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The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation 被引量:3
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作者 Lei ZHU Chunsong LU +5 位作者 Xiaoqi XU Xin HE junjun li Shi LUO Yuan WANG Fan WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期173-187,共15页
The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameteri... The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization. 展开更多
关键词 large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution
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Morphological disruption and visual tuning alterations in the primary visual cortex in glaucoma(DBA/2J)mice 被引量:1
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作者 Yin Yang Zhaoxi Yang +9 位作者 Maoxia Lv Ang Jia junjun li Baitao liao Jing’an Chen Zhengzheng Wu Yi Shi Yang Xia Dezhong Yao Ke Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第1期220-225,共6页
Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the pr... Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma. 展开更多
关键词 DBA/2J DEGENERATION gamma band oscillations GLAUCOMA primary visual cortex(V1) RETINA single-unit recording tuning curve
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A comparative study of the anti-fatigue activity of extracts from different parts of Cistanche tubulosa(Schenk)Wight
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作者 Jianteng Dong junjun li +7 位作者 Yizhou liu lingwen Cui Xiangning liu Gang Wang Qixin Wang David N.Criddle Pengfei Tu Chun li 《Journal of Traditional Chinese Medical Sciences》 CAS 2024年第2期222-231,共10页
Objective:To evaluate the anti-fatigue effects of different extracts from Cistanche tubulosa(Schenk)Wight(C.tubulosa,Rou Cong Rong),focusing on central and exercise-induced fatigue in mice.This study investigated the ... Objective:To evaluate the anti-fatigue effects of different extracts from Cistanche tubulosa(Schenk)Wight(C.tubulosa,Rou Cong Rong),focusing on central and exercise-induced fatigue in mice.This study investigated the pharmacological effects of the total oligosaccharides,polysaccharides,and phenylethanoid glycosides(CPhGs)extracted from C.tubulosa.Methods: Models of sleep deprivation and forced swimming fatigue were established to simulate central and exercise-induced fatigue.The mice were treated with different extracts of C.tubulosa,and their effects were assessed using behavioral tests to measure exercise capacity,learning,and memory function.Biochemical analyses were performed to evaluate the changes in serum and brain neurotransmitter levels,liver and muscle glycogen storage,and various fatigue-related biomarkers.Results: This study found that treatment with C.tubulosa extract improved exercise capacity,learning,and memory in mice.Total oligosaccharides from C.tubulosa enhanced adrenocorticotropic hormone,cholinesterase,and thyroid-stimulating hormone levels,reduced cortisol levels in central fatigue models,and ameliorated biochemical markers of exercise-induced fatigue,including lowering lactic acid,blood urea nitrogen,and malondialdehyde levels.Among the tested extracts,the total oligosaccharides showed the most comprehensive anti-fatigue effects.Conclusion: The anti-fatigue effects of C.tubulosa,particularly those of its total oligosaccharides,are pronounced in both central and exercise-induced fatigue.These effects are mediated by the regulation of neurotransmitter levels,enhancement of glycogen storage,and improvement of antioxidant enzyme activity,suggesting potential therapeutic benefits in fatigue-related conditions. 展开更多
关键词 Cistanche tubulosa ANTI-FATIGUE Central fatigue Exercise fatigue OLIGOSACCHARIDES
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Physiological and molecular bases of the boron deficiency response in tomatoes
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作者 junjun li Huihui Fan +8 位作者 Qianqian Song lili Jing Hao Yu Ruishan li Ping Zhang Fei liu Weimin li liangliang Sun Jin Xu 《Horticulture Research》 SCIE CSCD 2023年第12期26-44,共19页
