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Development and evaluation of an online monitoring single-particle optical particle counter with polarization detection

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Journal of Environmental sciences 2024年第4期138卷 585-596页

作者： Weijie Yao Xiaole Pan Yu Tian Hang Liu Yuting Zhang Shandong Lei Junbo Zhang Yinzhou Zhang LinWu Yele Sun Zifa Wang State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

We developed a single-particle optical particle counter with polarization detection(SOPC)for the real-time measurement of the optical size and depolarization ratio(defined as the ratio of the vertical component to the parallel component of backward scattering)of atmospheric particles,the polarization ratio(DR)value can reflect the irregularity of the particles.The SOPC can detect aerosol particles with size larger than 500 nm and the maximum particle count rate reaches~1.8×10^(5)particles per liter.The SOPC uses a modulated polarization laser to measure the optical size of particles according to forward scattering signal and the DR value of the particles by backward S and P signal components.The sampling rate of the SOPC was 106#/(sec·channel),and all the raw data were processed online.The calibration curve was obtained by polystyrene latex spheres with sizes of 0.5-10μm,and the average relative deviation of measurement was 3.96% for sub 3μm particles.T-matrix method calculations showed that the DR value of backscatter light at 120°could describe the variations in the aspect ratio of particles in the above size range.We performed insitu observations for the evaluation of the SOPC,the mass concentration constructed by the SOPC showed good agreement with the PM_(2.5)measurements in a nearby state-controlled monitoring site.This instrument could provide useful data for source appointment and regulations against air pollution.

关键词： Instrument development Single particle detection Measurement uncertainty Optical simulation Mass concentration

Development of an automatic measurement system using atmospheric pressure photoionization ultrahigh-resolution mass spectrometry and application for on-line analysis of particulate matter

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Journal of Environmental sciences 2024年第4期138卷 516-530页

作者： Yayuan Dong Ranran Liu Ling Xie Xiaole Pan Yele Sun Lin Wu ZifaWang State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China Center for Excellence in Regional Atmospheric Environment Chinese Academy of SciencesInstitute of Urban EnvironmentXiamen 361021China

On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).

关键词： PM_(2.5) Chemical composition On-line measurement technique High resolution mass spectrometry

Tuning the electronic conductance of REHx（RE = Nd, Ce, Pr） by structural deformation

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Journal of Energy Chemistry 2024年第8期95卷 440-445页

作者： Shangshang Wang Weijin Zhang Jirong Cui Shukun Liu Hong Wen Jianping Guo Teng He Hujun Cao Ping Chen Dalian institute of Chemical physics Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences State Key Laboratory of Catalysis Chinese Academy of Sciences

Hydride ion（H-） conductors have drawn much attention due to their potential applications in hydrideion-based devices. Rare earth metal hydrides（REHx） have fast H-conduction which, unfortunately, is accompanied by detrimental electron conduction preventing their application as ion conductors. Here,REHx（RE = Nd, Ce, and Pr） with varied grain sizes, rich grain boundaries, and defects have been prepared by ball milling and subsequent sintering. The electronic conductivity of the ball-milled REHxsamples can be reduced by 2–4 orders of magnitude compared with the non-ball-milled samples. The relationship of electron conduction and miscrostructures in REHxis studied and discussed based on experimental data and previously-proposed classical and quantum theories. The H-conductivity of all REHxis about 10-4to 10-3S cm-1at room temperature, showing promise for the development of H-conductors and their applications in clean energy storage and conversion.

关键词： Crystal defect Electron conduction Electron scattering Hydride ion conduction Nanosized grain

ESM Cloud Toolkit: A Copilot for Energy Storage Material Research

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chinese physics Letters 2024年第5期41卷 40-46页

作者：许晶肖睿娟李泓 institute of physics Chinese Academy of SciencesBeijing 100190China School of Physical sciences University of Chinese Academy of SciencesBeijing 100049China

Searching and designing new materials play crucial roles in the development of energy storage devices. In today's world where machine learning technology has shown strong predictive ability for various tasks, the combination with machine learning technology will accelerate the process of material development. Herein, we develop ESM Cloud Toolkit for energy storage materials based on Mat Elab platform, which is designed as a convenient and accurate way to automatically record and save the raw data of scientific research. The ESM Cloud Toolkit includes multiple features such as automatic archiving of computational simulation data, post-processing of experimental data, and machine learning applications. It makes the entire research workflow more automated and reduces the entry barrier for the application of machine learning technology in the domain of energy storage materials. It integrates data archive, traceability, processing, and reutilization, and allows individual research data to play a greater role in the era of AI.

