Ferromagnetic Mn3+ Sawtooth Chains in A2(Mn2O)(SeO3)3 (A = K, Rb) Quaternary Selenites.

Two quaternary manganese selenites, A2(Mn2O)(SeO3)3 (A = K, Rb), have been synthesized by hydrothermal reactions. They both crystallize in a complex triclinic (P-1) structure built of Jahn-Teller (JT) distorted Mn3+O4+2 octahedra, connected into nearly isosceles [Mn3O14] triangles, themselves arranged into so-called "sawtooth (ST) chains". The K and Rb compounds show subtle variations in the orientations of the MnO4 planes inside the elementary triangles. The ST chains are structurally and magnetically isolated by SeO3 groups and alkali cations. In the ST chains, predominant ferromagnetic interactions were calculated and verified experimentally, which finally order antiferromagnetically between the chains around TN ≈ 22 K. The spin exchanges calculated by DFT + U and fitted by Monte Carlo simulations allow for the quantification of an effective "overall" model. The specific role of the µ3-O bridge on the ferromagnetic (FM) exchanges is discussed, together with spin reorientations observed in the ordered state. Magnetocrystalline anisotropy along the [110] direction stabilized by ∼50 meV per Mn by spin-orbit coupling (SOC) was found by DFT + U + SOC.

Identification of Ossnrk1a-1 Regulated Genes Associated with Rice Immunity and Seed Set.

Sucrose non-fermenting-1-related protein kinase-1 (SnRK1) is a highly conserved serine-threonine kinase complex regulating plants' energy metabolisms and resistance to various types of stresses. However, the downstream genes regulated by SnRK1 in these plant physiological processes still need to be explored. In this study, we found that the knockout of OsSnRK1a resulted in no obvious defects in rice growth but notably decreased the seed setting rate. The ossnrk1a mutants were more sensitive to blast fungus (Magnaporthe oryzae) infection and showed compromised immune responses. Transcriptome analyses revealed that SnRK1a was an important intermediate in the energy metabolism and response to biotic stress. Further investigation confirmed that the transcription levels of OsNADH-GOGAT2, which positively controls rice yield, and the defense-related gene pathogenesis-related protein 1b (OsPR1b) were remarkably decreased in the ossnrk1a mutant. Moreover, we found that OsSnRK1a directly interacted with the regulatory subunits OsSnRK1ß1 and OsSnRK1ß3, which responded specifically to blast fungus infection and starvation stresses, respectively. Taken together, our findings provide an insight into the mechanism of OsSnRK1a, which forms a complex with specific ß subunits, contributing to rice seed set and resistance by regulating the transcription of related genes.

Investigation of Charge-Ordered Barium Iron Fluorides with One-Dimensional Structural Diversity and Complex Magnetic Interactions.

Three mixed-valence barium iron fluorides, Ba7Fe7F34, Ba2Fe2F9, and BaFe2F7, were prepared through hydrothermal redox reactions. The characteristic structures of these compounds feature diverse distributions of FeIIF6 octahedra and FeIIIF6 groups. Ba7Fe7F34 contained one-dimensional infinite ∞[FeIIFeIII6F34]14- double chains, comprising cis corner-sharing octahedra along the b direction; Ba2Fe2F9 contained one-dimensional ∞[Fe2F9]4- double chains, consisting of cis corner-sharing octahedra along the chain (a-axis direction) and trans corner-sharing octahedra vertical to the chain, while BaFe2F7 revealed three-dimensional (3D) frameworks that consist of isolated edge-sharing dinuclear FeII2F10 units linked via corners by FeIIIF6 octahedra. Magnetization and Mössbauer spectroscopy measurements revealed that Ba7Fe7F34 exhibits an antiferromagnetic phase transition at ∼11 K, where ferrimagnetic ∞[FeIIFeIII6F34]14- double chains are arranged in a paralleling manner, while Ba2Fe2F9 shows canted antiferromagnetic ordering at ∼32.5 K, leading to noncollinear spin ordering.

Open-Framework Iron Fluoride Phosphates Based on Chain, Trinuclear, and Tetranuclear Chain FeIII Building Units: Crystal Structures and Magnetic Properties.

