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In situ anchoring in carbon matrix of Bi_(2)O_(2)CO_(3) as a high-performance anode material for Li-ion batteries

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Rare Metals 2024年第8期43卷 3634-3646页

作者： Pu-qiang he Jun guo Hui Huang Zhong-Cheng guo Faculty of Metallurgy and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Research Center of Metallurgical Electrode Materials Engineering Technology Kunming 650106China Kunming hendera Science and Technology Co. Ltd.Kunming 650106China

Bismuth-based anode materials have been regarded as promising Li-ion batteries due to their high theoretical ***,their low conductivity and associated volume expansion inhabited their *** this work,Bi_(2)O_(2)CO_(3)@C composites were successfully synthesized by in situ anchoring of flower-like Bi_(2)O_(2)CO_(3) nanosheets on a carbon-based substrate via *** unique composited structure of Bi_2O_(2)-CO_(3)@C leads to a stable specific capacity of 547 mAh·g^(-1)after 100 cycles at a current density of 0.1 A·g^(-1).Notably,it demonstrates excellent rate capability with a specific capacity of 210 mAh·g^(-1)at 5 A·g^(-1).After 550 cycles at a current density of 0.5 A·g^(-1),a high reversible capacity of nearly 400 mAh·g^(-1)was ***,in situ X-ray diffraction measurements clearly demonstrate the conversion between Bi and Li_(3)Bi during alloying/dealloying,confirming the good electrochemical reversibility of the materials for Li *** reaction kinetics of Bi_(2)O_(2)CO_(3)@C were further investigated using galvanostatic intermittent titration ***,Bi_2O_(2)-CO_(3)@C exhibited excellent long-term stability,maintaining its high reversible capacity for over 200 cycles at a current density of 0.5 A·g^(-1)in a full cell configuration using Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) as the cathode *** result further underscores its promising potential for lithium-ion *** work may provide inspiration for the design of alloy-type negative electrode materials for high-performance rechargeable batteries.

关键词： Bi_(2)O_(2)CO_(3) Composite materials Anode materials Full batteries

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碳酸钙还原低热耦合与二氧化碳绿色原位转化

化学试剂 2024年第6期46卷 39-45页

作者：王正义唐美张冰姿蔡正宇何国强中国计量大学材料与化学学院浙江杭州310018 广西大学物理科学与工程技术学院广西南宁530004 杭州职业技术学院生态健康学院浙江杭州310018 三亚学院盛宝金融科技商学院海南三亚572022

碳酸钙(CaCO_(3))是水泥和钢铁生产等行业常见的矿产资源。然而,其高温分解产生的能源损失和二氧化碳(CO_(2))排放是亟需解决的问题。因此,提出了利用甲烷(CH_(4))、氢气(H_(2))、碳(C)和乙醇(C 2H 5OH)与亚微米级CaCO_(3)的耦合反应以... 详细信息

碳酸钙(CaCO_(3))是水泥和钢铁生产等行业常见的矿产资源。然而,其高温分解产生的能源损失和二氧化碳(CO_(2))排放是亟需解决的问题。因此,提出了利用甲烷(CH_(4))、氢气(H_(2))、碳(C)和乙醇(C 2H 5OH)与亚微米级CaCO_(3)的耦合反应以降低分解温度并实现CO_(2)原位转化,在此基础上进行了热力学和耦合产物的分析,同时在经济层面上展开了对比。研究表明,CH_(4)对CaCO_(3)分解温度的降低最显著,H_(2)次之;C被用作还原剂时副产物最少;C 2H 5OH与CaCO_(3)的耦合反应中H_(2)和一氧化碳(CO)的产率最高。通过还原剂耦合不仅可以在较低温度下再生氧化钙(CaO),还可将CO_(2)原位转化为高值产物,如H_(2)和CO,从而减少CO_(2)排放。

关键词： CaCO_(3)分解耦合反应低热还原 CO_(2)原位转化 CO_(2)排放

Potential transformation of organic matter by microbes in cryoconite,Tibetan Plateau

