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Frontiers in Energy 2022年第2期16卷 321-335页

作者： Peiyuan PAN yunyun wu Heng CHEN Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation North China Electric Power UniversityBeijing 102206China

An advanced cogeneration system based on biomass direct combustion was developed and its feasibility was demonstrated. In place of the traditional single heat source (extraction steam), the extraction steam from the turbine, the cooling water from the plant condenser, and the low-pressure feedwater from the feedwater preheating system were collectively used for producing district heat in the new scheme. Hence, a remarkable energy-saving effect could be achieved, improving the overall efficiency of the cogeneration system. The thermodynamic and economic performance of the novel system was examined when taking a 35 MW biomass-fired cogeneration unit for case study. Once the biomass feed rate and net thermal production remain constant, an increment of 1.36 MW can be expected in the net electric production, because of the recommended upgrading. Consequently, the total system efficiency and effective electrical efficiency augmented by 1.23 and 1.50 percentage points. The inherent mechanism of performance enhancement was investigated from the energy and exergy aspects. The economic study indicates that the dynamic payback period of the retrofitting project is merely 1.20 years, with a net present value of 5796.0 k$. In conclusion, the proposed concept is validated to be advantageous and profitable.

关键词： biomass-fired cogeneration district heat production system absorption heat pump extraction steam cooling water low-pressure feedwater

Continuous-Wave Interference Mitigation for Acquisition Method in Unified Carrier TT&C Systems

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Journal of Beijing Institute of Technology 2018年第4期27卷 575-583页

作者： yunyun wu Xiuli Yu Yongqing Wang School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

An interference mitigation for acquisition method,based on both energy center and spectrum symmetry detection,has been proposed as a possible solution to the problem of signal acquisition susceptibility to continuous-wave interference(CWI)in unified carrier telemetry,tracking,and command(TT&C)*** subcarrier modulation index as a priori condition,the existence of CWI is determined by comparing the energy center with the symmetric *** the presence of interference,the interference frequency point is assumed and culled;sequentially,the spectral symmetry is used to verify whether the signal acquisition is *** analysis,simulations,and experimental results demonstrate that the method can realize the acquisition of the main carrier target signal with an interference-to-signal ratio of 31 dB,which represents an improvement over the existing continuous-wave interference mitigation for acquisition methods.

关键词： unified carrier telemetry tracking and command(TT&C) interference mitigation signal acquisition spectrum symmetry

Construction of Z-scheme Cu-CeO_(2)/BiOBr heterojunction for enhanced photocatalytic degradation of sulfathiazole

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Chinese Chemical Letters 2024年第7期35卷 167-172页

作者： Xingmin Chen yunyun wu Yao Tang Peishen Li Shuai Gao Qiang Wang Wen Liu Sihui Zhan College of Environmental Sciences and Engineering Nankai UniversityTianjin 300350China Laboratory for Micro-Sized Functional Materials&College of Elementary Education and Department of Chemistry Capital Normal UniversityBeijing 100048China College of Environmental Sciences and Engineering The Key Laboratory of Water and Sediment Sciences(MOE)Peking UniversityBeijing 100871China

The utilization of an efficient photocatalyst is crucial for the photocatalytic degradation of antibiotics in water through visible light,which is an imperative requirement for the remediation of water *** this study,a novel Cu-CeO_(2)/BiOBr Z-type heterojunction was synthesized by calcination and hydrothermal methods,and the degradation rate of sulfathiazole(STZ)antibiotic solution was studied using simulated illumination(300 W xenon lamp).The results indicated that 3%Cu-CeO_(2)/BiOBr achieved a degradation rate of 92.3%within 90 min when treating 20 mg/L STZ solution,demonstrating its potential for practical water treatment *** using various chemical instruments revealed that 3%Cu-CeO_(2)/Bi OBr exhibited the lowest electron-hole recombination rate and electron transfer ***,the utilization of ESR data and quenching experiments has substantiated the involvement of hydroxyl radicals(·OH)and superoxide radicals(·O_(2)^(-))as the primary active ***,a plausible degradation mechanism has been *** findings offer a prospective approach for the development of heterojunction materials with appropriate band matching.

