Scale Effects on the Calculation of Ecosystem Service Values: A Comparison among Results from Different LULC Datasets

Land use/land cover (LULC) has an important impact on the ecological environment and is crucial for calculating ecosystem service values (ESVs). However, whether and to what extent the ESVs vary when calculated by LULC product data at different spatial scales remain unclear. Data from two LULC products were used in this study, and two datasets with different spatial scales were obtained by resampling. Then, the ESVs were calculated by the equivalent factor method. Finally, the impacts of LULC on ESVs at different scales were studied, revealing the following: (1) The ESVs calculated by LULC products and by the same products at different scales are different. (2) The difference in the ESVs calculated by the two LULC datasets is approximately 28%, and the difference tends to decrease with increasing scale. (3) With an increase in the LULC scale, the overall change trend of ESVs also increases, and the increasing trend gradually moderates. In addition, the ESVs and LULC scale conform to a logarithmic relationship, and the coefficient of determination (R2) is greater than 0.7. These results have important reference value for obtaining reliable ESVs.

Data compression algorithms for sensor networks with periodic transmission schemes

The operating state of switch cabinet is significant for the reliability of the whole power system, collecting and monitoring its data through the wireless sensor network is an effective method to avoid accidents. This paper proposes a data compression method based on periodic transmission model under the condition of limited energy consumption and memory space resources in the complex environment of switch cabinet sensor networks. Then, the proposed method is rigorously and intuitively shown by theoretical derivation and algorithm flow chart. Finally, numerical simulations are carried out and compared with the original data. The comparisons of compression ratio and error results indicate that the improved algorithm has a better effect on the periodic sensing data with interference and can make sure the change trend of data by making certain timing sequence.

Analysis of Heart-Sound Characteristics during Motion Based on a Graphic Representation

In this paper, the graphic representation method is used to study the multiple characteristics of heart sounds from a resting state to a state of motion based on single- and four-channel heart-sound signals. Based on the concept of integration, we explore the representation method of heart sound and blood pressure during motion. To develop a single- and four-channel heart-sound collector, we propose new concepts such as a sound-direction vector of heart sound, a motion–response curve of heart sound, the difference value, and a state-change-trend diagram. Based on the acoustic principle, the reasons for the differences between multiple-channel heart-sound signals are analyzed. Through a comparative analysis of four-channel motion and resting-heart sounds, from a resting state to a state of motion, the maximum and minimum similarity distances in the corresponding state-change-trend graphs were found to be 0.0038 and 0.0006, respectively. In addition, we provide several characteristic parameters that are both sensitive (such as heart sound amplitude, blood pressure, systolic duration, and diastolic duration) and insensitive (such as sound-direction vector, state-change-trend diagram, and difference value) to motion, thus providing a new technique for the diverse analysis of heart sounds in motion.

Does Lockdown Improve Air Quality? Evidence from the blockade policy of county-level units in Hubei Province, China

Background The COVID-19 posed a great threat to the health of people all over the world. In response to the outbreak of COVID-19, Wuhan implemented the blockade policy on January 23, 2020. Subsequently, other cities in Hubei responded one after another. The flow of people, production and consumption activities were greatly reduced, and air pollution in some cities was obviously improved. Method We used the daily air pollution and weather data of 103 county-level units in Hubei Province from 2019 to 2020 to test whether the blockade policy affected the air quality. The method of regression discontinuity designs is adopted. And the blockade policy implemented by the government during COVID-19 is regarded as exogenous policy impact, so as to investigate whether the blockade policy will affect the air quality. Results (1) Lockdown has indeed brought about an improvement in air quality. During the lockdown period, the AQI decreased by 15.316%, and the concentrations of four air pollutants (PM10, NO2, PM2.5 and SO2) decreased by 19.607%, 12.395%, 11.448% and 1.278% respectively. (2) The improvement of air quality brought about by the blockade policy is not sustainable, and every index rebounded again about 30 days after lockdown. (3) RD estimation found that the concentrations of AQI, PM2.5, PM10 and NO2 decreased by 35.402%, 29.207%, 14.809% and 7.751% respectively. This is consistent with the change trend of the above results, but the change range is obviously larger than the previous one. Conclusion Although the study confirmed that most pollutant indexes decreased during the lockdown period, the blockade policy is not applicable to the prevention and improvement of air pollution. We put forward the policy suggestions from the following two aspects: Firstly, promote green travel and reduce traffic emission sources. Secondly, promote end-of-pipe governance and improve emission reduction efficiency.

