Constructing Efficient CuO-Based CO Oxidation Catalysts with Large Specific Surface Area Mesoporous CeO2 Nanosphere Support.

CeO2 is an outstanding support commonly used for the CuO-based CO oxidation catalysts due to its excellent redox property and oxygen storage-release property. However, the inherently small specific surface area of CeO2 support restricts the further enhancement of its catalytic performance. In this work, the novel mesoporous CeO2 nanosphere with a large specific surface area (~190.4 m2/g) was facilely synthesized by the improved hydrothermal method. The large specific surface area of mesoporous CeO2 nanosphere could be successfully maintained even at high temperatures up to 500 °C, exhibiting excellent thermal stability. Then, a series of CuO-based CO oxidation catalysts were prepared with the mesoporous CeO2 nanosphere as the support. The large surface area of the mesoporous CeO2 nanosphere support could greatly promote the dispersion of CuO active sites. The effects of the CuO loading amount, the calcination temperature, mesostructure, and redox property on the performances of CO oxidation were systematically investigated. It was found that high Cu+ concentration and lattice oxygen content in mesoporous CuO/CeO2 nanosphere catalysts greatly contributed to enhancing the performances of CO oxidation. Therefore, the present mesoporous CeO2 nanosphere with its large specific surface area was considered a promising support for advanced CO oxidation and even other industrial catalysts.

Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions.

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25-2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Structural and property changes of starch derivatives under microwave field: A review.

Native starches are commonly modified for desired properties because of their limited applications. Among various modifications, microwave irradiation has been gaining strong interests and becoming a focal area to transform starch during the last few years. Such interests reside in microwave irradiation's high heating rates, lesser extent of loss in nutritional qualities, and so on when compared with other approaches. This review summaries the effects of microwave field on the structural (e.g. morphology characteristic, lamellae structure, crystallinity, and molecular structure) and physicochemical properties (e.g. pasting properties and gelatinization) of naturally existing starch derivatives. Different microwave-assisted chemical derivatizations can directly or indirectly affect starch structure from the macroscopic to the microscopic level, thereby resulting in various functionalities. Moreover, conventional starch modification processes can be optimized by applying microwave irradiation to obtain modified starch with high degree of substitution and low viscosity. The future research will help to better understand the structural changes of microwave-assisted starch chemical derivatization and thereby creating a wide range of functionalities.

M2 Macrophage Hybrid Membrane-Camouflaged Targeted Biomimetic Nanosomes to Reprogram Inflammatory Microenvironment for Enhanced Enzyme-Thermo-Immunotherapy.

Excessive inflammatory reactions caused by uric acid deposition are the key factor leading to gout. However, clinical medications cannot simultaneously remove uric acid and eliminate inflammation. An M2 macrophage-erythrocyte hybrid membrane-camouflaged biomimetic nanosized liposome (USM[H]L) is engineered to deliver targeted self-cascading bienzymes and immunomodulators to reprogram the inflammatory microenvironment in gouty rats. The cell-membrane-coating endow nanosomes with good immune escape and lysosomal escape to achieve long circulation time and intracellular retention times. After being uptaken by inflammatory cells, synergistic enzyme-thermo-immunotherapies are achieved: uricase and nanozyme degraded uric acid and hydrogen peroxide, respectively; bienzymes improved the catalytic abilities of each other; nanozyme produced photothermal effects; and methotrexate has immunomodulatory and anti-inflammatory effects. The uric acid levels markedly decrease, and ankle swelling and claw curling are effectively alleviated. The levels of inflammatory cytokines and ROS decrease, while the anti-inflammatory cytokine levels increase. Proinflammatory M1 macrophages are reprogrammed to the anti-inflammatory M2 phenotype. Notably, the IgG and IgM levels in USM[H]L-treated rats decrease substantially, while uricase-treated rats show high immunogenicity. Proteomic analysis show that there are 898 downregulated and 725 upregulated differentially expressed proteins in USM[H]L-treated rats. The protein-protein interaction network indicates that the signaling pathways include the spliceosome, ribosome, purine metabolism, etc.

[Comparative Energy Consumption Structure and Mode between China and Major Energy-Consuming Countries Under the Background of Carbon Emission Reduction].

