Shitao Peng

In order to demonstrate the feasibility of the tunable diode laser absorption spectroscopy (TDLAS) technology for monitoring NO_x emissions from inland vessels, an equipment is designed to monitor emissions for inland vessels. The equipment was installed at the Jianbi locks, where experimental measurements were conducted on vessels passing through the locks, with a total of 330 vessels being measured. The detection rate for vessels was 50.3%, with a detection rate of 72.4% for fully loaded vessels and 24.7% for unloaded vessels. In addition, the exhaust emission patterns of inland vessels, the NO_x emission patterns and detection rate of fully loaded and unloaded vessels, and the key parameter of the NO_x emission factor of inland vessels were comprehensively analyzed. The experimental results show that CO₂ and NO_x in the exhaust gas of inland vessels have high signal intensity and good synchronization and can be applied to the regulatory monitoring of NO_x emissions from inland vessels. Furthermore, the ratios of NO/CO₂ and NO₂/CO₂ from fully loaded and unloaded vessels were significantly different. indicating that the NO₂ indicator must be included in the remote monitoring indicators for inland vessel exhaust gases. Otherwise, the remote monitoring results for NO_x may be significantly underestimated.

Scientific evaluation of the effectiveness of ecological restoration could provide support for sustainable management and protection of wetlands. However, due to the multiple and difficult to quantify factors affecting wetlands, commonly used spatiotemporal evaluation methods were difficult to scientifically reflect the actual effectiveness of ecological restoration. This paper took Tianjin Qilihai Wetland, a representative wetland in northern China, as the research object. Two representative time points, 2017 (before the start of the 2-year restoration project) and 2023 (4 years after the completion of the restoration project), were selected to construct a three-level monitoring and evaluation index system containing eight specific indicators from three aspects—water environment, biological community, and landscape topography. And then, a model based on fuzzy analytic hierarchy process was developed to systematically evaluate the ecological restoration effect. The evaluation results showed that after implementing a series of measures, the comprehensive evaluation index of wetland ecological environment increased by 37.68%. In addition, it was also found that compared to the water environment, the restoration of the ecosystem had a certain lag. It was recommended to further strengthen the follow-up and continuous monitoring and evaluation, as well as the monitoring and control of the stability of external water source quality. The method and model adopted in this paper further improved the theoretical and methodological system for evaluating the effectiveness of wetland ecological restoration.

Equivalent Static Wind Loads (ESWL) are desired in structural design to consider peak dynamic wind effects. Conventional ESWLs are for structures without control. For flexible structures with vibration control devices, the investigation of ESWL is required. Inerter-based Vibration Absorbers (IVAs), due to the light weight and high performance, gained much research attention recently. This paper established a generic analytical framework of ESWL for structures with IVAs. The analytical optimal design formulas for IVAs with different configurations and installation locations are provided. Subsequently, the solutions to uncontrolled and controlled wind-induced responses are derived based on the filter approach. Finally, the ESWL for controlled structures are presented with a gust response factor approach. The ESWL estimation for a tall chimney controlled by IVAs is illustrated, and the results revealed a significant ESWL reduction effect of the IVAs, particularly for the cross-wind vortex resonance. In the presented framework, the conventional uncontrolled ESWL can be converted to the controlled one with a control ratio. The closed form solution of the control ratio is provided, which enables a quick estimation of ESWL for controlled structures particularly in the preliminary design stage. The presented approach has the potential to be extended to more complex structures and vibration control devices.

Air pollutants emitted by ships are one of the major causes of global environmental and human health problems, especially for sulfur oxides (SO₂). In this study, a mini-sniffing sensor was mounted on the unmanned aerial vehicle (UAV) to monitor the concentration relationship between CO₂ and SO₂ in the exhaust gas of sailing ships, then the sulfur content of the ship’s fuel oil was estimated to evaluate the compliance of the fuel sulfur content (FSC) with IMO regulations. In the experiment, the measurement results of the exhaust gas of sailing ships in the Pearl River Delta were presented, the data set from February to April 2022 was provided, and 445 ships were comprehensively analyzed from the perspectives of ship length and ship type. From the experimental results, considering the error of the sensor, the compliance rate of the FSC of sailing ships entering and leaving the Pearl River reached 93.7%. To some extent, the current situation for meeting the 0.5% (m/m) limit is basically optimistic. The results represent the effectiveness of DECA policy implementation. This paper demonstrates the effectiveness and reliability of the UAV monitoring method in monitoring emissions from ships, and in more effectively monitoring the impact of shipping on air quality. Furthermore, an accurate and non-contact monitoring method is proposed, which can allow law enforcement officers to judge in advance whether the ships sailing is suspected of illegally using high-sulfur fuels. It can improve the efficiency of law enforcement and reduce the cost of supervision.

Strong wind has caused damage to group-arranged quayside container cranes in terminals and ports in recent years. Interference may amplify the wind loads in some cases. However, the interference effect among cranes has rarely been studied. In this study, high-frequency force balance tests were conducted to obtain the wind load of isolated and group-arranged container cranes. The results of the computational fluid dynamics simulation were validated by wind tunnel tests and provided the mean wind loads of all 15 types of member cranes. According to the results from wind tunnel tests, the fluctuating wind loads of each member were generated using the weighted amplitude wave superposition method. Based on dynamic finite element methods, the wind-induced responses were obtained considering the interference effect. It was found that the interference effect is the combined effects of both the shielding effect and the amplification of turbulence. Although in some cases the fluctuating and peak wind loads can increase by up to 16% and 6%, respectively, those in the most unfavorable cases are reduced by the interference effect. The interference factor for extreme nodal deformation is 0.56 and 0.69. The interference effect in container cranes mainly appears as a shielding effect, reducing the wind loads and response of the structures in unfavorable cases.