关键词： Toolkit Storage ESM

Dynamic simulation analysis of molten salt reactor-coupled air-steam combined cycle power generation system

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Nuclear Science and Techniques 2024年第2期35卷 222-233页

作者： Jing-Lei Huang Guo-Bin Jia Li-Feng Han Wen-Qian Liu Li Huang Zheng-Han Yang Shanghai institute of Applied physics Chinese Academy of SciencesShanghai 201800China University of chinese academy of sciences Beijing 100049China

A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power system.This model considers the impact of thermal properties of fluid variation on accuracy and has been validated with Simulink.This study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet parameters.Meanwhile,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also analyzed.The results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial values.This simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.

关键词： Molten salt reactor Combined cycle Dynamic characteristic Control

Coupled conditional nonlinear optimal perturbations and their application to ENSO ensemble forecasts

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Science China Earth sciences 2024年第3期67卷 826-842页

作者： Wansuo DUAN Lei HU Rong FENG LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of chinese academy of sciences Beijing 100049China

Limitations are existed in current ensemble forecasting initial perturbation methods for describing the interactions among various spheres of the Earth system. In this study, a new method is proposed, namely, the coupled conditional nonlinear optimal perturbation(C-CNOP) method, which incorporates multisphere interactions much appropriately. The El Nino-Southern Oscillation(ENSO) is a typical ocean-atmosphere “coupling”(or “interaction”) phenomenon. The C-CNOP method is applied to ensemble forecasting of ENSO. It is demonstrated that the C-CNOP method can generate coupled initial perturbations(CPs) that appropriately consider initial ocean-atmosphere coupling uncertainty for ENSO ensemble forecasts. Results reveal that the CPs effectively improve the ability of ENSO ensemble-mean forecasts in both temporal variability of Nio3.4 sea surface temperature anomalies(SSTAs) and spatial variability of ENSO mature-phase SSTAs. Notably, despite the weakest ocean-atmosphere coupling strength in the tropical Pacific occurring during the boreal spring and summer, CPs still capture the uncertainties of this weak coupling when ENSO predictions are initialized at these seasons. This performance of CPs significantly suppresses the rapid increase of ENSO prediction errors due to the high ocean-atmosphere coupling instability during these seasons, and thus effectively extends the lead time of skillful ENSO forecasting. Hence, the C-CNOP method is a suitable initial perturbation approach for ENSO ensemble forecast that can describe initial ocean-atmosphere coupling uncertainty. It is expected that the CCNOP method plays a significant role in predictions of other high-impact climate phenomena, and even future Earth system predictions.

关键词： Ensemble forecast Multisphere interaction Initial perturbations ENSO

Functional divergences of natural variations of TaNAM-A1 in controlling leaf senescence during wheat grain filling

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Journal of Integrative Plant Biology 2024年第6期66卷 1242-1260页

作者： Longxi Zhou Guowei Chang Chuncai Shen Wan Teng Xue He Xueqiang Zhao Yanfu Jing Zhixiong Huang Yiping Tong Key Laboratory of Seed Innovation Institute of Genetics and Developmental Sciences Chinese Academy of Sciences University of chinese academy of sciences The Innovative academy of Seed Design Chinese Academy of Sciences

