The TiO2/zeolite composite was synthesized through a hydrolysis deposition method combined with a calcination crystallization process. The composites were characterized by XRD, N2 ...adsorption-desorption, SEM, TEM, XPS and UV-vis DRS. The effect of acid leaching on the physicochemical property, adsorption capacity and photocatalytic performance of the TiO2/zeolite was analyzed. The characterization results revealed that well-dispersed anatase TiO2 nanoparticles were loaded on the surface of acid leaching zeolite. The photoactivities of composites were examined by degrading gaseous (formaldehyde) and aqueous (phenol, methyl orange and rhodamine B) organic pollutants. The results indicated that TiO2/acid leaching zeolite composite had the strong photoactivity than TiO2/natural zeolite composite. The enhanced photoactivity can be attributed to the higher surface area and more surface hydroxyl groups. The excellent activity reveals that TiO2/zeolite composite is a promising photocatalyst in pollutants degradation.
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•TiO2/acid leaching zeolite composite was synthesized.•The composite displayed enhanced photoactivities for abatement of pollutants.•The acid leaching contributed to high adsorption and photoactivities of composite.•The composite is promising photocatalyst in pollutants degradation.
Improving root growth is essential for enhancing the capacity of crops to acquire soil resources but redundant root growth can also limit productivity, especially in rain-fed farming areas where ...resources are limited. We conducted a two-year field experiment in the Loess Plateau region of China to explore the effects of different planting patterns (flat planting without film mulching; ridge–furrow plastic film mulching planting with three ridge–furrow ratios of 40:70 cm, 55:55 cm, and 70:40 cm) and nitrogen application rates (180 kg ha –1, 240 kg ha –1, and 300 kg ha –1) on the growth and activity of roots, root–shoot relationship, and grain yield and WUE of rain-fed spring maize. The planting pattern and nitrogen application rate only affected the root characteristic parameters in the shallow soil layer (0–40 m), where these parameters all increased as the ridge–furrow ratio and nitrogen application rate increased. The improvements in the root characteristic parameters were beneficial for increasing the root bleeding sap rate. The root–shoot ratio was only affected by the planting pattern. Compared with flat planting, increasing the ridge–furrow ratio enhanced the root–shoot ratio in the early growth stage, which was beneficial for allowing roots to acquire soil resources and promoting canopy establishment; however, the opposite results were observed in the late growth stage, thereby suggesting that increasing the ridge–furrow ratio promoted the distribution of dry matter to the shoots and reduced redundant root growth. The spring maize grain yield and water use efficiency were significantly positively correlated with the root characteristic parameters and the root bleeding sap rate but negatively correlated with the root–shoot ratio, thereby explaining the increases in the grain yield and water use efficiency as the ridge–furrow ratio and nitrogen application rate increased. However, there were generally no significant differences in the grain yield and water use efficiency between 240 kg ha −1 and 300 kg ha −1 under the same planting pattern. Therefore, the combination of ridge-furrow plastic film mulching planting with three ridge-furrow ratios of 70:40 cm and 240 kg ha −1 may be applied as a suitable field management practice for rain-fed spring maize production in the Loess Plateau region.
•Increasing ridge-furrow ratio and N application rate improves the root characteristic parameters in shallow soil layer.•The root-shoot relationship is affected by the planting pattern but not by the N application rate.•Increasing the ridge-furrow ratio reduces the redundancy of root growth.•RF70-40 and N2 (240 kg ha−1) can be used as a reasonable combination for rain-fed spring maize production.
•Spatiotemporal variability of hydrometeorological variables in the SRB was analyzed.•Records of 1960–2009 from 37 meteorological stations and 33 gauge stations were used.•Temperature significantly ...increased and precipitation declined during 1960–2009.•Annual and seasonal streamflow across the SRB decreased during 1960–2009.•Low and high flow patterns changed; both lowest and highest monthly flow declined.
The Songhua River Basin (SRB) is located in the high latitude region of China’s far northeast and is sensitive to global warming. This study utilized long-term meteorological and river discharge records in the SRB to assess spatiotemporal variability and trends in temperature, precipitation, and discharge. Daily precipitation and temperature data were collected from 37 meteorological stations across the SRB for the period from January 1960 to December 2009. Monthly discharges from 33 major river gauge stations in three sub-basins of the SRB were gathered for the same period. The modified Mann–Kendall tests, flow duration curves and correlation statistics were performed to identify the long-term trend and interrelation of the hydrometeorological variables. The results showed that temperature in the SRB has steadily increased in the past five decades, while precipitation fluctuated greatly among the years and the decades with a declining trend since 1980s. The largest change in temperature was found in the last two decades, with a decadal increase of about 1°C. Concurrently, a declining trend in annual discharge from the SRB was found after 1990, while intra-annual variation of discharge increased. Overall, annual discharge at most gauge stations across the SRB showed a downward trend in the past five decades, with a significantly decreasing trend in the Lower Songhua River. Seasonally, the declining trend in discharge was prevalent in spring and discharge mainly declined in the lower Nenjiang River and the Lower Songhua River throughout most of a year. The flow duration analysis showed a decrease in high flow (Q5), but an increase in low flow (Q95) after 1990 at most mainstream stations of the SRB. However, both the lowest and highest monthly discharge displayed a declining trend during 1960–2009. Because precipitation in this river basin is concentrated during the summer and fall months, annual discharge was closely and positively correlated with precipitation amount occurred during these two seasons.