The top 23 countries with energy consumption accounting for 80% of the worldwide total in 2020 were selected as the research objects for this study. The energy consumption structure of these countries has been compared and studied from the proportion of clean energy in primary energy, the clean utilization rate of fossil energy, and the proportion of electric energy in terminal energy consumption, and the characteristics of energy consumption intensity were also analyzed based on the energy consumption per unit GDP, capital, and unit land area. The energy consumption patterns of various countries in social-economic operation, production, and life were also discussed, combined with the characteristics of industrial structure and subsector energy consumption. The concept of natural carbon sink load ratio of energy consumption was put forward, and the advantages and challenges of energy consumption mode transformation under carbon peak and carbon neutralization goals in China were identified and analyzed. The results showed that:the proportion of clean energy in primary energy, the proportion of energy consumption for power generation, the clean utilization rate of fossil energy, and the proportion of electric energy in terminal energy consumption in China were 15.90%, 53.48%, 37.51%, and 26.54%,respectively,all of which were in the forefront among the major energy-consuming countries in the world. China has built a favorable structural foundation for energy-intensive and clean utilization and formed a green and low-carbon energy consumption model; the proportion of non-industrial and agricultural energy consumption, especially that of transportation energy consumption, were both the lowest among major energy-consuming countries, and there is still much room for improvement in overall energy productivity based on the optimization of industrial structure. However, the relatively short carbon peak and neutralization target period poses a great challenge to the development speed and scale of clean energy to China, and the international situation under the constraint of carbon emission also increases the difficulty for China to achieve the carbon reduction goal by optimizing and adjusting the industrial structure.

Designing Highly Efficient Cu2O-CuO Heterojunction CO Oxidation Catalysts: The Roles of the Support Type and Cu2O-CuO Interface Effect.

In this work, a series of Cu2O/S (S = α-MnO2, CeO2, ZSM-5, and Fe2O3) supported catalysts with a Cu2O loading amount of 15% were prepared by the facile liquid-phase reduction deposition-precipitation strategy and investigated as CO oxidation catalysts. It was found that the Cu2O/α-MnO2 catalyst exhibits the best catalytic activity for CO oxidation. Additionally, a series of Cu2O-CuO/α-MnO2 heterojunctions with varied proportion of Cu+/Cu2+ were synthesized by further calcining the pristine Cu2O/α-MnO2 catalyst. The ratio of the Cu+/Cu2+ could be facilely regulated by controlling the calcination temperature. It is worth noting that the Cu2O-CuO/α-MnO2-260 catalyst displays the best catalytic performance. Moreover, the kinetic studies manifest that the apparent activation energy could be greatly reduced owing to the excellent redox property and the Cu2O-CuO interface effect. Therefore, the Cu2O-CuO heterojunction catalysts supported on α-MnO2 nanotubes are believed to be the potential catalyst candidates for CO oxidation with advanced performance.

Oral supramolecular nanovectors for dual natural medicine codelivery to prevent gastric mucosal lesion.

The oral administration of a single formulation loaded with more than one natural medicine to treat chronic diseases has advantages such as convenience, effectiveness, and economy. Here, using biomaterials approved by the drug administration, we fabricated supramolecular nanovectors containing dual natural medicines to prevent gastric mucosal lesions. Nanovectors exhibited superior intestinal absorption and bioavailability, which might be due to their high dispersion, good muco-adhesiveness, blood-lymph circulation transport, lipid sensing, and protective effects. Molecular docking results clarified the possible mechanisms in aspects of efflux pump (p-glycoprotein and multidrug resistance protein 1) inhibition effects, metabolic enzyme (cytochrome P450 3A4/1A2) blocking effects, serum albumin deposit effects, and dual drug interaction effects. Nanovectors decreased ethanol-induced gastric mucosal lesions by lowering the gastric ulcer index, preventing oxidative damage, decreasing interleukin-6, tumor necrosis factor-α and malondialdehyde, increasing glutathione, superoxide dismutase, and prostaglandin E2 levels. The interactions of inhibitor of nuclear factor-κB or κB kinase-related proteins and dual drugs or nanovector components were simulated computationally to provide an understanding of the gastro-protective action mechanism. In all, industrializable supramolecular nanovectors could effectively co-deliver dual natural medicines via the oral route by improving the pharmacokinetic behavior and exerting protective efficacy of the gastric mucosa by decreasing the oxidative stress and inflammatory level.

