Jian Wang

Related publications (1,278)

Aerosol-into-liquid capture and detection of atmospheric soluble metals across the gas–liquid interface using Janus-membrane electrodes

Tianyu Cen, Min Gao, Christian Ludwig, Jian Wang

The soluble fraction of atmospheric transition metals is particularly associated with health effects such as reactive oxygen species compared to total metals. However, direct measurements of the soluble fraction are restricted to sampling and detection units in sequence burdened with a compromise between time resolution and system bulkiness. Here, we propose the concept of aerosol-into-liquid capture and detection, which allowed one-step particle capture and detection via the Janus-membrane electrode at the gas–liquid interface, enabling active enrichment and enhanced mass transport of metal ions. The integrated aerodynamic/electrochemical system was capable of capturing airborne particles with a cutoff size down to 50 nm and detecting Pb(II) with a limit of detection of 95.7 ng. The proposed concept can pave the way for cost-effective and miniaturized systems, for the capture and detection of airborne soluble metals in air quality monitoring, especially for abrupt air pollution events with high airborne metal concentrations (e.g., wildfires and fireworks).

2023

An elution-based method for estimating efficiencies of aerosol collection devices not affected by their pressure drops

Tianyu Cen, Christian Ludwig, Jiukai Tang, Jian Wang

2022

Automated identification of local contamination in remote atmospheric composition time series

Hélène Paule Angot, Andrea Baccarini, Ivo Fabio Beck, Lubna Dada, Julia Schmale, Jian Wang

A common challenge of atmospheric measurements in remote environments is to identify pollution from nearby activities that interfere with the purpose of the observations. Pollution, particularly from combustion, typically reveals itself in enhanced particle- , CO2 or CO concentrations and affects many atmospheric variables. It can vary in time scales from a few seconds to several hours. Here, we present an automated algorithm used to clean the year-long continuous (10s-time resolution) dataset of particle concentration measurements collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition onboard RV Polarstern. We identify pollution in our dataset based on the gradient, i.e., time derivative, of the particle number concentration. If this gradient exceeds a certain threshold, the data is flagged as polluted. We describe the performance of the algorithm and compare it to other commonly-used techniques. This method has two main advantages: It allows the detection of pollution from both stationary and non-stationary sources, and polluted periods can be identified without a need for other datasets (e.g., wind direction or CO2 concentration). This algorithm will be made open-source and user-friendly to allow wide use in the MOSAiC and larger atmospheric chemistry community.

2022

Integrated Aerodynamic/Electrochemical Microsystem for Collection and Detection of Nanogram-level Airborne Bioaccessible Metals

Tianyu Cen, Christian Ludwig, Jiukai Tang, Jian Wang

The soluble fraction of aerosol particulate matter containing trace metals has the potential to engender toxicity and exacerbate the adverse health effects of particulate matter. In this study, an inertial-impaction-based fluidic chip integrated with electrochemical detection was developed to achieve high collection efficiency and measurements of the bioaccessible metal fraction at the nanogram level. The average collection efficiency for ultrafine and fine particles larger than 50 nm, obtained at a flow rate of 2.5 L/min, was above 70%. The detection ranges of aerosol soluble copper depended on the collection duration and airflow rate. At a working flow rate of 3.1 L/min and collection efficiency of 70%, the microsystem was capable of detecting Cu concentrations above 53 ng/m3, 32 ng/m3 and 8 ng/m3 with 3 h, 5 h and 20 h collection periods, respectively, which were in the range of reported atmospheric concentrations. The detection ratio of real-world samples (i.e. PM10-like aerosol) was 100 ± 14%, indicating excellent aerodynamic collection and reliable electrochemical detection. The collection and sensing performance of the microsystem demonstrates a new step towards an online, mobile, low-cost, and miniaturized routine monitoring system for bioaccessible metals and possibly other soluble components in the aerosols.

2022

On the durability of surgical masks after simulated handling and wear

Baris Çaglar, Yann Albert Gérard Lebaupin, Véronique Michaud, René M. Rossi, Vincent Marc Varanges, Jian Wang

After the spread of COVID-19, surgical masks became highly recommended to the public. They tend to be handled and used multiple times, which may impact their performance. To evaluate this risk, surgical masks of Type IIR were submitted to four simulated treatments: folding, ageing with artificial saliva or sweat and washing cycles. The air permeability, mechanical integrity, electrostatic potential, and filtration efficiency (FE) of the masks were measured to quantify possible degradation. Overall, air permeability and mechanical integrity were not affected, except after washing, which slightly degraded the filtering layers. Electrostatic potential and FE showed a strong correlation, highlighting the role of electrostatic charges on small particle filtration. A slight decrease in FE for 100 nm particles was found, from 74.4% for the reference masks to 70.6% for the mask treated in saliva for 8 h. A strong effect was observed for washed masks, resulting in FE of 46.9% (± 9.5%), comparable to that of a control group with no electrostatic charges. A dry store and reuse strategy could thus be envisaged for the public if safety in terms of viral and bacterial charge is ensured, whereas washing strongly impacts FE and is not recommended.

