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Insights into the photocatalytic mechanism of the C4N/MoS2 heterostructure: A first-principle study

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Chinese Chemical Letters 2020年第9期31卷 2319-2324页

作者： Rui Zhang Wei Jian zhao-di yang Fu-Quan Bai College of Chemical and Environmental Engineering Harbin University of Science and TechnologyHarbin 150080China Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry and College of ChemistryJilin UniversityChangchun 130023China Beijing National Laboratory for Molecular Sciences(BNLMS) Beijing 100190China

Constructing heterostructures by combining COFs and TMD is a new strategy to design efficient photocatalysts for CO2 reduction reaction(CO2RR) due to their good stability,tunable band gaps and efficient charge *** on the synthesis of completely novel C4N-COF in our previous re ported work,a new C4N/MoS2 heterostructure was constructed and then the related structural,electronic and optical properties were also studied using first principle *** interlayer coupling effect and charge transfer between the C4N and MoS2 layer are systematically *** reduced band gap of the C4N/MoS2 heterostructure is beneficial to absorb more visible *** the formation of type-Ⅱ band alignment,a built-in electric field appears which separates the photogene rated electrons and holes into different layers efficiently and produces redox active *** band alignment of the heterostructure ensures its photocatalytic activities of the whole CO2 reduction ***,the charge density difference and charge carrier mobility confirm the existence of the built-in electric field at the interface of the C4N/MoS2 heterostructure ***,the high optical absorption indicates it is an efficient visible light harvesting ***,this wo rk could provide strong insights into the internal mechanism and high photocatalytic activity of the C4N/MoS2 heterostructure and offer guiding of designing and synthesizing COF/TMD heterostructure photocatalysts.

关键词： First-principles calculations C4N/MoS2 heterostructure Electronic structure Built-in electric field Charge separation Photocatalyst

differences and similarities in radial growth of Betula species to climate change

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Journal of Forestry Research 2024年第2期35卷 176-187页

作者： di Liu yang An zhao Li Zhihui Wang Yinghui zhao Xiaochun Wang Center for Ecological Research Key Laboratory of Sustainable Forest Ecosystem ManagementMinistry of EducationCollege of ForestryNortheast Forestry UniversityHarbin 150040People’s Republic of China Changan Park in Shijiazhuang Shijiazhuang 050000People’s Republic of China Shijiazhuang Landscape Greening Engineering Project Construction Center Shijiazhuang 050000People’s Republic of China Heilongjiang Institute of Meteorological Science Harbin 150030People’s Republic of China School of Life Qufu Normal UniversityQufu 273100People’s Republic of China

Betula platyphylla and Betula costata are important species in mixed broadleaved-Korean pine(Pinus koraiensis)***,the specific ways in which their growth is affected by warm temperatures and drought remain *** address this issue,60 and 62 tree-ring cores of *** and *** were collected in Yichun,*** dendrochronological methods,the response and adaptation of these species to climate change were examined.A“hysteresis effect”was found in the rings of both species,linked to May–September moisture conditions of the previous *** growth of *** was positively correlated with the standardized precipitation-evapotranspiration index(SPEI),the precipitation from September to October of the previous year,and the relative humidity in October of the previous *** of *** is primarily restricted by moisture conditions from September to *** contrast,*** growth is mainly limited by minimum temperatures in May–June of both the previous and current *** droughts,*** had a faster recovery rate compared to *** the context of rising temperatures since 1980,the correlation between *** growth and monthly SPEI became positive and strengthened over time,while the growth of *** showed no conspicuous *** findings suggest that the growth of *** is already affected by warming temperatures,whereas *** may become limited if warming continues or *** change could disrupt the succession of these species,possibly accelerating the succession of pioneer *** results of this research are of great significance for understanding how the growth changes of birch species under warming and drying conditions,and contribute to understanding the structural adaptation of mixed broadleaved-Korean pine(Pinus koraiensis)forests under climate change.

关键词： Tree rings Betula platyphylla Betula costata Climate response Moving correlation Extreme drought

Self-assembly Induced by Complexation of diblock Copolyelectrolytes and Oppositely Charged Homopolymers

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Chinese Journal of Polymer Science 2024年第9期42卷 1321-1332,I0006页

作者： Ling zhao Zhi-Yuan Yin Jia-di Jiang Er-Qiang Chen Shuang yang Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Mater Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

We investigate the solution self-assembly of a mixture of positively charged homopolymers and AB diblock copolymers,in which the A blocks are negatively charged,and the B blocks are *** electrostatic complexation between oppositely charged polymers drives the formation of many ordered *** microstructures and phase diagrams are calculated using self-consistent field theory(SCFT)based on an ion-pair model with an equilibrium constant K to characterize the strength of binding between positively and negatively charged *** effects of the charge ratio,representing the ratio of charges from the homopolymer over all charges from polymers in the system,on the ordered structure are systematically studied,both for hydrophobic and hydrophilic A *** charge ratio plays an important role in determining the phase boundaries in the phase diagram of salt concentration versus polymer *** also provide information about the varying tendency of the domain spacing and core size of the spherical phase when the charge ratio is changed,and the results are in good agreement with *** studies provide a deep understanding of the self-assembled microstructures of oppositely charged diblock copolymer-homopolymer systems.

