原子转移自由基细乳液聚合*

本文从正向、反向、同时正向/反向、电子转移活化剂等不同原子转移自由基聚合（ATRP）细乳液引发体系的角度,综述了近年来国内外关于ATRP细乳液聚合的研究进展。在细乳液体系中进行正向ATRP,聚合可控性不理想,反向ATRP相对适合于细乳液体系,其缺点是表面活性剂用量较大。同时正向/反向引发体系的ATRP中催化剂用量大为减少,并且聚合具有良好的可控性;电子转移活化剂（AGET）ATRP是通过电子转移反应来还原过渡金属的氧化态,克服了同时正向/反向ATRP中需要引入自由基引发剂的缺点。     

中空纤维膜换热器传热传质性能的实验研究

中空纤维膜换热器可同时实现传质传热, 该换热器可应用于吸收式制冷系统以改善制冷性能. 为探究该膜换热器在溴化锂吸收式制冷系统的运行工况下的传热传质特性, 搭建中空纤维膜换热器性能测试实验台, 采用控制变量法探究在热侧不同入口溶液流速、温度下该换热器的传热量及膜通量变化规律特性. 结果表明: 在热流体其它参数保持不变的情况下, 中空纤维膜换热器热侧溶液的入口流速由3.05 m/s 增至3.30 m/s 时, 换热器总传热量与膜通量均随之加大, 增幅分别为16.0%和2.2%; 该膜换热器的总传热量在冷侧溶液与热侧溶液入口温差10°C 至15°C 内, 增幅达到18.9%, 而膜通量受膜两侧溶液的入口温差变化影响较小, 增幅仅3.1%. 研究表示: 温度的变化对中空纤维膜换热器的传热传质性能影响更为显著, 而流速的变化对水分子的运动影响较小.     

POINTWISE CONVERGENCE FOR EXPANSIONS IN SPHERICAL MONOGENICS

We offer a new approach to deal with the pointwise convergence of FourierLaplace series on the unit sphere of even-dimensional Euclidean spaces. By using spherical monogenics defined through the generalized Cauchy-Riemann operator, we obtain the spherical monogenic expansions of square integrable functions on the unit sphere. Based on the generalization of Fueter＇s theorem inducing monogenic functions from holomorphic functions in the complex plane and the classical Carleson＇s theorem, a pointwise convergence theorem on the new expansion is proved. The result is a generalization of Carleson＇s theorem to the higher dimensional Euclidean spaces. The approach is simpler than those by using special functions, which may have the advantage to induce the singular integral approach for pointwise convergence problems on the spheres.     

齐次乘子算子的交换子

记H^l={w∈C^∞(R^k\{0}):w是l次齐次函数),R^_(-a)(m)是Taylor级数余项算子的n重叠合:m=(m₁,…,m_n)∈Zⁿ,Z记非负整数的集,α∈(R^k)ⁿ,定义 其中a=(a₁,…,a_n),a_i,f∈(R^k), 主要结果如下: 1.证明了几个介于算子T_^R(-a)^{(m)_w(ξ)),(a,f})的类与多线性奇异积分算子的类之间的对等定理; 2.作为应用,算子及 的某些有界性结果被给出,其中Ω∈H⁰,|β|≤|m|,且,m_i≥1。     

联系复平面上由弧长所引出的 Radon 测度的加权不等式

本文考虑联系 R~n 中 Radon 测度的极大算子的加权不等式,然后应用所得的结果得到沿复平面上正则曲线的极大算子及奇异积分的加权模不等式.     

THE DIFFERENTIAL INTEGRAL EQUATIONS ON SMOOTH CLOSED ORIENTABLE MANIFOLDS

1 IntroductionSillce tl1e limit value fOrlnula, viz. tl1e Plemelj fOrn1ula, of the Cauthe type integraJ withBochner-Martinelli kernel was proved in 1957[1], it has beell successfully used to the study Ofsingular i1ltegral equatious, solvi11g the 0b--equation, holomorphic extension, 0--closed exten-sion and C-R 111al1ifolds[2-51. Evideutly, the researcl1 of higher order singular integrals withBochuer-Martinelli kerllel itself also l1as important significallce. In 1952, J. Hadanmrd firstde…     

聚苯乙烯共价键合磷铵两性离子的结构修饰及血液相容性

利用形成碳-氧键将磷铵两性离子(1)共价键合到聚苯乙烯(PS)材料表面, 改善其抗凝血性能. 首先对PS进行氯甲基化反应, 生成苄氯结构, 然后通过自合成化合物1中的-OH与氯甲基化聚苯乙烯的-CH₂Cl反应形成醚键, 将两性离子接枝在PS上. 表征了产物结构, 并通过水接触角和血小板黏附实验对结构修饰前后材料的亲水性和抗凝血性能进行了比较. 结果表明, 磷铵两性离子结构修饰的聚苯乙烯材料可以有效地提高其血液相容性.     

HIGHER C0MMUTATORS OF PSEUDODIFFERENTIAL OPERATORS

In this paper the following result is established: For a_i, f∈(R~K), i=1, …, n, and T (a, f) (x)=ω(x, D)(multiply from i=1 to n P_(mi)(a_i, x, ·)f(·)),it holds that ‖T(a, f)‖_q≤C‖f‖_(po) multiply from i=1 to n ~m_ia_i‖_(p_4),where a=(a_1, …, a_n), q~(-1)=p_0~(-1)+ sum from i=1 to n p_i~(-1)∈(O, 1), p_i∈(1, ∞)or i, p_i=∞, p_0∈(1, ∞),for an integer m_i≥0, P_(m_1)(a_i, x, y)=a_i(x)-∑ |β|相似文献   

在33.4MeV/u 17N与9Be反应中中子发射的起源

在不同角度测得的33.4MeV/u ¹⁷N+⁹Be反应中,发射中子的能谱具有复杂的形式,而且随着角度的增大显示出有规律的变化.发射中子至少来源于靶弹核间的核子–核子碰撞、¹⁷N的破裂反应以及熔合热核的统计蒸发三种不同起源.分析结果表明:反应体系三种起源的发射中子截面分别为4.49,0.44和5.5b.     

MATCHING PURSUITS AMONG SHIFTED CAUCHY KERNELS IN HIGHER-DIMENSIONAL SPACES

Appealing to the Clifford analysis and matching pursuits, we study the adaptive decompositions of functions of several variables of finite energy under the dictionaries consisting of shifted Cauchy kernels. This is a realization of matching pursuits among shifted Cauchy kernels in higher-dimensional spaces. It offers a method to process signals in arbitrary dimensions.