Boron is an essential microelement for plant growth.Tomato is one of the most cultivated fruits and vegetables in the world,and boron deficiency severely inhibits its yield and quality.However,the mechanism of tomato ... Boron is an essential microelement for plant growth.Tomato is one of the most cultivated fruits and vegetables in the world,and boron deficiency severely inhibits its yield and quality.However,the mechanism of tomato in response to boron deficiency remains largely unclear.Here,we investigated the physiological and molecular bases of the boron deficiency response in hydroponically grown tomato seedlings.Boron deficiency repressed the expression of genes associated with nitrogen metabolism,while it induced the expression of genes related to the pentose phosphate pathway,thereby altering carbon flow to provide energy for plants to cope with stress.Boron deficiency increased the accumulation of copper,manganese and iron,thereby maintaining chlorophyll content and photosynthetic efficiency at the early stage of stress.In addition,boron deficiency downregulated the expression of genes involved in cell wall organization and reduced the contents of pectin and cellulose in roots,ultimately retarding root growth.Furthermore,boron deficiency markedly altered phytohormone levels and signaling pathways in roots.The contents of jasmonic acid,jasmonoy1-L-isoleucine,trans-zeatin riboside,abscisic acid,salicylic acid,and SA glucoside were decreased;in contrast,the contents of isopentenyladenine riboside and ethylene precursor 1-aminocyclopropane-1-carboxylic acid were increased in the roots of boron-deficient tomato plants.These results collectively indicate that tomato roots reprogram carbon/nitrogen metabolism,alter cell wall components and modulate phytohormone pathways to survive boron deficiency.This study provides a theoretical basis for further elucidating the adaptive mechanism of tomato in response to boron deficiency. 展开更多
关键词 BORON BASES thereby
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Integrating coaxial electrospinning and 3D printing technologies for the development of biphasic porous scaffolds enabling spatiotemporal control in tumor ablation and osteochondral regeneration
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作者 Wenbao He Chunlin li +7 位作者 Shitong Zhao Zhendong li Jing Wu junjun li Haichao Zhou Yunfeng Yang Yong Xu Huitang Xia 《Bioactive Materials》 SCIE CSCD 2024年第4期338-353,共16页
The osteochondral defects(OCDs)resulting from the treatment of giant cell tumors of bone(GCTB)often present two challenges for clinicians:tumor residue leading to local recurrence and non-healing of OCDs.Therefore,thi... The osteochondral defects(OCDs)resulting from the treatment of giant cell tumors of bone(GCTB)often present two challenges for clinicians:tumor residue leading to local recurrence and non-healing of OCDs.Therefore,this study focuses on developing a double-layer PGPC-PGPH scaffold using shell-core structure nanofibers to achieve“spatiotemporal control”for treating OCDs caused by GCTB.It addresses two key challenges:eliminating tumor residue after local excision and stimulating osteochondral regeneration in non-healing OCD cases.With a shell layer of protoporphyrin IX(PpIX)/gelatin(GT)and inner cores containing chondroitin sulfate(CS)/poly(lactic-co-glycolic acid)(PLGA)or hydroxyapatite(HA)/PLGA,coaxial electrospinning technology was used to create shell-core structured PpIX/GT-CS/PLGA and PpIX/GT-HA/PLGA nanofibers.These nanofibers were shattered into nano-scaled short fibers,and then combined with polyethylene oxide and hyaluronan to formulate distinct 3D printing inks.The upper layer consists of PpIX/GT-CS/PLGA ink,and the lower layer is made from PpIX/GT-HA/PLGA ink,allowing for the creation of a double-layer PGPC-PGPH scaffold using 3D printing technique.After GCTB lesion removal,the PGPC-PGPH scaffold is surgically implanted into the OCDs.The sonosensitizer PpIX in the shell layer undergoes sonodynamic therapy to selectively damage GCTB tissue,effectively eradicating residual tumors.Subsequently,the thermal effect of sonodynamic therapy accelerates the shell degradation and release of CS and HA within the core layer,promoting stem cell differentiation into cartilage and bone tissues at the OCD site in the correct anatomical position.This innovative scaffold provides temporal control for anti-tumor treatment followed by tissue repair and spatial control for precise osteochondral regeneration. 