期刊文献+
共找到163篇文章
< 1 2 9 >
每页显示 20 50 100
Quantum Dynamics Calculations on Isotope Effects of Hydrogen Transfer Isomerization in Formic Acid Dimer
1
作者 Fengyi Li Xiaoxi Liu +2 位作者 Xingyu Yang Jianwei Cao Wensheng Bian 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2023年第5期545-552,I0001,共9页
We present a quantum dynamics study on the isotope effects of hydro-gen transfer isomerization in the formic acid dimer,and this is achieved by multidimensional dy-namics calculations with an efficient quantum mechani... We present a quantum dynamics study on the isotope effects of hydro-gen transfer isomerization in the formic acid dimer,and this is achieved by multidimensional dy-namics calculations with an efficient quantum mechanical theoretical scheme developed by our group,on a full-dimensional neural network ab initio potential energy surface.The ground-state and fundamental tun-neling splittings for four deuterium isotopologues of formic acid dimer are considered,and the calculated results are in very good general agreement with the avail-able experimental measurements.Strong isotope effects are revealed,the mode-specific funda-mental excitation effects on the tunneling rate are evidently influenced by the deuterium sub-stitution of H atom with the substitution on the OH bond being more effective than on the CH bond.Our studies are helpful for acquiring a better understanding of isotope effects in the double-hydrogen transfer processes. 展开更多
关键词 Quantum dynamics ISOMERIZATION Isotope effect Tunneling splitting Double hydrogen transfer
下载PDF
Influence of preparation methods on the physicochemical properties and catalytic performance of MnO_x-CeO_2 catalysts for NH_3-SCR at low temperature 被引量:47
2
作者 Xiaojiang Yao Kaili Ma +4 位作者 Weixin Zou Shenggui He Jibin An Fumo Yang Lin Dong 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期146-159,共14页
This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature.... This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature. Five different methods, namely, mechanical mixing, impregnation,hydrothermal treatment, co‐precipitation, and a sol‐gel technique, were used to synthesizeMnOx‐CeO2 catalysts. The catalysts were characterized in detail, and an NH3‐SCR model reaction waschosen to evaluate the catalytic performance. The results showed that the preparation methodsaffected the catalytic performance in the order: hydrothermal treatment > sol‐gel > co‐precipitation> impregnation > mechanical mixing. This order correlated with the surface Ce3+ and Mn4+ content,oxygen vacancies and surface adsorbed oxygen species concentration, and the amount of acidic sitesand acidic strength. This trend is related to redox interactions between MnOx and CeO2. The catalystformed by a hydrothermal treatment exhibited excellent physicochemical properties, optimal catalyticperformance, and good H2O resistance in NH3‐SCR reaction. This was attributed to incorporationof Mnn+ into the CeO2 lattice to form a uniform ceria‐based solid solution (containing Mn‐O‐Cestructures). Strengthening of the electronic interactions between MnOx and CeO2, driven by thehigh‐temperature and high‐pressure conditions during the hydrothermal treatment also improved the catalyst characteristics. Thus, the hydrothermal treatment method is an efficient and environment‐friendly route to synthesizing low‐temperature denitrification (deNOx) catalysts. 展开更多
关键词 MnOx‐CeO2 catalyst Preparation method Nitrogen oxides Low‐temperature NH3‐SCR Electron interaction Surface acidity
下载PDF
Significant influence of doping effect on photovoltaic performance of efficient fullerene-free polymer solar cells 被引量:3
3
作者 Qian Kang Qi Wang +3 位作者 Cunbin An Chang He Bowei Xu Jianhui Hou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第4期40-46,共7页
The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the fur... The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the further enhancement of the PCE for polymer solar cells.Herein,we clarified the different effects of PFN and its derivatives,namely,poly[(9,9-bis(3’-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN-Br) in modifying fullerene-free PSCs.It is found for the first time that doping on IT-4F by the amino group of PFN leads to the unfavorable charge accumulation,and hence,forms a dense layer of electronegative molecule due to the poor electron transport capacity of the non-fullerene acceptor IT-4F.The electronegative molecular layer can block the electron transfer from the active layer to the interlayer and cause serious charge recombination at the active layer/cathode interface.This mechanism could be verified by the ESR measurement and electron-only devices.By replacing PFN with PFN-Br,the excessive doping effect between the cathode interlayer and IT-4F is eliminated,by which the charge transport and collection can be greatly improved.As a result,a high PCE of 13.5%was achieved in the fullerene-free PSCs. 展开更多