The variability of eco-hydrological condition caused by climate change and human activities exerted a significant detrimental influence on water and ecological security in watershed region and ...national scale. The eco-hydrological model is an important and efficient tool for revealing interactive mechanism between ecological processes and hydrological processes.This paper reviews concept,connotation,construction methodologies and classification as well as domestic and international development of eco-hydrological models,then focuses on the key fields in the studies: ecological regulation and water resources management in wetlands,wetlands restoration and conservation and adaptive water resources management for watershed scale as well as evaluation of eco-hydrological variability under the condition of climate change and corresponding mitigation measures. Considering the problems and weakness in studies,we proposed the development trends of future research and key problems to be solved in wetland eco-hydrologic
Natural porous mineral supported (TiO2/diatomite) photocatalyst was prepared via a modified sol–gel method using titanium (IV) butoxide (TBOT) and diatomite. The effect of TBOT dosage on adsorption ...capacity and photocatalytic activity for Rhodamine B (RhB) solution was investigated. The morphology and elemental distribution were determined by scanning electron microscopy with attached energy-dispersive X-ray detector. The porous and crystalline structures were characterized using nitrogen adsorption–desorption and X-ray diffraction techniques, respectively. The prepared TiO2/diatomite hybrid catalyst has shown relatively even porous structure and dispersion of TiO2 over the surface. This suggests that the diatomite matrix prevented the agglomeration of TiO2 particles. Initially, the surface area and pore volume of the hybrid catalyst were increased by adding TBOT then decreased for dosages higher than 1.0ml. The crystalline size of TiO2 immobilized on diatomite matrix by sol–gel method was around 20nm. When the experiments were carried out in the absence of diatomite, this value was increased to 33.73nm. The use of diatomite also promoted an increase of the transformation temperature of the crystalline phase anatase to rutile for the TiO2. The as-prepared TiO2/diatomite composite exhibited high photocatalytic activity (96.0% for 0.5h UV-light irradiation) for the degradation of RhB from wastewater as a result of its unique porous structure and optimum TiO2 loading. In addition, it can be easily separated from suspension and possess a good durability. This hybrid material holds great promise in the engineering field for the environmental remediation.
TiO2 nanoparticles were immobilized onto purified diatomite using a modified sol–gel method. The morphology of the as-prepared TiO2/diatomite hybrid catalyst is shown in the illustration. The effect of titanium (IV) butoxide dosage on degradation efficiency for dye Rhodamine B under UV-light irradiation was investigated, as well as durability. Display omitted
•The optimum loading dosage of TiO2 for TiO2/diatomite hybrids was investigated.•The composites were characterized by SEM/EDX, XRD and N2-adsorption instrument.•The effect of TBOT dosage and diatomite support on degradation was investigated.•The adsorption and photocatalysis for Rhodamine B in water were studied.•TiO2/diatomite hybrids show potential prospects in environmental remediation.
The machining precision of the milling head is primarily affected by the thermal errors that originated from the thermal deformation. Thermal error compensation is an economical and efficient method ...to overcome these thermal errors. The milling head’s heat source is analyzed to calculate the thermal boundary load based on component parameters of the milling head. The milling head’s thermal deformation is then simulated using ANSYS software to achieve the milling head’s temperature distribution and the amount of thermal deformation. Through the design and construction of the milling head temperature and thermal deformation experiment platform, the thermal deformation experiment of the milling head is performed. Accordingly, the measuring point temperature and the tooltip offset are obtained. Finally, a thermal error compensation method is proposed based on the homogeneous transformation. The research results give a theoretical reference and technical support for the thermal error compensation, optimized design, and development of milling heads.