展开更多
关键词 Spatiotemporal control Giant cell tumors of bone Shell-core structure Double-layered scaffold Osteochondral regeneration
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Strategies of functionalized GelMA-based bioinks for bone regeneration:Recent advances and future perspectives
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作者 Yaru Zhu Xingge Yu +5 位作者 Hao liu junjun li Mazaher Gholipourmalekabadi Kaili lin Changyong Yuan Penglai Wang 《Bioactive Materials》 SCIE CSCD 2024年第8期346-373,共28页
Gelatin methacryloyl(GelMA)hydrogels is a widely used bioink because of its good biological properties and tunable physicochemical properties,which has been widely used in a variety of tissue engineering and tissue re... Gelatin methacryloyl(GelMA)hydrogels is a widely used bioink because of its good biological properties and tunable physicochemical properties,which has been widely used in a variety of tissue engineering and tissue regeneration.However,pure GelMA is limited by the weak mechanical strength and the lack of continuous osteogenic induction environment,which is difficult to meet the needs of bone repair.Moreover,GelMA hydrogels are unable to respond to complex stimuli and therefore are unable to adapt to physiological and pathological microenvironments.This review focused on the functionalization strategies of GelMA hydrogel based bioinks for bone regeneration.The synthesis process of GelMA hydrogel was described in details,and various functional methods to meet the requirements of bone regeneration,including mechanical strength,porosity,vascularization,osteogenic differentiation,and immunoregulation for patient specific repair,etc.In addition,the response strategies of smart GelMA-based bioinks to external physical stimulation and internal pathological microenvironment stimulation,as well as the functionalization strategies of GelMA hydrogel to achieve both disease treatment and bone regeneration in the presence of various common diseases(such as inflammation,infection,tumor)are also briefly reviewed.Finally,we emphasized the current challenges and possible exploration directions of GelMA-based bioinks for bone regeneration. 展开更多
关键词 GelMA FUNCTIONALIZATION Bone regeneration STIMULI-RESPONSIVE 3D bioprinting
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导电金属有机框架材料在电催化中的成就,挑战和机遇 被引量:11
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作者 高增强 王聪勇 +3 位作者 李俊俊 朱亚廷 张志成 胡文平 《物理化学学报》 SCIE CAS CSCD 北大核心 2021年第7期124-137,共14页
开发用于各种能量转化过程的新型催化剂对于满足绿色和可持续能源的需求至关重要。由于其具有可调节的晶体结构,显著的化学和物理性质以及稳定性,金属有机骨架(MOFs)已经广泛应用于电化学能量转换领域,比如CO_(2)还原反应、N_(2)还原反... 开发用于各种能量转化过程的新型催化剂对于满足绿色和可持续能源的需求至关重要。由于其具有可调节的晶体结构,显著的化学和物理性质以及稳定性,金属有机骨架(MOFs)已经广泛应用于电化学能量转换领域,比如CO_(2)还原反应、N_(2)还原反应、析氧反应、析氢反应和氧还原反应。更重要的是,MOFs具有可调节的化学环境、孔径和孔隙率,这些性质将促进反应物在多孔网络中的扩散,从而改善其电催化性能。但是,由于高的电荷转移能垒和受限的自由载流子,大多数MOFs展示了差的导电性,阻碍了其多样化应用。在先前的报道中,MOFs常被用作多孔基质来限制纳米颗粒生长或经退火处理作为共掺杂电催化剂。而导电MOFs不仅结合了传统MOFs的优点,还具有电子导电性和高电催化活性,使其无需退火处理就可以通过电子或离子途径实现导电,从而极大提高了电催化性能,这有助于拓宽其在电化学能源领域或其他方面的潜在应用。在一些催化反应中,导电MOFs的催化活性甚至超过了商业化的RuO_(2)催化剂或Pt基催化剂。本文主要总结了构建导电MOFs的机制,并概述了其合成方法,如水/溶剂热合成和界面辅助合成。此外,本文阐述了导电MOFs在电催化应用中的最新研究进展。值得一提的是,导电MOFs的形态和结构可改变底物与MOFs之间的界面接触,从而影响其催化性能,需要进一步深入研究。基于系统的合成策略,在未来可以根据各种电催化反应的需求设计合成更多的导电MOFs。高性能的导电MOF基催化剂将有望获得突破。 展开更多
关键词 导电金属有机框架 电催化 二氧化碳还原反应 氮还原反应 析氧反应 析氢反应 氧还原反应
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Recent Advances in Interface Engineering for Electrocatalytic CO_(2) Reduction Reaction 被引量:13
