增长曲线模型中最小二乘估计的几种相对效率

对于一般的增长曲线模型Yn×m=Xn×pBp×qZq×m＋ε,ε~（0,δV∑）本文定义了B的最小二乘估计（相对于B的最佳线性无偏估计）的四种相对效率，并得到了它们的下界．     

Blocking analysis andT(1) theorem

TheT(1) theorem with a weak condition on the distribution kernel is proved by using a new method—blocking analysis. It improves a result of Meyer’s. Project supported by the National Natural Science Foundation of China (Grant No. 19631080) and the Foundation of Advanced Research Center, Zhongshan University.     

实际光栅系统的分辨本领

本文指出了传统的光栅分辨本领Ｒ＝ｋＮ只是在光源狭缝无限细的情况下的极限值。当光源狭缝还有一定宽度Ｗ时，衍射条纹将增宽，相应最小分辨角Δθｋ将增大，实际光栅系统的分辨本领将减小。文章运用衍射理论，给出了实际光栅系统分辨本领的修正公式。在实验中，在不同光栅宽度Ｄ的情况下，用ｋ＝１级衍射条纹，当测量恰能分辨钠黄光的双线结构的光源缝宽Ｗ时，这时光栅系统的分辨本领是λ／δλ≈１０００，与修正公式计算的理论值一致。     

Synthesis and structure of a mixed ligand complex of tris(1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5)bis(dimethyl sulfoxide) neodymium

A mixed ligand complex of l-phenyl-3-methyl-4-trifluoroacetyl pyrazolone-5 (HPMTFP) and dimethyl sulfoxide (DMSO) with neodymium having molecular formula Nd(PMTFP)₃ · 2DMSO has been synthesized. Its crystal and molecular structures have been determined by a four-circle X-ray diffractometer. The complex crystallizes in monoclinic with space group P 2₁/n. a = 21.897 (4), b = 23.339 (4), c = 8.958 (2)Å, β = 96.61 (3)°, Z = 4. The Nd atom is coordinated by eight oxygen atoms, which takes a distorted delta dodecahedron arrangement around the central Nd atom. The average bond length of Nd—O is 2.45 Å. The IR spectra have been discussed as well.     

磁性离子Fe和Ni替代YBCO体系的结构特征和载流子局域化

为阐明磁性离子在不同替代位置对YBCO体系超导电性的影响机制，利用正电子湮没及相关实验手段结合数值模拟，系统研究了Fe和Ni掺杂的YBa₂Cu₃O_7-δ体系. 结果表明，Fe和Ni离子在替代过程中均以离子团簇的形式进入晶格. 当离子进入CuO₂面时，由于团簇改变了周围的电子结构，造成电子的局域化，并直接影响了电子对的配对和输运，因而强烈抑制了体系的超导电性.而当掺杂离子进入Cu-O链区时，它们同样通过团簇的形式改变周围 关键词： YBCO超导体 磁性离子替代 正电子湮没 数值模拟     

Yb∶YAG晶体的晶胞参量及Yb~(3+)分凝系数的研究

应用提拉法生长出不同Yb3+ 浓度的Yb3xY3( 1-x) Al5O12 晶体 Yb3+ 离子的分凝系数 1是 1 .0 8±0 .0 1 ,与Yb3+ 离子掺杂浓度无关 研究了Yb3xY3( 1-x) Al5O12 晶体的晶胞参量 ,推导出联系晶胞参量、密度与Yb3+ 离子掺杂浓度的关系方程式     

Condorcet Winners for Public Goods

In this work, we consider a public facility allocation problem decided through a voting process under the majority rule. A location of the public facility is a majority rule winner if there is no other location in the network where more than half of the voters would have been closer to than the majority rule winner. We develop fast algorithms for interesting cases with nice combinatorial structures. We show that the computing problem and the decision problem in the general case, where the number of public facilities is more than one and is considered part of the input size, are all NP-hard. Finally, we discuss majority rule decision making for related models.     

Low-Threshold Random Laser with One Mirror and Feedbacks in PMMA Nano-Composite Films

A low-threshold random laser with one mirror and feedback is investigated in the PMMA film containing rhodamine 590 and TiO2 nano-particles. Incoherent and coherent laser emission is observed. Effect of particle concentration on light emission is explored, and the optimum particle concentration is obtained. Optical microscopy and scanning probe microscopy are used to investigate the film structure, and the principle of incoherent and coherent laser is analysed.     

含O=P—N基环膦二肽的结构研究

分离出环膦二肽的几何异构体。用高分辩~H NMR结合其它光谱确定了异构体的数目,用X射线确定了它们的立体结构,发现磷上苯环与其α-碳上取代基互为顺式,六元环采用扭船式构象。     

一种新的高聚物酶联免疫印迹法的建立及其在乙肝表面抗原检测中的应用

聚(N—异丙基丙烯酰胺)(PNIP)于室温下是一种水溶性聚合物。这个聚合物的水溶液在32℃左右,在一个宽的浓度范围内(可高达5％)具有下部临界会溶温度(LCST)。在研究中我们发现,PNIP和PNIP与酶标抗体的复合物可以快速紧密地吸附到醋酸、硝酸纤维素膜上。利用PNIP在纤维素膜上的高保留率的特性,我们建立了一种新的免疫分析方法:聚合物酶联免疫印迹法。该法简单、快速、特异性高,能检测到人血清中10ng/ml的乙肝表面抗原。