Leaf senescence is an essential physiological process related to grain yield potential and nutritional quality. Green leaf duration(GLD) after anthesis directly reflects the leaf senescence process and exhibits large genotypic differences in common wheat; however, the underlying gene regulatory mechanism is still lacking. Here,we identified TaNAM-A1 as the causal gene of the major loci q GLD-6A for GLD during grain filling by map-based cloning. Transgenic assays and TILLING mutant analyses demonstrated that TaNAM-A1 played a critical role in regulating leaf senescence, and also affected spike length and grain size. Furthermore, the functional divergences among the three haplotypes of TaNAM-A1 were systematically evaluated. Wheat varieties with TaNAM-A1d(containing two mutations in the coding DNA sequence of TaNAM-A1) exhibited a longer GLD and superior yield-related traits compared to those with the wild type TaNAM-A1a. All three haplotypes were functional in activating the expression of genes involved in macromolecule degradation and mineral nutrient remobilization,with TaNAM-A1a showing the strongest activity and TaNAM-A1d the weakest. TaNAM-A1 also modulated the expression of the senescencerelated transcription factors TaNAC-S-7A and TaNAC016-3A. TaNAC016-3A enhanced the transcriptional activation ability of TaNAM-A1a by protein–protein interaction, thereby promoting the senescence process. Our study offers new insights into the fine-tuning of the leaf functional period and grain yield formation for wheat breeding under various geographical climatic conditions.

关键词： allelic variation leaf senescence map-based cloning TaNAM-A1 transcription factor Triticum aestivum

Microscopic and spectroscopic analysis of atmospheric iron-containing single particles in Lhasa,Tibet

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Journal of Environmental sciences 2024年第7期141卷 40-50页

作者： Junyu Chen Daobin Zhang Yiran Fu Jinhu Wang Xiaomei Cui Ci-ren Qu-zong Qiangying Zhang Chan Jin Bu Duo School of Ecology and Environment Tibet UniversityLhasa 850000China Shanghai institute of Applied physics Chinese Academy of SciencesShanghai 201800China institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100101China

The Tibetan Plateau,known as the“Third Pole”,is currently in a state of perturbation caused by intensified human activity.In this study,56 samples were obtained at the five sampling sites in typical area of Lhasa city and their physical and chemical properties were investigated by TEM/EDS,STXM,and NEXAFS spectroscopy.After careful examination of 3387single particles,the results showed that Fe should be one of the most frequent metal elements.The Fe-containing single particles in irregular shape and micrometer size was about7.8%and might be mainly from local sources.Meanwhile,the Fe was located on the subsurface of single particles and might be existed in the form of iron oxide.Interestingly,the core-shell structure of iron-containing particles were about 38.8%and might be present as single-,dual-or triple-core shell structure and multi-core shell structure with the Fe/Si ratios of 17.5,10.5,2.9 and 1.2,respectively.Meanwhile,iron and manganese were found to coexist with identical distributions in the single particles,which might induce a synergistic effect between iron and manganese in catalytic oxidation.Finally,the solid spherical structure of Fe-containing particles without an external layer were about 53.4%.The elements of Fe and Mn were co-existed,and might be presented as iron oxide-manganese oxide-silica composite.Moreover,the ferrous and ferric forms of iron might be co-existed.Such information can be valuable in expanding our understanding of Fe-containing particles in the Tibetan Plateau atmosphere.

关键词： Fe-containing single particle Irregular shape Core-shell structure Solid spherical structure Transmission electron microscopy Synchrotron X-ray microscopy

A promising approach to steady-state fusion: High-temperature superconducting strong-field stellarator with precise omnigenity

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The Innovation 2024年第1期5卷 23-25页

作者： Guosheng Xu Zhiyuan Lu Dehong Chen Baonian Wan institute of Plasma physics Chinese Academy of SciencesHefei 230031China

The stellarator has inherent advantages over the tokamak in achieving steady-state operation,especially due to its absence of disruptions and lack of need for current drive and the associated recirculating power.In recent years,there have been remarkable advances in the field of stellarator optimization,where precisely quasi-symmetric and precisely quasi-isodynamic magnetic configurations have been achieved with coils,allowing the neoclassical transport and energetic particle losses of stellarators to be reduced to levels comparable to those of tokamaks.At the same time,the development of high-temperature superconducting magnet technology will potentially double the magnetic field strength of stellarators.While these strong fields are expected to introduce new challenges,and while turbulent transport remains a common challenge for both stellarators and tokamaks,the combination of these physical and technological advances results in the expectation that stellarators will become a competitive approach to tokamaks for realizing steady-state fusion.

关键词： field approach precise