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作者 junjun li Sulaiman Umar Abbas +2 位作者 Haiqing Wang Zhicheng Zhang Wenping Hu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第12期499-533,共35页
Electrocatalytic CO_(2) reduction reaction(CO_(2) RR) can store and transform the intermittent renewable energy in the form of chemical energy for industrial production of chemicals and fuels,which can dramatically re... Electrocatalytic CO_(2) reduction reaction(CO_(2) RR) can store and transform the intermittent renewable energy in the form of chemical energy for industrial production of chemicals and fuels,which can dramatically reduce CO_(2) emission and contribute to carbon-neutral cycle. E cient electrocatalytic reduction of chemically inert CO_(2) is challenging from thermodynamic and kinetic points of view. Therefore,low-cost,highly e cient,and readily available electrocatalysts have been the focus for promoting the conversion of CO_(2). Very recently,interface engineering has been considered as a highly e ective strategy to modulate the electrocatalytic performance through electronic and/or structural modulation,regulations of electron/proton/mass/intermediates,and the control of local reactant concentration,thereby achieving desirable reaction pathway,inhibiting competing hydrogen generation,breaking binding-energy scaling relations of intermediates,and promoting CO_(2) mass transfer. In this review,we aim to provide a comprehensive overview of current developments in interface engineering for CO_(2) RR from both a theoretical and experimental stand-point,involving interfaces between metal and metal,metal and metal oxide,metal and nonmetal,metal oxide and metal oxide,organic molecules and inorganic materials,electrode and electrolyte,molecular catalysts and electrode,etc. Finally,the opportunities and challenges of interface engineering for CO_(2) RR are proposed. 展开更多
关键词 Interface engineering CO_(2)reduction reaction ELECTROCATALYSIS HETEROSTRUCTURE
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铜基串联催化剂电催化CO_(2)还原的研究进展 被引量:5
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作者 石永霞 侯曼 +2 位作者 李俊俊 李丽 张志成 《物理化学学报》 SCIE CAS CSCD 北大核心 2022年第11期119-139,共21页
化石燃料的燃烧和其他人类活动排放了大量的CO_(2)气体,引发了诸多环境问题。电催化CO_(2)还原反应(CO_(2)RR)可以储存间歇可再生能源,实现人为闭合碳循环,被认为是获得高附加值化学品和燃料的有效途径。电催化CO_(2)RR涉及多个电子-质... 化石燃料的燃烧和其他人类活动排放了大量的CO_(2)气体,引发了诸多环境问题。电催化CO_(2)还原反应(CO_(2)RR)可以储存间歇可再生能源,实现人为闭合碳循环,被认为是获得高附加值化学品和燃料的有效途径。电催化CO_(2)RR涉及多个电子-质子转移步骤,其中^(*)CO通常被认为是关键中间体。铜由于对^(*)CO具有合适的吸附能,已被广泛证明是唯一能够有效地将CO_(2)还原为碳氢化合物和含氧化合物的金属催化剂。然而,纯Cu稳定性差、产品选择性低、过电位高,阻碍了工业级多碳产品的生产。构筑Cu基串联催化剂是提高CO_(2)RR性能的一种有前途的策略。本文首先介绍电催化CO_(2)RR的反应路线和串联机理。然后,系统地总结铜基串联催化剂对电催化CO_(2)RR的最新研究进展。最后,提出合理设计和可控合成新型电催化CO_(2)RR串联催化剂面临的挑战和机遇。 展开更多
关键词 CO_(2)还原 串联催化剂 溢流 电催化
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Exclusive CO_(2)-to-formate conversion over single-atom alloyed Cu-based catalysts 被引量:1
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作者 junjun li Zhicheng Zhang Wenping Hu 《Green Energy & Environment》 SCIE EI CSCD 2022年第5期855-857,共3页
Electrochemical CO_(2) reduction reaction(CO_(2) RR),powered by renewable energy sources,provides an appealing approach to convert emitted CO_(2) to value-added chemicals and fuels and achieve a carbon-neutral cycle.A... Electrochemical CO_(2) reduction reaction(CO_(2) RR),powered by renewable energy sources,provides an appealing approach to convert emitted CO_(2) to value-added chemicals and fuels and achieve a carbon-neutral cycle.Among various carbon-based products,formic acid(HCOOH) has been considered as a promising liquid hydrogen storage material due to its high energy density and hydrogen content.However,so far,the reported HCOOH-selective catalysts(e.g.,Bi,Sn,In,Pb and Pd) have failed in either activity(<500 mA cm^(-2)) or stability(<20 h),which significantly inhibits the industrialized feasibility of CO_(2) RR.In contrast,Cu takes the advantages of excellent