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C30H20O4N2Cl2S2, Orthorhombic, Pca21, a = 16.9808(14) Å, b = 7.5227(6) Å, c = 20.8027(16) Å, V = 2657.4(4) Å3, Z = 4, R gt (F) = 0.0642, wR ref(F 2) = 0.1809, T = 293 K.

C15H16ClNO2, triclinic, P 1 ‾ $‾{1}$ (no. 2), a = 7.4339(12) Å, b = 8.2564(14) Å, c = 12.184(2) Å, α = 108.804(6)∘, β = 93.672(5)∘, γ = 94.373(6)∘, V = 702.8(2) Å3, Z = 2, R gt(F) = 0.0650, wR ref(F 2) = 0.1974, T = 273 K.

The aim of the study was to investigate the chemical properties of the most popular commercial extra virgin olive oils (EVOOs) in China. A total of 14 EVOO samples were collected and evaluated, and significant differences were observed with respect to physicochemical properties, fatty acid composition, minor components, and the oxidation stability index (OSI). The results showed that the chemical properties of EVOOs were significantly affected by different producing areas. The oleic acid (C18:1) content (average value: 77.80%), squalene content (average value: 6052.28 mg/kg), and OSI (average value: 9.90 h) of the Spanish olive oil were higher than those of the other oils investigated, while the total phenolic content (average value: 308.34 mg/kg) was the lowest. Greek EVOOs had the lowest total sterol content (average value: 1023.48 mg/kg) and OSI (average value: 4.22 h). The C18:1 content (66.42%) and squalene content (3173.42 mg/kg) of the EVOO from China were lower than those of the other oils, while the palmitic acid (C16:0, 16.82%), linoleic acid (C18:2, 12.18%), total phenolic (553.17 mg/kg), and total sterol content (1904.77 mg/kg) were higher than those of the other olive oils. The EVOOs of the various countries could be distinguished by hierarchical cluster analysis (HCA). In addition, multiple linear regression (MLR) analyses between the OSI and chemical properties revealed that squalene (R = 0.729) and the unsaturation determined by the specific UV adsorption at 232 nm (K232, R = -0.300) were the main factors to affecting the EVOO oxidation stability.

C16H8O4, monoclinic, Pc (no. 7), a = 3.7133(1) Å, b = 9.7214(4) (2) Å, c = 15.5765(6) Å, β = 96.121(2)°, V = 559.08(3) Å3, Z = 2, R gt(F) = 0.0506, wR ref(F 2) = 0.1274, T = 150(2) K.

C23H13NO4, monoclinic, P21/n (no. 14), a = 11.6537(6) Å, b = 5.1315(2) Å, c = 26.8047(13) Å, β = 96.266(3)°, V = 1593.4(13) Å3, Z = 4, R gt(F) = 0.0531, wR ref(F 2) = 0.1432, T = 90.0(5) K.

Xanthium strumarium is an annual pseudometallophyte. To reveal the mechanisms of this species to adapt to metallicolous environmental conditions, phenological traits and biomass allocation of metallicolous and non-metallicolous populations of X. strumarium under six Mn2+ concentrations by pot culture experiments were performed. The results showed that both time to bolting and time to fruit setting in the metallicolous population were earlier than those in the non-metallicolous population. The number of flowers, fruits, seeds and 1000-seed weight in the metallicolous population were higher than those in the non-metallicolous population under Mn stress. Reproductive allocation and harvest index in the metallicolous population were higher than those in the non-metallicolous population. Furthermore, all the Mn concentrations in leaves, stems, roots, and fruits of the metallicolous population were higher than the counterparts of non-metallicolous population. These results suggested that metallicolous population had higher tolerance to Mn stress than non-metallicolous population, the earlier flowering and fruiting, and the enhancement in reproductive allocation may contribute to plant tolerance to Mn toxicity for X. strumarium.