Effects of combined ultrasonic and microwave vacuum drying on drying characteristics and physicochemical properties of Tremella fuciformis.

This study analyzes the effects of ultrasonic waves on the drying kinetics of Tremella fuciformis during microwave vacuum drying. The physicochemical properties and structural characteristics of T. fuciformis polysaccharides (TFPs) were studied by drying tremella samples using hot air drying (HAD), microwave vacuum drying, ultrasonic pretreatments with microwave vacuum drying (US + MVD), and air-borne ultrasonic pretreatments combined with microwave vacuum drying (USMVD) under acoustic energy densities of 0.14, 0.28, and 0.42 W/mL. The results showed that USMVD and US + MVD accelerated the mass transfer process of T. fuciformis. Compared with HAD treatment, TFP samples obtained by USMVD and US + MVD had a reduced molecular weight to a certain extent, and they had stronger shear thinning ability. In addition, USMVD-TFPs at 0.42 W/mL retained higher total sugar, reducing sugar, and uronic acid, and the degree of reduction in the monosaccharide component content was small.

Biomimetic lipidic nanovectors for effective asparaginase supramolecule delivery.

Effectiveness of enzyme therapy is limited by enzyme drawbacks such as short half-life, low bioavailability and high immunogenicity. We loaded asparaginase (Aase) into hydroxypropyl- or sulfonbutylether-beta cyclodextrin to form supramolecular amphiphilic molecules by self-assembly followed by entrapment inside the cores of two biomimetic lipidic nanovectors (AS-XLNs). Supramolecular structure was simulated by molecular docking. AS-XLNs maintained superior activity through isolating Aase from external environment due to docking with cyclodextrin and coating with biomimetic membrane. Fluorescent probes and computational simulations were used to reveal possible interactions between serum albumin/trypsin and Aase/nanovector membrane components which were partly responsible for enhanced bioavailability and bioactivity of AS-XLNs compared to Aase. AS-XLNs significantly increased cytotoxicity against pulmonary tumor cells due to synergistic effects of Aase and nanovector membrane components (killing tumor cells through apoptosis induced by asparagine depletion and autophagy inhibition or via targets such as vascular endothelial growth factor A, alpha-amylase, p-selectin or androgen receptor).

Establishment of a homogeneous immunoassay-light-initiated chemiluminescence assay for detecting anti-Müllerian hormone in human serum.

Anti-Müllerian hormone (AMH) is known as a reliable marker of ovarian reserve (OR). The determination of AMH is of great importance and most existed AMH detection methods are heterogeneous immunoassay. In this study, a novel homogeneous sandwich immunoassay-light-initiated chemiluminescence assay (LICA) for detecting AMH serum level was developed. This AMH-LICA was performed by incubating serum samples with AMH mouse monoclonal antibody coated with chemibeads, streptavidin-coated sensibeads, and biotinylated AMH mouse monoclonal antibody. Sensitivity, precision, accuracy and cross-reactivity of this assay were evaluated. Besides, a regression analysis showed a high correlation between AMH-LICA and Roche Elecsys® AMH assay (y = 0.9851x + 0.07147, R2 = 0.9569). As a homogeneous immunoassay, this AMH-LICA could accurately and rapidly determine the serum level of AMH with high-throughput. Thus, this new developed assay may be a new useful analytical tool for the determination of AMH.

[Simulated Ozone Damage on Gross Primary Productivity (GPP) in a Winter Wheat Field].

An eddy-covariance system combined with a semi-mechanistic model was used to analyze variations in gross primary productivity (GPP) and to simulate the impact of ozone (O3) on GPP under different levels O3 concentrations over a winter wheat field in Nanjing. The results showed that GPP was higher during the middle of the growth period and low during the early and late growth periods, reaching a maximum of 40 µmol·(m2·s)-1. Using high and low ozone sensitivity settings,O3-damage in 150, 100, 50 nL·L-1 and control treatment (CK) reduced GPP by -72%, -36%, -6%, and -10%, and by -13%, -6%, -1%, and -2%, respectively. These results provide a scientific basis for formulating defense strategies for O3 damage to crops.

[Long Term Variations of Ozone Concentration of in a Winter Wheat Field and Its Loss Estimate Based on Dry Matter and Yield].

