Chemical Potential Dependence of Dressed-Quark Propagator

A method for obtaining the low chemical potential dependence of the dressed quark propagator from an effective quark-quark interaction model is developed.Of particular interest here is to give a general recipe to find without arbitrariness the solution representing the “Wigner”phase at non-zero chemical potential for the purpose of studying QCD phase structure.     

氮氧杂链型配体合成与Cu(Ⅱ)和Zn(Ⅱ)配位性质研究

合成了4种氮氧杂链型配体N,N'-二-(2-羟乙基)-乙二胺(L¹)、N-(2-羟基苄基)-丙醇胺(HL²)、N-(2-羟乙基)-N'-(2-羟基苄基)-乙二胺(HL³)和N-(2-羟乙基)-二乙三胺-(L⁴),通过元素分析、IR和¹H NMR等手段表征了其结构,用pH电位滴定法在25℃、I=0.10(KNO₃)条件下,测定了L¹和HL²与Cu(Ⅱ)离子以及HL³和L⁴与Zn(Ⅱ)离子配位平衡常数.结果表明:L¹和HL²与Cu(Ⅱ)离子配位时,均可生成四配位配合物,其中第三配位点醇羟基配位较强,其质子离解常数pK_a1分别为7.28和7.32;第四配位点是第2个醇羟基或1个水分子配位,其pK_a2分别为9.33和9.04;HL³和L⁴与Zn(Ⅱ)均可生成五配位配合物,第四配位点均为醇羟基,其离解常数pK_a1分别为7.76和7.96,第五配位点均为H₂O,其pK_a2分别为9.47和9.57.从上述热力学结果可见,配合物在中性pH值范围能生成亲核试剂Cu(Ⅱ)…^-OR或Zn(Ⅱ)…^-OR,而且均具备双重催化酯类底物水解的条件.     

含铜类水滑石催化材料热分解过程的研究

共沉淀法合成了Cu0.13Mg0 6Al0.27(OH)2(CO3)0.135·xH2O类水滑石物质 (CuHTlc) ,采用XRD、DTA TG、BET、TEM和27AlMASNMR技术对其热分解过程进行了表征。结果表明 ,在较低焙烧温度时 (低于300℃ ),氢氧根和层间水部分脱除 ,但水滑石仍保持其层状结构 ;500℃时 ,其层状结构被完全破坏 ,出现氧化镁晶相结构 ,随着焙烧温度的进一步升高 ,尖晶石晶相生成。500℃时的焙烧产物具有最大比表面 (193m2·g-1)。当温度高于500℃ ,焙烧产物组成可表示为Cu0.13Mg0.6Al0.27O0.135,CuHTlc的热分解过程可表示为 :Cu0.13Mg0.6Al0.27(OH)2(CO3)0.135·xH2O→Cu0.13Mg0.6Al0.27O0.135 (1 x)H2O 0.135CO2。     

Characterization and Catalytic Properties of a Rapidly Quenched Ni-RE-P-AL Catalyst

IntroductionAmorphous.alloy has been found to have superior catalytic properties["']. However, asan applied catalyst, its small surface area and low thermal stability during the catalytic processare the encountered problems usually.In the previous study, we found that addition of a small amount of rare earth element effectively stabilized the amorphous phase in a Ni--P alloyL'~'j, and the surface area of the amorphous Ni--RE--P alloy could be greatly enlarged by introducing Al into the Ni-…     

Nonlocal Four-Quark Condensate and Vacuum Susceptibilities

Based on the quark propagator in the instanton dilute liquid approximation, we have determined the nonlocal four-quark condensate at the mean-field level in the framework of global color symmetry model. By making use of this formula, the vacuum susceptibility (pionsusceptibility) was calculated in this paper. The theoretical analysis and numerical calculation show that even at the mean-field level the naive vacuum saturation approximation is not a good approximation when we consider nonlocal four-quark condensate.     

磁控溅射淀积掺Er富Si氧化硅膜中Er~(3 ) 1.54μm光致发光

用磁控溅射淀积不同富Si程度的掺Er富Si氧化硅薄膜 .室温下测量其光致发光谱 ,观察到各谱中都含有 1.5 4和 1.38μm两个发光峰 ,其中 1.5 4和 1.38μm的光致发光峰分别来自Er3 和氧化硅中某种缺陷 .系统研究了Er3 1.5 4μm光致发光峰强度对富Si程度及退火温度的依赖关系 .还发现 1.5 4μm发光峰强度与 1.38μm发光峰强度相互关联 ,对此进行了讨论     

杯[4]芳烃衍生物的合成及其离子萃取性能

合成了两种含N的杯[4]芳烃衍生物,^1HNMR表明它们都是Cone构型,研究了它们和过渡金属离子的络合作用,结果表明,在杯[4]芳烃二个相对的酚羟基上引入Schiff碱桥联基因,可以大大增强其与金属离子的络合能力。     

新型Raney-Ni制备过程中的XRD,SEM和EDAX研究

采用急冷法及预处理制备Raney-Ni原始合金,以XRD,SEM和EDAX手段研究了其活化过程.此方法制备的Raney-Ni原始合金与传统方法制备的相比,晶粒变小,Ni₂Al₃相增多,从而使其具有中心为大量Ni₂Al₃,外围为少量NiAl3包裹的独特结构,使活化始终以铝向表面迁移为控制步骤,活化后残留较多的Ni₂Al₃相,催化剂中活性Ni均匀分布在残留的Ni₂Al₃上.     

Chemical Potential Dependence of the Dressed—Quark Propagator from an Effective Quark—Quark Interaction

We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagator from the dressed-quark propagator,which provides a means of determining the behavior of the chiral and deconfinement order parameters.A comparison with the results of previous researches is given.     

固定化扩展青霉脂肪酶的制备及其在玉米油转酯反应中的应用

采用吸附法对来源于扩展青霉Penicillium expansum的脂肪酶进行了固定化.从20种不同来源的树脂中筛选出固定化效率高且价格低廉的D4020树脂作为载体,系统研究了固定化条件对固定化效率及固定化酶转酯活力的影响.结果表明,最适加酶量、缓冲液pH和吸附时间分别为0.7 g/g、9.4和4 h.冻干时添加0.5%的半乳糖有助于提高固定化酶的转酯活力.在上述优化条件下,固定化酶的转酯活力为404.0 U/g,而所用的游离酶不能催化该转酯反应.利用该固定化酶催化玉米油转酯反应生产生物柴油时,叔戊醇为适宜的反应介质,其最适添加量为0.5 ml/g;适宜的酶量、加水量和反应温度分别为60.6 U/g、油重的1.2%和35℃.按醇/油摩尔比为1的比例分别在反应0、2和6 h时加入甲醇,在优化反应条件下,反应24 h后甲酯产率达85.0%;固定化脂肪酶具有较好的操作稳定性,反应10批次时,相对酶活力为62.8%.