Junjie Liu

Junjie Liu
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Junjie verified their affiliation via an institutional email.
Verified
Junjie verified their affiliation via an institutional email.
  • Doctor of Philosophy
  • Professor at Tianjin University

About

248
Publications
69,887
Reads
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5,654
Citations
Current institution
Tianjin University
Current position
  • Professor

Publications

Publications (248)
Article
Due to current lifestyle trends and heightened sensitivity to health, particularly in the post-COVID-19 era, the importance of indoor air quality (IAQ) and odor emissions has increased. Volatile organic compounds (VOCs), which are emitted from various indoor materials are significant air pollutants that adversely affect IAQ and occupant health. In...
Article
Due to the challenges of adjustment after installation and the elevated failure rate associated with the use of electric valves, which contributes to increased weight among other issues, single-hole restrictors (SHRs) are commonly employed within the ventilation system of the manned space station. These restrictors are pre-configured with parameter...
Article
Wet scrubbers are often used in various types of industrial workshops to separate dust particles from the air. Nonuniform gas–liquid ffow patterns above the sieve plate can result in signiffcant losses in puriffcation efffciency for particles. To improve the ffow pattern via sieve plate design and to more accurately predict puriffcation efffciency,...
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Full-text available
High heat loads in industrial buildings potentially form strong natural convective flows. These flows exhibit significant unsteadiness and anisotropy, which can profoundly impact indoor air distribution. To study the flow characteristics of thermal convective flows in large indoor spaces, we built a large-scale test bench with controllable thermal...
Article
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The dispersion of particulate pollutants around buildings raises concerns due to adverse health impacts. Accurate prediction of particle dispersion is important for evaluating health risks in urban areas. However, rigorous validation data using particulate tracers is lacking for numerical models of urban dispersion. Many prior studies rely on gas d...
Article
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Cooking can emit high concentrations of particles and gaseous pollutants. Cooking has contributed to the major source of indoor air pollutants, especially for particle pollutants in residential buildings. Many studies already analyzed the emission characteristics of Chinese cooking-related UFPs and PM2.5, while less for the fine particle size distr...
Article
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Objective. The aim is to explore the effect and mechanism of indoor toluene exposure on orienting network. Methods. Twenty-two healthy adults were exposed to 0 ppb, 17.5 ppb, 35 ppb, and 70 ppb toluene for 4 hours, respectively. All subjects underwent attention network behavioral test, and their electroencephalographic activity was recorded simulta...
Article
Full-text available
Over the past few years, surface ozone (O3) pollution has dominated China’s air pollution as particulate matter has decreased. In Beijing, the annual average concentrations of ground-level O3 from 2015 to 2020 regularly increased from 57.32 to 62.72 μg/m³, showing a change of almost 9.4%, with a 1.6% per year increase. The meteorological factors ar...
Chapter
Smart control of window is a means of effectively reducing concentrations of indoor PM2.5 (particulate matter with aerodynamic diameter less than 2.5 μm) in naturally ventilated residential buildings without air cleaning devices. This study aimed to develop a reinforcement learning (RL) approach to automatically control window behavior in real time...
Chapter
Fast fluid dynamics (FFD) could provide efficient airflow and concentration simulation. The commonly used turbulence model in FFD was RNG k-\(\varepsilon \) turbulence model which solved two transport equations to obtain eddy viscosity. To improve computing speed, this investigation implemented no turbulence model, Smagorinsky model and dynamic Sma...
Article
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The environment inside airliner cabins has attracted increasing attention. Instantaneous airflow, as one of the fundamental parameters of airflow field, affects aspects of the airliner cabin environment such as occupant comfort and airborne disease transmission. This study evaluated the characteristics of instantaneous airflow in airliner cabins wi...
Article
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With the spread of SARS-CoV-2 virus all over the world, the indoor air quality of commercial buildings has received intense attention. The evaluation of high-volume air purifiers (HAP, CADR≥800m³/h) is of unprecedented importance. According to the national standard GB/T 18801-2015, the purification performance of HAP and its three different replace...
Article
Full-text available
