,1''H-4,4''-联吡唑,H2BDC=对苯二甲酸)。化合物1具有三维孔道,其孔壁内有多个-CH3基团和自由的羧基氧原子,甲基基团的存在显著提高了MOF的疏水性和稳定性。另外,甲基和未配位的羧基氧原子可通过氢键或范德瓦耳斯作用力增强与多巴胺(DA)分子作用。1对 DA 具有灵敏的电化学传感性能。制备的 1/GCE 电极的差分脉冲伏安(DPV)测试结果显示其检测 DA 的线性范围为 0.4~764.7 μmol·L-1,检出限为56.8 nmol·L-1。在常见干扰物的存在下,电极的DPV响应电流无明显变化。电极用于实际样品检测时的回收率在95.23%~100.90%之间。 相似文献
43.
The efficient red material Sr2CeO4:Eu3+ (SCOE) has been studied as a potential thermographic phosphor for application in the single-color fluorescence thermometry technique. The temperature-dependent photoluminescence spectra and the integrated emission intensity of SCOE at different temperatures indicate that this red-light-emitting phosphor is extremely sensitive to ambient temperature. On this basis, we designed another three red materials as potential thermographic phosphors that have higher brightness and temperature sensitivity than SCOE, by means of adding Li+, Na+, and K+ ions into the lattice. 相似文献
44.
Fabrication of a superhydrophobic surface on a wood substrate 总被引:2,自引:0,他引:2
Shuliang WangJunyou Shi Changyu LiuCheng Xie Chengyu Wang 《Applied Surface Science》2011,257(22):9362-9365
A layer of lamellar superhydrophobic coating was fabricated on a wood surface through a wet chemical process. The superhydrophobic property of the wood surface was measured by contact angle (CA) measurements. The microstructure and chemical composition of the superhydrophobic coating were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). An analytical characterization revealed that the microscale roughness of the lamellar particles was uniformly distributed on the wood surface and that a zinc stearate monolayer (with the hydrophobic groups oriented outward) formed on the ZnO surface as the result of the reaction between stearic acid and ZnO. This process transformed the wood surface from hydrophilic to superhydrophobic: the water contact angle of the surface was 151°, and the sliding angle was less than 5°. 相似文献
45.
分析了以黑碳和水组成的内混合强吸收气溶胶粒子体系有效吸收系数随时间变化的规律,并讨论了不同波长、不同半径比等对有效吸收系数的影响。结果表明:波长越短,内混合气溶胶粒子体系有效吸收系数越大,在1~100 s内随时间增大的速度也越快,1~100 s内的增幅比100~1000 s内的大,最大增幅达到132.65%;不同的内外半径比对内混合气溶胶粒子体系的有效吸收系数有较大影响,内外半径比越大,有效吸收系数越大,在1~100 s有效吸收系数增加速度越快,1~100 s内增幅较大,最大增幅达到138.66%。 相似文献
46.
化学链合成氨是一种新型的、环境友好的低压合成氨技术, 其借助于载氮体的传递作用实现固氮与释氮制氨的循环, 已受到产学界的广泛关注. 构建高效、绿色的载氮体是化学链合成氨技术的关键. 本工作通过一步热解法制备了负载型钼基载氮体, 并对其释氮、固氮及稳定性进行了研究. 结果表明: 在释氮阶段, 当热解制备温度为450 ℃时, 钼基载氮体的氢化产氨速率为最大, 可达20000 μmol•g-1•h-1; 固氮过程中, 氢气的引入加快了钼基载氮体从氮气中补充晶格氮的速率, 实现了载氮体的高效再生; 历经12次循环后, 负载型钼基载氮体(制备温度为600 ℃)的产氨速率基本稳定在1500 μmol•g-1•h-1. 本研究探索了负载型钼基载氮体化学链合成氨的可行性, 结果可为新型过渡金属基载氮体的开发及其化学链合成氨研究提供理论基础. 相似文献
47.
基于刚性苯多羧酸H4BPTC (联苯-3,3'',5,5''-四甲酸),构筑了一例孔壁修饰高密度自由羧基氧的三维刚性锌基金属有机骨架:{[Zn2(BPTC)(H2O)(DMF)2]·DMF·H2O}n(SXNU-5-Zn)。SXNU-5-Zn具有好的酸碱稳定性(pH=3~8)和热稳定性。以SXNU-5-Zn构建了基于纯MOFs材料的电化学传感器(SXNU-5-Zn/GCE),其可高灵敏、选择性的检测对乙酰氨基酚(AC),检测的线性范围宽(0.02~765 μmol·L-1),检测限低至0.013 8 μmol·L-1(S/N=3)。此外,所制备的SXNU-5-Zn/GCE传感器已成功应用于实际样品复方对乙酰氨基酚片中AC含量的检测。 相似文献
48.
传统对含缺陷管道失效应力的预测方法存在误差偏大的问题。针对该问题,利用MATLAB软件建立基于PSO–GPR(particle swarm optimization–Gaussian process regression)含缺陷管道失效应力预测模型。通过对60组含缺陷管道的试验数据进行测试,发现预测结果与实测结果均在95%置信区间内,表明可以将均值作为预测结果。对预测结果进行分析表明:高斯过程回归的预测结果与实测结果的最小相对误差为0.003%,最大相对误差为1.205%,平均相对误差为0.319%,基于预测结果和实测结果的散点均落在曲线y = x的 ±1.3%误差带中,验证了高斯过程回归预测模型的准确性,为管道的工程实际应用与维修提供较为精准的判断依据。
相似文献49.
Wenfeng Zhang Gaomin Ye Donghui Liao Xuelin Chen Chengyu Lu Alireza Nezamzadeh-Ejhieh M. Shahnawaz Khan Jianqiang Liu Ying Pan Zhong Dai 《Molecules (Basel, Switzerland)》2022,27(21)
With the continuous evolution of bacteria and the constant use of traditional antibiotics, the emergence of drug-resistant bacteria and super viruses has attracted worldwide attention. Antimicrobial therapy has become the most popular and important research field at present. Coordination Polymer (CP) and/or metal-organic framework (MOF) platforms have the advantages of a high biocompatibility, biodegradability, and non-toxicity, have a great antibacterial potential and have been widely used in antibacterial treatment. This paper reviewed the mechanism and antibacterial effect of three typical MOFs (pure Ag-MOFs, hybrid Ag-MOFs, and Ag-containing-polymer @MOFs) in silver-based coordination polymers. At the same time, the existing shortcomings and future views are briefly discussed. The study on the antibacterial efficacy and mechanism of Ag-MOFs can provide a better basis for its clinical application and, meanwhile, open up a novel strategy for the preparation of more advanced Ag-contained materials with antibacterial characteristics. 相似文献
50.