We report the synthesis and characterization of a series of new open-framework iron fluoride-fluorophosphates based on linear, trinuclear, and tetranuclear chain FeIII building units. KFe2(PO3F)2F3 (I) consists of {Fe2(O3F)2F2}10- zigzag chains interconnected by P(O/F)4 tetrahedra forming a three-dimensional (3D) open framework. K2Fe(PO2.5F1.5)2F2 (II) is built up by {Fe(PO2.5F1.5)2F2}2- chains separated by K+ cation layers. The framework for K3Fe3(PO4)(PO3F)2F5 (III) contains two-dimensional {Fe3O4F4(PO3F)2}2- sheets, which are built from trimeric Fe-octahedra insulated by PO3F tetrahedra. The macroanionic framework of K3Fe4(PO4)2F9 (IV) comprises linear {Fe4O8F9}10- chains consisting of tetranuclear magnetic clusters of [Fe4O8F9]10- formed via corner-sharing fluorine atoms decorated with PO4 groups. The magnetic characterization of three iron fluorophosphates reveals diversified magnetism: S = 5/2 spin chains for I, antiferromagnetically coupled triangular Fe units for III, and coupled tetrahedral S = 5/2 spin chains for IV. IV shows strong geometric frustration thanks to its spin motifs of corner-shared tetrahedral clusters.

Variable Structures and One-Dimensional-Canting Antiferromagetism Found in Fluoride Selenates, A2Mn(SeO4)F3 (A = K, Rb, Cs).

Three new alkali-metal manganese fluoride selenates, A2Mn(SeO4)F3 (A = K, Rb, Cs), were prepared through hydrothermal redox reactions. The products consisted of one-dimensional polymeric anionic ∞[Mn(SeO4)F3]2- chains, where the A+ cations are connected by O and/or F atoms to form blocks with two-dimensional layers. A2Mn(SeO4)F3 (A= Rb, Cs) is isostructural with the monoclinic space group P21/c, while K2Mn(SeO4)F3 crystallizes in the orthorhombic space group Pbcn. A2Mn(SeO4)F3 (A = K, Rb, Cs) forms spin chains of Mn3+ with different Mn-F-Mn bridges, which showed canting antiferromagnetic behaviors. Single-crystal magnetic measurements revealed that the magnetic moments of the Mn ions were more canted for larger alkali-metal compounds in an antiferromagnetically ordered state.

Cycloidal Magnetic Order Promoted by Labile Mixed Anionic Paths in M2(SeO3)F2 (M = Mn2+, Ni2+).

Two M2(SeO3)F2 fluoro-selenites (M = Mn2+, Ni2+) have been synthesized using optimized hydrothermal reactions. Their 3D framework consists of 1D-[MO2F2]4-chains of edge-sharing octahedra with a rare topology of alternating O-O and F-F µ2 bridges. The interchain corner-sharing connections are assisted by the mixed O vs F anionic nature and develop a complex set of M-X-M superexchanges as calculated by LDA+U. Their interplay induces prominent in-chain antiferromagnetic frustration, while the interchain exchanges are responsible for the cycloidal magnetic structure observed below TN ≈ 21.5 K in the Ni2+ case. For comparison the Mn2+ compound develops a nearly collinear spin (canted) ordering below TN ≈ 26 K with ferromagnetic chain units.

Characterization of algal organic matter as precursors for carbonaceous and nitrogenous disinfection byproducts formation: Comparison with natural organic matter.

Algal organic matter (AOM) and natural organic matter (NOM) from a typical eutrophic lake were comprehensively investigated in terms of their physico-chemical property, components and disinfection byproduct formation potentials (DBPFPs). The relationships between specific chemical properties of AOM and NOM with their corresponding DBPFPs were further evaluated during chlorination. Results indicated that AOM had lower specific UV absorbance (SUVA) but richer organic nitrogen contents than NOM. Fluorescence excitation emission matrix spectroscopy further demonstrated that AOM were chiefly composed of aromatic protein-like and soluble microbial byproduct-like matters, while NOM were mainly contributed from humic acid-like and soluble microbial byproduct-like substances. Although the molecular weight (MW) distribution of AOM and NOM showed no significant difference, size-exclusion chromatography with organic carbon as well as organic nitrogen detection (LC-OCD-OND) revealed that AOM were concentrated with the fraction of building blocks and NOM had higher concentrations of biopolymers and humics (HS). Moreover, AOM displayed higher DBPFPs than NOM, especially for nitrogenous DBPFP (N-DBPFP). MW < 1 kDa fractions both in AOM and NOM contributed the largest proportion to the formation of carbonaceous disinfection byproducts (C-DBPs). In addition, Pearson correlation analysis showed that bulk parameter SUVA was significantly relevant to the formation potentials of trihalomethane both in AOM and NOM, but was ineffective for carbonaceous DBPFP (C-DBPFP) prediction. Dissolved organic nitrogen contents in biopolymer and HS characterized by LC-OCD-OND had strong correlations with N-DBPFPs from AOM and NOM, indicating that LC-OCD-OND quantitative analysis could improve the prediction accuracy of the DBP formation than bulk parameters during NOM and AOM chlorination.

