丙烯酸生产外排废水化学需氧量与总有机碳相关性研究

化学需氧量（COD_Cr）与总有机碳（TOC）指标均可用来表征废水的有机物污染程度.不过,以COD_Cr表征有机物污染程度一般只能反映水中部分有机物的量,而TOC能更全面地反映废水中有机物的含量.以丙烯酸生产外排废水为研究对象,分析结果表明：在一定范围内,废水中COD_Cr与TOC满足关系式y=1.147 4x+74.75（R²=0.955 26）,回收率范围98%~115%,TOC测定结果的精密度高、可靠、准确,在一定条件下,可使用TOC来间接换算COD_Cr.     

Compact and broadband waveguide taper based on partial bandgap photonic crystals

Partial bandgap characteristics of parallelogram lattice photonic crystals are proposed to suppress the radiation modes in a compact dielectric waveguide taper so as to obtain high transmittance in a large wavelength range. Band structure of the photonic crystals shows that there exists a partial bandgap, The photonie crystals with partial bandgap are then used as the cladding of a waveguide taper to reduce the radiation loss efficiently. In comparison with the conventional dielectric taper and the complete bandgap photonic crystal taper, the partial bandgap photonic crystal taper has a high transmittance of above 85% with a wide band of 170 nm.     

Optimization of line-tapered MMI devices using a genetic algorithm

We discuss the optimal design of line-tapered multimode interference （MMI） devices using a genetic algorithm （GA）. A 1×4 MMI device is designed as a numerical example. Compared with the conventional design based on self-imaging theory, the present method demonstrates superior performance with low in- sertion loss and small non-uniformity.     

Diophantine方程nx~2+2~m=y~n(英文)

设n是大于3的奇数.本文运用Y.Bilu,G.Hanrot和P.M.Voutier关于Lehmer数本原素因子存在性的新近结果,证明了方程nx~2+2~m=y~n没有适合gcd(x,y)=1且m为奇数的正整数解(x,y,m).     

重视力学题中关键词的理解

每次物理考试后，总会有不少同学因为一时的疏忽而丢了许多冤枉分，要避免犯这种低级错误，除了要仔细读题外，还要从概念入手，把握关键词的理解，下面举几例供同学们参考。     

A Multilayered Configuration Broadband Polarization Insensitive Reflector Utilizing a Multi-Subpart Profile Grating Structure

A multilayered configuration broad bandwidth polarization insensitive reflector realized by a multi-subpart profile grating structure is presented. The properties of the reflector are investigated by rigorous coupled-wave analysis. It is shown that over a broadband spectrum of 1.62-1.76μm, the reflector demonstrates high reflectivity （R 〉 99%）, low polarization-dependent loss （PDL〈 0.02 dB） and good angular insensitivity of about 29.6% for both transverse electric and transverse magnetic polarized waves.     

关于七阶广义商高数的Terai猜想

设m是正偶数.运用初等数论方法证明了:当m≡2(mod 4)时,方程|m(m~6-21m~4+35m~2-7)|~x+|7m~6-35m~4+21m~2-1|~y=(m~2+1)~z仅有正整数解(x,y,z)=(2,2,7).并且指出了相关文献中的一个不足之处.     

一个有理分式Diophantine方程

本文研究了方程(x2-1)/(y2-1)=(z2-1)2.利用四次和二次方程的性质,获得了它的全部正整数解(x,y,z).     

椭圆曲线y~2=x~3+27x-62的整数点

根据四次Diophantine方程的已知结果,运用初等数论方法证明了:椭圆曲线y~2=x~3+27x-62仅有整数点(x,y)=(2,0)和(28844402,±154914585540).     

A novel accelerometer based on microring resonator

A novel microring resonator accelerometer is proposed. It is realized by a suspended straight waveguide coupled with a microring resonator. Under the external acceleration, the coupling coefficient is a function of gap spacing between the two waveguides. The mathematical model of the sensing element is established. Both the finite element method and coupled mode theory are adopted to analyze and optimize the proposed structure. Simulation results show that the mechanical sensitivity is 0.015 μm/g with the working frequency below 500 Hz and cross-axis sensitivity less than 0.001%, which is promising in seismic related applications.