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A theoretical study on gaseous pollutant flushing of natural ventilation driven by buoyancy forces in industrial buildings

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Building Simulation 2024年第4期17卷 575-589页

作者： Jiawei Zhuang Genyang Chen Rumeng Yang Kun Han Dongdong Tian Yongfa Diao Henggen Shen School of Urban Construction Changzhou UniversityChangzhou213164China School of Petroleum and Natural Gas Engineering School of EnergyChangzhou UniversityChangzhou213164China College of Environmental Science and Engineering Donghua UniversityShanghai201620China School of Architecture and Urban Planning Nanjing UniversityNanjing210093China

The acceleration of industrialization worsening indoor environments of industrial buildings has drawn more attention in recent *** ventilation can improve indoor air quality(IAQ)and reduce carbon *** evaluate gaseous pollutant levels in industrial buildings for the development of buoyancy-driven natural ventilation,two theoretical models of pollutant flushing(Model I and Model II)are developed based on the existing thermal stratification theory in combination with the mixing characteristics of lower *** results show that indoor pollutant flushing is mainly dependent on the pollution source intensity and effective ventilation *** mixing characteristics of lower pollutant has an important effect on pollutant stratification and evolution during ventilation,but it does not change the prediction results at steady *** the dimensionless pollution source intensity is larger than 1,the pollution source should be cleaned up or other ventilation methods should be used instead to improve *** addition,the comparisons between Model I and Model II on instantaneous pollutant concentration are significantly influenced by the pollution source intensity,and the actual pollutant concentration is more likely to be between the predicted values of Model I and Model *** reduce pollutant concentration to a required level,the pollution source intensity should be in a certain *** theoretical models as well as the necessary conditions for ventilation effectiveness obtained can be used for the ventilation optimization design of industrial buildings.

关键词： industrial buildings buoyancy-driven natural ventilation gaseous pollutants evolution model pollution sources

The centrosymmetric to non-centrosymmetric transformation induced by alkaline-earth cations producing infrared nonlinear optical AeMn_(6)Ga_(6)S_(16)(Ae=Ca,Sr)

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Science china Chemistry 2024年第9期67卷 2941-2948页

作者： Yang-Ping Zhang Shao-Min Pei Wen-Fa Chen Bin-Wen Liu Xiao-Ming Jiang Guo-Cong Guo State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of china Fuzhou 350108China School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China

Non-centrosymmetric(NCS)structure is an indispensable prerequisite for second-order nonlinear optical(NLO)***,the mainstream approach for designing new NCS structures still relies on chemical substitution,necessitating an urgent infusion of fresh *** this work,two isomorphic sulfides AeMn_(6)Ga_(6)S_(16)(Ae=Ca,1;Sr,2)are afforded by modifying the skeleton of centrosymmetric(CS)Mn_(2)Ga_(2)S_(5) via introducing strong electropositive alkaline-earth ***,the incorporation of Ca^(2+)/Sr^(2+)cations allows the elementary[MnGaS_(9)]_(∞)chains to reconfigure into bumpy[MnS_(6)]-[GaS_(4)]layers in a new engagement manner,thus enabling the conversion from CS to NCS *** modifications cause not only strong second-harmonic generation(SHG)responses(~1.5×benchmark AgGaS_(2)@1,700 nm),but also significantly feasible bandgaps(2.60-2.64 e V)compared to the sulfide Mn_(2)Ga_(2)S_(5)(1.36 e V),which ultimately facilitate ultrahigh laser-induced damage thresholds(4.4-6.6×AgGaS_(2)@1,064 nm for compounds 1 and 2).The present study offers an ingenious approach for the transformation of CS to NCS structure.