Effective phytoremediation of manganese (Mn) requires the careful selection of a species that has a relatively high manganese tolerance. Exploring the physiological mechanisms related to Mn stress responses is crucial for identifying and employing species for Mn phytoremediation. Xanthium strumarium is a species that can accumulate high levels of Mn, thus it is a candidate species for Mn-phytoremediation. To reveal the tolerance mechanisms of this species to manage Mn stress, the morphological, physiological, and biochemical responses of seedlings grown in water cultures under six different Mn concentrations were analyzed. The results showed that X. strumarium can accumulate high levels of Mn, even as plant growth was inhibited by rising Mn concentrations. Malondialdehyde (MDA) content increased and catalase (CAT) activity decreased along with the increased Mn concentrations, while soluble protein and proline content, as well as the superoxide dismutase (SOD) and peroxidase (POD) enzymes, all increased initially and then declined. The highest value of POD, SOD, soluble protein and proline all occurred at 5000 µM of Mn stress, which means that X. strumarium can adapt to low concentration of Mn stress. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) decreased, and the stomatal limitation (Ls) increased in response to Mn stress. Furthermore, water use efficiency (WUE) and intrinsic water use efficiency (WUEi) increased first under low concentration of Mn, and then reduced as the concentration of Mn increased. The maximum quantum efficiency of PSII photochemistry (Fv/Fm), efficiency of excitation capture by open PSII reaction centers (Fv′/Fm′), electron transport rate (ETR) declined as Mn concentration increased. In conclusion, the above results showed that X. strumarium can be effectively used for phytoremediation of Mn-contaminated soils.

Flavoured rapeseed oils prepared using traditional technologies (oils A and B) and a fragrant rapeseed oil obtained using an enzymatic Maillard reaction (oil C) were analysed to show that oil C featured basic indicators and a fatty acid composition similar to those of traditional oils while exhibiting a higher comprehensive sensory evaluation score. Volatile component, odour activity value (OAV), and relative odour activity value (ROAV) analyses revealed that oil C had an elevated content of pyrazines (20.83%) and aldehydes (38.15%), which resulted in stronger charred and caramel flavours. The aroma of oil C was directly impacted by 3-methylbutyraldehyde (OAV > 1) and was modified by 3-methylthiopropionaldehyde and nonanal (RAOV > 1 in both cases). Thus, the developed technology was found to be well suited for the production of novel and safe fragrant rapeseed oil.

Unprecedented asymmetric exo′-selective [3 + 2] cycloaddition reactions of CF3-containing isatin-derived azomethine ylides with methyleneindolinones have been disclosed. Under bifunctional organocatalysis by cinchona-derived squaramide catalysts, a series of potential biologically important trifluoromethylated 3,3′-pyrrolidinyl-dispirooxindoles were efficiently constructed in a highly stereoselective manner (84%–99% yields, up to >20 : 1 dr and >99% ee). The reaction leads to the formation of four contiguous stereogenic centers, including two adjacent spiro quaternary stereocenters.

Xanthium strumarium L. is a candidate species for manganese (Mn)-phyto-remediation. To reveal the mechanism of this species adaptive to Mn stress, the growth, Mn subcellular distribution, chemical forms, as well as micro-structure and ultra-structure responses of the mining ecotype (ME) of X. strumarium to Mn stress were studied with the non-mining ecotype (NME) as the reference by a hydroponic experiment. The results showed the ME demonstrated a higher tolerance to Mn stress with a superior growth and a higher tolerance index (TI) when compared with the NME. The concentrations of Mn in leaves, stems, and roots of the ME were 1.1–1.8, 1.2–1.9, and 1.3–1.9 times higher than those in the corresponding organs of the NME, respectively. The micro-structure and ultra-structure showed abnormal alterations, such as shrunken ducts and sieve canals, round-shaped chloroplasts, increased starch and osmiophilic granules, as well as expanded and non-compact granum thylakoids in the NME, compared to the ME. More than 83% of Mn was localized in cell wall and soluble fraction, while the Mn concentration in all fractions had a direct linear relationship with Mn treatment in the ME. The proportions of pectates and protein integrated-Mn, phosphate-Mn, and oxalate-Mn forms were dominant in leaves and stems of the ME, whereas, in the NME the relative proportions of inorganic Mn and water-soluble Mn forms in the roots was higher than the other forms. Altogether, the combination of preferential distribution of Mn in the cell wall and soluble fraction, and storage of Mn in low toxicity forms, such as phosphate-Mn, pectates and protein-bound Mn, and oxalate-Mn, might be responsible for alleviating Mn toxicity in the ME.