The ship exhaust sniffing unmanned aerial vehicle (UAV) system can be applied to monitor vessel emissions in emission control areas (ECAs) to improve the efficiency of maritime law enforcement and reduce ship pollution. To solve the problems of large size, heavy weight and high cost of ship exhaust sniffing sensors, in this paper, a unique diffused mini-sniffing sensor was designed, which provides a low-cost, lightweight, and highly adaptable solution for ship exhaust sniffing UAV. To verify the measurement accuracy of the system, a large number of on-site tests were performed based in the mouth of the Yangtze River, and some cases of violation of the fuel sulfur content (FSC) were verified and punished. Maritime law enforcement officers boarded the ship to take oil samples from eight suspected ships and sent them to the laboratory for testing. The results showed that the FSCs of the eight ships in chemical inspection were all greater than the regulatory limit 0.5% (m/m) of the International Maritime Organization (IMO). The system enables authorities to monitor emissions using rotary UAVs equipped with diffused mini-sniffing sensors to measure the FSC of navigating ships, which couple hardware and operational software with a dedicated lab service to produce highly reliable measurement results. The system offers an effective tool for screening vessel compliance.

In order to evaluate the pollution characterization of PM_2.5 (particles with aerodynamic diameters less than or equal to 2.5 μm) and secondary aerosol formation under the different photochemical activity levels, CO was used as a tracer for primary aerosol, and hourly maximum of O₃ (O_3,max) was used as an index for photochemical activity. Results showed that under the different photochemical activity levels of L, M, LH and H, the mass concentration of PM_2.5 were 29.8 ± 17.4, 32.9 ± 20.4, 39.4 ± 19.1 and 42.2 ± 18.9 μg/m³, respectively. The diurnal patterns of PM_2.5 were similar under the photochemical activity and they increased along with the strengthening of photochemical activity. Especially, the ratios of estimated secondary aerosol to the observed PM_2.5 were more than 58.6% at any hour under the photochemical activity levels of LH and H. The measured chemical composition included water soluble inorganic ions, organic carbon (OC), and element carbon (EC), which accounted for 73.5 ± 14.9%, 70.3 ± 24.9%, 72.0 ± 21.9%, and 65.8 ± 21.2% in PM_2.5 under the photochemical activities of L, M, LH, and H, respectively. Furthermore, the sulfate (SO₄²⁻) and nitrate (NO₃⁻) were nearly neutralized by ammonium (NH₄⁺) with the regression slope of 0.71, 0.77, 0.77, and 0.75 between [NH₄⁺] and 2[SO₄²⁻] + [NO₃⁻]. The chemical composition of PM_2.5 was mainly composed of SO₄²⁻, NO₃⁻, NH₄⁺ and secondary organic carbon (SOC), indicating that the formation of secondary aerosols significantly contributed to the increase in PM_2.5. The formation mechanism of sulfate in PM_2.5 was the gas-phase oxidation of SO₂ to H₂SO₄. Photochemical production of nitric acid was intense during daytime, but particulate nitrate concentration was low in the afternoon due to high temperature.

Based on the demand of vehicle emission research and control, this paper presents the development of a portable vehicle measurement system (PEMS) based on SEMTECH-DS and ELPI+, the vehicle emission tests carried out on actual roads, and the data obtained for the establishment and validation of a vehicle emission model. Based on the results of the vehicle emission test, it was found that vehicle driving conditions (speed, acceleration, vehicle specific power (VSP), etc.) had a significant impact on the pollutant emission rate. In addition, local driving cycles were generated and the frequency distribution of VSP-bin under different cycles was analyzed. Then, through the establishment of an emission rate database, calculation of emission factors and validation of the emission model, a vehicle emission model based on actual road driving conditions was developed by taking VSP as the “surrogate variables”. It showed that the emission factor model established in this study could better reflect the vehicle transient emissions on the actual road with high accuracy and local adaptability. Through this study, it could be found that due to the great differences in traffic development modes and vehicle driving conditions in different cities in China, the emission model based on driving conditions was a better choice to carry out the research on vehicle emission in Chinese cities. Compared with directly applying international models or quoting the recommended values of relevant macroscopic guidelines, the emission factor model established in this study, using actual driving conditions, could better reflect the vehicle transient emissions on the actual road with high accuracy and local adaptability. In addition, due to the rapid development of China’s urban traffic and the rapid change of driving conditions, it was of great significance to regularly update China’s urban conditions to improve the accuracy of the model, no matter which model was chosen.

Behavioral response experiment of fish to mirror images is one of the main ways to test the social and aggressive behavior. The behavior changes of Zrbrafish Danio rerio in tanks contain different number of mirrors was tested in this study. The result indicated that the latency of zebrafish from entry tank which contains mirrors to start moving (P < 0.05) and their frequency of midline crossing (P < 0.001) were all lower than control group (contains no mirror), and decreased with increasing numbers of mirrors. The total swimming time of zebrafish in tank contains mirrors increased with increasing numbers of mirrors and significantly higher than control group (P < 0.001). Additionally, the time spent of zebrafish in side that contains mirrors significantly higher than the reverse side (P < 0.05), and this difference degree increased with increasing numbers of mirrors.