activity and low cost,making it more commercially viable.To date,one of the most challenging issues of Cu-based catalysts lies in unsatisfactory selectivity,that is,tending to produce mixed products rather than specific one,due to the complicated reaction paths involved.Very recently,Zheng et al.have developed a single-atom alloy(SAAs) strategy for the exclusive CO_(2)-to-formate conversion over Cu-based catalysts.The as-prepared Pb single-atom alloyed Cu catalyst(Pb_(1)Cu)(Fig.la) exhibited near unity selectivity towards HCOOH and impressive stability,providing the prospect of industrial production of HCOOH from CO_(2). 展开更多
关键词 SELECTIVITY stability NEUTRAL
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Relationships between Cloud Droplet Spectral Relative Dispersion and Entrainment Rate and Their Impacting Factors
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作者 Shi LUO Chunsong LU +9 位作者 Yangang liU Yaohui li Wenhua GAO Yujun QIU Xiaoqi XU junjun li Lei ZHU Yuan WANG Junjie WU Xinlin YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第12期2087-2106,I0016-I0019,共24页
Cloud microphysical properties are significantly affected by entrainment and mixing processes.However,it is unclear how the entrainment rate affects the relative dispersion of cloud droplet size distribution.Previousl... Cloud microphysical properties are significantly affected by entrainment and mixing processes.However,it is unclear how the entrainment rate affects the relative dispersion of cloud droplet size distribution.Previously,the relationship between relative dispersion and entrainment rate was found to be positive or negative.To reconcile the contrasting relationships,the Explicit Mixing Parcel Model is used to determine the underlying mechanisms.When evaporation is dominated by small droplets,and the entrained environmental air is further saturated during mixing,the relationship is negative.However,when the evaporation of big droplets is dominant,the relationship is positive.Whether or not the cloud condensation nuclei are considered in the entrained environmental air is a key factor as condensation on the entrained condensation nuclei is the main source of small droplets.However,if cloud condensation nuclei are not entrained,the relationship is positive.If cloud condensation nuclei are entrained,the relationship is dependent on many other factors.High values of vertical velocity,relative humidity of environmental air,and liquid water content,and low values of droplet number concentration,are more likely to cause the negative relationship since new saturation is easier to achieve by evaporation of small droplets.Further,the signs of the relationship are not strongly affected by the turbulence dissipation rate,but the higher dissipation rate causes the positive relationship to be more significant for a larger entrainment rate.A conceptual model is proposed to reconcile the contrasting relationships.This work enhances the understanding of relative dispersion and lays a foundation for the quantification of entrainment-mixing mechanisms. 展开更多
关键词 CLOUDS entrainment rate relative dispersion of cloud droplet size distribution mixing and evaporation
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Insight into the Effect of Metal Cations in the Electrolyte on Performance for Electrocatalytic CO_(2)Reduction Reaction
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作者 junjun li Zhicheng Zhang Wenping Hu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2022年第4期1008-1009,共2页
This highlight indicates that the local electrostatic interactions between metal cations and key intermediates facilitate the electrocatalytic CO_(2) reduction reaction.Electrocatalytic CO_(2) reduction reaction(CO_(2... This highlight indicates that the local electrostatic interactions between metal cations and key intermediates facilitate the electrocatalytic CO_(2) reduction reaction.Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)has been considered as a promising strategy to achieve a carbon-neutral cycle and produce valuable fuels and feedstocks. 展开更多