关键词： second-harmonic generation non-centrosymmetrical structure NLO functional motif solid-state method

Privacy-Preserving Healthcare and Medical Data Collaboration Service System Based on Blockchain and Federated Learning

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Computers, Materials & Continua 2024年第8期80卷 2897-2915页

作者： Fang Hu Siyi Qiu Xiaolian Yang ChaoleiWu Miguel Baptista Nunes Hui Chen College of Information Engineering Hubei University of Chinese MedicineWuhan430065China College of Information Engineering Zhongnan University of Economics and LawWuhan430073China School of Advanced Technologies Xi’an Jiaotong-Liverpool UniversitySuzhou215400China School of Information Management Central China Normal UniversityWuhan430079China

As the volume of healthcare and medical data increases from diverse sources,real-world scenarios involving data sharing and collaboration have certain challenges,including the risk of privacy leakage,difficulty in data fusion,low reliability of data storage,low effectiveness of data sharing,*** guarantee the service quality of data collaboration,this paper presents a privacy-preserving Healthcare and Medical Data Collaboration Service System combining Blockchain with Federated Learning,termed *** system is composed of three layers:Data extraction and storage,data management,and data *** on healthcare and medical data,a healthcare and medical blockchain is constructed to realize data storage,transfer,processing,and access with security,real-time,reliability,and *** improved master node selection consensus mechanism is presented to detect and prevent dishonest behavior,ensuring the overall reliability and trustworthiness of the collaborative model training ***,healthcare and medical data collaboration services in real-world scenarios have been discussed and *** further validate the performance of FL-HMChain,a Convolutional Neural Network-based Federated Learning(FL-CNN-HMChain)model is investigated for medical image *** model achieves better performance compared to the baseline Convolutional Neural Network(CNN),having an average improvement of 4.7%on Area Under Curve(AUC)and 7%on Accuracy(ACC),***,the probability of privacy leakage can be effectively reduced by the blockchain-based parameter transfer mechanism in federated learning between local and global models.

关键词： Blockchain technique federated learning healthcare and medical data collaboration service privacy preservation

Towards the universal defense for query-based audio adversarial attacks on speech recognition system

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Cybersecurity 2024年第1期7卷 53-70页

作者： Feng Guo Zheng Sun Yuxuan Chen Lei Ju School of Cyber Science and Technology Shandong UniversityQingdaoChina Quancheng Laboratory QCLJinanChina

Recently,studies show that deep learning-based automatic speech recognition(ASR)systems are vulnerable to adversarial examples(AEs),which add a small amount of noise to the original audio *** AE attacks pose new challenges to deep learning security and have raised significant concerns about deploying ASR systems and *** existing defense methods are either limited in application or only defend on results,but not on *** this work,we propose a novel method to infer the adversary intent and discover audio adversarial examples based on the AEs generation *** insight of this method is based on the observation:many existing audio AE attacks utilize query-based methods,which means the adversary must send continuous and similar queries to target ASR models during the audio AE generation *** by this observation,We propose a memory mechanism by adopting audio fingerprint technology to analyze the similarity of the current query with a certain length of memory ***,we can identify when a sequence of queries appears to be suspectable to generate audio *** extensive evaluation on four state-of-the-art audio AE attacks,we demonstrate that on average our defense identify the adversary’s intent with over 90%*** careful regard for robustness evaluations,we also analyze our proposed defense and its strength to withstand two adaptive ***,our scheme is available out-of-the-box and directly compatible with any ensemble of ASR defense models to uncover audio AE attacks effectively without model retraining.

关键词： Adversarial attacks Defense Memory mechanism Query-based

Increased KIF21B expression is a potential prognostic biomarker in hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2020年第3期12卷 276-288页

作者： Hui-Qi Zhao Bao-Long Dong Min Zhang Xiao-Hua Dong Yu He Shi-Yong Chen Biao Wu Xiao-Jun Yang Department of General Surgery Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Department of Pathology Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina School of Clinical Medicine Gansu University of Chinese MedicineLanzhou 730000Gansu ProvinceChina School of Clinical Medicine Ningxia Medical UniversityYinchuan 750000Gansu ProvinceChina

