季节变化和光周期性对体外受精胚胎移植结局的影响

目的探讨季节变化和光周期性对体外受精(IVF)或单精子胞质内注射(ICSI)-胚胎移植(ET)治疗结局的影响。方法回顾性分析首次行IVF/ICSI-ET治疗、年龄<38岁、体重指数(BMI)<25kg/m2、采用黄体期长方案超排卵及取卵后第3天行新鲜胚胎移植的1222例患者的临床资料。根据取卵日期将其分为春、夏、秋、冬组,或长、短日照期组,比较各季节组间及长、短日照期组间优胚率、种植率和临床妊娠率等的差异。结果各季节组间及长、短日照期组间,患者的年龄、体重指数、不孕时间、基础FSH值和不孕因素的构成差异均无统计学意义(P>0.05);卵巢反应性、HCG日子宫内膜厚度、成熟卵率、正常受精率(2PN率)、卵裂率、优胚率和移植胚胎数等指标差异均无统计学意义(P>0.05)。各季节组间患者的HCG阳性率、种植率和临床妊娠率差异亦无统计学意义(P>0.05);但长日照期组患者的种植率和临床妊娠率高于短日照期组,差异有统计学意义(P<0.05)。结论季节变化对IVF/ICSI治疗结局无明显影响,但长日照期IVF/ICSI周期较短日照期可以获得更好的临床结局。

两模光场与原子相互作用中光场周期性和频效应-理想Kerr介质腔中非关联双模相干态光场与V型三能级原子相互作用系统中光场的不等阶和压缩效应

利用多模压缩态理论 ,通过数值计算研究了高QKerr介质腔中非关联双模相干态光场与V型三能级原子相互作用系统中双模光场的不等幂次高次和压缩效应 ,分别绘出了两模光场第一模i次方第二模j次方不等幂次和压缩度的第一正交分量 (Sh1 ij) ,第二正交分量(Sh2 ij)的时间演化曲线 结果表明 :1 )Kerr介质的存在和嵌放在介质中的V型三能级原子是产生双模光场不等阶和压缩效应的物质条件 ,二者缺一不可 2 )腔中光场和原子发生光子交换是导致双模光场不等幂次和压缩效应的微观机制 3)在不考虑坐标度的情况下 ,不同条件下的时间演化曲线呈现非常相似的“崩坍 -复原 -凹谷”式结构 ,且复原区的波型振荡次数及凹谷区的振荡下降和振荡上升型式一样 4)在 χ以及〈n1 〉 ,〈n2 〉不变的条件下 ,不等幂次高次和压缩度时间演化曲线的崩坍 -复原 -凹谷式结构的持续时间随压缩阶次的升高而缩短 ,压缩度随压缩阶数的升高而迅速下降 5 )在平均光子不变 (即〈n1 〉 ,〈n2 〉恒定 ) ,但Kerr介质不同 (即 χ变化 )的条件下 ,不等幂次高次和压缩度曲线的周期随Kerr介质的三阶非线性极化系数 χ的增加而缩短 ,幅度则不受Kerr介质的三阶非线性极化系数变化的影响 6)不等幂次高次和压缩效应的持续时间等强烈地依赖于Kerr介质的?

周期性光信号测量光速的研究

传统测量方法是通过采用测定光信号的传播距离和传播时间来确定光速的.作者利用周期性光信号测量光速,即首先把光信号转变为电信号,经过混频滤波,进而测量相位差和时间增量求得光速.

高粱2421光周期现象研究初报

本文通过遮光实验旨在研究高粱品种2421的光周期性.结果表明该品种对日照长度较为敏感,即在出苗后20d内对日照长度敏感,其临界日长为11～12h,光周期为9～12d.

基于光学相控阵双周期光场的关联成像

关联成像近年来成为光学成像领域的研究热点,光学相控阵集成度高、成本低和调制速率高等优点非常适合应用于关联成像.本文使用二维独立相位控制的光学相控阵,研究了光学相控阵产生的周期性赝热光场赋予关联成像的新特性:分别在暗室、有相位干扰和有热光噪声的条件下基于双周期光场进行了无分束器的关联成像实验;并利用光学相控阵双周期光场实现了图像拼接.研究结果对于促进关联成像技术的进步、拓展光学相控阵的应用有重要的意义.