2022

Search for relativistic fractionally charged particles in space

Johan Juul Chang, Jie Chen, Jennifer Maria Frieden, Ming Gao, Wei Li, Xuan Li, Junqiu Liu, Hao Liu, Shuai Liu, Chiara Perrina, Arshia Ruina, Jian Wang, Siyuan Wang, Yi Wang, Xiao Wang, Songmei Wu, Zhirui Xu, Yong Yang, Yi Zhang, Yan Zhang

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles (FCPs) still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Most of the previously conducted searches for FCPs in cosmic rays were based on experiments underground or at high altitudes. However, there have been few searches for FCPs in cosmic rays carried out in orbit other than AMS-01 flown by a space shuttle and BESS by a balloon at the top of the atmosphere. In this study, we conduct an FCP search in space based on on -orbit data obtained using the Dark Matter Particle Explorer (DAMPE) satellite over a period of five years. Unlike underground experiments, which require an FCP energy of the order of hundreds of GeV, our FCP search starts at only a few GeV. An upper limit of 6.2 x 10-10 cm-2 sr-1 s-1 is obtained for the flux. Our results demonstrate that DAMPE exhibits higher sensitivity than experiments of similar types by three orders of magnitude that more stringently restricts the conditions for the existence of FCP in primary cosmic rays.

2022

Angular analysis of B0->D-Ds+ with Ds+-> Ds+gamma decays

Hossein Afsharnia, Liupan An, Vladislav Balagura, Aurelio Bay, Violaine Bellée, Federico Betti, Frédéric Blanc, Alexey Boldyrev, Maxim Borisyak, Sara Celani, Chunhui Chen, Serhii Cholak, Peter Clarke, Victor Coco, Tommaso Colombo, Adam Davis, Michel De Cian, Hans Dijkstra, Paolo Durante, Dipanwita Dutta, Surapat Ek-In, François Fleuret, Christoph Frei, Elena Graverini, Marco Guarise, Guido Haefeli, Xiaoxue Han, Maxim Karpov, Veronica Sølund Kirsebom, Almagul Kondybayeva, Yiming Li, Ho Ling Li, Hao Liu, Shuai Liu, Vladimir Macko, Maurizio Martinelli, Simone Meloni, Tatsuya Nakada, Tara Nanut, Matthew Needham, Niko Neufeld, Preema Rennee Pais, Anton Petrov, Guillaume Max Pietrzyk, Renato Quagliani, Gerhard Raven, Federico Leo Redi, Olivier Schneider, Maxime Schubiger, Sebastian Schulte, Lesya Shchutska, Evgenii Shmanin, Pavol Stefko, Maria Elena Stramaglia, Liang Sun, Frédéric Teubert, Mark Tobin, Minh Tâm Tran, Carina Trippl, Yi Wang, Rui Wang, Mingkui Wang, Zheng Wang, Jian Wang, Zhirui Xu, Yong Yang, Hang Yin, Ettore Zaffaroni, Lei Zhang, Yi Zhang, Yu Zheng, Yao Zhou, Xiaoqing Zhou

The first full angular analysis of the B0 -> D-Ds+ decay is performed using 6 fb(-1) of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The Ds+-> Ds+gamma and D*- -> D0- vector meson decays are used with the subsequent Ds+ -> K+K-pi (+) and D0 -> K+pi (-) decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be f(L) = 0.578 +/- 0.010 +/- 0.011 with world-best precision, where the first uncertainty is statistical and the second is systematic. The pattern of helicity amplitude magnitudes is found to align with expectations from quark-helicity conservation in B decays. The ratio of branching fractions [B(B0 -> D-Ds+) x B(Ds+-> Ds+gamma)]/B(B-0 -> D(-)Ds+) is measured to be 2.045 +/- 0.022 +/- 0.071 with world-best precision. In addition, the first observation of the Cabibbo-suppressed B-s -> D(-)Ds+ decay is made with a significance of seven standard deviations. The branching fraction ratio B(B-s -> D(-)Ds+)/B(B-0 -> D(-)Ds+) is measured to be 0.049 +/- 0.006 +/- 0.003 +/- 0.002, where the third uncertainty is due to limited knowledge of the ratio of fragmentation fractions.