Synthesis, crystal structures, and magnetic properties of one-dimensional alkali metal copper chlor-tellurites A(NH4)Cu4Te2O6Cl6 (A = K, Cs), NaCu4Te2Cl5O6 and Rb3(NH4)2Cu12Te6Cl16.5O18(OH)0.5.

Four new alkali metal copper chlor-tellurites, [Cs(NH4)]layer[Cu4Te2O6Cl6]layer (I), [Rb3(NH4)2(OH)0.5]layer[Cu12Te6Cl16.5O18]layer (II), [K(NH4)]layer[Cu4Te2O6Cl6]layer (III) and [NaCl]layer[Cu4Te2O6Cl4]layer (IV), have been synthesized via hydrothermal reactions using mixtures of AF (A = Cs, Rb, K, Na), CuCl2·2H2O, TeO2, and hydrazine monohydrate. They have two-dimensional (2D)-layered [Cu4Te2Cl5+x-yO6]∞ (x = 0, 2/3, 1; y = 0, 1/6) structures that are separated by different layers comprised of various cations and anions, including A+, NH4+ Cl- OH-, etc. The blocks feature S-shaped ∞[Cu2O3Cl3-x] chains linked by TeO3 trigonal pyramids. The magnetic susceptibility shows a broad maximum at 220 K for I and 240 K for III, which is well simulated by using an alternating antiferromagnetic chain model. The J2/J1 ratio within the alternating chain is estimated to be 0.60(1), and the spin gaps are refined to be 152 K for I and 136 K for III.

Transition-Metal Monofluorophosphate Ba2M2(PO3F)F6 (M = Mn, Co, and Ni): Varied One-Dimensional Transition-Metal Chains and Antiferromagnetism.

Four transition-metal monofluorophosphates, with a chemical formula of Ba2M2(PO3F)F6 (M = Mn, Co, Ni, and Cu), have been synthesized hydrothermally using phosphoric and fluorophosphoric acids. The structures of Ba2M2(PO3F)F6 were intensively investigated by single-crystal and powder X-ray diffraction. Their networks exhibited three-dimensional frameworks formed by cis-MO2F4 octahedra and PO3F tetrahedra. Ba2M2(PO3F)F6 (M = Mn, Co, and Cu) are isostructural, crystallizing in the monoclinic space group P21/c, while Ba2Ni2(PO3F)F6 adopted an unpredetermined structure, crystallizing in the monoclinic space group P21/n. The different arrangements of the same cis-MO2F4 moieties and PO3F groups within one-dimensional chains lead to different frameworks in this late-first-row transition-metal series. By a comparison of normalized bond lengths with their normal counterparts, the more elongated octahedral cis-MO2F4 units in Ba2Cu2(PO3F)F6 reveal the presence of static Jahn-Teller distortion, uncovering the puzzling reason for the exceptional structure of Ba2Ni2(PO3F)F6 in the series. Ba2M2(PO3F)F6 (M = Mn, Co, and Ni) forms spin chains of M2+ made of coupled dimers or tetramers, showing dominant antiferromagnetic behavior.

Lone-pair self-containment in pyritohedron-shaped closed cavities: optimized hydrothermal synthesis, structure, magnetism and lattice thermal conductivity of Co15F2(TeO3)14.

A new oxofluoride Co15F2(TeO3)14 has been prepared by optimized hydrothermal synthesis involving a complex mineralization process. The crystal structure consists of a three-dimensional network of CoO5(O,F) octahedra, distorted CoO5 square pyramids, TeO3 trigonal pyramids and grossly distorted TeO3+3 octahedra, which are linked by sharing corners and edges. The Te(iv) lone pairs are accommodated within novel pyritohedron-shaped [(TeO3)14]28- units. This special framework provides a much larger free space that allows Te atoms to vibrate with a large amplitude, which leads to extremely low lattice thermal conductivity. Magnetic susceptibility data for Co15F2(TeO3)14 show antiferromagnetic ordering below 9.6 K with a substantial orbital component to the effective magnetic moment. An S = 3/2 honeycomb-like spin network was carefully analyzed by experimental techniques and first principles calculations.