Surface ozone pollution and its negative effects on crops and food safety have attracted the attention of many people. In this study, ozone concentration and meteorological parameters in a winter wheat field were measured from 2014 to 2016. We analyzed the variations in ozone concentration and AOT40 during the growing season for winter wheat. According to the revised stomatal model, the leaf stomatal conductance of winter wheat was simulated and verified by comparing with measured results. Based on the flux model, the leaf stomatal fluxes of winter wheat were calculated. In addition, we estimated the effects of ozone concentration on winter wheat dry matter and yield by using exposure-response relationships and flux-response relationships. The results suggested that the concentration of ozone gradually increased during the growing season for winter wheat and showed a distinct unimodal pattern of diurnal variation. The mean concentrations of ozone were 36.2, 37.7, and 33.6 nL·L-1, respectively, and the ozone AOT40 values were 17.08, 17.90, and 11.84 µL·(L·h)-1, respectively, during the growing seasons for winter wheat from 2014 to 2016. The Jarvis-type factorial model of stomatal conductance could be used to simulate the stomatal conductance of winter wheat in the region, and approximately 81% of the variation of measured stomatal conductance could be accounted for by the model. The leaf stomatal ozone fluxes of winter wheat were 9.36, 9.32, and 8.65 mmol·m-2, respectively, from 2014 to 2016. Winter wheat yield decreased about 18.03%, and its dry matter decreased about 19.31% under ozone stress during these three years.

[Influencing Mechanism and Spatio-temporal Pattern of Stomatal Ozone Flux of Winter Wheat Under Ozone Pollution].

As one of the main atmospheric pollutants over surface layer,researches on the increasing surface ozone concentration and its impact on main crops have become the focus of every government and the public.In this paper,based on the observations in Nanjing using the main local cultivars in China's major winter wheat producing areas,it was expected to obtain the data including ozone concentration,meteorological data and stomatal conductance by continuous observation.Stomatal conductance model was used and parameterized,combined with flux model,we analyzed the characteristics of stomatal flux in winter wheat under ozone pollution.At the same time,the stomatal conductance and stomatal ozone absorption flux of winter wheat were simulated in Jiangsu Province.The main results were as follows:Elevated ozone concentration could reduce stomatal conductance of winter wheat leaf and stomatal conductance decreased with the increase of ozone concentration.According to the observational data through the experiment,based on the boundary line technology,stomatal conductance model was parameterized to simulate stomatal conductance of wheat leaves from environmental factors.Approximately 90%,77% and 83% variation of measured stomatal conductance could be explained by the stomatal conductance model.In the experiment,the total ozone absorption flux in ozone concentration of CK (53.67 nL·L-1),100nL·L-1,150nL·L-1 was 6.42 mmol·m-2,12.27 mmol·m-2,13.90 mmol·m-2 respectively.The ozone concentration gradually increased from early period to late period during the period of winter wheat growth in Jiangsu area.The average stomatal conductance followed the order of the middle stage >the later stage >the early stage.Winter wheat ozone cumulative absorption flux was the highest during the middle stage.

[Ozone Deposition and Risk Assessment for a Winter Wheat Field:Partitioning Between Stomatal and Non-stomatal Pathways].

To better understand the ozone deposition and risk assessment over agroecosystems based on the ozone flux indices, an eddy-covariance system was used for measuring the ozone deposition continuously and dynamically in a winter wheat field. We analyzed the variations in ozone concentration, total ozone flux, and stomatal and non-stomatal flux. The relationships between stomatal/non-stomatal ozone deposition velocity and the main meteorological factors were investigated. Finally, the yield losses of winter wheat based on the ozone-dose index (AOT40) and ozone flux index (DFs06) were calculated. Results showed that average daily ozone concentration (cO3) was 32.9 nL·L-1. The daytime (08:00-18:00) and nighttime total ozone flux (FO3) were -7.6 nmol·(m2·s)-1 and -3.1 nmol·(m2·s)-1, respectively, and the mean diurnal FO3 was -5.1 nmol·(m2·s)-1. The mean daily stomatal ozone flux (Fs) and non-stomatal ozone flux (Fns) ranged from 0 to -5.1 nmol·(m2·s)-1 and from -1.43 to -10.31 nmol·(m2·s)-1, respectively. The mean diurnal Fs and Fns were -1.43 nmol·(m2·s)-1 and -3.66 nmol·(m2·s)-1. High solar radiation (SR), high temperature (T), and moderate humidity were used to analyze stomatal ozone deposition; high SR, moderate T, and high humidity were suitable to analyze non-stomatal ozone deposition. The cumulative total ozone flux (DFO3), cumulative stomatal ozone flux (DFs), and cumulative non-stomatal ozone flux (DFns) were 31.58, 9.99, and 21.59 mmol·m-2 during the entire experimental period, and DFs and DFns accounted for 32% and 68% of DFO3. The ranges of yield loss in winter wheat were estimated at 11.58%-20.37% and 20%-23.56% using different assessment models based on the ozone dose index AOT40 and ozone flux index DFs06, respectively.