关键词： Cu-CeO_(2)/BiOBr nanoheterojunction Photocatalytic degradation Sulfathiazole Z-scheme

Analysis and Monitoring of Indoor Radon Concentrations of 37 Kindergartens — Beijing Municipality, China, 2023

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China CDC weekly 2024年第13期6卷 272-276页

作者： Meinan Yao Kuke Ding Xiaozhe Tang yunyun wu Yanchao Song Shuyuan Liu Bin Bai Li Zhang Yongzhong Ma Institute for Radiation Hygiene Protection Beijing Center for Disease Prevention and ControlBeijingChina Chinese Center for Disease Control and Prevention BeijingChina Key Laboratory of Radiological Protection and Nuclear Emergency&National Institute for Radiological Protection Chinese Center for Disease Control and PreventionBeijingChina

Introduction:Radon(222Rn or 222radon)is a radioactive gas emitted from building materials,foundations,and *** are especially susceptible to radon exposure,underscoring the need to assess indoor radon levels in *** study monitored radon concentrations in 37 Beijing kindergartens from June to October ***:A random sample of 37 kindergartens was selected from 18 administrative districts in *** indoor radon concentration was measured using the solid track accumulation method,with radon detectors continuously monitored over a 3-month ***:The mean indoor radon level in 37 kindergartens,observed at 252 monitoring points,was 84.3 Bq/m^(3),with values varying from 12.9 to 263.5 Bq/m^(3).About 20.2%of points showed radon levels between 100.0 and 200.0 Bq/m^(3),while 2.4%exceeded 200.0 Bq/m^(3).Notably,radon levels were significantly elevated on the ground floor compared to the upper ***:Indoor radon levels in 37 kindergartens remained below the national standard limit of 300.0 Bq/m^(3) for buildings(GB/T 16146-2015).Nonetheless,18.9%of the kindergartens exceeded the 100.0 Bq/m^(3) limit set for new *** is advised to improve radon monitoring in kindergartens and consider developing a national standard for maximum permissible radon levels in such facilities.

关键词： Radon limit floor

Silver nanocubes monolayers as a SERS substrate for quantitative analysis

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Chinese Chemical Letters 2021年第4期32卷 1497-1501页

作者： Ziang Zhou Xiuhui Bai Peishen Li Changzheng Wang Ming Guo Yang Zhang Peiren Ding Shaowei Chen yunyun wu Qiang Wang Laboratory for Micro-sized Functional Materials College of Elementary Education and Department of ChemistryCapital Normal UniversityBeijing 100048China School of Chemistry Beijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing 100191China Beijing Key Laboratory of Functional Materials for Building Structure and Environment Remediation Beijing University of Civil Engineering and ArchitectureBeijing 100044China College of Chemistry Beijing Normal UniversityBeijing 100875China Department of Chemistry and Biochemistry University of CaliforniaSanta CruzUnited States

Surface-enhanced Raman scattering(SERS)is a powerful spectroscopic tool in quantitative analysis of molecules,where the substrate plays a critical role in determining the detection ***,a silver nanocubes/polyelectrolyte/gold film sandwich structure was prepared as a reproducible,highperformance SERS substrate by the wate r/oil inte rfacial assembly *** addition to the hot spots on the nanocubes surface,the edge-to-edge interspace of the Ag nanocubes led to marked enhancement of the SERS intensity,with a limit of detection of 10~(11)mol/L and limit of quantitation of 10~(10)mol/L for crystal *** rhodamine 6 G and crystal violet were co-adsorbed on the Ag nanocube surfaces,the characteristic SERS peaks of the two molecules remained well resolved and separated,and the peak intensities varied with the respective concentration,which could be exploited for concurrent detection of dual *** from this work indicate that organized ensembles of Ag nanocubes can serve as effective SERS substrate can for sensitive analysis for complex molecular systems.

关键词： Silver nanocube Surface enhanced raman scattering Quantitative analysis Rhodamine 6G Crystal violet

Indoor Radon Survey in 31 Provincial Capital Cities and Estimation of Lung Cancer Risk in Urban Areas of China

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Biomedical and Environmental Sciences 2024年第11期37卷 1294-1302页

作者： Xiaoxiang Miao Yinping Su Changsong Hou Yanchao Song Bowei Ding Hongxing Cui yunyun wu Quanfu Sun Key Laboratory of Radiological Protection and Nuclear Emergency China CDCNational Institute for Radiological ProtectionChinese Center for Disease Control and PreventionBeijing 100088China

Objective We aimed to analyze the current indoor radon level and estimate the population risk of radon-induced lung cancer in urban areas of *** Using the passive monitoring method,a new survey on indoor radon concentrations was conducted in 2,875 dwellings across 31 provincial capital cities in Chinese mainland from 2018 to *** attributable risk of lung cancer induced by indoor radon exposure was estimated based on the risk assessment *** The arithmetic mean(AM)and geometric mean(GM)of indoor radon concentrations were 65 Bq/m^(3)and 55 Bq/m^(3),respectively,with 13.6%of measured dwellings exceeding 100 Bq/m^(3)and 0.6%exceeding 300 Bq/m^(3).The estimated number of lung cancer deaths induced by indoor radon exposure was 150,795,accounting for 20.30%(95%CI:20.21%-20.49%)of the lung cancer death *** This study provided the most recent data on national indoor radon levels in urban areas and the attributable risk of lung *** results served as an important foundation for further research on the disease burden of indoor radon exposure and radon mitigation efforts.