关键词 CATHODE INTERLAYER DOPING effect Electron transport Power conversion efficiency Electron-only device
下载PDF
Engineering Spin States of Isolated Copper Species in a Metal-Organic Framework Improves Urea Electrosynthesis 被引量:8
4
作者 Yuhang Gao Jingnan Wang +4 位作者 Yijun Yang Jian Wang Chuang Zhang Xi Wang Jiannian Yao 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第9期536-549,共14页
The catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for elec... The catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for electrocatalytic urea via a coordination strategy in a metal–organic frameworks: Cu^(Ⅲ)-HHTP and Cu^(Ⅱ)-HHTP. Cu^(Ⅲ)-HHTP exhibits an improved urea production rate of 7.78 mmol h^(−1)g^(−1) and an enhanced Faradaic efficiency of 23.09% at-0.6 V vs. reversible hydrogen electrode, in sharp contrast to Cu^(Ⅱ)-HHTP.Isolated CuⅢspecies with S = 0 spin ground state are demonstrated as the active center in Cu^(Ⅲ)-HHTP, different from Cu^(Ⅱ) with S = 1/2 in Cu^(Ⅱ)-HHTP. We further demonstrate that isolated Cu^(Ⅲ)with an empty dx2-y20orbital in Cu^(Ⅲ)-HHTP experiences a single-electron migration path with a lower energy barrier in the C–N coupling process, while Cu^(Ⅱ)with a single-spin state( d_(x2-y2)^(1)) in Cu^(Ⅱ)-HHTP undergoes a two-electron migration pathway. 展开更多
关键词 ELECTROCATALYSIS Urea synthesis Metal-organic framework Spin catalysis C-N coupling
下载PDF
Large scale fabrication of nitrogen vacancy-embedded diamond nanostructures for single-photon source applications 被引量:1
5
作者 姜倩晴 李无瑕 +6 位作者 唐成春 常彦春 郝婷婷 潘新宇 叶海涛 李俊杰 顾长志 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第11期594-599,共6页
Some color centers in diamond can serve as quantum bits which can be manipulated with microwave pulses and read out with laser,even at room temperature.However,the photon collection efficiency of bulk diamond is great... Some color centers in diamond can serve as quantum bits which can be manipulated with microwave pulses and read out with laser,even at room temperature.However,the photon collection efficiency of bulk diamond is greatly reduced by refraction at the diamond/air interface.To address this issue,we fabricated arrays of diamond nanostructures,differing in both diameter and top end shape,with HSQ and Cr as the etching mask materials,aiming toward large scale fabrication of single-photon sources with enhanced collection efficiency made of nitrogen vacancy(NV) embedded diamond.With a mixture of O2 and CHF3 gas plasma,diamond pillars with diameters down to 45 nm were obtained.The top end shape evolution has been represented with a simple model.The tests of size dependent single-photon properties confirmed an improved single-photon collection efficiency enhancement,larger than tenfold,and a mild decrease of decoherence time with decreasing pillar diameter was observed as expected.These results provide useful information for future applications of nanostructured diamond as a single-photon source. 展开更多
关键词 diamond fabrication pillar diameters photon etching collection microwave decreasing toward
下载PDF
Ring Polymer Molecular Dynamics of the C(^(1)D)+H_(2) Reaction on the Most Recent Potential Energy Surfaces
6
作者 Jianwei Cao Yanan Wu Wensheng Bian 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2021年第6期833-842,I0003,I0004,共12页
Ring polymer molecular dynamics(RPMD)calculations for the C(^(1)D)+H_(2)reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces(PESs)recently constructed by our group,which are unique in very g... Ring polymer molecular dynamics(RPMD)calculations for the C(^(1)D)+H_(2)reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces(PESs)recently constructed by our group,which are unique in very good descriptions of the regions around conical intersections and of van der Waals(vdW)interactions.The calculated reaction thermal rate coefficients are in very good agreement with the latest experimental results.The rate coefficients obtained from the ground˜a^(1)A′ZMB-a PES are much larger than those from the previous RKHS PES,which can be attributed to that the vdW saddles on our PESs have very different dynamical effects from the vdW wells on the previous PESs,indicating that the RPMD approach is able to include dynamical effects of the topological structures caused by vdW interactions.The importance of the excited˜b^(1)A′′ZMB-b PES and quantum effects in the title reaction is also underscored. 展开更多
