High-spin states in 160Lu

High-spin states of ¹⁶⁰Lu have been studied through the ¹⁴⁴Sm( ¹⁹F, 3n) reaction. The previously known πh _11/2⊗υi _13/2 yrast band is extended from I ^π = 21^- to 25^- and a four quasiparticle band with configuration πh _11/2[523]7/2 ^-⊗υh _9/2[521]3/2 ^-⊗ (υi _13/2)² is reported. Received: 21 May 2001 / Accepted: 19 July 2001     

基于光谱法舌诊的脂肪肝快速诊断

提出了一种基于光谱技术的脂肪肝无创、快速诊断新方法。由于舌体能较客观的反映人体生理、病理变化,因此采集志愿者舌体舌尖部位的反射光谱,然后对数据进行分析,计算反射光谱的归一化反射率。建立3层BP网络模型,从采集来的115例样本中抽取32例健康人和44例脂肪肝患者的光谱归一化反射率作为神经网络的输入,再对未知的14例健康人样本和25例脂肪肝患者样本进行分类预测,分类正确率达到89.7%,实验结果表明了光谱法运用于脂肪肝快速无创诊断的可行性。同时,实验结果说明光谱法能更客观全面地反映人舌所携带的组织细胞、微循环等方面的信息,有可能为临床提供一种快速、简便的诊断手段,也为今后的中医证侯的度量提供借鉴。     

干冻磨削用低温冷风发生系统的设计

低温冷风发生系统是研究和应用低温冷风磨削的前提,低温冷风磨削是绿色磨削技术的重要分支之一。采用以单级蒸汽压缩制冷系统为核心,设计了一套干冻磨削用低温冷风发生系统,对该系统流程做了详细的描述及各个系统装置进行了详细的介绍。该低温冷风发生系统设计合理、结构简单、易于控制和操作。     

White matter abnormalities in children and adolescents with temporal lobe epilepsy

Background and Purpose

The widespread propagation of synchronized neuronal firing in seizure disorders may affect cortical and subcortical brain regions. Diffusion tensor imaging (DTI) can noninvasively quantify white matter integrity. The purpose of this study was to investigate the abnormal changes of white matter in children and adolescents with focal temporal lobe epilepsy (TLE) using DTI.

Materials and Methods

Eight patients with clinically diagnosed TLE and eight age- and sex-matched healthy controls were studied. DTI images were obtained with a 3-T magnetic resonance imaging scanner. The epileptic foci were localized with magnetoencephalography. Fractional anisotropy (FA), mean diffusivity (MD), parallel (λ_||) and perpendicular (λ_⊥) diffusivities in the genu of the corpus callosum, splenium of the corpus callosum (SCC), external capsule (EC), anterior limbs of the internal capsule (AIC), and the posterior limbs of the internal capsule (PIC) were calculated. The DTI parameters between patients and controls were statistically compared. Correlations of these DTI parameters of each selected structure with age of seizure onset and duration of epilepsy were analysed.

Results

In comparison to controls, both patients' seizure ipsilateral and contralateral had significantly lower FA in the AIC; PIC and SCC and higher MD, λ_|| and λ_⊥ in the EC, AIC, PIC and SCC. The MD, λ_|| and λ_⊥ were significantly correlated with age of seizure onset in the EC and PIC. λ_|| was significantly correlated with the duration of epilepsy in the EC and PIC.

Conclusion

The results of the present study indicate that children and adolescents with TLE had significant abnormalities in the white matter in the hemisphere with seizure foci. Furthermore, these abnormalities may extend to the other brain hemisphere. The age of seizure onset and duration of epilepsy may be important factors in determining the extent of influence of children and adolescents TLE on white matter.     

Stop-like modification of the dental fricative /ð/: an acoustic analysis

This study concentrates on one of the commonly occurring phonetic variations in English: the stop-like modification of the dental fricative /e/. The variant exhibits a drastic change from the canonical /e/; the manner of articulation is changed from one that is fricative to one that is stop-like. Furthermore, the place of articulation of stop-like /e/ has been a point of uncertainty, leading to confusion between stop-like /e/ and /d/. In this study, acoustic and spectral moment measures were taken from 100 stop-like /e/ and 102 /d/ tokens produced by 59 male and 23 female speakers in the TIMIT corpus. Data analysis indicated that stop-like /e/ is significantly different from /d/ in burst amplitude, burst spectrum shape, burst peak frequency, second formant at following-vowel onset, and spectral moments. Moreover, the acoustic differences from /d/ are consistent with those expected for a dental stop-like /e/. Automatic classification experiments involving these acoustic measures suggested that they are salient in distinguishing stop-like /e/ from /d/.     

Enhancement of the critical temperature of HgBa₂CuO(4+δ) by applying uniaxial and hydrostatic pressure: implications for a universal trend in cuprate superconductors

It is well known that the superconducting transition temperature (T(c)) of cuprate superconductors can be enhanced by varying certain structural and electronic parameters, such as the flatness of the CuO? planes or their doping level. We determine the uniaxial and hydrostatic pressure derivatives of T(c) in the structurally simple tetragonal compound HgBa?CuO(4+δ) near optimal doping. Our results provide experimental evidence for two further methods to enhance T(c): (i) reducing the area of the CuO? planes, and (ii) increasing the separation of the CuO? planar groups. T(c) is found to couple much more strongly to the ratio c/a of the lattice constants than to the unit cell volume. A comparison with prior results for structurally more complicated cuprates reveals a general trend of uniaxial pressure derivatives with T(c).     

Passively harmonic mode-locked erbium-doped fiber soliton laser with a nonlinear polarization rotation

Based on the nonlinear polarization rotation technique, we report on a stable passive 23rd harmonic mode-locked erbium-doped fiber soliton laser for the first time to the best of our knowledge. In this laser, 23 solitons are uniformly distributed in the cavity simultaneously, and all solitons have the same energy and duration. The increase of the coupler output enhances the dispersive radiation, and the longer cavity strengthens the interaction between solitons and dispersive waves. The two above factors play the key function to generate the 23rd harmonic mode-locked operation.     

基于高通量微弱荧光快速检测的高分辨熔解曲线分析仪

高分辨熔解(HRM)曲线分析技术是近年发展起来的一种用于基因突变检测和单核苷酸多态性(SNP)分析的新方法,它通过实时监测PCR产物升温过程中双链DNA饱和染料的荧光强度变化来分析核酸序列的微小差异.根据HRM分析仪对荧光检测的时间和灵敏度需求,提出基于光开关阵列的多路高速荧光激发和检测模块实现高通量的微弱荧光快速检测;并根据HRM荧光数据特点,对原始荧光曲线进行滤波、基线探测、归一化和对温度微分等处理,从熔解曲线两端的线形区域自动提取基线作为归一化的标准,可以在不损失曲线形态特征信息的情况下获得更为精确的熔解温度,从而实现不同基因型熔解曲线的快速、准确识别.