Macleaya cordata is a perennial herb, a candidate phytoremediation plant with high biomass and manganese (Mn) tolerance. To study the mechanism underlying its Mn adaptability, Mn2+ at various concentrations (0, 1000, 5000, 10000, 15000, and 20000 μM) were applied to M. cordata to investigate the subcellular distribution and chemical forms of Mn, as well as the resulting physiological and biochemical changes by pot culture experiment under natural light in a greenhouse. According to our results, Mn level in M. cordata increased with exogenous Mn concentrations; and Mn contents in different tissues exhibited a leaf > root > stem pattern. Meanwhile, biomass and the level of photosynthetic pigments increased at lower Mn concentrations but declined as Mn concentration further ascended. Subcellular distribution analysis revealed that Mn was sequestered in cell wall and vacuole; in addition, it was incorporated into pectates and protein, phosphates, and oxalates. These findings revealed a possible effective strategy for M. cordata to reduce Mn mobility and toxicity. Moreover, a continuous boost in the level of malondialdehyde was observed with Mn gradient; whereas contents of soluble proteins and proline, and the activities of superoxide dismutase and peroxidase were initially increased and then dropped. Altogether, these results indicated that most Mn was trapped in the cell wall and soluble fractions in low toxicity forms such as pectates and protein, phosphates, and oxalates. These strategies, that is functioning cooperatively with the well-coordinated antioxidant defense systems and the non-enzymatic metabolites, confer strong resistance to Mn in M. cordata.

Cleome viscosa L. is a promising species for the phytoremediation of Mn-contaminanted soil. To reveal the adaptive mechanisms of species to Mn stress, plant growth, Mn subcellular distribution, Mn chemical forms, and plant physiological and biochemical traits were characterized in plants grown under different concentrations of Mn2+ (0, 1000, 5000, 10000, 15000 and 20000 μM). The results showed that C. viscosa plant biomass initially increased and then decreased with rising Mn treatment concentration. C. viscosa plants can accumulate high levels of Mn in roots and leaves, and both the bioconcentration factor (BCF) and the translocation factor (TF) exhibited values higher than one. Mn was primarily retained in the cell wall and soluble fractions. Predominant chemical forms of Mn were pectate and protein, phosphates, and oxalates-integrated Mn. The activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and the contents of proline, soluble sugar, and soluble protein initially increased and then decreased with enhancing Mn treatment concentration, whereas the malondialdehyde (MDA) content simultaneously displayed a gradual increase. Combined, these results indicate that C. viscosa can tolerate Mn-stress conditions by increasing antioxidant enzyme activities and non-enzymatic metabolites contents. In addition, Mn immobilization in the cell wall and soluble fractions, alongside the storage of Mn in low-activity chemical forms are further important mechanisms to cope with high environmental Mn concentration. This study reveals the adaptive mechanisms of plants to Mn stress, and provides a theoretical basis for the use of C. viscosa as a candidate phytoremediation plant for Mn-contaminated soil.

Five rice varieties were planted to determine the variation of the yield and quality traits in five different regions in a cold area of China. The results showed that the number of the panicles, the number of grains per panicle and percentage of head-milled rice displayed quadratic curves against the accumulated temperature, and the sterile rate decreased with greater accumulated temperature. However, 1 000-grain weight had no correlation with the accumulated temperature and protein content, amylose content and taste also had no obvious relation with the accumulated temperature. The results from the accumulated temperature differed with rice variety, so the temperature insensitive type variety should be proposed for production.

Sponge-Nafion membranes were prepared by electro-spinning (ES) method and with polyacrylonitrile (PAN) or polyvinylpyrrolidone (PVP) as additives. First the optimum conditions of ES were achieved to prepare Nafion membranes with sponge-like structure. Then the membranes were further processed by electrostatic spray method to enhance their properties. SEM, IR were used to characterize the morphologies and structure. Proton conductivity was measured by the CHI66C electrochemical workstation (Shanghai Chen Hua Instrument Company). Results showed that the sponge-Nafion membranes possessed better proton conductivity especially at relatively high temperatures than that of commercial Nafion membranes.

The present study aimed to investigate the change of proton leak and discuss the role of cerebral uncoupling proteins (UCPs) and its regulatory molecules non-esterified fatty acid (NEFA) in high altitude mitochondrial oxidative phosphorylation deficiency. The model group animals were exposed to acute high altitude hypoxia, and the mitochondrial respiration, protein leak, UCPs abundance/activity and cerebral NEFA concentration were measured. We found that in the model group, cerebral mitochondrial oxidative phosphorylation was severely impaired with decreased ST3 respiration rate and ATP pool. Proton leak kinetics curves demonstrated an increase in proton leak; GTP binding assay pointed out that total cerebral UCPs activity significantly increased; Q-PCR and western blot showed upregulated expression of UCP4 and UCP5. Moreover, cerebral NEFA concentration increased. In conclusion, UCPs mediated proton leak is closely related to cerebral mitochondria oxidative phosphorylation deficiency during acute high altitude hypoxia and NEFA is involved in this signaling pathway.

