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For triple-frequency radar, the attenuation attributed to atmospheric gases and stratiform clouds is diverse due to different snowfall microphysical properties, particularly in regions far from the radar. When using triple-frequency ground-based radar measurements, evaluating the attenuation of the three radars at different heights is common to derive attenuation-corrected effective reflectivity. Therefore, this study proposes a novel quality-controlled approach to identify radar attenuation due to gases and stratiform clouds that can be neglected due to varying snowfall microphysical properties and assess attenuation along the radar observation path. The key issue lies in the lack of information about vertical hydrometeor and cloud distribution. Therefore, European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data are employed. The Self-Similar-Rayleigh-Gans Approximation (SSRGA) for the nonspherical scattering model in the Passive and Active Microwave TRAnsfer model 2 (PAMTRA2) is compared and analyzed against other scattering models to obtain the optimal triple-frequency radar attenuation correction strategies for stratiform cloud meteorological conditions with varying snowfall microphysical properties. This methodology paves the way for understanding differential attenuation attributed to gas and stratiform clouds with snowfall microphysical properties. Simultaneously, the bin-by-bin approximation method is used to perform the attenuation correction. The two-way attenuation correction increased up to 4.71 dB for heights above 6 km, remaining minimal for regions with heights below 6 km. These values, attributable to gases and stratiform clouds’ two-way attenuation, are nonnegligible, especially at distances far from the W-band radar at heights above 6 km. Both values are relatively small for the X- and Ka-band radars and can be neglected for the varying snowfall microphysical properties. The attenuation correction of triple-frequency radar reflectivity is validated using the cross-calibration and dual-frequency reflectivity ratios. The results show that the method is valid and feasible.

Accurate snowfall forecasting and quantitative snowfall estimation remain challenging due to the complexity and variability of snow microphysical properties. In this paper, the microphysical characteristics of snowfall in the Yanqing mountainous area of Beijing are investigated by using a Particle Size and Velocity (PARSIVEL) disdrometer. Results show that the high snowfall intensity process has large particle-size distribution (PSD) peak concentration, but the distribution of its spectrum width is much smaller than that of moderate or low snowfall intensity. When the snowfall intensity is high, the corresponding Dm value is smaller and the Nw value is larger. Comparison between the fitted μ−Λ relationship and the relationships of different locations show that there are regional differences. Based on dry snow samples, the Ze−SR relationship fitted in this paper is more consistent with the Ze−SR relationship of dry snow in Nanjing, China. The fitted ρs−Dm relationship of dry snow is close to the relationship in Pyeongchang, Republic of Korea, but the relationship of wet snow shows greatly difference. At last, the paper analyzes the statistics on velocity and diameter distribution of snow particles according to different snowfall intensities.

Millimeter waves have been recognized as carriers for 5G cellular networks. We carried out a series of millimeter-wave measurements in Beijing, China, and studied the atmospheric impacts on millimeter-wave transmission. Our measurement design is an exemplary LOS transmission link. We also studied a 3 km long commercial E-band millimeter-wave backhaul link in Göteborg, Sweden. We monitored the variation of received signal in the rain, and compared the theoretical rain-induced signal attenuation with the practically monitored signal attenuation. Our results show that there is 1.5-4.5 dB uncertainty between the practical and theoretical rain-induced signal attenuation. Assuming the prediction of rain intensity is available, we have proposed a novel rain-aware radio resource management strategy which adapts the modulation and coding schemes of an OFDM system to rainfall events. We have applied the proposed algorithm to an OFDM - based 5G system, and the throughput result is improved. The result shows that the throughput of a fixed modulation and coding scheme system is between 12%-95% of the system employing the proposed algorithm during rainfall events.