关键词 Rate coefficients Ring polymer molecular dynamics Complex-forming reactions Potential energy surfaces van der Waals interactions
下载PDF
Photodissociation Branching Ratios of 12C^16O from 108000 cm^-1 to 113200 cm^-1 Measured by Two-Color VUV-VUV Laser Pump-Probe Time-Slice Velocity-Map Ion Imaging Method:Observation of Channels for Producing O(1D)
7
作者 Hong Gao Yu Song +1 位作者 William M.Jackson Cheuk-Yiu Ng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第1期91-100,共10页
The photoabsorption and photodissociation of carbon monoxide(CO)in the vacuum ultraviolet(VUV)region is one of the most important photochemical processes in the interstellar medium,thus it has attracted numerous exper... The photoabsorption and photodissociation of carbon monoxide(CO)in the vacuum ultraviolet(VUV)region is one of the most important photochemical processes in the interstellar medium,thus it has attracted numerous experimental and theoretical studies.Here,we employed the two-color VUV-VUV laser pump-probe time-slice velocity-map ion imaging method to measure the relative branching ratios[C(3P0)+O(1D)]/{[C(3P0)+O(3P)]+[C(3P0)+O(1D)]}and[C(3P2)+O(1D)]/{[C(3P2)+O(3P)]+[C(3P2)+O(1D)]}in the VUV photoexcitation energy range of 108000-113200 cm^−1.Here,one tunable VUV laser beam is used to excite CO to speci c rovibronic states,and a second independently tunable VUV laser beam is used to state-selectively ionize C(3P0)and C(3P2)for detection.State-selective photoionization through the 1VUV+1UV/visible resonance-enhanced multiphoton ionization scheme has greatly enhanced the detection sensitivity,which makes many new weak absorption bands observable in the current study.The branching ratio measurement shows that the spin-forbidden channels C(3P0)+O(1D)and C(3P2)+O(1D)only open at several discrete narrow energy windows.This might be caused by certain accidental resonanceenhanced spin-orbit interactions between the directly excited Rydberg states and valence states of triplet type which nally dissociate into the spin-forbidden channels. 展开更多
关键词 Carbon monoxide PHOTODISSOCIATION Vacuum ultraviolet Branching ratio
下载PDF
Structural Dynamics of Amyloid β Peptide Binding to Acetylcholine Receptor and Virtual Screening for Effective Inhibitors
8
作者 Yan-jun Hou Xuan Zheng +3 位作者 Hong-mei Zhong Feng Chen Gui-vang Yan Kai-cong Cai 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2021年第3期323-333,I0048,共12页
The interaction between Amyloid β(Aβ) peptide and acetylcholine receptor is the key for our understanding of how Aβ fragments block the ion channels within the synapses and thus induce Alzheimer’s disease.Here,mol... The interaction between Amyloid β(Aβ) peptide and acetylcholine receptor is the key for our understanding of how Aβ fragments block the ion channels within the synapses and thus induce Alzheimer’s disease.Here,molecular docking and molecular dynamics(MD)simulations were performed for the structural dynamics of the docking complex consisting of Aβ and α7-n ACh R(α7 nicotinic acetylcholine receptor),and the inter-molecular interactions between ligand and receptor were revealed.The results show that Aβ_(25-35) is bound toα7-n ACh R through hydrogen bonds and complementary shape,and the Aβ_(25-35) fragments would easily assemble in the ion channel of α7-n ACh R,then block the ion transfer process and induce neuronal apoptosis.The simulated amide-I band of Aβ_(25-35) in the complex is located at 1650.5 cm^(-1),indicating the backbone of Aβ_(25-35) tends to present random coil conformation,which is consistent with the result obtained from cluster analysis.Currently existing drugs were used as templates for virtual screening,eight new drugs were designed and semi-flexible docking was performed for their performance.The results show that,the interactions between new drugs and α7-n ACh R are strong enough to inhibit the aggregation of Aβ_(25-35) fragments in the ion channel,and also be of great potential in the treatment of Alzheimer’s disease. 展开更多