Climate Change and Variability in the Northeastern Himalayan Region of India

Mountainous regions are considered highly vulnerable to the affects of climate change. The extent of change and variability of climatic parameters is still unexamined in many remote mountainous areas. This paper aims in understanding the change in pattern of rainfall and temperature for a period of 30 years in Mizoram. The analysis of time series changing trend in climatic variables is carried out by using Coefficient of Variation (CV), Mann-Kendall (M-K) and Sen’s Slope estimator. The analysis reveals that high variation is observed for both the variables in all the decadal, three decadal and seasonal change. The CV analysis shows that the highest seasonal rainfall variation occurs during winter and the highest seasonal temperature variation occurs during spring. Mann-Kendall test shows a significant change in rainfall with November showing the highest negative trend of rainfall. The temperature trend analysis in the study also reveals drastic change of temperature. An understanding of climatic change, trend and variability helps in predicting for better natural resources from the susceptibility of climate change.

Study on Precipitation Evolution Characteristics in Tongzhou District of Beijing in Recent 65 Years

Based on the 65a (1956–2020) precipitation series data of 11 rainfall stations and 5 surrounding rainfall stations in Tongzhou District, Beijing, the evolution characteristics of precipitation in Tongzhou District on spatial, interannual and intra annual scales are comprehensively analyzed using cumulative anomaly method, 5a moving average method and spectral analysis method, and the future change trend is predicted using ARIMA model. The results show that: 1) the annual average precipitation in Tongzhou District is higher in the middle and northwest and lower in the southwest, and the precipitation between June to August, accounts for more than 70% of the annual precipitation; 2) In general, the precipitation shows a fluctuating downward trend at the rate of -2.42 mm a-1, in which the precipitation in summer decreases at the rate of -2.68 mm a-1, while the precipitation in spring and autumn increases at the rates of 0.35 mm a-1 and 0.26 mm a-1 respectively; 3) The abrupt change of precipitation occurred in 1959 and 2000, which were 990.2mm and 239.4mm respectively; 4) There are 3∼8a and 14∼16a oscillation periods on the inter annual scale of precipitation, the prediction results of ARIMA model show that the precipitation will increase about 40 mm in the next five years.

Prediction Study of Tianjin Port Throughput Based on GM (1, 1) Extended Model

Tianjin Port is the largest comprehensive main hub port and one of the main transshipment ports for energy and raw materials transportation in northern China. It has freight business with many countries. At the same time, Tianjin Port is the first port to carry out international maritime container transportation in China’s coastal areas. Tianjin Port was built in the 1950s, and the container business has been started since 1973, In recent years, with the rapid development of large-scale, intensive and intelligent container ships in Tianjin Port, cargo throughput is an important indicator in the comprehensive evaluation of port development, which represents the development level of a port. At the same time, it also brings new tasks to the navigation guarantee work, in particular, it puts forward systematic requirements for port and wharf construction, navigation aids layout, navigation aids efficiency display and navigation aids base layout. The annual throughput of port cargo or container is one of the bases of world ports. As an output index, port enterprises, shipping companies, navigation guarantee departments and shipping economic analysis departments attach great importance to it. Therefore, the prediction of Tianjin Port cargo throughput can provide reference for Tianjin Port’s next development planning, waterway use and navigation guarantee planning and layout, navigation aids setting, wharf construction, route mapping, etc. the article constructs of Tianjin Port. The average error is 0.29%, and the prediction accuracy is first class. This model can better predict the change trend of cargo for Tianjin Port, which is a better way to analyze the change trend for Tianjin port.

Effects of dodecyl benzene sulfonic acid between hydrate particles and droplets

In order to understand the effect of Dodecyl benzene sulfonic acid (DBSA) on the aggregation mechanism of hydrate, the interaction between cyclopentane (CyC5) hydrate particles and droplets under different concentrations of DBSA and different temperatures was measured by micro mechanical force device (MMF). The mass concentration range of DBSA used in the experiment is 0.0001% ~ 0.05%, and the experimental temperature is 1°C and 5°C, respectively. The experimental results show that DBSA can effectively reduce the interfacial tension between oil and water, thus reducing the adhesion between hydrate particles and droplets and preventing hydrate aggregation. In the experimental concentration range, the higher the concentration of DBSA, the stronger the ability to reduce the adhesion. The adhesion can be reduced by 97.56% at 1°C and 90.95% at 5°C. The change trend of the adhesion with the concentration is almost the same at the two temperatures.