Research Progress on Mechanized Mixed Sowing Seed Production Technology of Hybrid Rice

Hybrid rice planting has been widely popularized and applied in the world. However, the high cost of seed production and the complicated procedures have become a bottleneck in the development of hybrid rice. The research progress on mixed sowing seed production techniques of hybrid rice was introduced from the aspects of rice resources creation, breeding, sowing seed technology research and cost benefit analysis. The production technology of the new mixed seeding combina- tion ＂Xinhunyou 6＂ was investigated, including the research and validation of benta- zon treatment period and dosage, mixing ratio of male and female parents, and the comparative test of different different sowing methods, which revealed that the mechanization technology of seed production of hybrid rice was mature and feasible and would be one of the most important development trend of technological devel- opment of hybrid rice production.

Effect of Doping Cerium in the Support of Catalyst Pd-Co/Cu-Co-Mn Mixed Oxides on the Oxidative Carbonylation of Phenol

Effect of doping cerium in the support on the catalytic activity and side product of the reaction in the oxidative carbonylation of phenol to diphenyl carbonate (DPC) over the catalyst Pd-Co/Cu-Co-Mn mixed oxides was studied. The specific surface areas, crystal phase, valency, and content of the element on the surface of the catalysts were determined, and the products were detected by gas chromatograph/mass spectrometry (GC-MS). It is found that the catalyst without Ce shows higher activity than that with Ce, and the yields of DPC for the two cata-lysts can reach 30% and 23%, respectively. However, doping cerium can prevent the formation of 2-hydroxyphenyl benzoate and p-bromophenyl phenyl carbonate.

Phenotypic and genetic characterization of a novel strain of Acidithiobacillus ferrooxidans(AF2)

A comparative study on the phenotypic and genetic characteristics among Acidithiobacillus ferrooxidans （AF2）, a typic strain ATCC23270 and a previously isolated strain AF3 was performed. AF2 can use ferrous ion （Fe^2＋） or elemental sulfur （S^0） as sole energy source, but oxidizes So more effectively than Fe^2＋, which is different from ATCC23270 and AF3. The G＋C content of AF2 is 51.8% （molar fraction）, however, ATCC23270 and AF3 strains have G＋C content of 63.7% and 64.8% （molar fraction）, respectively. The DNA-DNA hybridization results show that AF2 has 41.53% and 52.38% genome similarity to ATCC 23270 and AF3, respectively, but AF3 has a high genome similarity of 89.86% to ATCC 23270 strain. Rusticyanin （rus） and subunit III of aa3-type cytochrome oxidase （coxC） genes are not detected in AF2, but Fe^2＋ oxidase （iro） gene can be detected. To understand the genomic organization of iro gene, a cosmid library of AF2 genome was constructed and iro gene-containing clone was screened. The sequencing result shows that although the nucleotide sequence of iro gene in AF2 is completely identical to that of ATCC 23270 strain, its genomic organization is different from that of ATCC 23270. In AF2, iro is located at downstream ofpurA gene, while it is located at downstream ofpetC-2 gene in ATCC 23270 strain. These results indicate that AF2 is a novel strain ofA. ferrooxidans, and that phenotypic differences among the strains ofA. ferrooxidans are closely correlated with their genetic polymorphisms.

Preparation of Luminescent Tb^3＋ Doped CaO Green Phosphor

CaCO3 was chosen as main raw material and Solid State method was used to prepare the sample. The precursor was directly sintered at 1100 ℃ with reducing atmosphere for 3 h to obtain new green CaO：Tb^3＋, Li^＋ Phosphors. The effects of the content of the doping ions Tb^3＋ on the luminescent properties have been studied. The structure, morphology and luminescent properties of the phosphors were characterized by XRD, SEM, UV and PL-PLE spectra respectively. The results showed that the CaO：Tb^3＋, Li^＋ was a single face-centered cubic crystals, the phosphor particle distributed uniformly. The phosphor has a strong absorptive capacity excited by 282 nm ultraviolet ray, and could emit the strong green light with the wavelength of 543 nm （^5D4→^7F5）. The CaO：Tb^3＋, Li^＋ is a new type of green fluorescent material.