Wireless communication has become a very important part of our lives, and it is well known that meteorological factors affect the quality of communication links, especially at higher frequencies because the physical dimensions of raindrops, hail stones, and snowflakes are on a similar wavelength to the propagating radio frequency. Millimeter-waves are an important technology for fifth-generation cellular networks which are currently being deployed all over the world. Since atmospheric effects are challenging in millimeter-wave transmissions, in this paper, we conducted line-of-sight field measurements at 25 GHz and 38 GHz. We monitored the received signal during rainfall events and compared the theoretical attenuation and the recorded rain-induced attenuation. We also derived the rain-induced attenuation (A) and rainfall rate (R) relation for stratiform and convective rain, respectively, using local rain drop size distribution (DSD) information at our measurement site collected during the period of two years. Furthermore, opportunistic sensing of atmospheric phenomena using microwave or millimeter-wave communication links in commercial cellular networks has recently attracted more attention in meteorological research worldwide. The accuracy of calculating rainfall rates from microwave links highly depends on the retrieval model and values of coefficients in the model, i.e., a and b of the A-R relation model. Here, the coefficients a and b are estimated based on local DSD measurement, and the performance of the improved A-R model is evaluated using propagated signal power based on measurement data. Compared to the (a, b) coefficients in the International Telecommunication Union Recommendation (ITU-R) P.838 document, the derived coefficients achieved an improved rainfall rate estimation.

A new dimeric quaternary protoberberine alkaloid, bispalmatrubine (1), and thirteen known compounds (2-14) were purified from the tubers of Tinospora dentata. Their structures were determined by spectroscopic and spectrometric analytical methods. Among the isolates, eight compounds were examined for their in vitro anti-inflammatory potential and several tested alkaloids displayed moderate inhibitory effects of N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release. [ABSTRACT FROM AUTHOR]

The physical properties and radiative role of cirrus clouds remain one of the uncertainties in the Earth-atmosphere system. In this study, we present a detailed analysis of cirrus properties based on four years of surface millimetre wavelength radar measurements in Beijing, China, where summer monsoon from the ocean and winter monsoon from the continent prevails alternately, resulting in various cirrus clouds. More than 6600 cirrus clusters were studied to quantify the properties of cirrus clouds, such as the height, optical depth and horizontal extent, which can serve as a reference for parameterization and characterization in global climate models. In addition, comparison between cirrus clusters formed under summer monsoon and winter monsoon indicates the different formation and evolution mechanisms of cirrus. Statistically, the temperature of more than 90% of cirrus bins are below -15 °C. The dependence of the radar reflectivity of cirrus particles on the height and temperature was also observed in this study, indicating that the reflectivity of cirrus bins increases (decreases) as the temperature (height) increases. In addition, it was found that there is a strong linear relationship between the mean reflectivity and the cirrus cloud depth. Due to various synoptic circumstances, the cirrus clouds in summer are warmer, higher, and thicker, with larger reflectivity than that in winter; in particular, the mean cloud-top height of cirrus clouds in summer is 2.5 km higher than that in winter. It was found that most cirrus clusters in winter are likely to be the in situ origin type cirrus but some cirrus clusters in summer are the in situ origin cirrus and others are the liquid origin type cirrus. [ABSTRACT FROM AUTHOR]

To better understand the accuracy of cloud top heights (CTHs) derived from passive satellite data, ground-based Ka-band radar measurements from 2016 and 2017 in Beijing were compared with CTH data inferred from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Himawari Imager (AHI). Relative to the radar CTHs, the MODIS CTHs were found to be underestimated by −1.10 ± 2.53 km and 49 % of CTH differences were within 1.0 km. Like the MODIS results, the AHI CTHs were underestimated by −1.10 ± 2.27 km and 42 % were within 1.0 km. Both the MODIS and AHI retrieval accuracy depended strongly on the cloud depth (CD). Large differences were mainly occurring for the retrieval of thin clouds of CD < 1 km, especially clouds higher than 4 km. For clouds with CD > 1 km, the CTH difference decreased to −0.48 ± 1.70 km for MODIS and to −0.76 ± 1.63 km for AHI. MODIS CTHs greater than 6 km showed better agreement with the radar data than those less than 4 km. Statistical analysis showed that the average AHI CTHs were lower than the average MODIS CTHs by −0.64 ± 2.36 km. The monthly accuracy of both retrieval algorithms was studied and it was found that the AHI retrieval algorithm had the largest bias in winter while the MODIS retrieval algorithm had the lowest accuracy in spring. [ABSTRACT FROM AUTHOR]