Open-framework ammonium transition metal fluorophosphates with a Kagomé lattice network: synthesis, structure and magnetic properties.

Two open-framework transition metal fluorophosphates (NH4)M3(PO3F)2(PO2F2)F2 (M = Mn and Co) have been synthesized under fluoride-rich hydrothermal conditions at 493 K. The structure consists of triplets of face-sharing trans-MO4F2 octahedra linked by PO3F groups to form 2D layers. These 2D layers with formula [M3(PO3F)2O2F2]3- in the ab plane are bridged by PO2F2 groups to generate a 3D open framework with 1D channels filled with ammonium cations. The XPS spectra suggested the existence of Mn(ii) and Co(ii) in the corresponding compounds. Further, the XPS F 1s spectra indicated that fluorine anions bridged both the M and P centres. The two compounds feature transition metal layers with a staircase Kagomé network. This topology promotes magnetic frustration, which exhibits a canted antiferromagnetic ground state (Tc = 8.0 K for Mn and Tc = 9.2 K for Co).

Variable Dimensionality, Valence, and Magnetism in Fluoride-Rich Iron Phosphates Ba xFe x(PO4)F y (1 ≤ x ≤ 3, 2 ≤ y ≤ 12).

We report the synthesis and characterization of three fluoride-rich barium iron phosphates Ba xFe x(PO4)F y (1 ≤ x ≤ 3, 2 ≤ y ≤ 12), which exhibited abundant structural chemistry, exhibiting diverse frameworks and connecting modes between [FeO nF6- n] m- octahedra surrounding Fe2+ or Fe3+ ions. BaFe(PO4)F2 (I) consisted of two-dimensional [Fe(PO4)F2]2- sheets built from linear ∞[Fe2O6F4]10- moieties formed by fluorine corner-sharing FeO4F2 and FeO2F4 octahedra with linking PO4 tetrahedra. Mixed-valence Ba2Fe2(PO4)F6 (II) possessed a three-dimensional framework containing Fe4O6F12 tetramers formed by the edge-sharing oxygen or fluorine atoms of cis-FeF4O2 octahedra. Ba3Fe3(PO4)F12 (III) contained one-dimensional columns of ∞[Fe3(PO4)F12]6- infinite sections built from cis-FeF4O2 and FeF5O octahedra and tetrahedral PO4 linkers. The magnetic characterization of Ba xFe x(PO4)F y unveiled diverse magnetism: an S = 5/2 spin chain for (I), a weak ferrimagnet or canted antiferromagnet for (II) thanks to the presence of distinct Fe2+ and Fe3+ sites identified by Mössbauer spectroscopy, and coupled spin-trimers for (III).

Carbonaceous and nitrogenous disinfection byproduct precursor variation during the reversed anaerobic-anoxic-oxic process of a sewage treatment plant.

Disinfection byproduct (DBP) precursors in wastewater during the reversed anaerobic-anoxic-oxic (A2/O) process, as well as their molecular weight (MW) and polarity-based fractions, were characterized with UV scanning, fluorescence excitation emission matrix, Fourier transform infrared and nuclear magnetic resonance spectroscopy. Their DBP formation potentials (DBPFPs) after chlorination were further tested. Results indicated that the reversed A2/O process could not only effectively remove the dissolved organic carbon (DOC) and dissolved total nitrogen in the wastewater, but also affect the MW distribution and hydrophilic-hydrophobic properties of dissolved organic matter (DOM). The accumulation of low MW and hydrophobic (HPO) DOM was possibly due to the formation of soluble microbial product-like (SMP-like) matters in the reversed A2/O treatment, especially in the anoxic and aerobic processes. Moreover, DOM in the wastewater displayed a high carbonaceous disinfection byproduct formation potential (C-DBPFP) in the fractions of MW>100kDa and MW<5kDa, and revealed an increasing tendency of nitrogenous disinfection byproduct formation potential (N-DBPFP) with decrease of MW. For polarity-based fractions, the HPO fraction of wastewater showed significantly higher C-DBPFP and N-DBPFP than hydrophilic and transphilic fractions. Therefore, although the reversed A2/O process could remove most DBP precursors by DOC reduction, it led to the enhancement of DBPFP with the formation and accumulation of low MW and HPO DOM. In addition, strong correlations between C-DBPFPs and SUVA, and between N-DBPFPs and DON/DOC, were observed in the wastewater, which might be helpful for DBPFP prediction in wastewater and reclaimed water chlorination.