BACKGROUND The kinesin superfamily protein member KIF21B plays an important role in regulating mitotic progression;however,the function and mechanisms of KIF21B in cancer,particularly in hepatocellular carcinoma(HCC),are *** To explore the role of KIF21B in hepatocellular carcinoma and its effect on prognosis after *** First,data on the differential expression of KIF21B in patients with HCC from The Cancer Genome Atlas database was ***,the expression levels of KIF21B in HCC cell lines and hepatocytes were detected by reverse transcription-polymerase chain reaction,and its biological effect on BEL-7404 cells was evaluated by KIF21B *** analysis was used to validate the differential expression of KIF21B in HCC tissues and adjacent normal tissues from 186 patients with HCC after *** Kaplan-Meier method was used to assess prognosis *** KIF21B expression levels were significantly higher in HCC tissues than in corresponding adjacent normal *** expression levels of KIF21B in four HCC cell lines were higher than that in normal liver *** experiments showed that KIF21B knockdown remarkably suppressed cell proliferation and induced ***,immunohistochemistry results are consistent with The Cancer Genome Atlas analysis,with KIF21B expression levels being increased in HCC tissues compared to adjacent normal *** and multivariate analyses revealed KIF21B as an independent risk factor for overall survival and disease-free survival in patients with HCC after *** Taken together,our results provide evidence that KIF21B plays an important role in HCC progression and may be a potential diagnostic and prognostic marker for HCC.

关键词： Hepatocellular carcinoma KIF21B Proliferation Apoptosis Prognosis

Structural Stability of Natural Magnesiochromite at High-Temperature-Pressure Conditions

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Journal of Earth Science 2024年第4期35卷 1196-1203页

作者： Shuyu Jin Xiang Wu Yungui Liu Yanfei Zhang Chao Wang State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan430074China College of Gems and Materials Hebei GEO UniversityShijiazhuang050031China

The podiform chromitites in the Luobusha ophiolite have been thought to experience a very deep formation,but the maximum depth is still an open ***,we have investigated the structural stability of natural magnesiochromite using the synchrotron-based powder X-ray diffraction and diamond anvil cells up to 48.6 GPa and 2450 *** results have shown that spinel-type magnesiochromite first decomposes into corundum-type‘Cr_(2)O_(3)’+B1-type‘MgO’at 11–14 GPa and 1250–1450 K,then modified ludwigite(mLd)-type‘Mg_(2)Cr_(2)O_(5)’+corundum-type‘Cr_(2)O_(3)’at 14.3–20.5 GPa and 1300–2000 K,and finally CaTi_(2)O_(4)-type phase at 24.5 *** the quenching procession from high-temperature-pressure conditions,the mLd-type phase appeared again and was kept at ambient *** also obtained the isothermal equation states of spinel-type and CaTi_(2)O_(4)-type phases,revealing the composition effect on their *** on the updated results,we propose chromitites could not experience pressure exceeding∼14.3 GPa(approximate maximum depth∼400 km)in the subduction-recycling genesis model.

关键词： chromite high-temperature and high-pressure phase transitions equation of state chromitites genesis

Real-Time Observation of Instantaneous ac Stark Shift of a Vacuum Using a Zeptosecond Laser Pulse

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Chinese Physics Letters 2024年第1期41卷 11-15页

作者：苏丹丹江淼 Key Laboratory for Laser Plasmas(Ministry of Education)and School of Physics and Astronomy Collaborative Innovation Center for IFSA(CICIFSA)Shanghai Jiao Tong UniversityShanghai 200240China School of Science China University of Mining and TechnologyBeijing 100083China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing 100083China

Based on the numerical solution of the time-dependent Dirac equation,we propose a method to observe in real time the ac Stark shift of a vacuum driven by an ultra-intense laser *** overlapping the ultra-intense pump pulse with another zeptosecond probe pulse whose photon energy is smaller than 2mc^(2),electron–positron pair creation can be controlled by tuning the time delay between the pump and probe *** the pair creation rate depends sensitively on the instantaneous vacuum potential,one can reconstruct the ac Stark shift of the vacuum potential according to the time-delay-dependent pair creation rate.