The optimal allocation of agricultural water and land resources is of great significance in ensuring sustainable food production and economic benefits of farmers. However, agriculture, as an ...important carbon cycle ecosystem, has paid limited attention to carbon sequestration in the optimal allocation of water and land resources. Therefore, this study developed a new water-carbon-economy coupling model (WCECM) for optimal allocation of agricultural water and land resources. In this model, the minimum water scarcity, maximum carbon sequestration and maximum economic benefits are taken as the optimization objectives. In addition, surface water volume and groundwater volume and planting area etc. were defined as constraints, respectively. Then, the model was solved using the Non-dominated Sorting Genetic Algorithm III (NSGA-III) and the Entropy-weighted-TOPSIS evaluation method. The developed model was demonstrated in the largest Farm, Youyi Farm, which is one of commercial grain production base in China to analyze the optimization of water and land resources from 2010 to 2019. We found that the new WCECM, based on the simulation of a complex coupled water-carbon-economy system, can realize the optimal allocation of agricultural water and land resources to protect regional water resources, increase carbon sequestration and adjust the agricultural planting structure. In detail, through the multi-objective optimization model, the planting structure and the allocation ratio of surface water and groundwater irrigation water consumption are more suitable for this study area. After the optimization, the area planted with Rice was significantly reduced, the area planted with Maize was increased, and the area planted with Soybean did not change significantly compared with the first two crops. The planting structure has changed from focusing on paddy cultivation to dryland cultivation, with the ratio of Rice area, Maize area and Soybean area being 3:6:1. The water consumption is constrained within manageable limits, with an average annual irrigation water consumption of 2.01 × 108 m3. The amount of carbon sequestered has increased significantly, with an average annual increase of 7.8 × 108 kg. Meanwhile, the optimized economic benefits increased slightly, with a value of ¥2.35 billion. In short, optimization of water and land resources is beneficial for improving farmers' incomes, increasing carbon sequestration in agriculture, and conserving water resources.
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•A new water-carbon-economy coupling model was developed.•Optimizing planting structure is beneficial for improving carbon sequestration.•Optimizing resource allocation contributes to sustainable food production.
Fibrinogen is an extracellular matrix protein composed of three polypeptide chains with fibrinogen alpha (FGA), beta (FGB) and gamma (FGG). Although fibrinogen and its related fragments are involved ...in tumor angiogenesis and metastasis, their functional roles are incompatible. A recent genome-scale screening reveals that loss of
affects the acceleration of tumor growth and metastasis of lung cancer, but the mechanism remains elusive. We used CRISPR/Cas9 genome editing to knockout (KO)
in human lung adenocarcinoma (LUAD) cell lines A549 and H1299. By colony formation, transwell migration and matrix invasion assays,
KO increased cell proliferation, migration, and invasion but decreased the expressions of epithelial-mesenchymal transition marker E-cadherin and cytokeratin 5/8 in A549 and H1299 cells. However, administration of FGA inhibited cell proliferation and migration but induced apoptosis in A549 cells. Of note,
KO cells indirectly cocultured by transwells with
wild-type cells increased FGA in the culture medium, leading to decreased migration of
KO cells. Furthermore, our functional analysis identified a direct interaction of FGA with integrin α5 as well as FGA-integrin signaling that regulated the AKT-mTOR signaling pathway in A549 cells. In addition, we validated that
KO increased tumor growth and metastasis through activation of AKT signaling in an A549 xenograft model. IMPLICATIONS: These findings demonstrate that that loss of
facilities tumor growth and metastasis through the integrin-AKT signaling pathway in lung cancer.
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•Flood pulses and inundation patterns were evaluated for a large low-gradient river.•Altered flood pulse and inundation patterns affected downstream floodplain wetlands.•Identified a ...hydrograph-based inundation threshold for protecting floodplain wetlands.
Floodplain wetlands of low-gradient rivers are especially sensitive to alteration of hydrologic conditions. Although many studies have investigated changes in downstream hydrologic regimes caused by river dam construction, no study has specifically quantified the long-term effect of altered flood pulse on floodplain wetlands. Such knowledge is needed to develop effective dam operation strategies and plans for downstream wetland protection and restoration. We applied data time series from 1984 to 2018 to delineate the inundation extent of floodplain wetlands during the pre- (1984–2005) and post-dam (2006–2018) periods. Four segments of the 360-km river reach were selected to investigate how inundation frequency of floodplain wetlands responded to changes in flow regimes and flood pulse for both periods associated with dam operation. The results showed that the water area slightly increased as a result of recharging water from dam, while the inundation frequency of adjacent floodplain wetlands overall reduced because of lower magnitude of flood pulse. Inundation area of four segments show less variation during the post-dam period compared to the pre-dam period. These findings clearly indicate that decreased flood pulses caused by dam operations reduce both inundation frequency and areal extent of floodplain wetlands. Based on the findings, we propose an inundation threshold that can be used for dam operation to protect and restore river corridor and floodplain ecosystems.
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