关键词： Self-assembly Polyelectrolyte complexation Self-consistent field theory Ion-pair

Detecting compromised email accounts via login behavior characterization

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Cybersecurity 2024年第1期7卷 16-36页

作者： Jianjun zhao Can yang di Wu Yaqin Cao Yuling Liu Xiang Cui Qixu Liu Institute of Information Engineering Chinese Academy of SciencesBeijing100085China School of Cyber Security University of Chinese Academy of SciencesBeijing100049China China Cybersecurity Review Technology and Certification Center Beijing100013China Zhongguancun Laboratory Beijing100089China

The illegal use of compromised email accounts by adversaries can have severe consequences for enterprises and *** compromised email accounts is more challenging than in the social network field,where email accounts have only a few interaction events(sending and receiving).To address the issue of insufficient features,we propose a novel approach to detecting compromised accounts by combining time zone differences and alternate logins to identify abnormal *** on this approach,we propose a compromised email account detection framework that relies on widely available and less sensitive login logs and does not require *** framework characterizes login behaviors to identify logins that do not belong to the account owner and outputs a list of account-subnet pairs ranked by their likelihood of having abnormal login *** approach reduces the number of account-subnet pairs that need to be investigated and provides a reference for investigation *** evaluation demonstrates that our method can detect most email accounts that have been accessed by disclosed malicious IP addresses and outperforms similar ***,our framework has the capability to uncover undisclosed malicious IP addresses.

关键词： Compromised account detection Mixture model Login log analysis Attribution and forensic

Mechanism of Qili Qiangxin Capsule for Heart Failure Based on miR133a-Endoplasmic Reticulum Stress

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Chinese Journal of Integrative Medicine 2024年第5期30卷 398-407页

作者： JI Xiao-di yang ding CUI Xi-yuan LOU Li-xia NIE Bo zhao Jiu-li zhao Ming-jing WU Ai-ming Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine Key Laboratory of Chinese Internal Medicine of Ministry of Education and BeijingBeijing 100700China Department of Traditional Chinese Medicine Fuwai HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100037China

Objective:To investigate the pharmacological mechanism of Qili Qiangxin Capsule(QLQX)improvement of heart failure(HF)based on miR133a-endoplasmic reticulum stress(ERS)***:A left coronary artery ligation-induced HF after myocardial infarction model was used in this *** were randomly assigned to the sham group,the model group,the QLQX group[0.32 g/(kg·d)],and the captopril group[2.25 mg/(kg·d)],15 rats per group,followed by 4 weeks of *** function such as left ventricular ejection fraction(EF),fractional shortening(FS),left ventricular systolic pressure(LVSP),left ventricular end diastolic pressure(LVEDP),the maximal rate of increase of left ventricular pressure(+dp/dt max),and the maximal rate of decrease of left ventricular pressure(–dp/dt max)were monitored by echocardiography and *** and eosin(HE)and Masson stainings were used to visualize pathological changes in myocardial *** m RNA expression of mi R133a,glucose-regulated protein78(GRP78),inositol-requiring enzyme 1(IRE1),activating transcription factor 6(ATF6),X-box binding protein1(XBP1),C/EBP homologous protein(CHOP)and Caspase 12 were detected by *** protein expression of GRP78,p-IRE1/IRE1ratio,cleaved-ATF6,XBP1-s(the spliced form of XBP1),CHOP and Caspase 12 were detected by Western *** T-mediated d UTP nick-end labeling(TUNEL)staining was used to detect the rate of ***:QLQX significantly improved cardiac function as evidenced by increased EF,FS,LVSP,+dp/dt max,-dp/dt max,and decreased LVEDP(Pdiac pathologic damage to some *** staining indicated that QLQX significantly reduced collagen volume fraction in myocardial tissue(P<0.01).Results from RT-PCR and Western blot showed that QLQX significantly increased the expression of mi R133a and inhibited the m RNA expressions of GRP78,IRE1,ATF6 and XBP1,as well as decreased the protein expressions of GRP78,cleave

关键词： heart failure Qili Qiangxin Capsule miR133a endoplasmic reticulum stress apoptosis

Role of heterogenous microstructure and deformation behavior in achieving superior strength-ductility synergy in zinc fabricated via laser powder bed fusion

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International Journal of Extreme Manufacturing 2024年第4期6卷 225-245页