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Science China Earth Sciences 2024年第6期67卷 1978-1989页

作者： Bixi guo Yongqin LIU Kevin Xu ZHONG Quan SHI Chen he qiang ZheNG Ruanhong CAI State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for the Pan-Third Pole Environment Lanzhou UniversityLanzhou 730000China Department of Earth Oceanand Atmospheric SciencesUniversity of British ColumbiaVancouverBC V6T 1Z4Canada State Key Laboratory of heavy Oil Processing Petroleum Molecules Engineering Center(PMEC)China University of PetroleumBeijing 102249China State Key Laboratory for Marine Environmental Science Collage of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Fujian Key Laboratory of Marine Carbon Sequestration Xiamen UniversityXiamen 361005China

Microorganisms play an essential role in the glacier carbon cycle;how they transform organic matter in mountain glacial cryoconite remains to be ***,we applied ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)and deep sequencing of 16S rRNA gene,to investigate the temporal microbial transformation of dissolved organic matter(DOM)of the Tibetan Plateau *** the 60-day incubation,we found that DOM in cryoconite underwent a three-stage transformation,with decreasing bioavailability over *** microbial community did not change much in the first week while degrading DOM molecules that were associated with higher H/C_(wa)and lower O/C_(wa).During days 15-30,DOM composition remained stable while microbial diversity *** day 60,the DOM was microbially converted into a higher state of recalcitrance,with higher values of aromatic index,O/C_(wa),and lower H/C_(wa),which contained molecules containing more *** among various microbial taxa,like Cyanobacteria,Bacteroidota,Gammaproteobacteria,Firmicutes,and Actinobacteriota,drove the DOM transformation in *** study sheds light on the in-situ transformation of DOM composition meditated by microbial populations in cryoconite at a temporal scale,providing new insights into understanding the microbial roles in the glacier organic carbon transformation.

关键词： Cryoconite Dissolved organic matter Biodegradation Microbial community Temporal variation

Intramolecular energy transfer between chromophores separated by a rigid steroid bridge Ⅱ.Energy transfer as a probe to determine the ratio of two epimers

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Chinese Journal of Chemistry 1990年第1期8卷 61-67页

作者： TONG Zhen-he YANG guo-qiang WU Shi-Kang Institute of Photographic Chemistry,Academia Sinica,Beijing 100012 Institute of Photographic Chemistry Academia Sinica Beijing 100012

The singlet-singlet intramolecular energy transfer between naphthalene moiety and dansyl group held apart by a rigid steroid bridge was investigated for two molecules:3β-(1-naphthyl)acetoxy- 17α-dansyl-△~5androstene(3a)and 3β-(1-naphthyl)acetoxy-17β-dansyl-△~5androstene(3b).The rates of energy transfer for 3a and 3b in cyclohexane are 6.9×10~6 and 1.1×10~8s^(-1) *** difference in energy transfer rate between 3a and 3b is attributed to the different donor-acceptor separation and *** ratio of the two epimers in the synthesized product mixture was obtained from the fluorescence decay measurements.

关键词： Energy transfer as a probe to determine the ratio of two epimers

Spontaneous Infection and Periodic Evolving of Domain in a Diffusive SIS Epidemic Model

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 164-191页

作者： qiang Wen guo-qiang Ren Bin Liu School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan430074China

In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the uniform boundedness of solution is established. In addition, the spatial-temporal risk index R0(ρ) depending on the domain evolution rate ρ(t) as well as its analytical properties are discussed. The monotonicity of R0(ρ)with respect to the diffusion coefficients of the infected dI, the spontaneous infection rate η(ρ(t)y) and interval length L is investigated under appropriate conditions. Further, the existence and asymptotic behavior of periodic endemic equilibria are explored by upper and lower solution method. Finally, some numerical simulations are presented to illustrate our analytical results. Our results provide valuable information for disease control and prevention.