Antioxidant xanthones and anthraquinones isolated from a marine-derived fungus Aspergillus versicolor

Chemical examination of an EtOAc extract of cultured Aspergillus versicolor fungus from deep-sea sediments resulted in the isolation of four xanthones, eight anthraquinones and five alkaloids, including a new xanthone, oxisterigmatocystin D （1） and a new alkaloid, aspergillusine A （13）. High resolution electron impact mass spectrometry （HR-EI-MS）, FT-IR spectroscopy, and NMR techniques were used to elucidate the structures of these compounds, and the absolute configuration of compound 1 was established by its NMR features and coupling constant. Furthermore, the biosynthesis pathway of these xanthones and anthraquinones were deduced, and their antioxidant activity and cytotoxicity in human cancer cell lines （HTC-8, Bel-7420, BGC-823, A549, and A2780） were evaluated. The trolox equivalent antioxidant capacity （TEAC） assay indicated most of the xanthones and anthraquinones possessing moderate antioxidant activities. The Nrf2-dependent luciferase reporter gene assay revealed that compounds 6, 7, 9, and 12 potentially activated the expression of Nrf2-regulated gene. In addition, compounds 5 and 11 showed weak cytotoxicity on A549 with the ICs0 values of 25.97 and 25.60 gmol·L^-1, respectively.

A novel organic-inorganic hybrid monolith for trypsin immobilization

In proteomics, attention has focused on various immobilized enzyme reactors (IMERs) for the realization of high throughput digestion. In this report, a novel organic-inorganic hybrid monolith based IMER was prepared in a 100 μm i.d. capillary with 3-glycidoxypropyltrimethoxysilane (GLYMO) as the monomer and tetraethoxysilane (TEOS) as the crosslinker. Trypsin immobilization was achieved via the reaction between vicinal diol groups, which were obtained from hydrolysis of epoxy groups, and the amino groups of trypsin. Bovine serum albumin was digested thoroughly by this IMER in 47 s. After micro-reverse phase liquid chromatography-tandem mass spectrometry (μRPLC-MS/MS) analysis and database searching, beyond 35% sequence coverage was obtained, and the result was comparable to that of 12 h in solution digestion. The present IMER has potential for high throughput digestion.

Petroleum heteroatom compounds in various commercial delayed coking liquids： characterized by FT-ICR MS and GC techniques

Delayed coking is an important petroleum resid conversion process.The processability of coking liquids is known to be dependent on the heteroatom compounds present in the coking liquids.Eight commercial delayed coking liquids were characterized by electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS)and gas chromatographic techniques.High relatively abundant heteroatom compounds in the coking liquids were 1-4 aromatic-ring pyridinic nitrogen compounds,carbazoles,benzocarbazoles,phenols,mercaptans,benzothiophenes,dibenzothiophenes,and naphthobenzothiophenes.Coking liquids derived from various feeds had similar compound class types,molecular weight distribution ranges,and double bond equivalents(DBE).However,the concentration of individual compounds and the distribution of DBE versus carbon number of heteroatom compounds varied.A comparison of heteroatom compounds in coker feeds and products revealed the various reaction mechanism of heteroatom compounds occurred during the coking process.The results suggested that molecular-level process models can be developed for optimization of unit operation to obtain desirable products that meet the environmental specifications and quality requirements.

A novel catalytic application of heteropolyacids:chemical transformation of major ginsenosides into rare ginsenosides exemplified by Rg1

High performance liquid chromatography coupled with quadruple-time-of-flight mass spectrometry(HPLC-Q-TOF-MS)method was developed for analyzing the hydrolytic mixtures of ginsenoside R_(g1) in acidic conditions(pH 3). Three catalysts, a heteropolyacid(H_4SiW_(12)O_(40), SiW_(12) for short), its complex with γ-CD(SiW_(12)/γ-CD for short) and formic acid, were used for comparison. The chemical transformation products were identified based on the accurate mass measurement and the fragment ions obtained from tandem mass spectrometry. It was concluded that the catalytic efficiency of SiW_(12)(≈SiW_(12)/γ-CD) is ca. 410 times higher than that of formic acid, thus becoming the most efficient catalyst for chemical transformations of ginsenosides.