Background: In patients with hypertension, psychosocial factors, such as depressive symptoms and anxiety, are associated with reduced quality of life and triple the risk of nonadherence with medical treatment regimens. Thus, screening tests are crucial to identify patients who may require further assessment and treatment. Objectives: The objective of the current study was to test the psychometric properties of the Chinese version of the Mood and Anxiety Symptoms Questionnaire Short Form (MASQ-SF-C) in patients with essential hypertension. Methods: Y The MASQ-SF-C, the Center for Epidemiologic Studies Depression Scale (CES-D), and the State-Trait Anxiety Inventory (STAI) were administered to a convenience sample of 869 hypertensive patients in 4 hospitals. A confirmatory factor analysis was used to test the tripartite model. We evaluate the internal consistency of the MASQ-SF-C and we used the Bland-Altman approach to evaluate convergent validity between the MASQ-SF-C t score and symptoms of (1) depressive symptoms and (2) anxiety. Results: Cronbach's α coefficient for the total MASQ-SF-C was .95, and Cronbach's α coefficients for the 3 subscales were .83 for anhedonic depression (AD), .91 for anxiety arousal (AA), and .94 for general distress (GD), indicating adequate internal consistency reliability. The mean interitem correlation coefficients were as follows: MASQ-SF-C, 0.29; AD, 0.28; AA, 0.38; and GD, 0.40. The 1-month test-retest reliability for the MASQ-SF-C was 0.72. Confirmatory factor analyses indicated that the 3 first-order factors (GD, AD, and AA) fit the data well (nonnormed fit index = 0.953, comparative fit index = 0.936, incremental fit index = 0.936, root-mean-square error of approximation = 0.038). Conclusions: This study supported the reliability and validity of the MASQ-SF-C, indicating that it can be used for assessing depressive symptoms and anxiety concurrently in Chinese-speaking patients with hypertension. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the effects of consecutive turnover of green manure (ryegrass (Lolium perenne L.)) on soil microbial biomass C and N and enzyme activities. The results showed that the incorporation of green manure in tobacco-planted fields generally significantly enhanced enzyme activities (soil para nitrophenol (PNP), urease, catalase, and sucrase) and soil microbial biomass contents. The extent of enhancement increased with the increase in consecutive turnover. The C and N contents in microbial biomass were significantly lower in conventionally cultivated soil than in soils from the green manure-incorporated field. This finding indicated that incorporation of green manure could stimulate the activity of soil microorganisms. The average improvement gained from the T3 treatment (three-year consecutive cultivation of green manure since the harvest of tobacco) relative to the T0 treatment (conventional cultivation without any green manure) over the whole growth period of tobacco was 1.34 to 1.52 times for urease activity, 1.11 to 1.19 times for PNP activity, 1.58 to 1.17 times for sucrase activity, and 1.24 to 1.50 times for catalase activity. Overall, the activities of soil enzymes correlated well with the soil microbial biomass C and N. This study provides guidance on the measurement of green manure to manage the activation of soil microbial biomass and improve the quality of tobacco-planted soil. [ABSTRACT FROM AUTHOR]

