批注——学习物理的好方法

现在全国各地都使用了新教材，课本样式设计新颖，栏目很多，特别引人注目的是，教材每页的一侧都留下一条空白；这样做的意图是什么呢？对我们的高中物理教学有什么作用呢？     

Design of magnet and control of the beam emittance for Penning H- ion source

The design requirement and principle of the deflection magnet for Magnetron and Penning H- ion source are discussed.It is proved that there exists a maximum emittance for the beam that may be transformed by the magnet into a state with equal Twiss parameters of αr=αy and βr =βy,which is the requisite condition to get a minimum emittance at the entrance of RFQ after transporting by a LEBT with solenoids.For this maximum emittance,the corresponding magnetic field gradient index is 1.     

Design of the low energy beam transport line for the China spallation neutron source

The design of the China Spallation Neutron Source (CSNS) low-energy beam transport (LEBT) line, which locates between the ion source and the radio-frequency quadrupole (RFQ), has been completed with the TRACE3D code. The design aims at perfect matching, primary chopping, a small emittance growth and sufficient space for beam diagnostics. The line consists of three solenoids, three vacuum chambers, two steering magnets and a pre-chopper. The total length of LEBT is about 1.74 m. This LEBT is designed to transfer 20 mA of H-pulsed beam from the ion source to the RFQ. An induction cavity is adopted as the pre-chopper.The electrostatic octupole steerer is discussed as a candidate. A four-quadrant aperture for beam scraping and beam position monitoring is designed.     

不可压缩流动问题混合Galerkin型方法稳定性的数值研究

研究了求解不可压缩流动问题的混合Galerkin型方法的稳定性问题,提出了一种在混合Galerkin型方法中满足离散LBB条件的一般性方法,即速度逼近空间维数大于压力逼近空间维数,并且两个逼近空间同时连续时,离散LBB条件可以得到满足.文中以混合有限元方法和混合无单元Galerkin方法为例,通过数值实验,验证了结论的正确性.     

乙醇酸和DL─乳酸交替共聚物的合成和表征

乙醇酸和ＤＬ－乳酸交替共聚物具有不同于其无规共聚物的理化性能和生物降解性。以ＤＬ－３－甲基－１，４－二烷－２，５－二酮为单体，通过在辛酸亚锡引发下的本体开环聚合，合成了该交替共聚物，并进行了结构表征。     

Metal Ion Complexation of Bilirubin Monolayer

Recently.biomimeticstrategieshavefocusedontheapplicationofbioinorganicnanocompositesandshapedhybridmaterialswithmicroscaleorganization'.Becauseoftheimportanceofbilepigmentsinphysiologicalsystemsuchascalciumbilirubinates,themaincomponentofblack-pigmentgallstones,anabnormalproductofbiomineralizationinmammalbodiesandcopperbilirubinate,afree-radicalscavengerinbileandprotectingphospholipidsfromperoxidation',agreatdealofattentionhasalreadybeengiventothestudyofbilirubin(BR)andotherbilepigments'.Excel…     

THE CHEMICAL COMPOSITIONS OF MINERALS IN QINGZHEN METEORITE AND ITS GEOCHEMISTRY SIGNIFICANCE

The chemical compositions of silicate minerals, sulphide minerals and metal Fe-Ni in theQingzhen meteorite were measured by the microprobe analyses. Based upon these chemicalcompositions, the cosmochemical behaviour and characteristics of the existing forms of themajor elements in the Qinzhen meteorite have been discussed. These characteristics show thatunder the S-rich, O-poor, and strongly reducing conditions, the light metal elements, such asCa, Mg, K, Na may form sulphide, and metal Fe-Ni may contain Si and P. However, we con-sider that the light metal-sulphide can be stable in the lower mantle and there are some Siand P in the Fe-Ni core. Finally, an earth core-mantle model is established, where the Fe-Ni core contains some Si and P; the lower mantle is composed of Mg-rich silicate, SiO_2 andsulphide; the upper mantle, of silicate and oxide.     

固相微萃取-气相色谱/质谱联用快速鉴定香稻香味特征化合物2-乙酰基吡咯啉

建立了固相微萃取-气相色谱/质谱(SPME-GC/MS)联用快速鉴定香稻香味特征化舍物2-乙酰基吡咯啉的方法.香米加入内标物2,4,6-三甲基吡啶,密封,在80℃水浴条件下经固相微萃取(萃取纤维头为100 μm聚二甲基硅氧烷)提取2 h,提取物经毛细管气相色谱柱HP-5MS(30 mx0.25mm×0.25μm)分离,...     

非离子型表面活性剂辅助酶水解玉米秸杆蒸爆渣

研究纤维素酶对蒸汽爆破预处理玉米秸杆的水解过程. 实验结果表明,玉米秸杆蒸爆渣中的木质素对纤维素酶存在非生产性吸附,降低了纤维素酶对玉米秸杆蒸爆渣的水解率;通过添加非离子型表面活性剂PEG 6000,减少纤维素酶的非生产性吸附,改善纤维素酶对玉米秸杆蒸爆渣的水解性能;在pH值为4.8,温度为50℃,PEG 6000浓度为3.5g/L的优化条件下,纤维素酶水解玉米秸杆蒸爆渣48h,还原糖水解率和葡萄糖水解率分别为83.61%和64.15%.