关键词 CO_(2)reduction reaction ELECTROCATALYSIS metal cations
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A New Classifier for Imbalanced Data Based on a Generalized Density Ratio Model
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作者 junjun li Wenquan Cui 《Communications in Mathematics and Statistics》 SCIE CSCD 2023年第2期369-401,共33页
Achieving higher true positive rate when decreasing false positive rate is always a great challenge to the imbalance learning community.This work combines penalized empirical likelihood method,lower bound algorithm an... Achieving higher true positive rate when decreasing false positive rate is always a great challenge to the imbalance learning community.This work combines penalized empirical likelihood method,lower bound algorithm and Nyströmmethod and applies these techniques along with kernel method to density ratio model.The resulting classifier,density ratio classifier(DRC),is a combination of kernelization,regularization,efficient implementation and threshold moving,all of which are critical to enable DRC to be an effective and powerful method for solving difficult imbalance problems.Compared with other methods,DRC is competitive in that it is widely applicable and it is simple and easy to use without additional imbalance handling skills.In addition,the convergence rate of the estimate of log density ratio is discussed as well.And the results of numerical analysis also show that DRC outperforms other methods in AUC and G-mean score. 展开更多
关键词 CLASSIFIER Density ratio model Imbalance problems Kernel method ROC curve
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三参数冰相云微物理方案在CIESM模式中的应用
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作者 贺欣 陆春松 +6 位作者 史湘军 朱磊 张文韬 李特 李君俊 吴尚 徐晓齐 《科学通报》 EI CAS CSCD 北大核心 2024年第17期2417-2428,共12页
由于云的时空尺度非常宽广,云微物理参数化方案一直是气候模式中的薄弱环节.本文借鉴中尺度模式云微物理方案从双参数向三参数扩展的思路方法,发展了联合地球系统模式(Community Integrated Earth System Model,CIESM)三参数冰相云微物... 由于云的时空尺度非常宽广,云微物理参数化方案一直是气候模式中的薄弱环节.本文借鉴中尺度模式云微物理方案从双参数向三参数扩展的思路方法,发展了联合地球系统模式(Community Integrated Earth System Model,CIESM)三参数冰相云微物理方案,弥补了默认双参数方案不能预报冰晶粒径分布谱形参数(μ)的不足,进而分析了双、三参数方案对气候模拟的影响.模拟结果表明,相较于双参数方案(μ为0),三参数方案预报得出的μ更为合理,其在垂直分布上整体呈现出“高层小低层大”的特点,高层的低值主要是由于冰晶核化以及较大的冰晶粒子沉降后粒子之间相互混合导致的,而低层的高值主要是由于冰晶粒子在沉降过程中的粒子分选机制导致的.与双、三参数方案中μ的差异相呼应,模式模拟的气候平均态出现明显差异,其中三参数方案模拟的总云云量、低云云量、中云云量和总降水相较于双参数方案更接近观测结果,高云云量的误差增大.其中总降水的改进主要是由于高云云量的增加,大气稳定度增加,对流性降水减少.此外,还调整了相关参数,以改善模式对辐射的模拟能力.总之,本文在全球气候模式中评估了双、三参数方案对于模拟气候平均态的不同影响,为气候模式中云微物理方案的发展改进提供了一定的参考意义. 展开更多
关键词 冰晶谱形参数 三参数方案 微物理 气候模式
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Enhancement of CH_(3)CO^(*) adsorption by editing d-orbital states of Pd to boost C–C bond cleavage of ethanol eletrooxidation
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作者 Yuchen Qin Fengqi Wang +11 位作者 Pei liu Jinyu Ye Qian Wang Yao Wang Guangce Jiang lijie liu Pengfang Zhang Xiaobiao liu Xin Zheng Yunlai Ren junjun li Zhicheng Zhang 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第2期696-704,共9页
Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts... Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts the C–C bond cleavage.Inspired by the molecular orbital theory,we proposed the d-state-editing strategy to construct more unoccupied d-states of Pd for the enhanced interaction with CH_(3)CO^(*) to break C–C bonds.As expected,the reduced number of e_g electrons and more unoccupied d-states of Pd successfully formed on as-prepared porous Rh Au–Pd Cu nanosheets(PNSs).Theoretical calculations show that the optimized d-states of Rh Au–Pd Cu PNS can effectively improve the adsorption of CH_(3)CO^(*) and drastically reduce the energy barrier of C–C bond cleavage,thus boosting the complete oxidation of ethanol.The charge ratio of C_1 pathway on Rh Au–Pd Cu PNSs is 51.5%,more than 2 times higher than that of Pd NSs.Our finding provides an innovative perspective for the design of highly-efficient noble-based electrocatalysts. 展开更多