关键词 Amyloidβpeptide Acetylcholine receptor Molecular dynamics simulation Molecular docking Virtual screening
下载PDF
Research advances in smart responsive-hydrogel dressings with potential clinical diabetic wound healing properties 被引量:1
9
作者 Ying Chen Xing Wang +5 位作者 Sheng Tao Qi Wang Pan-Qin Ma Zi-Biao Li Yun-Long Wu Da-Wei Li 《Military Medical Research》 SCIE CAS CSCD 2024年第4期543-566,共24页
The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem.Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds ... The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem.Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds due to their excellent hydrophilicity,good drug-loading ability and sustained drug release properties.As a typical example,hyaluronic acid dressing(Healoderm)has been demonstrated in clinical trials to improve wound-healing efficiency and healing rates for diabetic foot ulcers.However,the drug release and degradation behavior of clinically-used hydrogel wound dressings cannot be adjusted according to the wound microenvironment.Due to the intricacy of diabetic wounds,antibiotics and other medications are frequently combined with hydrogel dressings in clinical practice,although these medications are easily hindered by the hostile environment.In this case,scientists have created responsive-hydrogel dressings based on the microenvironment features of diabetic wounds(such as high glucose and low pH)or combined with external stimuli(such as light or magnetic field)to achieve controllable drug release,gel degradation,and microenvironment improvements in order to overcome these clinical issues.These responsive-hydrogel dressings are anticipated to play a significant role in diabetic therapeutic wound dressings.Here,we review recent advances on responsive-hydrogel dressings towards diabetic wound healing,with focus on hydrogel structure design,the principle of responsiveness,and the behavior of degradation.Last but not least,the advantages and limitations of these responsive-hydrogels in clinical applications will also be discussed.We hope that this review will contribute to furthering progress on hydrogels as an improved dressing for diabetic wound healing and practical clinical application. 展开更多
关键词 Responsive-hydrogel Diabetic wound ANTI-INFLAMMATION Tissue remodeling
下载PDF
High-Performanceα-Diimine Nickel Complexes for Facile Access of PE Elastomers with Exceptional Material Properties
10
作者 Li-Dong Qin Xin-Yu Wang +5 位作者 Qaiser Mahmood Zhi-Xin Yu Yi-Zhou Wang Song Zou Tong-Ling Liang Wen-Hua Sun 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第5期620-635,I0008,共17页
For practicable elastomeric polyethylene,achieving high catalyst thermal stability and activity,along with precise control of polymer properties such as branching density,molecular weights,and distribution,is crucial ... For practicable elastomeric polyethylene,achieving high catalyst thermal stability and activity,along with precise control of polymer properties such as branching density,molecular weights,and distribution,is crucial but challenging.In this study,two sets of symmetricalα-diimine nickel complexes,each comprising four nickel bromide or chloride complexes,were synthesized and investigated their performance for ethylene polymerization under various reaction conditions.Upon activation with either Et2AlCl or MMAO cocatalysts,these complexes displayed not only high activity but also generated high molecular weight polyethylenes with controlled polydispersity and a substantial number of branches.The catalyst with the least steric hindrance displayed the remarkable high activity(up to 1.2×10^(7) g·mol^(-1)·h^(-1)).Notably,nickel bromides demonstrated higher activity compared to their chloride counterparts.The investigation into the effect of reaction temperature on catalytic performance revealed that NiBrMe-MMAO system displayed high thermal stability(activity up to 2.51×10^(6) g·mol^(-1)·h^(-1) at 100℃)and consistently yielded high polymer molecular weights with narrow polydispersity over a broad temperature range of 30-100℃.Of significant note,mechanical analysis of the resulting polyethylene demonstrated excellent ultimate tensile strength and high strain at break.Particularly,the polyethylene sample prepared at 100℃exhibited ultimate tensile strength up to 10 MPa with 1863%maximum strain at break and a strain recovery of up to 54.9%after ten cycles at a fixed strain of 300%,indicating excellent material properties of prepared thermoplastic polyethylene elastomers(TPE). 展开更多
