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1.
Hui Qiang Tao Chen Zhuo Wang Wenqian Li Yunzhe Guo Jie Yang Xueshun Jia Hui Yang Weibo Hu Ke Wen 《中国化学快报》2021,31(12):3225-3229
The development of heterogeneous catalysts with substrate shape, size or electronic constitution selectivity is a huge challenge in photocatalysis. Reported herein is a host-guest interaction strategy to endow photocatalysts with special selectivity. By adjusting the precursors, conjugated macrocycle polymers (CMPs) with pillar[5]arene struts (CMP-1 and CMP-2) and a corresponding non-pillar[5]arene-contained conjugated organic polymer (COP-1) were prepared and the photocatalytic activities toward sulfide derivatives were investigated. The sulfides showed similar conversions when COP-1 was used as a photocatalyst, but exhibited significant differences when it turned to the CMPs. Remarkably, the conversion yield of S-1 achieved near 18 folds over the one of S-2 when CMP-2 was used as a catalyst. Mechanism studies confirmed that the “host-guest” effect of pillar[5]arene struts in CMPs was the main cause of the difference. The present work establishes CMPs as novel heterogeneous photocatalysts with substrate selectivity, and such a method will inspire the researchers concerning preparation of heterogeneous catalysts with excellent selectivity. 相似文献
2.
Feng Jundong Wang Weitai Zhao Xida Liu Wenqian Yang Yingqing 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(7):3093-3105
Journal of Radioanalytical and Nuclear Chemistry - In this paper, the effects of three coexisting ion systems (Cs, Sr), (Cr, Sr) and (Cs, Cr, Sr) on the adsorption of Sr(II) by irradiated... 相似文献
3.
Penetration depth and spatial resolution of Raman hyperspectral imaging system were studied for effective detection of benzoyl peroxide in flour. The determinations of parameters were achieved by using the single-band background-correct image of a benzoyl peroxide Raman characteristic band and a simple threshold method. The selected parameters were used to detect mixture samples with different concentrations. Percentage of detected benzoyl peroxide pixels was positively correlated to its concentration. The result shows that parameters selected in this study are effective for the detection of benzoyl peroxide additive in flour and can be used for quantitative analysis in the future. 相似文献
4.
Shuo Gu Tingting Mou Jian Chen Jing Wang Ying Zhang Meirong Cui Wenqian Hao Yue Sun Chengqin Zhang Tiantian Zhao Binbin Wei 《Journal of separation science》2022,45(10):1656-1671
Baihe-Dihuang Tang is a commonly prescribed remedy for depression. In this study, component screening with untargeted and targeted metabolomics was used to identify potential biomarkers for depression in chronic unpredictable mildly stressed rats. Using this novel identification method, the screening of organic acids, lily saponins, iridoids, and other ingredients formed the basis for subsequent metabolomics research. Baihe-Dihuang Tang supplementation in chronic unpredictable mild-stress-induced depression models, increased their body weight, sucrose preference, brain-derived neurotrophic factor deposition, and spatial exploring. Untargeted metabolomics revealed that Baihe-Dihuang Tang exerts its antidepressant effects by regulating the levels of lipids, organic acids, and its derivatives, and benzenoids in the brain, plasma, and urine of the depressed rats. Moreover, it also modulates the d -glutamine and d -glutamate metabolism and purine metabolism. Targeted metabolomics demonstrated significant reduction in l -glutamate levels in the brains of depressed rats. This could be a potential biomarker for depression. Baihe-Dihuang Tang alleviated depression by regulating the levels of l -glutamate, xanthine, and adenine in the brains of depressed rats. Together, these findings conclusively established the promising therapeutic effect of Baihe-Dihuang Tang on depression and also unraveled the underlying molecular mechanism of its potential antidepressant function. 相似文献
5.
A Selective Release System Based on Dual‐Drug‐Loaded Mesoporous Silica for Nanoparticle‐Assisted Combination Therapy
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Dr. Wenqian Wang Prof. Yongqiang Wen Prof. Liping Xu Prof. Hongwu Du Yabin Zhou Prof. Xueji Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(25):7796-7802
A selective release system was demonstrated with a dual‐cargo loaded MSNs. When stimulated by different signals (UV or H+), this system could selectively release different kinds of cargoes individually. Furthermore, this system has been used to provide a combination of chemotherapy and biotherapy for cancer treatment. This controlled release system could be an important step in the development of more effective and sophisticated nanomedicine and nanodevices, due to the possibility of selective release of a complex multi‐drug. 相似文献
6.