关键词 C–C bond cleavage CH_(3)CO^(*)adsorption unoccupied d-states ethanol oxidation reaction RhAu–PdCu porous nanosheets
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Development of composite functional tissue sheets using hiPSC-CMs and hADSCs to improve the cardiac function after myocardial infarction
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作者 Jingbo Zhang junjun li +8 位作者 Xiang Qu Yuting liu lifu Sun Akima Harada Ying Hua Nagako Sougawa Akiko Tabata li liu Shigeru Miyagawa 《Bioactive Materials》 SCIE CSCD 2024年第7期533-548,共16页
Human-induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CMs)have been widely used in therapy of ischemic heart disease.However,there are still remaining issues that limit the therapeutic efficacy,such as immu... Human-induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CMs)have been widely used in therapy of ischemic heart disease.However,there are still remaining issues that limit the therapeutic efficacy,such as immune rejection and low retention of hiPSC-CMs.Human adipose mesenchymal stromal cells(hADSCs)have been reported to be able to regulate the immune response,promote angiogenesis and promote the maturation of hiPSC-CMs.In this study,we co-cultured these two types of cells on fiber scaffold made of biodegradable poly(D,L-lactic-co-glycolic acid)(PLGA)polymer for several days to develop a composited 3D cardiac tissue sheet.As expected,the cells formed 231.00±15.14μm thickness tissue,with improved organization,alignment,ECM condition,contractile ability,and paracrine function compared to culture hiPSC-CMs only on PLGA fiber.Furthermore,the composited 3D cardiac tissue sheet significantly promoted the engraftment and survival after transplantation.The composited 3D cardiac tissue sheet also increased cardiac function,attenuated ventricular remodeling,decreased fibrosis,and enhanced angiogenesis in rat myocardial infarction model,indicating that this strategy wound be a promising therapeutic option in the clinical scenario. 展开更多
关键词 Human induced pluripotent stem cell-derived cardiomyocyte Human adipose-derived mesenchymal stem cell Tissue engineering Myocardial infarction Regenerative medicine
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Bimetallic phthalocyanine heterostructure used for highly selective electrocatalytic CO_(2) reduction 被引量:4
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作者 Chenhuai Yang Zengqiang Gao +8 位作者 Dingjia Wang Shuyu li junjun li Yating Zhu Haiqing Wang Wenjuan Yang Xuejiao J.Gao Zhicheng Zhang Wenping Hu 《Science China Materials》 SCIE EI CAS CSCD 2022年第1期155-162,共8页
Heterogeneous molecular catalysts,such as metal phthalocyanines,are efficient electrocatalysts for CO_(2) reduction reaction(CO_(2)RR).However,the rational design and synthesis of a molecular catalyst-based heterostru... Heterogeneous molecular catalysts,such as metal phthalocyanines,are efficient electrocatalysts for CO_(2) reduction reaction(CO_(2)RR).However,the rational design and synthesis of a molecular catalyst-based heterostructure for CO_(2)RR remains challenging.Herein,we developed a crystalline bimetallic phthalocyanine heterostructure electrocatalyst(CoPc/FePc HS),which achieved an excellent CO_(2)-to-CO conversion efficiency(99%)and outstanding long-term stability after 10 h of electrocatalysis.Density functional theory calculations revealed that the enhancement of CO_(2)RR performance could be attributed to the distinct electron transfer pattern between FePc and CoPc.The heterostructural engineering in molecular catalysts would inspire a unique approach for improving CO_(2)RR performance. 展开更多
关键词 molecular catalyst phthalocyanine heterostructure CO_(2)reduction electronic effect
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Analysis of whole genome-wide microRNA transcriptome profiling in invasive pituitary adenomas and non-invasive pituitary adenomas 被引量:1