关键词 Thermoplastic polyethylene elastomers α-Diimine nickel pre-catalysts Ethylene polymerization Mechanical properties Highly branched polyethylene
原文传递
Recovery and in-situ reduction of precious metals by graphdiyne and graphdiyne oxide for antibacterial use
11
作者 Ming-Ji Jiang Ya-Na Zhang +3 位作者 Ling-Shen Meng Jing Kang Yong-Jun Li Alideertu Dong 《Rare Metals》 SCIE EI CAS CSCD 2024年第4期1747-1757,共11页
Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH valu... Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH values and interfering ions.Under strong acidity at pH=1,these two agents demonstrate high select recovery towards the three precious metal ions,which could be insitu reduced to nanoparticles(NPs).In addition,superparamagnetic Fe_(3)O_(4)NPs are deposited on the surfaces of GDY and GDYO.The magnetic responses enable GDYFe_(3)O_(4)to recover precious metals conveniently and efficiently by the aid of an external magnetic field.This study also confirms the antibacterial activity of the as-recovered NPs deposited on GDY and GDYO against Escherichia coli and Staphylococcus aureus(1×10^(5)colony-forming unit(CFU)·mL^(-1)),and the antibacterial rates are 100%.This strategy of recovering precious metals and subsequently reusing to combat pathogens will be of great significance for environmental remediation and biomedical applications. 展开更多
关键词 Graphdiyne In-situ reduction RECOVERY Precious metals ANTIBACTERIAL
原文传递
Core-shell meso/microporous carbon host for sulfur loading toward applications in lithium-sulfur batteries 被引量:4
12
作者 Juan Zhang Huan Ye +1 位作者 Yaxia Yin Yuguo Guo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第3期308-314,共7页
Lithium-sulfur(Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries.However,sulfur cathodes suffer from inherent problems of its poor electronic conductivity and... Lithium-sulfur(Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries.However,sulfur cathodes suffer from inherent problems of its poor electronic conductivity and the shuttling of highly dissoluble lithium polysulfides generated during the cycles.Loading sulfur into porous carbons has been proved to be an effective approach to alleviate these issues.Mesoporous and microporous carbons have been widely used for sulfur accommodation,but mesoporous carbons have poor sulfur confinement,whereas microporous carbons are impeded by low sulfur loading rates.Here,a core-shell carbon,combining both the merits of mesoporous carbon with large pore volume and microporous carbon with effective sulfur confinement,was prepared by coating the mesoporous CMK-3 with a microporous carbon(MPC) shell and served as the carbon host(CMK-3 @MPC) to accommodate sulfur.After sulfur infusion,the as-obtained S/(CMK-3@MPC) cathode delivered a high initial capacity of up to 1422 mAh·g-1 and sustained 654 mAh·g-1 reversible specific capacity after 36 cycles at 0.1 C.The good performance is ascribed to the unique core-shell structure of the CMK-3@MPC matrix,in which sulfur can be effectively confined within the meso/microporous carbon host,thus achieving simultaneously high electrochemical utilization. 展开更多
关键词 core-shell structure microporous carbon coating mesoporous carbon lithium-sulfur batteries sulfur cathode
下载PDF
Environmental chamber study of the photochemical reaction of ethyl methyl sulfide and NO_x 被引量:2
13
作者 WANG Kun DU Lin GE Maofa 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第2期137-141,共5页
A series of experiments were conducted in a self-made smog chamber at (300 + 1) K and 1.01 × 10^5 Pa to simulate the photochemical reaction of ethyl methyl sulfide (EMS) and NOx. The results showed that the ... A series of experiments were conducted in a self-made smog chamber at (300 + 1) K and 1.01 × 10^5 Pa to simulate the photochemical reaction of ethyl methyl sulfide (EMS) and NOx. The results showed that the higher the initial concentration of EMS, the more ozone was generated in the simulative reactions. It was found that the light intensity plays a very important role in the evaluation of ozone formation potential for EMS. The parameters of d(Oa-NO) and IR (incremental reactivity) were used to quantify the potential of EMS on ozone formation. The obtained maximum IR values in this article for the five simulative reactions were 1.55 × 10^-2, 0.99 × 10^-2, 1.36 × 10^-2, 2.47 × 10^-2, and 1.65 × 10^-2, respectively. A comparison between the results we obtained here and the results we obtained previously for di-tert-butyl peroxide and acetylene showed that the potential reactivity of EMS on ozone formation was at a relatively low level. 展开更多