Indoor air quality (IAQ) influences individual physical and mental health. Laboratory studies conducted in environmental chambers have shown that IAQ parameters such as temperature, humidity, CO 2 , and volatile organic compounds (VOCs) may impact participants’ productivity and cognitive performance. To better understand the influence of VOC at low...
Article
With the development of IoT technology and low-cost indoor air quality (IAQ) sensors, the IoT-based IAQ monitoring platform has garnered significant research interest and demonstrated its potential in enhancing IAQ management. This study presents a comprehensive review of previous research on the development and application of IoT-based IAQ platfor...
Article
Aerosols such as PM2.5 and PM10 can have an immense impact on human health. With the outbreak of SARS-CoV-2, it is urgent to filter aerosols by media filtration technology. Electrospun nanofibers are a promising material for achieving high efficiency, low resistance, light weight, and environmentally friendly air filtration. But research on filtrat...
Article
In China, the regulation of a district heating (DH) station is mainly based on weather compensation control. This control method leads to large room temperature fluctuations and high energy consumption as the regulation of supply water temperature is solely based on outdoor meteorological parameters, which the influence of pipe delay, thermal inert...
Article
The Himalayas, which include delicate and unspoiled ecosystems, have the third-largest glacier ice store in the world. Recent research reveals that anthropogenic and natural factors contribute to the deteriorating air quality in the region. Rising particulate matter (PM) levels might have devastating effects on the regional climate, hydrologic cycl...
Article
The durability of polymer electrolyte membrane fuel cells (PEMFCs) is impacted by airborne contaminants, and it is necessary to install a cathode air filter to remove harmful pollutants. To learn more about the effect of key process variables (particle size and bulk density) on the adsorption performance of cathode air filters, the breakthrough beh...
Article
Objective: While high concentrations of toluene are known to affect multiple human organ systems, research concerning the influence of immediate, short-term exposure to toluene indoors and at low concentrations is scarce. Here, we studied effects of indoor toluene exposure on neural network alterations during working memory (WM) encoding. Methods...
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Humans are the primary source of particulate contamination in biological cleanrooms. Emitted particles can carry microorganisms, which severely reduces cleanliness. Due to the uncertainty of human particle emission rates, there is excessive ventilation in the cleanroom, resulting in waste of energy consumption. To resolve this problem, in this stud...
Article
The health hazards of cooking oil fume (COF) exposure underscore the importance of effectively controlling air pollution in kitchens, especially during cooking. The effectiveness of ventilation for gaseous pollutant control deserves more attention due to its toxicity, odor and strong diffusivity. In this study, field measurements of 23 carbonyl com...
Article
Full-text available
Although toluene is a typical in-vehicle pollutant, the impacts of in-vehicle toluene exposure on cognitive functions remain unestablished. Therefore, this study aimed to investigate the effects of short-term toluene exposure in vehicles on working memory based on neural oscillations. In total, 24 healthy adults were recruited. Each subject was exp...
Article
Full-text available
The indoor environment has a significant impact on our wellbeing. Accurate prediction of the indoor air distribution can help to create a good indoor environment. Reynolds-averaged Navier-Stokes (RANS) models are commonly used for indoor airflow prediction. However, the Boussinesq hypothesis used in the RANS model fails to account for indoor anisot...
Article
Full-text available
Air is a diverse mixture of gaseous and suspended solid particles. Several new substances are being added to the air daily, polluting it and causing human health effects. Particulate matter (PM) is the primary health concern among these air toxins. The World Health Organization (WHO) addressed the fact that particulate pollution affects human healt...
Article
To reduce hazards due to the radon dispersion on occupants, careful consideration of multi-parameters of stratum ventilation is necessary, including air supply velocity, temperature, angle and air outlet position. In this study, the radon dispersion in a typical office with stratum ventilation was evaluated based on experimental measurements and co...
Article
The airliner cabin environment is very important to the health of passengers and crew members, and the use of high‐efficiency particulate air (HEPA) filters for recirculated air in the environmental control systems (ECS) is essential for the removal of airborne particles such as SARS CoV‐2 aerosols. A HEPA filter should be high efficiency, low‐pres...
Article