QI Yuxue LI Tingting HU Yajie XIANG Jiahong SHAO Wenqian CHEN Wenhua MU Xueqin LIU Suli CHEN Changyun YU Min MU Shichun 《高等学校化学研究》2022,38(5):1282-1286
Constructing atomically dispersed active sites with densely exposed and dispersed double metal-Sx catalytic sites for favorable OER catalytic activity remains rare and challenging. Herein, we design and construct a Fe1Sx@Co3S4 electrocatalyst with Fe single atoms epitaxially confined in Co3S4 nanosheets for catalyzing the sluggish alkaline oxygen evolution reaction(OER). Consequently, in ultralow concentration alkaline solutions(0.1 mol/L KOH), such a catalyst is highly active and robust for OER with low overpotentials of 300 and 333 mV at current densities of 10 and 30 mA/cm2, respectively, accompanying long-term stability without significant degradation even for 350 h. In addition, Fe1Sx@Co3S4 shows a turnover frequency(TOF) value of 0.18 s−1, nearly three times that of Co3S4(0.07 s−1), suggesting the higher atomic utilization of Fe single atoms. Mössbauer and in-situ Raman spectra confirm that the OER activity of Fe1Sx@Co3S4 origins from a thin catalytic layer of Co(Fe)OOH that interacts with trace-level Fe species in the electrolyte, creating dynamically stable active sites. Combined with experimental characterizations, it suggests that the most active S-coordinated dual-metal site configurations are 2S-bridged (Fe-Co)S4, in which Co-S and Fe-S moieties are shared with two S atoms, which can strongly regulate the adsorption energy of reaction intermediates, accelerating the OER reaction kinetics. 相似文献
7.
准确测定并控制材料中杂质元素含量是发挥高纯材料性能不可或缺的环节。辉光放电质谱法(GDMS)是准确、快速、高灵敏分析高纯材料中痕量及超痕量硫的理想方法。对GDMS分析高纯铜和镍基高温合金中痕量硫的质谱干扰进行了讨论,优化了放电电流和放电电压,采用多种标准物质对硫的相对灵敏度因子(RSF)进行了校准和验证,并与二次离子质谱法(SIMS)进行分析结果比对,验证了GDMS定量分析结果的准确性和可靠性。 相似文献
8.
Yang W Fan H Gao X Gao S Karnati VV Ni W Hooks WB Carson J Weston B Wang B 《Chemistry & biology》2004,11(4):439-448
Carbohydrate antigens with subterminal fucosylation have been implicated in the development and progression of several cancers, including hepatocellular carcinoma (HCC). Fluorescent sensors targeting fucosylated carbohydrate antigens could potentially be used for diagnostic and other applications. We have designed and synthesized a series of 26 diboronic acid compounds as potential fluorescent sensors for such carbohydrates. Among these compounds, 7q was able to fluorescently label cells expressing high levels of sLex (HEPG2) within a concentration range of 0.5 to 10 microM. This compound (7q) did not label cells expressing Lewis Y (HEP3B), nor cells without fucosylated antigens (COS7). This represents the first example of a fluorescent compound labeling cells based on cell surface carbohydrate structures. 相似文献
9.
Yuhao Yang Enzhou Liu Jun Fan Xiaoyun Hu Wenqian Hou Feng Wu Yongning Ma 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(3):478-483
TiO2 (P25)/graphene nanocomposite photocatalyst have been successfully synthesized with P25 and different ratios of graphene oxide through a green and facile one-step microwave-assisted method. Graphene oxide was restored to graphene sheets and P25 was coated on it simultaneously during the reaction. The method offers easy access to the semiconductor/graphene nanocomposites with a uniform coating and strong interactions between semiconductor and the underlying graphene sheets. The prepared P25/graphene nanocrystals hybrid has superior photocatalytic activity in the degradation of methylene blue, showing an impressive photocatalytic enhancement over P25. The improved photocatalytic activities may be attributed to increased adsorptivity of dyes, extended light absorption range, and efficient charge separation properties of a two-dimensional graphene network. 相似文献
10.
Spatiotemporal complexity of a diffusive planktonic system with prey-taxis and toxic effects
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In this paper, we propose a three-species reaction-diffusion planktonic system with prey-taxis and toxic effects, in which the zooplankton can recognize the nontoxic and toxin-producing phytoplankton and can make proper response. We first establish the existence and stability of the unique positive constant equilibrium solution by utilizing the linear stability theory for partial differential equations. Then we obtain the existence and properties of nonconstant positive solutions by detailed steady state bifurcation analysis. In addition, we obtain that change of taxis rate will result in the appearance of time-periodic solutions. Finally, we conduct some numerical simulations and give the conclusions. 相似文献