关键词 smog chamber photochemical reaction ethyl methyl sulfide incremental reactivity
下载PDF
An Efficient Trap Passivator for Perovskite Solar Cells:Poly(propylene glycol)bis(2‑aminopropyl ether) 被引量:2
14
作者 Ningli Chen Xiaohui Yi +6 位作者 Jing Zhuang Yuanzhi Wei Yanyan Zhang Fuyi Wang Shaokui Cao Cheng Li Jizheng Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2020年第12期251-263,共13页
Perovskite solar cells(PSCs)are regarded as promising candidates for future renewable energy production.High-density defects in the perovskite films,however,lead to unsatisfactory device performances.Here,poly(propyle... Perovskite solar cells(PSCs)are regarded as promising candidates for future renewable energy production.High-density defects in the perovskite films,however,lead to unsatisfactory device performances.Here,poly(propylene glycol)bis(2-aminopropyl ether)(PEA)additive is utilized to passivate the trap states in perovskite.The PEA molecules chemically interact with lead ions in perovskite,considerably passivate surface and bulk defects,which is in favor of charge transfer and extraction.Furthermore,the PEA additive can efficiently block moisture and oxygen to prolong the device lifetime.As a result,PEA-treated MAPbI3(MA:CH3NH3)solar cells show increased power conversion efficiency(PCE)(from 17.18 to 18.87%)and good longterm stability.When PEA is introduced to(FAPbI3)1-x(MAPbBr3)x(FA:HC(NH2)2)solar cells,the PCE is enhanced from 19.66 to 21.60%.For both perovskites,their severe device hysteresis is efficiently relieved by PEA. 展开更多
关键词 Defects Grain boundaries PASSIVATION Stability Perovskite solar cells
下载PDF
Natural Products Diversity of Marine Ascidians(Tunicates;Ascidiacea)and Successful Drugs in Clinical Development 被引量:2
15
作者 Satheesh Kumar Palanisamy N.M.Rajendran Angela Marino 《Natural Products and Bioprospecting》 CAS 2017年第1期1-111,共111页
This present study reviewed the chemical diversity of marine ascidians and their pharmacological applications,challenges and recent developments in marine drug discovery reported during 1994–2014,highlighting the str... This present study reviewed the chemical diversity of marine ascidians and their pharmacological applications,challenges and recent developments in marine drug discovery reported during 1994–2014,highlighting the structural activity of compounds produced by these specimens.Till date only 5%of living ascidian species were studied from\3000 species,this study represented from family didemnidae(32%),polyclinidae(22%),styelidae and polycitoridae(11–12%)exhibiting the highest number of promising MNPs.Close to 580 compound structures are here discussed in terms of their occurrence,structural type and reported biological activity.Anti-cancer drugs are the main area of interest in the screening of MNPs from ascidians(64%),followed by anti-malarial(6%)and remaining others.FDA approved ascidian compounds mechanism of action along with other compounds status of clinical trials(phase 1 to phase 3)are discussed here in.This review highlights recent developments in the area of natural products chemistry and biotechnological approaches are emphasized. 展开更多
关键词 Cancer Cytotoxicity DIVERSITY METABOLITES PHARMACOLOGY
下载PDF
Efficient Syntheses of 2-Substituted Benzimidazoles and Benzoxazoles from β-Keto Esters 被引量:2
16
作者 XIAO Li-wei ZHANG Min SUN Wen-hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第2期228-231,共4页
An efficient synthetic method was developed to synthesize 2-substituted benzimidazoles and benzo- xazoles with β-keto esters as starting materials under mild reaction conditions, during which other functional groups ... An efficient synthetic method was developed to synthesize 2-substituted benzimidazoles and benzo- xazoles with β-keto esters as starting materials under mild reaction conditions, during which other functional groups are bearable from reactants to products. 展开更多
关键词 BENZIMIDAZOLE BENZOXAZOLE β-Keto ester
下载PDF
SYNTHESIS,CHARACTERIZATION AND CATALYTIC BEHAVIOR OF DIMERIC Co(Ⅱ) AND Ni(Ⅱ) COMPLEXES CONTAINING N,N’-(PHENYL-2-PYRIDINYLMETHYLENE)-3,3’,5,5’-TETRAMETHYLBENZIDINE 被引量:1
17
作者 孙文华 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第5期539-545,共7页