The Effect of Elevated Ozone Concentrations with Varying Shading on Dry Matter Loss in a Winter Wheat-Producing Region in China.

Surface-level ozone pollution causes crop production loss by directly reducing healthy green leaf area available for carbon fixation. Ozone and its precursors also affect crop photosynthesis indirectly by decreasing solar irradiance. Pollutants are reported to have become even more severe in Eastern China over the last ten years. In this study, we investigated the effect of a combination of elevated ozone concentrations and reduced solar irradiance on a popular winter wheat Yangmai13 (Triticum aestivum L.) at field and regional levels in China. Winter wheat was grown in artificial shading and open-top-chamber environments. Treatment 1 (T1, i.e., 60% shading with an enhanced ozone of 100±9 ppb), Treatment 2 (T2, i.e., 20% shading with an enhanced ozone of 100±9 ppb), and Control Check Treatment (CK, i.e., no shading with an enhanced ozone of 100±9 ppb), with two plots under each, were established to investigate the response of winter wheat under elevated ozone concentrations and varying solar irradiance. At the field level, linear temporal relationships between dry matter loss and cumulative stomatal ozone uptake were first established through a parameterized stomatal-flux model. At the regional level, ozone concentrations and meteorological variables, including solar irradiance, were simulated using the WRF-CMAQ model (i.e., a meteorology and air quality modeling system). These variables were then used to estimate cumulative stomatal ozone uptake for the four major winter wheat-growing provinces. The regional-level cumulative ozone uptake was then used as the independent variable in field data-based regression models to predict dry matter loss over space and time. Field-level results showed that over 85% (T1: R(2) = 0.85 & T2: R(2) = 0.89) of variation in dry matter loss was explained by cumulative ozone uptake. Dry matter was reduced by 3.8% in T1 and 2.2% in T2 for each mmol O3·m(-2) of cumulative ozone uptake. At the regional level, dry matter loss in winter wheat would reach 50% under elevated ozone concentrations and reduced solar irradiance as determined in T1, and 30% under conditions as determined in T2. Results from this study suggest that a combination of elevated ozone concentrations and reduced solar irradiance could result in substantial dry matter loss in the Chinese wheat-growing regions.

Calycosin-7-O-ß-D-glucoside promotes oxidative stress-induced cytoskeleton reorganization through integrin-linked kinase signaling pathway in vascular endothelial cells.

BACKGROUND: Dysfunction of vascular endothelium is implicated in many pathological situations. Cytoskeleton plays an importance role in vascular endothelial permeability barrier and inflammatory response. Many Chinese herbs have the endothelial protective effect, of which, "Astragalus membranaceus" is a highly valued herb for treatment of cardiovascular and renal diseases in traditional Chinese medicine, In this study, we tested whether calycosin-7-O-ß-D-glucoside (Calycosin), a main effective monomer component of "Astragalus membranaceus", could protect endothelial cells from bacterial endotoxin (LPS)-induced cell injury. METHODS: Endothelial cell injury was induced by exposing human umbilical vein endothelial cells (HUVECs) to LPS. The effects of calycosin on LPS-induced changes in cell viability, apoptosis rate, cell migration, nitric oxide synthase (NOS), generationof intracellular reactive oxygen species (ROS) and cytoskeleton organization were determined. Microarray assay was employed to screen the possible gene expression change. Based on the results of microarray assay, the expression profile of genes involved in Rho/ROCK pathway and AKT pathway were further evaluated with quantitative real-time RT-PCR or western blot methods. RESULTS: Calycosin improved cell viability, suppressed apoptosis and protected the cells from LPS-induced reduction in cell migration and generation of ROS, protein level of NOS at a comparable magnitude to that of Y27632 and valsartan. Similar to Y27632 and valsartan, Calycosin, also neutralized LPS-induced actomyosin contraction and vinculin protein aggregation. Microarray assay, real-time PCR and western blot results revealed that LPS induced expression of FN, ITG A5, RhoA, PI3K (or PIP2 in western blotting), FAK, VEGF and VEGF R2, and inhibited expression of MLCP. We believed multiple pathways involved in the regulation of calycosin on HUVECs. Calycosin are considered to be able to activate MLCP through promoting the generation of NO, decreasing PMLC, suppressing the cytoskeleton remodeling caused by activation of Rho/ROCK pathway and inhibiting AKT pathway by decreasing VEGF, VEGF R2 and PI3K level. CONCLUSION: Calycosin protected HUVEC from LPS-induced endothelial injury, possibly through suppression of Rho/ROCK pathway and regulation of AKT pathway.