关键词： diffusive SIS model spontaneous infection periodically evolving domain periodic endemic equilibrium

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乳酸菌发酵对雪菊体外活性的影响研究

河西学院学报 2024年第2期40卷 41-47页

作者：王丽贺国强任晓艳魏瑞瑛党敏王恩军河西学院甘肃张掖734000

目的:为对比研究乳酸菌发酵前、后雪菊水提取物体外抗氧化活性、XOD抑制活性、抑菌活性的变化情况。方法:运用紫外-可见分光光度法测定发酵前、后水提物清除DPPH·和ABTS+能力、抑制黄嘌呤氧化酶能力;к-B法检测发酵前、后水提物对大肠... 详细信息

目的:为对比研究乳酸菌发酵前、后雪菊水提取物体外抗氧化活性、XOD抑制活性、抑菌活性的变化情况。方法:运用紫外-可见分光光度法测定发酵前、后水提物清除DPPH·和ABTS+能力、抑制黄嘌呤氧化酶能力;к-B法检测发酵前、后水提物对大肠杆菌和金黄色葡萄球菌的抑菌能力。对比研究乳酸菌发酵对雪菊水提物体外活性的影响。结果:乳酸菌发酵后雪菊水提物在0.15mg/ml DPPH·和ABTS+清除率较发酵前有明显增加。发酵前、后0.5mg/mL雪菊水提物对XOD抑制率分别为43.16%,62.19%。发酵前、后雪菊水提物对大肠杆菌的抑制性均强于金黄色葡萄球菌。相同浓度下,发酵后抑菌效果高于发酵前。结论:对乳酸菌发酵前、后雪菊水提物体外活性对比研究显示,经乳酸菌发酵后其体外抗氧化活性、抑制XOD活性、抑菌活性均增强,这为初步筛选治疗痛风的药物奠定理论基础。

关键词：雪菊水提物乳酸菌发酵体外活性痛风

Recent Advances in Pd-Catalyzed Reactions Involving the “On-Water” Mechanism

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Chinese Journal of Chemistry 2024年第5期42卷 533-542页

作者： Dong Wei guo-qiang Lin State Key Laboratory of Systems Medicine for Cancer Shanghai Cancer InstituteShanghai Key Laboratory of Systems Regulation and Clinical Translation for CancerRen Ji HospitalShanghai Jiao Tong University School of MedicineShanghai200127 China State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai200032 China

As the chemical industry grapples with the need for more eco-friendly practices,the use of water as a reaction medium is gaining attraction in organic *** mini-review delves into Pd-catalyzed reactions that utilize the "on-water" mechanism,spanning from 2019 to late *** reactions are neatly categorized into several types: (A) Catalytic C—H activations,(B) Mizoroki- heck-type reactions,(C) Suzuki-Miyaura reactions,and (D) Cyclization *** showcasing the potential of water as a sustainable reaction medium for organic transformations,these reactions leave no doubt about the importance of embracing eco-friendly practices in the chemical *** Scientists In 1980,a seminal work by Breslow et *** an acceleration of reaction rate in the Diels-Alder *** and co-workers noted a significant increase in the rate of the [2σ+2σ+2π] cycloaddition of quadricyclane and dimethyl azodicarboxylate (DMAD) when the reaction was conducted in water,as opposed to when it was carried out in organic *** term "on-water" was then coined to describe this *** strategy was further expanded to transition-metal catalyzed transformations by Ackermann in ***,Varma and Leazer disclosed a Pd-catalyzed Mizoroki-heck type arylation of alkenes with diaryliodonium salts “on-water”.The enantioselective version of "on-water" process was not realized until 2014 by the Zhou *** on,the Schaub group described a Pd-catalyzed Suzuki–Miyaura coupling reaction of electron-poor aryl chlorides with water,using only 50 ppm of catalyst *** recently,Liu and Lin extended the "on-water" strategy to Pd-catalyzed double Mizoroki-heck *** mini-review has focused on Pd-catalyzed reactions involving the “on-water” mechanism.

关键词： Pd-catalyzed “On-water” Green chemistry Aqueous reactions Mechanism Methodology and reactions Mizoroki-heck reaction Cross-coupling