The N,N -(phenyl-2-pyridinylmethylene)-3,3 ,5,5 -tetramethylbenzidine and its dimeric Co(Ⅱ)and Ni(Ⅱ) complexes were synthesized.The organic compound was characterized by elemental analyses,IR and NMR spectra,while t... The N,N -(phenyl-2-pyridinylmethylene)-3,3 ,5,5 -tetramethylbenzidine and its dimeric Co(Ⅱ)and Ni(Ⅱ) complexes were synthesized.The organic compound was characterized by elemental analyses,IR and NMR spectra,while the bimetal complexes were determined by elemental analyses,IR spectra as well as the single-crystal X-ray diffraction.The nickel complex showed high activity for ethylene polymerization and its cobalt analogue showed negligible active in ethylene activation. 展开更多
关键词 Bis-pyridinylimino ligand Nickel complex Cobalt complex Ethylene polymerization
下载PDF
Scientific and technological challenges toward application of lithium–sulfur batteries 被引量:1
18
作者 殷雅侠 姚胡蓉 郭玉国 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第1期205-211,共7页
Recent progress in improving Li-S batteries' cathodes, anodes, and electrolytes via different approaches is summa- rized. The poor conductivity of sulfur cathodes, the dissolution of polysulfide intermediates, and th... Recent progress in improving Li-S batteries' cathodes, anodes, and electrolytes via different approaches is summa- rized. The poor conductivity of sulfur cathodes, the dissolution of polysulfide intermediates, and the high reactivity of metal Li anodes currently motivate a great deal of research. Urgent challenges concerning Li anodes are also emphasized. 展开更多
关键词 lithium-sulfur batteries sulfur cathode lithium anode ELECTROLYTE
下载PDF
Systematical Study on Photodissociation Dynamics of BrCN from 225 nm to 260 nm
19
作者 Tonghui Yin Liying Ma +1 位作者 Hong Gao Min Cheng 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第1期86-94,I0063,共10页
The photodissociation dynamics of Br-C bond cleavage for BrCN in the wavelength region from 225 nm to 260 nm has been studied by our homebuilt time-slice velocity-map imaging setup.The images for both of the ground st... The photodissociation dynamics of Br-C bond cleavage for BrCN in the wavelength region from 225 nm to 260 nm has been studied by our homebuilt time-slice velocity-map imaging setup.The images for both of the ground state Br(^(2)P_(3/2))and spin-orbit excited Br^(*)(^(2)P_(1/2))channels are obtained at several photodissociation wavelengths.From the analysis of the translational energy release spectra,the detailed vibrational and rotational distributions of CN products have been measured for both of the Br and Br^(*) channels.It is found that the internal excitation of the CN products for the Br^(*) channel is colder than that for the Br channel.The most populated vibrational levels of the CN products are v=0 and 1 for the Br and Br^(*) channels,respectively.For the Br channel,the photodissociation dynamics at longer wavelengths are found to be different from those at shorter wavelengths,as revealed by their dramatically different vibrational and rotational excitations of the CN products. 展开更多
关键词 Photodissociation dynamics Cyanogen bromide Ro-vibronic distribution Energy partitioning Velocity-map imaging
下载PDF
Time-Resolved FTIR Study on the Reaction of CHCl2 with NO2
20
作者 Kun-hui Liu Chun-fan Yang +2 位作者 Huan Wang Wei-qiang Wu Hong-mei Su 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第2期134-138,共5页
The environmentally important free radical reaction of chlorinated methyl CHCl2 with NO2 was investigated by step-scan time-resolved FTIR (TR-FTIR) emission spectroscopy. Vibrationally excited products of CHClO, NO,... The environmentally important free radical reaction of chlorinated methyl CHCl2 with NO2 was investigated by step-scan time-resolved FTIR (TR-FTIR) emission spectroscopy. Vibrationally excited products of CHClO, NO, CO, and HCl are observed in the high-resolution IR emission spectra and three possible reaction channels are therefore elucidated. In particular, the product CO is newly detected and the product HCl is identified explicitly as a yield from the CHCl2+NO2 reaction, taking advantage of the sensitive detection of HCl and CO with TR-FTIR. These results are of particular interests to understand the related realistic chemical processes including atmospheric photochemistry, biofuel combustion, waste destruction, and smoking fire. 展开更多
关键词 TR-FTIR Dichloromethyl NO2 Reaction product channel
下载PDF
上一页 1 2 9 下一页 到第
使用帮助 返回顶部