In this paper, a novel hydrophobic modified cationic polyacrylamide flocculant P(AM⁃DAC⁃APG) was successfully synthesized by copolymerization of acrylamide (AM) as the main monomer, acryloxyethyl trimethyl ammonium chloride (DAC) as the cationic monomer and alkyl glycoside (APG) as the hydrophobic monomer, initiated by low⁃pressure ultraviolet light. FTIR, SEM and 1H⁃NMR were used to observe and analyze its chemical structure and surface morphology. The effects of other factors such as total monomer concentration and initiator concentration on the polymerization were studied. Optimum polymerization conditions were confirmed as total monomer concentration of 35.0%, initiator concentration of 0.2%, illumination time of 90 min, m（AM）/m（DAC）of 3, hydrophobic monomer concentration of 2.0%, urea concentration of 3.0%. The novel hydrophobic modified polyacrylamide flocculant with intrinsic viscosity and cationic charge density of 1 384.8 mL/g and 5.091 mmol/g was obtained under these conditions.

MnFe2O4/TiO2 Fenton⁃like photocatalyst was successfully prepared by sol⁃gel method, the structure and morphology of the sample were characterized by XRD, SEM and UV⁃vis. MB was used as the target pollutant for degradation, and the photocatalytic properties of products with different doping amounts were investigated in visible light. The results show that: The degradation rate of TMF Fenton⁃like photocatalytic reaction to MB is up to 96.8%, under the optimum conditions, in the iodine⁃tungsten lamp with a light source of 300 W, the doping amount of MnFe2O4 to TiO2 is 2%, the mass of catalyst is 60 mg, pH=11, and the concentration of H2O2 is 8 mmol/L . Under the same conditions, compare with the undoped pure TiO2, the catalytic performance of MnFe2O4/TiO2 for MB under visible light is significantly improved.

A chlorinefree composite as oilwell cement early strength agent named LL was developed. Combining organic acids A, alcohol amines B and nitrate compound C in a certain ratio, the compressive of cement stone in 6 h as the strength examining index can be designed in optimization test using the orthogonal method. The optimum formula determined by orthogonal was as follows: the weight of organic acids D is 1.0% based on cement，the weight of alcohols amines E is 0.04%，the weight of nitrates F is 4%. Under the optimum proportion, and the performance test of early strength agent LL was carried out after its addition of 2.5% in the cement. The ratio of the thickening time of early strength agent LL slurry to cement slurry is 0.436 less than 0.5, and the compressive strength of cement stone 6 h (39 ℃ and atmospheric pressure) is 11.0 MPa more than 4.0 MPa, they are all meeting the requirement of early strength agent industry standard SY/T5504.4—2008. And it has a good compatibility with the homemade retarders MAM, dispersants FASA and fluid loss AS.

The contents of eleven mineral elements（Mg，Al，Ca，Mn，Fe，Cu、Zn，K，Na，Co and Pb） in twentythree green tea samples from different areas were analyzed by microwave plasma torch atomic emission spectrometry (MPTAES). Then principal component analysis (PCA) and cluster analysis (CA) were applied to differentiate the geographical origins of these tea. The result indicated that This method can discriminate the geographical origins of these tea from AnHui、ZheJiang、SiChuan and JiangXi, the classification performance was clearly, the content of the mineral elements in teas were good chemical descriptors for differentiating their geographical origins.

As the cement slurry hydration speed is slow, the curing time is long and the increase of cement early compressive strength is slow in the low temperature cementing of conductor and surface casing, it is easy to result in oil, gas and water invasion which impairs cementing quality and operation safety. In view of the fact that the accelerator is lack in cementing of low temperature shallow formation currently at home, some accelerators have poor effectiveness and significant negative impact on slurry rheology etc, a new compound accelerator WSA1 was selected by laboratory study. The performance of slurry that mixed WSA1 was systematically evaluated. The result shows that the accelerator WSA1 can enhance the hydration of oil well cement, shorten the thickening time of cement slurry and significantly improve the early compressive strength of cementstones, which all accord with the requirement of the accelerator evaluation criterion. When WSA1 addition amount is 3%, the thickening time of cement slurry can be shortened more than 50%, the 6 h strength of cementstones enhanced from 3.2 MPa to 11.3 MPa and the 24 h strength of cementstones enhanced from 24.3 MPa to 46.1 MPa. Accelerator WSA1 is a kind of highperformance compound accelerator, which can be used in low temperature shallow formation and has no effect on the initial consistency and rheological parameter of cement slurry. 