SPRINGER2021

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The branching fraction of the rare B-s(0) -> phi mu(+)mu(-) decay is measured using data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 6 fb(-1), respectively. The branching fraction is reported in intervals of q(2), the square of the dimuon invariant mass. In the q(2) region between 1.1 and 6.0 GeV2/c(4) , the measurement is found to lie 3.6 standard deviations below a standard model prediction based on a combination of light cone sum rule and lattice QCD calculations. In addition, the first observation of the rare B-s(0)-> f(2)' (1525)mu(+)mu(-) decay is reported with a statistical significance of 9 standard deviations and its branching fraction is determined.

AMER PHYSICAL SOC2021

Computational design of highly signaling active membrane receptors through de novo solvent-mediated allosteric networks

Patrick Daniel Barth, Jian Wang

Protein catalysis and allostery require the atomic-level orchestration and motion of residues, ligand, solvent and protein effector molecules, but the ability to design protein activity through precise protein-solvent cooperative interactions has not been demonstrated. Here, we report the design of a dozen novel membrane receptors catalyzing G-protein nucleotide exchange through diverse de novo engineered allosteric pathways mediated by cooperative networks of intra-protein, protein-ligand and solvent molecule interactions. Consistent with the predictions, designed protein activities strongly correlated with the level of solvent-mediated interaction network plasticity at flexible transmembrane helical interfaces. Several designs displayed considerably enhanced thermostability and activity compared to related natural receptors. The most stable and active variant crystallized in an unforeseen signaling active conformation, in excellent agreement with the design models. The allosteric network topologies of the best designs bear limited similarity to those of natural receptors and reveal a space of allosteric interactions larger than previously inferred from natural proteins. The approach should prove useful for engineering proteins with novel complex protein catalytic and signaling activities. Competing Interest Statement The authors have declared no competing interest.

2021

Electron and photon reconstruction and identification with the CMS experiment at the CERN LHC

Muhammad Ahmad, Benjamin William Allen, Georgios Anagnostou, Konstantin Androsov, Tagir Aushev, Thomas Berger, Michele Bianco, Rakesh Chawla, Yixing Chen, Chunhui Chen, Tian Cheng, Pratyush Das, João Miguel das Neves Duarte, Abhisek Datta, Milos Dordevic, Dipanwita Dutta, Matthias Finger, Francesco Fiori, Bertrand François, Sebastiana Gianì, Ruchi Gupta, Seungkyu Ha, Csaba Hajdu, Peter Hansen, Ali Harb, Miao Hu, Muhammad Ansar Iqbal, Alexis Kalogeropoulos, Viktor Khristenko, Doohyun Kim, Donghyun Kim, Ji Hyun Kim, Sanjeev Kumar, Ajay Kumar, Vineet Kumar, Ekaterina Kuznetsova, Federica Legger, Yiming Li, Jing Li, Zhen Liu, Werner Lustermann, Maren Tabea Meinhard, Ioannis Papadopoulos, Anton Petrov, Vladimir Petrov, Jessica Prisciandaro, Quentin Python, Andrea Rizzi, Paolo Ronchese, Valérie Scheurer, Sourav Sen, Arvind Shah, Varun Sharma, Ashish Sharma, Wei Shi, Kun Shi, Muhammad Shoaib, Bandeep Singh, Jan Steggemann, Wei Sun, Andromachi Tsirou, David Vannerom, Joao Varela, Zheng Wang, Jian Wang, Xiao Wang, Hui Wang, Qian Wang, Yi Wang, Siyuan Wang, Matthias Weber, Matthias Wolf, Meng Xiao, Yong Yang, Kai Yi, Yi Zhang, Hua Zhang, Jian Zhao

The performance is presented of the reconstruction and identification algorithms for electrons and photons with the CMS experiment at the LHC. The reported results are based on proton-proton collision data collected at a center-of-mass energy of 13 TeV and recorded in 2016-2018, corresponding to an integrated luminosity of 136 fb(-1). Results obtained from lead-lead collision data collected at root S-NN = 5.02 TeV are also presented. Innovative techniques are used to reconstruct the electron and photon signals in the detector and to optimize the energy resolution. Events with electrons and photons in the final state are used to measure the energy resolution and energy scale uncertainty in the recorded events. The measured energy resolution for electrons produced in Z boson decays in proton-proton collision data ranges from 2 to 5%, depending on electron pseudorapidity and energy loss through bremsstrahlung in the detector material. The energy scale in the same range of energies is measured with an uncertainty smaller than 0.1 (0.3)% in the barrel (endcap) region in proton-proton collisions and better than 1(3)% in the barrel (endcap) region in heavy ion collisions. The timing resolution for electrons from Z boson decays with the full 2016-2018 proton-proton collision data set is measured to be 200 ps.

2021