关于生物光化学中几个问题

生物光化学是研究光在生物体内所引起的一种生化现象．本文就光引起的现象，如视觉、光合作用。

陆地棉野生种系在育种工作中的潜力

美国和我国一样,生产上栽培的棉花主要是陆地棉。从育种上来说,种质窄在美国也是面临的一大问题。丰富的种质资源是棉花育种的基础,所以现在美国十分重视搜集和研究新的棉花种质资源。

Photoperiod Control of Apical Bud and Leaf Senescence in Pumpkin ( Cucurbita pepo ) Strain 185

Short_day (SD) induced the plant senescence in pumpkin ( Cucurbita pepo Linn.) strain 185. Structural assay, gene expression and a series of biochemical analyses were performed to analyze the senescence mechanism in pumpkin strain 185 exposed to SD. Two aspects of important changes initiated in SD exposure contributed to the senescence process. SD functionally led to the initiation of the apical transformation from vegetative to reproductive growth, and then programmed cell death (PCD) in the apical meristem, causing the loss of vigorous growth activity. Moreover, SD treatment resulted in the formation of a great number of dying cells in mesophyll tissue later in the development compared with the phenotype of plants under long_day (LD) conditions. During the senescence process, high expression of nuclease is an important molecular event. These results indicate that the initiation of senescence process in pumpkin stain 185 plants is closely related to the death of cells in apical meristem and mesophyll.

High power output quasi-continuous-wave nanosecond optical parametric generator based on periodically poled lithium niobate

We report on a high power output quasi-continuous-wave nanosecond optical parametric generator （OPG） of congruent periodically poled lithium niobate （PPLN） pumped by a 1 064 nm acousto-optically Q-switched Nd:YVO4 laser （duration: 70 ns,repetition rate:45 kHz,spatial beam quality M2<1.3）.The OPG consists of a 38.7 mm long PPLN crystal with a domain period of 28.93 μm. With 5.43 W of average pump power the maximum average output power is 991 mW at 1 517.1 nm signal wave of the PPLN OPG.

Effect of surface roughness on femtosecond laser ablation of 4H-SiC substrates

Ablation threshold is an important concept in the study of femtosecond laser micro-and nano-machining.In this paper,the ablation experiments of three kinds of surface roughness 4H-Si C substrates irradiated by femtosecond laser were carried out.The feature thresholds were systematically measured for three surface roughness Si C substrates and found in the modification and annealing regions ranging from coincidence(R_(a)=0.5 nm)to a clear demarcation(R_(a)=5.5 nm),eventually being difficult to identify the presence of the former(R_(a)=89 nm).Under multi-pulse laser irradiation,oriented ripple structures were generated in the annealing region,where deep subwavelength ripples(about 110 nm,Λ≈0.2λ)can be generated above substrates with surface roughness higher than 5.5 nm.We investigated the effect of surface roughness on the ablation morphology,ablation threshold,and periodic structures of femtosecond laser ablation of 4H-Si C substrates,while the ablation threshold was tended to decrease and stabilize with the increase of pulse number N≥500.

New method of preparing 2D photonic crystals with big scale based on UV photosensitivity

A new method based on UV photosensitivity is proposed to fabricate big scale two dimensional photonic crystal.The optical transmission properties of designed periodic structure are investigated by numerical analysis.The results show that the 2D photonic crystal fabricated by the new method has a desirable photonic bandgap of TE mode.

Study of light signal receptor of Stephanopyxis palmeriana during sexual reproduction

We collected centric diatom Stephanopyxis palmeriana samples in coastal waters of Xiamen for charac- teristic red light/far red light (R/FR) phytochrome reactions to identify its photoreceptor in the course of sexual repro- duction. The result showed that pre-illumination of 2-3h red light before darkness could induce sexualization of S. palmeriana, while the follow-up illumination of far red light could reverse the effect of red light, which is a featured reaction of phytochrome. The Southern Dot Blot was carried out to identify the type of phytochrome that induces the sexualization. The result also showed high homogeneity of DNA fragment of S. palmeriana with phyB, but phyA. This means the photoreceptor in the process of sexual reproduction of S. palmeriana is phytochrome B (phyB).

Laser-Manipulating Macroscopic Quantum States of a Bose-Einstein Condensate Held in a Kronig-Penny Potential

We investigate the boundary vaJue problem （BVP） of a quasi-one-dimensional Gross-Pitaevskii equation with the Kronig-Penney potential （KPP） of period d, which governs a repulsive Bose-Einstein condensate. Under the zero and periodic boundary conditions, we show how to determine n exact stationary eigenstates {Rn} corresponding to different chemical potentials {μn} from the known solutions of the system. The n-th eigenstate P~ is the Jacobian elliptic function with period 2din for n = 1,2,…, and with zero points containing the potential barrier positions. So Rn is differentiable at any spatial point and R2 describes n complete wave-packets in each period of the KPP. It is revealed that one can use a laser pulse modeled by a 5 potential at site xi to manipulate the transitions from the states of {Rn} with zero Point x≠xi to the states of {Rn＇} with zero Point x= Xi. The results suggest an experimental scheme for applying BEC to test the BVP and to observe the macroscopic quantum transitions.

Envelope Periodic Solutions to Bose-Einstein Condensation in Linear Magnetic Field and Time-Dependent Laser Field

In this paper, by applying the extended 3acobi elliptic function expansion method, the envelope periodic solutions and corresponding dark soliton solution, bright soliton solution to Bose-Einstein condensation in linear magnetic field and time-dependent laser field are obtained.