作者： Zhi Dong Changjun Han Yanzhe zhao Jinmiao Huang Chenrong Ling Gaoling Hu Yunhui Wang di Wang Changhui Song Yongqiang yang School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510641People's Republic of China

Zinc(Zn)is considered a promising biodegradable metal for implant applications due to its appropriate degradability and favorable osteogenesis *** this work,laser powder bed fusion(LPBF)additive manufacturing was employed to fabricate pure Zn with a heterogeneous microstructure and exceptional strength-ductility *** optimized processing window of LPBF was established for printing Zn samples with relative densities greater than 99%using a laser power range of 80∼90 W and a scanning speed of 900 mm s−*** Zn sample printed with a power of 80 W at a speed of 900 mm s−1 exhibited a hierarchical heterogeneous microstructure consisting of millimeter-scale molten pool boundaries,micrometer-scale bimodal grains,and nanometer-scale pre-existing dislocations,due to rapid cooling rates and significant thermal gradients formed in the molten *** printed sample exhibited the highest ductility of∼12.1%among all reported LPBF-printed pure Zn to date with appreciable ultimate tensile strength(∼128.7 MPa).Such superior strength-ductility synergy can be attributed to the presence of multiple deformation mechanisms that are primarily governed by heterogeneous deformation-induced hardening resulting from the alternative arrangement of bimodal Zn grains with pre-existing ***,continuous strain hardening was facilitated through the interactions between deformation twins,grains and dislocations as strain accumulated,further contributing to the superior strength-ductility *** findings provide valuable insights into the deformation behavior and mechanisms underlying exceptional mechanical properties of LPBF-printed Zn and its alloys for implant applications.

关键词： laser powder bed fusion zinc heterogeneous microstructure bimodal grains strength-ductility synergy

A DFT Study for Electronic Properties of 2D Porous Graphenes and BN Co-doped Derivatives

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A DFT Study for Electronic Properties of 2D Porous Graphenes...

Autonomous multi-drone racing method based on deep reinforcement learning

中国化学会第十二届全国量子化学会议

作者： Si Li zhao-di yang College of Chemical and Environmental Engineering Harbin University of Science and Technology

Recently,a novelπ-conjugated microporous frameworks have been attracted a lot of interest for possible application as low-dimensional electronics.1,2 Especially,such structures similar to aza-fused conjugated-microporous-polymer（CMPs）has been successfully synthesized.1 In this work we investigated electronic properties of a series of 2D Benzo-CMPs and their BN co-doped derivatives based on PBE/DFT method using the SIESTA package,as shown in Figure 1n-Benzo-CMPs（n=3,4,5）can be viewed as n-fused benzenes replacing each double bond in graphene and BN-n-Benzo-CMPs are their corresponding BN co-doped *** calculated results indicate that all porous graphenes in Figure 1 are semiconductors with a direct band gap from 0.57-1.75e V and can possess nanometer-scale pore *** pore size increases,the band gap *** co-doping could make the band gap *** tunable electronic properties via BN co-doping and pore size offered by Benzo-CMPs may be exploited for applications in low-dimensional electronics.

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Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu KANG Jian di Ming LI Yunbo zhao Yuhui WANG Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： racing drone autonomous multi-drone racing sim-to-real deep reinforcement learning Markov game

An aptamer-driven DNA nanodevice for improved delivery of synthetic immunostimulants

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Nano Research 2024年第10期17卷 9078-9083页

作者： Dejie Lu Zhenghan di Lele Li Jian zhao Li Zheng Guangxi Engineering Center in Biomedical Materials for Tissue and Organ Regeneration Collaborative Innovation Centre of Regenerative Medicine and Medical BioResource Development and ApplicationGuangxi Key Laboratory of Regenerative MedicineThe First Affiliated Hospital of Guangxi Medical UniversityGuangxi Medical UniversityNanning 530021China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and TechnologyBeijing 100190China

Efficient delivery of therapeutics to immune cells remains a formidable challenge for cancer *** this work,we demonstrate that an aptamer-driven DNA nanodevice,constructed through linkage of a synthetic immunostimulant(Toll-like receptor 9 agonist:CpG motif)to an aptamer,could significantly enhance the immunostimulatory activity by facilitating the uptake and retention of therapeutics in *** administration of the DNA nanodevice results in efficient tumor growth inhibition in both breast cancer and melanoma mouse *** studies suggest that the DNA nanodevice leads to reeducation of tumor-associated macrophages and ultimately to reversing the tumor immune *** strategy for aptamer-mediated and vehicle-free delivery of immunostimulatory oligonucleotides provides a potential platform for cancer immunotherapy.

关键词： aptamer immunostimulatory oligonucleotides DNA nanodevice tumor-associated macrophages cancer therapy