Aim To investigate antioxidant activities and life span prolonging effects of the extracts from the roots of Incarvillea younghusbandii Sprague, and to study the correlations between these activities and the polar intensity of the extracts. Method Five extracts (IYS1, IYS2, IYS3, IYS4 and YS5) with different polar intensity were prepared. Antioxidant activities in vitro were determined by LPO inhibitory and free radicals scavenging experiments. Life span prolonging effects in vivo were evaluated by feeding Drosophila melanogaster . Result Total phenolic content in extracts were solvent-dependent and decreased in the order of IYS4 > IYS1 >> IYS3 > IYS5 > IYS2. Organic extracts (IYS1 and IYS4) showed excellent LPO inhibitory activity, O 2 · − and ·OH scavenging activity compared to ascorbic acid (or benzoic acid, or BHT), while aqueous extracts (IYS2, IYS3 and IYS5) did not. The antioxidant activities ( in vitro ) were solvent dependent and decreased in the order of IYS4 > IYS1 > IYS3 > IYS5 ≥ IYS2. Drosophila melanogaster was fed with organic extracts (IYS1 or IYS4) at 5.0 mg mL −1 . The mean life span were increased by 24.4% (IYS1) or 23.0% (IYS4) in female and 15.3% (IYS1) or 16.9% (IYS4) in male; the maximum life span were increased by 8.4% (IYS1) or 11.2% (IYS4) in female and 9.7% (IYS1) or 15.8% (IYS4) in male, and the survival curves were significantly shifted to the right after fifteen days in both sexes survival period. Feeding aqueous extracts (IYS2, IYS3 or IYS5) at 5.0 mg·mL −1 , the significant life span prolonging effects were not achieved. The life span prolonging effects of the extracts were solvent-dependent and decreased in the order of IYS4 ≥ IYS1 >> IYS3 > IYS2 > IYS5. Conclusion Extracts from the roots of Incarvillea younghusbandii Sprague showed excellent antioxidant activities and significant life span prolonging effects in Drosophila melanogaster . Positive correlations existed between the antioxidant activities and total phenolic content. Life span prolonging effect was positively correlated with the total phenolic content or antioxidant activities. The extracts possess better life span prolonging effect in females than in males.

The field induced stereo regular polymerization of polymer dispersed nematic liquid crystal both positive and negative dielectric character are experimentally studied,the picture in kind and polarizing microscope photograph of samples are given.The experiment results show that there are obvious distinguish with in different area of electric field applied or not,the electric field has the induced stereo regular polymerization action under the polymer dispersed liquid crystal sample preparation process.The experiment results are useful to understand the influence of polymer border condition to liquid crystal micro drop configuration,and are in a sense of gaining a good deal to design a new type liquid crystal display device.

The properties of polymer dispersed liquid crystal(PDLC) and stressed liquid crystal(SLC) are introduced;the construction,principle and preparation process of stressed liquid crystal tunable glass are introduced.The SLC tunable display glass is prepared under the process of expose with writing pattern,the area covered becomes transmissible and the other side is changed into scattering.It looks like a frosted glass in scattering state with pattern display without stress applied,and it can be changed into translucent state and the pattern disappeared at the same time after sheared applied.As a kind of other display mode,the novel function SLC light tunable glass can be applied in the products of moveable windows or doors without power consuming,there will be the application prospect in the fields of construct fit up engineering for the user of company,market,hotel and so on.

1-Butyl-3-methylimidazolium dodecatungstophosphate catalyst ([bmim]3PW12O40) with high water tolerance was prepared from 1-butyl-3-methylimidazolium bromide ([bmim]Br) and phosphotungstic acid (H3PW12O40). The catalyst was characterized by means of Fourier transform infrared spectroscopy, thermogravimetry-differential scanning calorimetry, n-BuNH2 potentiometric titration, elemental analysis and so on. Its catalytic activity for esterification of ethanol and acetic acid to ethyl acetate was measured. The results show that there were three crystal-water molecules in the [bmim]3PW12O40 catalyst, and it preserved the primary Keggin structure and acid strength of H3PW12O40. The acid amount of [bmim]3PW12O40 catalyst was less than that of H3PW12O40. The [bmim]3PW12O40 catalyst exhibited higher catalytic activity and reusability in the esterification of ethanol and acetic acid to ethyl acetate.