Simultaneous measurement of temperature and refractive index based on a core-offset Mach-Zehnder interferometer cascaded with a long-period fiber grating

An all-fiber sensor based on a cascaded optical fiber device is proposed and demonstrated, and its sensor head is composed of a core-offset Mach-Zehnder interferometer(MZI) and a long-period fiber grating(LPFG). In the experiment, two dips shaped by the intermodulation between the interference fringe of MZI and the resonant wavelength of LPFG are monitored. Experimental results show that temperature sensitivities of two dips are 0.060 7 nm/°C and 0.056 3 pm/°C, and the refractive index(RI) sensitivities are –18.025 nm/RIU and –55.06 nm/RIU, respectively. The simultaneous measurement of the temperature and external RI is demonstrated based on the sensitive matrix. Its low fabrication cost, simple configuration and high sensitivity make this sensor have potential applications in chemical and biological sensing.

Optical transmission through silver film with compound periodic array of annular apertures

Recently,some kinds of structures have been found to show the property of extraordinary optical transmission(EOT).In this paper,we present a novel composite structure based on array of annular apertures(AAA)with compound lattice.The lattice includes two kinds of annular apertures with the same outer radius and different inner radii.The transmission spectrum of this compound periodic AAA can be achieved by adding up the spectra of two corresponding simple periodic AAAs,and the transmission shows EOT property.The transmission peaks of this kind of structure can be adjusted to desire wavelengths by changing the inner radius of aperture or the index of the dielectric material in the aperture.This structure can be used as a filter with dual pass bands when the difference between inner radii or indices of dielectric inside is large enough for two kinds of apertures.

Exergetical Analysis of Organic Flash Cycle with Two-Phase Expander for Recovery of Finite Thermal Reservoirs

In this work exergetical performance analysis is carried out based on the second law of thermodynamics for organic flash cycle(OFC) using a two-phase expander instead of throttle expansion in order to recover efficiently finite thermal reservoirs.The exergy destructions(anergies) at various components of the system are theoretically investigated as well as the exergy efficiency.Results show that the anergy of heat exchanger or two-phase expander decreases while the anergy of throttle valve increases with increasing flash temperature,and the exergy efficiency has an optimum value with respect to the flash temperature.Under the optimal conditions with respect to the flash temperature,exergy efficiency increases with the heating temperature and the component having the largest exergy destruction varies with the flash temperature or heating temperature.

Influence of background pressure on the microstructure and optical properties of Mo/Si multilayers fabricated by magnetron sputtering

Mo/Si multilayers were fabricated by using magnetron sputtering method at different background pressures:6×10-5 Torr,3×10-5 Torr,and 3×10-6 Torr.The reflectivity of the Mo/Si multilayers increased from 1.93% to 16.63%,and the center wavelength revealed a blue shift to 0.12 nm with the decrease of background pressure.Grazing incident X-ray diffraction(GIXRD) indicated that multilayers fabricated at high background pressure possessed better periodic structure and thinner Mo-on-Si interlayers.Low crystallization degree in(110) preferred the orientation of Mo layers and serious interdiffusion in the Mo/Si multilayers fabricated at low background pressure were observed by transmission electron microscopy(TEM).According to quantitative analysis of microstructural parameters,the Mo layers thickness and thickness ratio of Mo/Si multilayers both decreased and approached the design value gradually by the decrease of background pressure.In addition,the thicknesses of Mo-on-Si and Si-on-Mo interlayers were 1.17 nm and 0.85 nm respectively.It is suggested that the influence of background pressures on the microstructure has a critical role in determining the optical properties of Mo/Si multilayers.

Sodium guide star laser generation by single-pass frequency doubling in a periodically poled near-stoichiometric LiTaO_3 crystal

We report in this work a continuous wave(CW) narrowband 589 nm light generation for the purpose of laser guide assisted adaptive optics.A 39 mm long 1 mm thick periodically poled near stoichiometric LiTaO3 crystal with duty cycle near 50% was fabricated using electrical poling at room temperature and pumped by a Raman fiber amplifier.We tested two temperature control ovens,and a maximum conversion efficiency of about 14.3%,corresponding to 4 W of yellow light with 28 W of fundamental power,and bandwidth less than 0.18 GHz was achieved.

Boundary element method for calculation of elastic wave transmission in two-dimensional phononic crystals

A boundary element method(BEM) is presented to compute the transmission spectra of two-dimensional(2-D) phononic crystals of a square lattice which are finite along the x-direction and infinite along the y-direction.The cross sections of the scatterers may be circular or square.For a periodic cell,the boundary integral equations of the matrix and the scatterers are formulated.Substituting the periodic boundary conditions and the interface continuity conditions,a linear equation set is formed,from which the elastic wave transmission can be obtained.From the transmission spectra,the band gaps can be identified,which are compared with the band structures of the corresponding infinite systems.It is shown that generally the transmission spectra completely correspond to the band structures.In addition,the accuracy and the efficiency of the boundary element method are analyzed and discussed.