Search

The movement protein (MP) and coat protein (CP) of tobamoviruses play critical roles in viral cell-to-cell and long-distance movement, respectively. Cucumber green mottle mosaic virus (CGMMV) is a member of the genus Tobamovirus. The functions of CGMMV MP and CP during viral infection remain largely unclear. Here, we show that CGMMV MP can interact with CP in vivo, and the amino acids at positions 79-128 in MP are vital for the MP-CP interaction. To confirm this finding, we mutated five conserved residues within the residue 79-128 region and six other conserved residues flanking this region, followed by in vivo interaction assays. The results showed that the conserved threonine residue at the position 107 in MP (MP

Emerging pollutants are frequently detected in surface water, threatening the regional aquatic ecosystem and human health. Due to their complex types and large differences in risk and toxicity, research based on the comprehensive assessment of the pollution characteristics to determine the new priority pollutants remains incomplete. This study established a multi-criterion scoring method targeting 41 emerging pollutants with the goal of protecting aquatic organisms and human health, using five key indicators including environmental exposure level, persistence, bioaccumulation, ecological risk, and health risk of pollutants. The emerging pollutants were screened and identified in the surface water of Tianjin. The priority levels of different congeners were divided, and the ecological and health risks of pollutants in the priority control list were evaluated. The results showed that 41 emerging pollutants were generally detected in the study area. The average concentration of sulfonamide antibiotics (SAs) and other drugs (Others) were the largest, with 200.04 ng·L

A series of novel fluorescent poly(methyl methacrylate) microbeads with narrow size distribution and intense solid state emission were designed and prepared by dispersion polymerization. The featured polyhedral oligosilsesquioxane was introduced into the perylene bisimides fluorophore system to fabricate polymeric microspheres. With poly (12-hydroxystearic acid) chains grafted to poly(methyl methacrylate) backbone as stabilizer, the obtained microspheres were narrow distributed as well as easily dispersed which are shown in the dynamic light scattering and scanning electron microscope measurement. Fluorescence microscope images of petroleum-ether dispersion of the sample exhibited strong orange emission with stability against photobleaching. More importantly, due to the steric hindrance of bulky polyhedral oligosilsesquioxane moieties, the aggregation-induced fluorescence quenching of perylene bisimides can be suppressed significantly, thus the solid-state quantum yield of the microspheres can be boosted to 68%, which is the highest record for perylene bisimide along polymeric microspheres. The excellent luminescent property, in combination with the monodisperse nature and the high stability against photobleaching of the polyhedral-oligosilsesquioxane containing microspheres, makes them a kind of promising material for fabrication of luminescent devices.

Based on commercial V 2 O 5 -WO 3 /TiO 2 catalysts, the formations of ammonium bisulfate (ABS) and ammonium sulfate were detected from the reactions among SO 3 , NH 3 and H 2 O in the flue gas during the process of selective catalytic reduction (SCR) of NO with NH 3 , leading to the deactivation of the catalyst and the increased number concentration of fine particles. The mechanism of formation and decomposition of ABS during SCR of NO with NH 3 was investigated through the In Situ Diffuse Reflectance Infrared Spectroscopy (DRIFTS) and the Thermo Gravimetric analyzer coupled with Fourier Transform Infrared analyzer (TG-FTIR). The results of the in situ DRIFTS showed that ABS deposited on the surface of the catalysts could be generated from the adsorption activation of NH 3 with SO 2 in presence of O 2 . It also could be produced by the direct reaction between NH 3 and the intermediate metal sulfates on the surface of the catalysts. In addition, it suggested that the reaction between NO and NH 4 + in ABS promoted ABS decomposition. TG-FTIR demonstrated that the process of ABS decomposition on the catalysts was composed of two steps. Moreover, the temperature window of the complete pyrolysis of ABS was delayed by catalysts.

This paper proposed an improved method based on adaptive with threshold wavelet transform denoising, according to image is often affected by noise pollution in the process of acquisition and transmission, compared with the advantages and disadvantages of traditional digital filtering method. It extracts the structure information and details of the image. It can adaptively select wavelet transform of optimal decomposition level and soft threshold to achieve the optimal noise reduction effect. The Simulation results demonstrate that this theory can effectively filter Gaussian noise and Salt and pepper noise, at the same time well protect the image details and achieve better visual effects.