关键词： Indoor radon Urban Attributable risk Lung cancer

Effect of TiO_2 on the Sinterability and Microstructure of Mullite Sythesized from Al(OH)_3 and SiO_2

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China's Refractories 2006年第2期15卷 3-6页

作者： LIANG Yonghe YIN Yucheng wu yunyun WANG Jibao The Hubei Province Key Laboratory of Refractory Ceramics Ministry-Province Jointly Constructed Cultivation Base for State Key Laboratory Hubei Wuhan 430081

Using analytical pure Al（ OH）3 , SiO2 , TiO2 as raw materials, effect of TiO2 on the sinterability and microstructure of mullite synthesized from Al （ OH）3 and SiO2 was investigated in this paper by XRD , SEM and EPAX. Results show that TiO2 can promote the sintering property when the amount is below 6%, the sinterability of samples becomes better with the increase of the amount of TiO2, microstructure of samples densify gradually, and the best effect can be achieved when the amount of TiO2 is 6%. It was shown by XRD analysis that no Al2TiO5 present when the amount of TiO2 is below 6%, TiO2 existed in the form of solid-solution and glass phase; When the amount of TiO2 is up to 6%, the sinterability of samples becomes worse with the increase of TiO2 added, microstructure of samples began to loosen, Al2TiO5 can be observed in samples and its amount increase with the increase of TiO2.

关键词： Mullite sinterability TiO2 Microstructure

^(222)Rn-^(220)Rn分辨探测器的刻度与比对

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核技术 2008年第12期31卷 920-924页

作者：武云云尚兵中国疾病预防控制中心辐射防护与核安全所北京100088

为了保证测量质量,采用实验室新改进的222Rn-220Rn分辨探测器在南华大学氡实验室进行了刻度,并参加了日本NIRS组织的国际比对。结果显示,222Rn、220Rn暴露量与径迹密度之间有很好的线性关系,相关系数分别是0.9894、0.9885;222Rn、220Rn... 详细信息

为了保证测量质量,采用实验室新改进的222Rn-220Rn分辨探测器在南华大学氡实验室进行了刻度,并参加了日本NIRS组织的国际比对。结果显示,222Rn、220Rn暴露量与径迹密度之间有很好的线性关系,相关系数分别是0.9894、0.9885;222Rn、220Rn刻度因子分别为4.27±0.40Tackscm-2(kBq·m-3·h)–1、2.33±0.39Trackscm-2(kBq·m-3·h)–1。纯222Rn条件,测量值与NIRS提供的参考值的相对百分偏差(RPD)和变异系数(COV)分别为12%、7.7%,达到了英国NRPB规定的B级水平,在美国EPA规定的可接受的控制限之内;高220Rn条件,220Rn测量值的RPD和COV分别为22%、4.8%。有关220Rn测量偏差偏高的原因有待进一步探讨。

关键词： ^222Rn ^220Rn 刻度比对分辨探测器

Study on the effect of Fresh Air Ventilation system for reducing indoor ^(222)Rn

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Radiation Medicine and Protection 2024年第1期5卷 49-52页

作者： Yanchao Song Dexing Lian Hongxing Cui Changsong Hou yunyun wu Key Laboratory of Radiological Protection and Nuclear Emergency National Institute for Radiological ProtectionChinese Center for Disease Control and PreventionBeijing 100088China National Center for Occupational Safety and Health NHCBeijing 102308China

Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in ***:The indoor concentrations of Rn and its decay products(RnD)in three residential rooms,two in Beijing and one in Hefei city,Anhui province,before and after FAVS functioned were measured using an active continuous *** air exchange rate was monitored by measuring CO_(2) concentration using the tracer gas ***:In the three rooms,the FAVS reduced the Rn concentrations from(162±80)Bq/m^(3) to(63±22)Bq/m^(3) and decreased the RnD concentrations from(64±35)Bq/m^(3) to(13±6)Bq/m^(3) on average,a decrease of(59±25)% in the Rn concentrations and a drop of(77±18)%in the RnD *** dose conversion factors of Rn and RnD,FAVS decreased the exposure dose by(76±20)%.Besides,FAVS increased the air exchange rates from 0.17 h^(-1) to 0.56 h^(-1) on ***:FAVS can effectively reduce indoor Rn and RnD concentrations by improving the air exchange,serving as a valuable supplement to existing radon mitigation methods,especially in extreme climates.

关键词： FAVS Rn Decay product Air exchange rate

Topical treatment of all-trans retinoic acid inhibits murine melanoma partly by promoting CD8+ T-cell immunity

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Topical treatment of all-trans retinoic acid inhibits murine...