In order to improve high temperature heat pumps (HTHP), firstly, after theoretical analysis is conducted about the heat transfer of non-azeotropic working fluids in the condenser, the possibility of incomplete condensation of non-azeotropic working fluids in the condenser of a HTHP is presented. Secondly, an experimental plan is designed to study the phenomenon, and many working conditions experiments (flow rate, temperature and frequency are changed) are done on a water-to-water heat pump unit. Finally, the incomplete condensation is found, and some relationships are presented between the phenomenon and the parameters, which are helpful to improve the control strategy of the HTHP.

C23H24N4O9S, triclinic, P1̄ (no. 2), a = 8.297(1) Å, b = 11.199(1) Å, c = 13.876(2) Å, α = 88.856(2)°, β = 76.540(2)°, γ = 80.098(2)°, V = 1235.0 Å3, Z = 2, Rgt(F) = 0.0405, wRref(F2) = 0.1084, T = 296 K.

Hexagonal aluminium nitride (AIN) microrods with high crystalline quality were grown by physical vapor transport (PVT) method at low growth temperature between 1700 and 1850 degrees C. The length of as-grown microrod is around 1 cm, and the width between 200-400 mu m. The microrod exhibits typical hexagonal geometrical shape with pale yellow color under optical microscopy. Scanning electron microscope (SEM) and atomic force microscope (AFM) images show each microrod with closely arranged step waviness, of which the step interval is 2-4 mu m and the height several nanometers. Raman spectrum characterization showed characteristic peaks of high crystalline AlN. The rod-like structure is attributed to slow growth velocity at lower crystalline temperature, enabling Al and N atoms having enough time to move to the lower energy site and to form heiagonal microrod along direction. High quality hexagonal AlN microrod is an enrichment to one-dimensional semiconductor materials. Data from this study suggest that, by further study on size and impurity control, high performance miniaturized opto-electronic device is hopeful to be achieved.

Diaryl disulfides were reduced efficiently by a Zn/Cp2TiCl2 system at room temperature in dry THF to give the corresponding nucleophilic sulfur anion–titanocene complex, followed by reaction with α, β-unsaturated esters (ketones or nitriles) to afford the corresponding β-arylthioesters(ketone or nitrile) in good yields.

In this paper, PTFE (polytetrafluoroethylene)/SiO2 organic–inorganic hybrids were prepared with PTFE emulsion and tetraethoxysilanes (TEOS) through in-situ Sol–gel process, and then modified by PTFE grafted polymer. The studies included Sol–gel manufacturing process, the effects of SiO2 content and graft polymer on the properties of the hybrids. The result showed that, cosolvent ethanol was not needed during the process of Sol–gel because it could make PTFE emulsion colloidal particles agglomerated. When the mass fraction of SiO2 was 1.05 %, the tensile strength reached 20.96 MPa, which was nearly twice as much as that of the pure PTFE sample. Hybrids were treated by PTFE grafted glycidyl methacrylate (PTFE-g-GMA) and silane coupling agent KH-550, after which the tensile properties of hybrids were all enhanced. SEM (scanning electron microscope) images showed that SiO2 changed the original fracture morphology of PTFE. The diameter of SiO2 could reach 110 nm in the hybrid, and the size of SiO2 was further refined by modification. Hybrids with different contents of SiO2 were also analyzed with TGA (thermogravimetric analyzer), through which it could be found that decomposition temperature were improved with an increasing SiO2 content. Furthermore, the crystallinity reached a maximum value 47.03 % measured by DSC (different scanning calorimetry) when the SiO2 content was 2.55 %. Additionally, more SiO2 could hinder the motion of chain segment and destroy the crystallization sequence length, so the crystallinity and crystallization velocity both decreased at the mass fraction of 7.37 %, but the crystallization behavior was enhanced after modification with graft polymer. It has been found that PTFE-g-GMA contributes to the compatibility between PTFE and SiO2.

The title compound, C19H19N3O7S·CH3OH, was synthesized from syringic acid and sulfamethoxazole. The benzene rings make a dihedral angle of 41.8 (1)° and the isoxazole ring is twisted by 74.3 (1)° from the central benzene ring. The crystal packing features O—H...O and O—H...N hydrogen bonds in which the hydroxy groups from the main molecule and methanol solvent molecules serve as donor groups.