Currently, efficient and cost-efficient methods are needed to manage fields in order to maximize economic return, minimize environmental impact, and improve soil and crop site-specific management. Management zones (MZs) of uniform production potential may offer a solution to the problems associated with grid soil sampling while still effectively describing variability in soil properties. In this study, a hillside field of 4 ha was selected as the study site and 111 soil samples were taken from the topsoil (0–20 cm), on an ∼20-m grid. Soil samples were analyzed for pH, organic matter, active soil organic matter, total nitrogen, alkalytic nitrogen, available phosphorous, available potassium and cation-exchange capacity. Their spatial variability was analyzed and spatial distribution maps were constructed using geostatistical techniques. Principal component analysis (PCA) and fuzzy c-means clustering algorithm were then performed to delineate MZs, and eigenvalues were used to select the principal components (PCs) for cluster analysis. Fuzzy performance index and normalized classification entropy were used to determine the optimum cluster number. The results revealed that the optimum number of MZs for this study area was three and analysis of variance indicated that the MZs were reasonable for the area. Based on the description of MZs, it was concluded that the area could be managed in a site-specific way. [ABSTRACT FROM AUTHOR]

The inhibition effect of Jasminum nudiflorum Lindl. leaves extract (JNLLE) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was investigated by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The results show that JNLLE acts as a very good inhibitor, and the inhibition efficiency increases with the concentration of JNLLE. The adsorption of JNLLE obeys Langmuir adsorption isotherm. Values of inhibition efficiency obtained from weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) are in good agreement. Polarization curves show that JNLLE behaves as a mixed-type inhibitor in hydrochloric acid. EIS shows that charge-transfer resistance increase and the capacitance of double layer decreases with the inhibitor concentration, confirming the adsorption process mechanism. The adsorbed film on CRS surface containing JNLLE inhibitor was also measured by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). A probable inhibitive mechanism is proposed from the viewpoint of adsorption theory. [ABSTRACT FROM AUTHOR]

The inhibition effect of tween-85 on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss and potentiodynamic polarization methods. The results show that tween-85 is a good inhibitor in 1.0 M HCl and its maximum inhibition efficiency (IE) is 92% at very low concentration. Its adsorption obeys the Langmuir adsorption isotherm equation. The thermodynamic parameters of adsorption enthalpy (Δ H0), adsorption free energy (Δ G0) and adsorption entropy (Δ S0) were calculated and discussed. Polarization curves show that tween-85 acts as a mixed-type inhibitor in hydrochloric acid. IE values obtained from weight loss and polarization are consistent. The adsorbed film on a CRS surface containing an optimum dose of tween-85 was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). An inhibitive mechanism is proposed from the viewpoint of adsorption theory. [ABSTRACT FROM AUTHOR]

Objective: To explore the effects of atorvastatin on expression of cyclooxygenase-2 (COX-2) in human pulmonary epithelial cells (A549). Methods: A549 cells were incubated in DMEM medium containing lipopolysaccharide (LPS) in the presence or absence of atorvastatin. After incubation, the medium was collected and the amount of prostaglandin E2 (PGE2) was measured by enzyme-linked immunosorbent assay (ELISA). The cells were harvested, and COX-2 mRNA and protein were analyzed by RT-PCR and western-blot respectively. Results: LPS increased the expression of COX-2 mRNA and production of PGE2 in a dose- and time-dependent manner in A549. Induction of COX-2 mRNA and protein by LPS were inhibited by atorvastatin in a dose-dependent manner. Atorvastatin also significantly decreased LPS-induced production of PGE2. There was a positive correlation between reduced of COX-2 mRNA and decreased of PGE2 (r = 0.947, P < 0.05). Conclusion: Atorvastatin down-regulates LPS-induced expression of the COX-2 and consequently inhibits production of PGE2 in cultured A549 cells. [ABSTRACT FROM AUTHOR]

The image displaying methods used in a millimeter wave radiometric imaging system have great influence on its imaging quality. In order to obtain high quality millimeter wave radiometric images, intensive studies on the image displaying methods are needed. This paper describes the image displaying method of Ground-based 8mm Millimeter Wave Radiometric Imaging (GMWRI) system and compares two different image displaying methods. The experimental results prove the unequal size element arc displaying method fits GMWRI system better. [ABSTRACT FROM AUTHOR]