Based on commercial catalysts (V2O5–WO3/TiO2), the effects of a selective catalytic reduction (SCR) system on the emission characteristics of fine particles were investigated. The size distribution, morphology, element compositions, and chemical compositions of fine particles at the outlet of the SCR system were measured by an electrical low pressure impactor (ELPI), particulate matter (PM10/PM2.5) samplers, field emission scanning electron microscopy/energy dispersive spectrometry (FSEM–EDS), X-ray diffraction (XRD), etc. The influences of reaction conditions and flue gas components on fine particle formation were also studied. The results reveal that a large number of fine particles can be generated during the SCR process. These fine particles are mostly in the submicrometer size range and appear to be nonuniform. The main components of these fine particles are ammonium sulfate or ammonium bisulfate. There is a good correlation between the formation of fine particles and the SO2 oxidation rate. Fine par...

The oxidation of binary Co-5Al alloys in 1 atm of pure O2 at 700 and 800°C was investigated. Oxide scales generally showed good adherence to alloys during oxidation process, although scale spallation on cooling was observed inevitably due to difference in the thermal expansion coefficients between oxides and alloys. It indicated that oxidation of the two alloys approximately obeyed parabolic rate law (n=2). The parabolic rate constants as functions of temperature at 700 and 800°C were 8.38×10-11, 3.45×10-10 g2cm-4s-1, respectively. The binary Co-5Al alloys presented a non-protective oxidation behavior because the Al content was not enough to support the growth of a dense, stable Al2O3 layer. The scales were mainly composed of oxides of cobalt, coupled with a little Al2O3 present at the inner part of the scales.

Experiments were conducted in pot culture and field plots to study the effects of Anaerobic Digested Residues (ADR) on nitrate accumulation in leaf vegetables, which is critical for the safety of food. The results showed that compared to chemical fertilizer, ADR could decrease the nitrate accumulation in rape and spinach. Furthermore, nitrate content in plant tissue was increased with the increase of percentage of chemical nitrogen in the mixture of chemical fertilizer and ADR. A comparison of spraying digested slurry with irrigation showed that spraying method could reduce the nitrate content of rape, however, a reverse result was found in spinach. The nitrate accumulation in rape affected by ADR was more apparent in high fertility soil than that in low fertility one. To regulate the nitrate accumulation in plant, it was more apparent in rape under greenhouse cultivation, while more apparent in spinach under open-air cultivation. The results demonstrated that the ADR was effective in the safe food production and it may convert the technology to be more profitable.

In this paper, setting out from typical structures — metal plate, and discussing the relation of RCS with incident angle, frequency of radar wave, and geometry of metal plate, the formula, which characterizes the RCS of the plate with inclined angle, has been derived by physical optics theory. Through the formula, the optimal inclined angle can be determined at single frequency and multiple frequencies. Also, an example is presented to illustrate how to make a compromised design according to formulas considering stealthy of the ship and volume of the cabin. The results are significant to the stealthy design of ship.

Concentrations and composition of 16 polycyclic aromatic hydrocarbons (PAHs) listed for prior control by US EPA were detected by analyzing 28 surface soil samples from the chemical industrial areas of Tianjin Binhai New Area with a gas chromatography equipped with mass spectrometry (GC/MS). Relative concentrations of PAH compounds with different benzene rings and principal component analysis were used to identify the possible sources of soil PAHs. The maximum PAH concentration in all the samples was 5,991.7 ng x g(-1), with a mean values of 1,185.0 ng x g(-1). The concentrations of four and five rings PAH components were higher than that of the other PAH components in Tanggu and Hangu chemical industrial areas, and three rings PAH components were major PAHs in Dagang petroleum industrial area. There is significant positive correlation (n = 28, R2 = 0.847, p0.01) between PAH concentrations and total organic carbon (TOC) contents in the soil samples. Coal combustion was the dominant source of PAHs in chemical industrial areas, while petroleum volatilization and leakage were main contributors of PAHs in Dagang petroleum industrial area.

Based on environmental statistics data from 1993 to 2005, spatial distribution and temporal tendency of the environmental pollution and destruction accidents and their external causes were analyzed by using GIS and non-parametric correlation methods. It was concluded that (1) during the study period, annual environmental pollution accidents was maximally 3001 times in 1994 and minimally 1406 in 2005, while the frequency decreased in general. In addition, water and air accidents occupied the most; (2) environmental pollution and destruction accidents centralized in southeast and middle parts of China, mainly in Hunan, Sichuan, and Guangxi; (3) factors including population, GDP, company number and industrial waste water discharge had positive impacts on frequency of environmental pollution and destruction accidents, while in developed provinces the frequency was only correlated with company number.