Renewable energy usage is continuing to increase as many countries worldwide are aiming to reach peak carbon emission and achieve carbon neutrality in the near future. One inherent problem with renewable energy is that its generation profile does not often fit well with the electricity usage profile. Therefore, it is of utmost importance that termi...
Article
Conventional district heating (DH) substations in China use a feed-forward adjustment method that predicts the water supply temperature based on the outdoor temperature. This method does not consider the delay of the pipe network and the thermal inertia of the building. Most importantly, the lack of closed-loop feedback on the indoor temperature re...
Article
The use of wet scrubbing to remove airborne molecular contaminants in cleanroom make-up air units has economic benefits and good application prospects. Still, problems with this method include low removal efficiency and large water consumption. To improve scrubbing performance, we built a full-scale scrubbing experiment platform using SO2 as the re...
Article
Ammonia is a harmful gas in semiconductor cleanrooms. Activated carbons are widely used to remove ammonia. However, the existence of ambient moisture significantly impacts ammonia adsorption on adsorbents. Therefore, it is necessary to understand their adsorption performance on activated carbons to improve the product yield in semiconductor cleanro...
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Full-text available
The ongoing COVID-19 pandemic made us re-realize the importance of environmental disinfection in indoor areas. Several studies have documented that the air purification system combining UV light and high-efficiency particulate air (HEPA) filtration can successfully remove the virus from the air. However, UV light cannot penetrate deep into the HEPA...
Article
The influence of volatile organic compounds (VOCs) on cognitive performance has been widely recognized but is still imperfectly understood. This article hypothesized that the influence of low concentrations of VOCs on cognitive function would occur without triggering subjective awareness. Toluene is a representative VOC commonly found in Chinese dw...
Article
The operating resistance of a high-efficiency particulate air (HEPA) filter is affected by the environment and cannot be obtained through the dust holding capacity (DHC) test in the laboratory. For non-flat HEPA filters, studies on the effect of non-uniform deposition of particles on operating resistance were insufficient. We proposed an equivalent...
Article
Despite accumulative literature reporting negative impacts of high‐concentration toluene, cognitive effects of toluene at low concentration are still unclear. Twenty‐two healthy college students were exposed in a closed environmental chamber to investigate the influence of indoor toluene on cognitive performance and brain activity. During each tolu...
Article
The integration of air volume measurement and control has become a trend. However, one of the challenges in researching the integration of measurement and control dampers is that the coupling effect between local components (e.g., dampers, elbows, reducers and tees) in the duct system exerts a substantial effect on the measurement. This paper optim...
Article
Indoor volatile organic compounds (VOCs) produce odours that reduce perceived air quality. Furnitures and indoor decoration are the main sources of indoor VOCs. Considering the increase in outdoor and indoor ozone concentrations, ozone, as a strong oxidant, can have an impact on indoor odour. Herein, medium-density fibreboard (MDF) and flame retard...
Article
Full-text available
The falling film flow characteristics of a liquid on the surface of corrugated sheet packing are crucial for its mass transfer performance in various industrial applications. In this study, a falling film flow experiment with laser-induced fluorescence technology was conducted to validate the flow characteristics of a falling film simulated using c...
Article
Wet scrubbers, with the advantages of high efficiency and efficient water savings, are often used in various industries. The internal gas-liquid two-phase pattern flow in a wet scrubber is complex and unstable, which affects the purification efficiency. However, the purification efficiency of a wet scrubber is rather difficult to measure in real ti...
Article
The purpose of this field study was to evaluate the performance of heat recovery ventilation (HRV) systems in daily usage. A one-year field measurement campaign was conducted in 25 dwellings with an HRV system among three climate zones in China. The operating pattern of ventilation systems obviously varies from that in developed countries. The occu...
Article
Full-text available
Epidemiological surveys have shown a significant association between indoor airborne particle exposure and adverse health effects. Duct-type electrostatic precipitators (ESPs) are effective in controlling airborne particles in buildings. Although several studies have examined the initial performance of duct-type ESPs, there are no comprehensive dat...

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