Syntheses, Structures, and Characterization of Quaternary Tellurites, Li3MTe4O11 (M = Al, Ga, and Fe).

Three new quaternary lithium metal tellurites, Li3MTe4O11 (M = Al, Ga, and Fe), have been synthesized through hydrothermal and solid-state reactions by heating a mixture of LiOH·H2O, TeO2, and M2O3. The structures of the title compounds have been determined by single-crystal and powder X-ray diffraction. Li3MTe4O11 reveal three-dimensional (3D) frameworks that consist of MO6 octahedra, TeO3 trigonal pyramids, and TeO4 polyhedra. The variable coordination mode of Te4+ within the framework leads to the formation of 1D channels that host Li+ cations on both tetrahedral and octahedral sites. The bulk and grain boundary Li+ ion conductivities for a Li3FeTe4O11 pellet in open air are estimated to be 1.0 × 10-4 and 2.7 × 10-6 S cm-1, respectively, at room temperature from the impedance profile analysis. A lower activation energy of 19.9 kJ mol-1 is obtained for the system, which is similar to that of Li10GeP2S12 (24 kJ mol-1). Detailed characterizations such as thermal, spectroscopic, and magnetic properties for the reported materials are also reported.

[Transformation of Disinfection Byproduct Precursors During the Wastewater Regeneration Processes].

Disinfection byproduct(DBP) precursors during the wastewater regeneration processes were separated into hydrophilic fraction(HPI), hydrophobic fraction(HPO) and transphilic fraction(TPI) with macroporous resin. DBP precursors in these water samples were characterized with fluorescence excitation emission matrix, Fourier transformation infrared and nuclear magnetic resonance, and were further tested for their DBP formation potential(DBPFP) after chlorination. The results indicated that main DBP precursors in sewage were humic acid and aliphatic hydrocarbons, and were mainly dominated by HPI. Primary treatment(sedimentation) could effectively remove hydrophobic humic acid through the mutual exclusion between HPO and water. The removal of humic acid would lead to the obvious reduction of carbonaceous disinfection byproduct formation potential(C-DBPFP). In addition, nitrogenous disinfection byproduct formation potential(N-DBPFP) was found to be increased due to the increase of DON/DOC value. Although secondary treatment(biotreatment) was effective in removing humic acid and aliphatic hydrocarbons, it could produce a large amount of soluble microbial products(SMP), which led to the enhancement of HPO percentage. And the accumulation of SMP resulted in the significant increase of C-DBPFP and N-DBPFP. Humic acid and hydrophobic SMP could be removed by the advanced treatment(cloth filtration), leading to the reduction of HPO percentage and the increase of HPI percentage. The decrease of humic acid and hydrophobic SMP would cause the reduction of C-DBPFP and N-DBPFP in the advanced treatment.

Investigation of new alkali bismuth oxosulfates and oxophosphates with original topologies of oxo-centered units.

Two new alkali bismuth oxosulfates, [Bi12O15]Li2(SO4)4 (I) and [Bi7K2O8]K(SO4)4 (II), have been synthesized by heating a mixture of Bi2O3, CuSO45H2O, and A2CO3 (A = Li, K), and characterized by single crystal XRD, transmission electron microscopy, and multiphoton SHG and IR spectroscopy. In the above formula the [BixOy] subunits denote the 3D-porous (I) or 1D-columnar (II) polycationic host-lattice formed of edge-sharing OBi4 or O(Bi,K)4 oxocenterd tetrahedra. The SO4(2-) groups and alkali ions are arranged into channels in the interstices leading to original opened crystal structures for these two first reported alkali oxo-bismuth sulfates. The strong adaptability of the oxocentered framework is demonstrated by the possibility of preparing single crystals of [Bi8.73K0.27O8]K1.54(PO4)4 (III) whose crystal structure is similar to those of II with disorder between OBi4 and O(Bi3,K) tetrahedra and different channel occupancy due to the aliovalent replacement of SO4(2-) for PO4(3-).

Content determination of the flavonoids in the different parts and different species of Abelmoschus esculentus L. by reversed phase-high performance liquid chromatograph and colorimetric method.