关键词： pump tuning vacuum

Quantifying the impact of earthquakes and geological factors on spatial heterogeneity of debris-flow prone areas:A case study in the Hengduan Mountains

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Journal of Mountain Science 2024年第5期21卷 1522-1533页

作者： HU Xudong SHEN Yitong HU Kaiheng XU Wennian LIU Daxiang HE Songtang GAO Jiazhen WEI Li LIU Shuang Hubei Provincial Engineering Research Center of Slope Habitat Construction Technique Using Cement-based Materials(china Three Gorges University) Yichang 443002China Hubei Key Laboratory of Disaster Prevention and Mitigation(china Three Gorges University) Yichang 443002China College of Civil Engineering and Architecture China Three Gorges UniversityYichang 443002China Shanghai Investigation Design&Research Institute Co.Ltd.Shanghai 200335China Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of SciencesChengdu 610041China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China Wuhan Polytechnic Wuhan 430074China

Understanding the spatial heterogeneity of debris-flow-prone areas holds significant implications for regional risk management, particularly in seismically active regions with geological faults. Despite the significance of this knowledge, a comprehensive quantification of the influence of regional topographical and geological factors on the spatial heterogeneity of debris-flow-prone areas has been lacking. This study selected the Hengduan Mountains, an earthquake-prone region characterized by diverse surface conditions and complex landforms, as a representative study area. An improved units zoning and objective factors identification methodology was employed in earthquake and fault analysis to assess the impact of seismic activity and geological factors on spatial heterogeneity of debrisflow prone areas. Results showed that the application of GIS technology with hydrodynamic intensity and geographical units analysis can effectively analyze debris-flow prone areas. Meanwhile, earthquake and fault zones obviously increase the density of debrisflow prone catchments and make them unevenly distributed. The number of debris-flow prone areas shows a nonlinear variation with the gradual increase of geomorphic factor value. Specifically, the area with 1000 m-2500 m elevation difference, 25°-30° average slope, and 0.13-0.15 land use index is the most favorable conditions for debris-flow occurrence;The average annual rainfall from 600 to 1150 mm and landslides gradient from 16° to 35° are the main causal factors to trigger debris flow. Our study sheds light on the quantification of spatial heterogeneity in debris flow-prone areas in earthquake-prone regions, which can offer crucial support for post-debris flow risk management strategies.

关键词： debris-flow prone areas causal factors GIS-based method spatial heterogeneity Hengduan Mountains

Mn incorporated RuO_(2) nanocrystals as an efficient and stable bifunctional electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction in acid and alkaline

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Chinese Chemical Letters 2024年第10期35卷 194-200页

作者： Jing Cao Dezheng Zhang Bianqing Ren Ping Song Weilin Xu State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China University of Science and Technology of china Hefei 230026China

The development of efficient and stable bifunctional overall water-splitting is a crucial goal for clean and renewable energy,which is a challenging ***,we report an Mn-incorporated RuO_(2)(MnRuO_(2))catalyst for highly efficient electrocatalytic oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)in acid and alkaline *** from a more electrochemical active area with the incorporation of Mn,the Mn-RuO_(2)required an overpotential of 200 mV to attain a current density of 10 mA/cm^(2)for OER in *** result indicates that the doping of Mn into RuO_(2)can enhance the OER *** acidic overall water-splitting electrolyzer with good stability constructed by bifunctional Mn-RuO_(2)only requires a cell voltage of 1.50 V to afford 10 m A/cm^(2)and can operate stably for 50 h at50 mA/cm^(2),which is better than the state-of-the-art Ru-based ***,the Mn-Ru O_(2)exhibits excellent HER and OER activity in alkaline media,and it shows superior activity and durability for overall water-splitting,only needing a cell voltage of 1.49 V to attain 10 m A/cm^(2).The present work provides an efficient approach to designing and constructing efficient Ru-based electrocatalysts for overall water-splitting.

关键词： RuO_(2)-based solid solution electrocatalysts Oxygenevolution reaction Hydrogen evolution reaction Overall watersplitting Acid andalkaline