An acaricidal substance extracted from the external seed coat of Ginkgo biloba L. was identified by UV (ultraviolet), IR (infrared), EI-MS (electron impact ion source mass spectrometry), 1H NMR (nuclear magnetic resonance) and 13C NMR as 6-[(Z)-10-heptadecenyl]-2-hydroxybenzoic acid (compound 1). Laboratory bioassay on citrus red mite, Panonychus citri (Mcg), showed that compound 1 possessed the following properties. (i) Powerful contact toxicity with an LC50 of 5.2 mg litre−1 after 24 h that was similar to that of pyridaben (LC50 = 3.4 mg litre−1) and significantly superior to that of omethoate (LC50 = 122 mg litre−1). Furthermore, its LC90 was 13.4 mg litre−1 after 24 h, which is significantly superior to both pyridaben (LC90 = 69.6 mg litre−1) and omethoate (LC90 = 453 mg litre−1). (ii) Quick-acting acaricidal activity. At identical concentrations, compound 1 was much faster-acting than pyridaben or omethoate. (iii) Compound 1 had strong corrosive action on the cuticle of P. citri but no phytotoxicity to plants. Copyright © 2006 Society of Chemical Industry

C21H20N4O7S, monoclinic, P21/c (no. 14), a = 17.003(2) A, b = 14.403(2) A, c = 9.211(1) A, = 97.941(2)°, V = 2233.9 A 3 , Z =4 ,Rgt(F) = 0.0461, wRref(F 2 ) = 0.1261, T = 296 K. Source of material Syringic acid (4-hydroxy-3,5-dimethoxy benzoic acid, 50 g, 250 mmol) was added to acetic anhydride (350 mL) for hydroxyl protecting. The acetylation compound (10.0 g, 38.66 mmol) of syringic acid was poured into SOCl2 (60 mL) and stirred for 6-7 hours at 80 °C. Then the excess of SOCl2 was evaporated. The intermediate 3,5-dimethoxy-4-acetoxy-benzoyl chloride was obtained. Then, sulfadiazine (4.23 g, 16.91 mmol), tetrahydrofuran (THF, 43.7 mL) and pyridine (8 mL) were added to the intermediate (4.37 g, 16.90 mmol) and stirred for 24 hours in an ice bath. Among them, pyridine was the catalyst for the reaction [6]. When the reaction was completed, the solvent was evaporated under vacuum, and the residue was washed with water. Recrystallized from methanol and THF for more than 10 days, the title product was obtained. The m. p. was determined as 588-590 K using a XT-4 melting point instrument (Beijing Taike Instrument Co., Ltd, Beijing, China). NMR spectra were recorded on an AVANCE III 300 NMR instrument (Bruker, Germany). 1 H

The binding properties of chrysin with serum albumin (SA) were investigated under physiological conditions by calorimetry, circular dichroism (CD) spectroscopy, and molecular modeling. Based on the thermodynamic data, molar reaction enthalpy, reaction order ( n) and the rate constant ( k) were calculated. The results of CD spectroscopy showed that chrysin could bind to SA and the conformation of SA did not have any high-ordered structural change. Computational mapping revealed chrysin binding to the subdomain IB in SA. The chrysin-serum albumin complex was stabilized by hydrophobic force and hydrogen bonding and the reaction was a spontaneous process.

The crystal structures, electronic structures and optical properties of nitrogen or/and praseodymium doped anatase TiO2 were calculated by first principles with the plane-wave ultrasoft pseudopotential method based on density functional theory. Highly efficient visible-light-induced nitrogen or/and praseodymium doped anatase TiO2 nanocrystal photocatalyst were synthesized by a microwave chemical method. The calculated results show that the photocatalytic activity of TiO2 can be enhanced by N doping or Pr doping, and can be further enhanced by N+Pr codoping. The band gap change of the codoping TiO2 is more obvious than that of the single ion doping, which results in the red shift of the optical absorption edges. The results are of great significance for the understanding and further development of visible-light response high activity modified TiO2 photocatalyst. The photocatalytic activity of the samples for methyl blue degradation was investigated under the irradiation of fluorescent light. The experimental results show that the codoping TiO2 photocatalytic activity is obviously higher than that of the single ion doping. The experimental results accord with the calculated results.

Crystal structures, electronic structures and optical properties of nitrogen and ytterbium doping anatase TiO2 were calculated by first principles with the plane-wave ultrasoft pseudopotential method based on the density functional theory. The calculated results show that the octahedral dipole moments in TiO2 increase due to the changes in lattice parameters, bond length and charges on atoms, which is very effective for the separation of photoexcited electron-hole pairs and the improvement of the photocatalytic activity of TiO2. The interband transition between OPπ states and Yb4f states make nitrogen and ytterbium doped TiO2 manifest greater absorption coefficients in the visible-light region.