BACKGROUND: This research will establish the ultraviolet colorimetric method to determine the total flavonoid content in different species and different parts of Abelmoschus esculentus L. MATERIALS AND METHODS: We establish the reversed-phase high-performance liquid chromatograph (RP-HPLC) method to determine the content of the three flavonoid glycosides in different species and different parts of the A. esculentus. Adopt the NaNO2-Al (NO3)3-NaOH colorimetric method to determine the total flavonoid content; at the same time, adopt the RP-HPLC method to determine the contents of the three flavonoid glycosides. Using the methods of ultraviolet colorimetry and RP-HPLC, we determined and analyzed the total flavonoid content and the content of the three flavonoid glycosides in different species and different parts of A. esculentus. RESULTS: There are great distribution differences of the total flavonoids and the three flavonoid glycosides in different species and parts of A. esculentus. Among them, the content of the effective constituents in the flower is relatively high, next is in the fruit. In the different species of A. esculentus, the content of the flavonoids of finger relatively high. The HPLC method established in this research is simple and convenient and its results are accurate and reliable. In addition, it has a very good repeatability. CONCLUSION: The results provided the reference data for the medicinal use of A. esculentus and it can be used in quality analyzing of its effective constituents.

Revised Bi/M layered oxo-sulfate (M = Co, Cu): a structural and magnetic study.

The combination of oxo-bismuthite slabs with counter oxo-anions main often leads to a series of layered Sillen-related compounds. For electroneutrality, it is convenient that the structure incorporates aliovalent cations such as Bi(3+)/M(2+) ions that could be confined either in the Bi/O slabs or in the interleave. In the case of SO4(2-) oxo-anions, only two compounds have been reported for M = Co, Cu, while interesting magnetic topologies emerge in absence of any prior characterization. Our reinvestigation of these systems using crystal growth in Bi2O3 flux led to the full structural characterization of [Bi2CoO3](SO4) (I) and [Bi6.2367Cu1.6O8](SO4)3 (II), which both exhibit pleated [Bi/M/O] slabs running in doubled cells comparatively to previous reports. (I) shows an interesting weak ferromagnetism (∼0.2 µB/Co) below 17 K arising from Dzyaloshinskii-Moriya interactions in Co(2+) zigzag chains, while (II) is essentially a paramagnet despite the presence of Cu2O6 dimers. Finally in the novel [Bi6O6](CoO2)(SO4)2 (III), the Co(2+) ions are ordered with sulfate in the interleaves, leading to a noncentrosymmetric crystal structure.

Multidimensional open-frameworks: combinations of one-dimensional channels and two-dimensional layers in novel BI/M oxo-chlorides.

Here we discuss the synthesis and characterization of three novel bismuth oxo-chlorides ([Bi6Na0.5O7.5][Na0.5Cl3]channel[Cl]layer; [Bi17PbO22][Cl6]channel[Cl3]layer; [Bi9(Pb0.2Mn0.8)O12][Cl3]channel [Cl2]layer) which all show an original multidimensional crystal structure. It is formed of two-dimensional (2D)-layered blocks separated by Cl(-) layers. The blocks are porous with triangular one-dimensional (1D)-Cl(-) channels with various section sizes. This multidimensional feature is unique in the field of Bi and Pb oxo-halides, while so far only 1D or 2D halides units have been reported. The stability of the framework is allowed by Bi(3+)/M(n+) aliovalent substitution to balance charge neutrality. The channel and tunnel walls are formed by edge-sharing O(Bi,M)4 oxocentered tetrahedra, while the triangular tunnel junctions are achieved by O(Bi,M)5 pyramids. The three compounds are rather stable, but only [Bi6Na0.5O7.5][Na0.5Cl3]tunnel[Cl]layer was obtain as a single-phase material so that its photoluminecence properties have been investigated. It shows an unusual red bright luminescence with a maximum at 14150 cm(-1) at low temperatures due to Bi(3+) transitions that are well explained by the Bi-Cl bonding scheme.

Enhancement of Taihu blue algae anaerobic digestion efficiency by natural storage.

Taihu blue algae after different storage time from 0 to 60 d were anaerobic fermented to evaluate their digestibility and process stability. Results showed that anaerobic digestion (AD) of blue algae under 15 d natural storage led to the highest CH4 production of 287.6 mL g(-1) VS at inoculum substrate ratio 2.0, demonstrating 36.69% improvement comparing with that from fresh algae. Storage of blue algae led to cell death, microcystins (MCs) release and VS reduction by spontaneous fermentation. However, it also played an important role in removing algal cell wall barrier, pre-hydrolysis and pre-acidification, leading to the improvement in CH4 yield. Closer examination of volatile fatty acids (VFA) variation, VS removal rates and key enzymes change during AD proved short storage time (≤ 15 d) of blue algae had higher efficiencies in biodegradation and methanation. Furthermore, AD presented significant biodegradation potential for MCs released from Taihu blue algae.