Genotype Distribution and Molecular Epidemiology of Hepatitis C Virus in Hubei, Central China.

BACKGROUND: Little is known about the molecular epidemiology of hepatitis C virus (HCV) infection in Central China. METHODOLOGY/PRINCIPAL FINDINGS: A total of 570 patients from Hubei Province in central China were enrolled. These patients were tested positive for HCV antibody prior to blood transfusion. Among them, 177 were characterized by partial NS5B and/or Core-E1 sequences and classified into five subtypes: 1b, 83.0% (147/177); 2a, 13.0% (23/177); 3b, 2.3% (4/177); 6a, 1.1% (2/177); 3a, 0.6% (1/177). Analysis of genotype-associated risk factors revealed that paid blood donation and transfusion before 1997 were strongly associated with subtypes 1b and 2a, while some subtype 2a cases were also found in individuals with high risk sexual behaviors; subtypes 3b, 6a, and 3a were detected only in intravenous drug users. Phylogeographic analyses based on the coalescent datasets demonstrated that 1b, 2a, 3b, and 6a were locally epidemic in Hubei Province. Among them, subtype 1b Hubei strains may have served as the origins of this subtype in China, and 2a and 3b Hubei strains may have descended from the northwest and southwest of China, respectively, while 6a Hubei strains may have been imported from the central south and southwest. CONCLUSION/SIGNIFICANCE: The results suggest that the migration patterns of HCV in Hubei are complex and variable among different subtypes. Implementation of mandatory HCV screening before donation has significantly decreased the incidence of transfusion-associated HCV infection since 1997. More attention should be paid to intravenous drug use and unsafe sexual contact, which may have become new risk factors for HCV infection in Hubei Province.

[Effects of reduced solar radiation on winter wheat flag leaf net photosynthetic rate].

Taking winter wheat Triticum aestivum L. (cv. Yangmai 13) as test material, a field experiment was conducted in Nanjing City to study the effects of simulated reduced solar radiation on the diurnal variation of winter wheat flag leaf photosynthetic rate and the main affecting factors. Five treatments were installed, i. e., 15% (T15), 20% (T20) , 40% (T40), 60% (T60), and 100% (CK) of total incident solar radiation. Reduced solar irradiance increased the chlorophyll and lutein contents significantly, but decreased the net photosynthetic rate (Pn). Under different solar irradiance, the diurnal variation of Pn had greater difference, and the daily maximum Pn was in the order of CK > T60 > T40 > T 20 > T15. In CK, the Pn exhibited a double peak diurnal curve; while in the other four treatments, the Pn showed a single peak curve, and the peak was lagged behind that of CK. Correlation analysis showed that reduced solar irradiance was the main factor affecting the diurnal variation of Pn, but the physiological parameters also played important roles in determining the diurnal variation of Pn. In treatments T60 and T40, the photosynthesis active radiation (PAR), leaf temperature (T1) , stomatal conductance (Gs) , and transpiration rate (Tr) were significantly positively correlated with Pn, suggesting their positive effects on Pn. The intercellular CO2 concentration (Ci) and stomatal limitation (Ls) had significant negative correlations with Pn in treatments T60 and T40 but significant positive correlations with Pn in treatments T20 and T15, implying that the Ci and Ls had negative (or positive) effects on Pn when the solar irradiance was higher (or lower) than 40% of incident solar irradiance.