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作者 Chao Zhang Yuan Qian +4 位作者 Yisheng Qiao Yao li Wei Wang junjun li Xingli Deng 《Chinese Neurosurgical Journal》 CSCD 2019年第4期196-202,共7页
Background:Dysregulation of microRNAs(miRNAs)plays a critical role during the occurrence and progress of pituitary adenomas(PAs).However,the roles of miRNAs in the invasiveness of PA are poorly understood.This study a... Background:Dysregulation of microRNAs(miRNAs)plays a critical role during the occurrence and progress of pituitary adenomas(PAs).However,the roles of miRNAs in the invasiveness of PA are poorly understood.This study aims to more comprehensively and specific define the relationship between altered miRNA and PA invasion.Methods:The differential expression of miRNAs(DEMs)between invasive PAs(IPAs)and non-invasive PAs(NPAs)was explored by RNA sequencing and which functions were analyzed by gene ontology(GO)as well as Kyoto Encyclopedia of Genes and Genomes(KEGG).The miRNA-mRNA network was predicted with bioinformatics.Results:We identified 31 upregulated miRNAs and 24 downregulated miRNAs in IPAs compared with NPAs.GO analysis and KEGG pathway analysis showed the DEMs were mainly associated with cell proliferation and cell cycle pathway.In addition,on the count of predicted miRNA-mRNA network,two hub miRNAs were identified.Conclusions:Our results demonstrate the miRNA-mRNA network in detail,which suggest that miRNA may be a promising target in diagnosis and therapy for IPAs. 展开更多
关键词 PITUITARY ADENOMA INVASIVE MICRORNA TRANSCRIPTOME
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三参数冰相云微物理方案的构建及在单柱大气模式中的应用 被引量:3
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作者 贺欣 陆春松 +5 位作者 史湘军 张文韬 朱磊 徐晓齐 李君俊 李丹 《科学通报》 EI CAS CSCD 北大核心 2023年第15期1971-1984,共14页
云微物理的参数化对天气及气候的准确模拟至关重要,其中云粒子谱分布特征通过改变云演化发展和云辐射效应,必然进一步影响气候模拟.目前广泛使用的双参数云微物理方案,无法预报云粒子谱分布的谱形参数,阻碍了气候模式对云物理过程的准... 云微物理的参数化对天气及气候的准确模拟至关重要,其中云粒子谱分布特征通过改变云演化发展和云辐射效应,必然进一步影响气候模拟.目前广泛使用的双参数云微物理方案,无法预报云粒子谱分布的谱形参数,阻碍了气候模式对云物理过程的准确描述.鉴于此,本文在单柱大气模式SCAM5.3(Single Column Atmosphere Model,Version 5.3)中增加雷达反射率因子的预报方程,构建了三参数冰相云微物理方案,实现了冰晶粒子谱分布谱形参数的预报.利用该模式,模拟了大气辐射观测计划在1997年夏季实施的为期29 d的观测个例(ARM97),分析了双、三参数方案对云量和辐射的模拟差异.结果表明:首先,三参数方案预报的冰晶粒子谱的谱形参数主要集中在0~4,峰值在2左右,至少有85%的μ都大于默认的0.其次,与双参数方案相比,三参数方案对云量的模拟更接近观测;利用辐射通量密度的观测值进行评估,发现无论是短波还是长波辐射通量密度,三参数方案的误差都比双参数方案小.最后,揭示了三参数方案对云量和辐射模拟效果的改进机理:主要是因为三参数方案减弱了冰晶到雪的自动转化过程,增强了冰晶凝华增长过程,从而增大了冰晶浓度和冰云云量.本文构建的三参数冰相云微物理方案,将有利于增强模式对云-气候反馈等过程的模拟能力. 展开更多
关键词 谱形参数 三参数方案 微物理 单柱大气模式
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Two-dimensional covalent organic frameworks for electrocatalysis:Achievements,challenges,and opportunities 被引量:2
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作者 Ruoyu Zhao Teng Wang +5 位作者 junjun li Yongxia Shi Man Hou Yong Yang Zhicheng Zhang Shengbin Lei 《Nano Research》 SCIE EI CSCD 2023年第7期8570-8595,共26页
Covalent organic frameworks(COFs)represent an emerging class of crystalline porous polymers with high porosity,good stability,and adjustable structure,and their excellent characteristics lay a solid foundation for ele... Covalent organic frameworks(COFs)represent an emerging class of crystalline porous polymers with high porosity,good stability,and adjustable structure,and their excellent characteristics lay a solid foundation for electrocatalysis.This review systematically introduces the design principles of the catalytic sites in two-dimensional(2D)COF-based electrocatalysts and analyzes the relationship between 2D COF structure and their electrocatalytic performances.In particular,the recent progress in the field of 2D COFs as electrocatalysts is comprehensively summarized.Finally,we discuss the current shortcomings and challenges on tailoring 2D COF for high-performance electrocatalysts in details,and look forward to promoting more researches on 2D COF-based electrocatalysts. 展开更多
关键词 covalent organic frameworks ELECTROCATALYSTS TWO-DIMENSIONAL active centers
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