Analytic hierarchy process and a specialist investigation were applied to value the three PCBs treatment technologies qualitatively and quantitatively, in which the environmental, technological, social and economic factors were considered. The most important factor is thought to be environmental impact. Incineration is proved to be the most suitable technology in this period according to the research. For the high concentration of PCBs pollutants, or the low concentration of PCBs pollutants with good economic performance and large quantity of waste, incineration is considered the best. For the low concentration of PCBs pollutants in the area with bad economic performance and with little quantity of waste, cement kiln and landfill are thought to be suitable. It is also suggested that pollutants be treated at the nearest place. What's more, the measures to improve the three technologies are discussed and the policy comments on PCBs treatment are presented.

Topsoil samples around the Guanting Reservoir ranging from 2 - 10km were measured for heavy metals concentrations. GIS and geostatistical techniques were applied to analyze the special variation and eco-environmental risk of heavy metals. The results show that Cd is the major contamination in this area, 3.4 fold higher than the national background level, with a mean of 0.68 mg/kg and a standard deviation of 0.17. The area in which Cd concentration is higher than the second level of national standard accounts for about 40% of the whole study area. Spacial variation of heavy metals (except Ni) mainly is induced by the stochastic factors-mostly anthropogenic activities, e.g. fertilizer application, cultivation and planting modes, etc. The spatial pattern of heavy metals approximately declines in the W-N and N-S direction, with the highest value in the region between Yanghe River and Huailai County. The complex contamination index of heavy metals has the same distribution as their concentrations. However, the complex eco-risk index with higher value mainly occurs in vicinities of Huailai County, Yanqing County and Beixinpu town. It suggests that the town with higher population density and industrialization will induce both environmental pollution and ecological risk.

An assessment of the current state of pollution from polychlorinated biphenyls (PCBs) and PCBs spatial character in sediments are represented. The sources of PCBs and relative factors are also analyzed. Songhua River and Dalian Bay in Northeast, Baoding in Hebei Province, Ya-er Lake in Wuhan City, Pearl River and Taiwan Province in Southeast of China have relatively high level of PCBs, while most other regions have lower average concentrations of PCBs. Serious pollution of PCBs is found in some locations, most of which are harbors, industrial areas, the places where improper disposal of and leakage from PCB containers taken place Point source pollution is the common pattern of contamination, influenced primarily by local geographic, economic, management and historical factors, with Pearl River/Estuary as an example.

For improving the environmental quality and ensuring supply of wood and non-timber forest products, many forests have been planted in plain areas of China. Scientists have studied their benefits, almost all of the approaches were based on fixed-point data, and few was considered on the non-efficient factors and temporal scale effects. This paper studies the positive and negative benefits at a large temporal scale, and the effects of plain afforestation on stockbreeding and rural economy. The benefits of plain afforestation, correlation coefficiency of agroforestry and production factors are analyzed via stochastic frontier modeling in Huanghuaihai Plain Area of China; elastic coefficient of agroforestry, husbandry, farming, and total output of agricultural sector are calculated through adopting partial differential equation. Some conclusions can be drawn that, plain forests have an important effect on the development of plain agriculture. But shelterbelts and small-scale forests have different effect on the development of agricultural economy. Shelterbelts have negative effect on the industries, but small-scale forest has positive effect. On the whole, contribution of forest resource to value of animal husbandry and gross production value of agriculture is positive, and to the value of farming is negative.

The development of Persistent Organic Pollutants (POPs) control policy in China in the context of international concerns on POPs was reviewed. The aspects of the Chinese POPs control strategies were analyzed, and compared with those of developed counterparts (e.g. U.S., E.U., Japan). Currently, while the legal framework on POPs management, which complies with international guidelines has been established, it should be improved in the areas of special POPs management, risk assessment, the precautionary principle, life-cycle management and technical support capacity. The analysis of Chinese POPs policy and suggestions for strengthening the science-based decision making capacity are not only useful for Chinese decision-makers, but also a case study for developing world and make a great contribution for the global elimination of POPs to make a toxic-free future.