一个非齐次核的半离散型Hilbert型不等式的改进

Hilbert型不等式是分析学中的重要不等式．本文利用权函数、实分析技巧以及加强的Holder不等式对半离散的Hilbert型不等式作了改进，建立了一些新的不等式．     

素拟环上的幂零导子

设N是零对称的素拟环,证明了：（i）若N是2-挠自由的,d1,d2是N上的两个导子,则下列3条件等价：（1）d1d2是一个导子;（2）d1（x）d2（y）＋d2（x）d1（y）=0,任意x,y∈N;（3）d1=0或d2=0．（ii）设N是挠自由的,若N容纳两个非零导子d1,d2,使得[d1（x）,d2（y）]=0,任意x,y∈N,则N不能容纳任何非零的幂零导子．     

Preparation and characterization of microcapsule containing epoxy resin and its self-healing performance of anticorrosion covering material

Microencapsulated healing agents that possess adequate strength, long shelf-life, and excellent bonding to the host material are required for self-healing materials. The in situ encapsulation method is demonstrated over an order of magnitude size reduction for the preparation of urea-formaldehyde (UF) capsules filled with a healing agent, a mixture epoxy resin of the epoxy 711 and E-51. Capsules with diameters as small as about 100 ??m are achieved under the agitation rate of 800 r min^?1. The capsules possess a uniform UF shell wall (4 ??m average thickness). By using the analysis of scanning electronic microscope (SEM), thermal analysis (TG-DTA) and FTIR, the characteristics of the microcapsules were investigated respectively. Successful self-healing has been demonstrated for anticorrosion covering materials with microcapsules.     

Preparation and characterization of microcapsule containing epoxy resin and its self-healing performance of anticorrosion covering material

Microencapsulated healing agents that possess adequate strength,long shelf-life,and excellent bonding to the host material are required for self-healing materials. The in situ encapsulation method is demonstrated over an order of magnitude size reduction for the preparation of urea-formaldehyde(UF) capsules filled with a healing agent,a mixture epoxy resin of the epoxy 711 and E-51. Capsules with diameters as small as about 100 μm are achieved under the agitation rate of 800 r min-1. The capsules possess a uniform UF shell wall(4 μm average thickness) . By using the analysis of scanning electronic microscope(SEM) ,thermal analysis(TG-DTA) and FTIR,the characteristics of the microcapsules were investigated respectively. Successful self-healing has been demonstrated for anticorrosion covering materials with microcapsules.     

Starch grain analysis reveals ancient diet at Kuahuqiao site, Zhejiang Province

Charred residues adhering to sherds of ceramic cooking vessels,pots (Fu),excavated from the Kuahuqiao site (8000-7000 cal a BP) in Zhejiang Province were examined using the method of starch grain analysis.Ancient starch grains were recovered from charred residues and were classified into 8 genera.Remains from rice (Oryza spp.),job's-tears (Coix chinesis T.),bean (Vigna spp.),acorn (Quercus spp.) as well as possibly buckeye tree (Aesculus chinensis B.) were identified.Other starch grains from unidentified pl...     

Magnetostratigraphic dating of mammalian fossils in Junggar Basin, northwest China

The first detailed chronology for the late Oligocene to early Miocene continental record in northern Junggar Basin is presented,based on rock magnetic experiments and magnetostratigraphic investiga-tions of a 192 m thick mammal-bearing section in the Ulungur River area. Magnetites and hematites were identified as the main carriers for the characteristic remanent magnetization,and the resulting polarity sequence allows an unambiguous correlation to the geomagnetic polarity time scale (GPTS). Furthermore,the Tieersihabahe fauna layer occurs below the Paleocene/Neocene boundary,and the Suosuoquan fauna layer is just above the Neocene onset. Therefore,the age of the Tieersihabahe fauna and Suosuoquan fauna layers can be definitely estimated to be about 25.2 Ma and 22.5 Ma,respectively.