Absolutely Direct Frequency Measurement of Two-Photon Transition Using Multi-Peak Fitting Approach

The optical frequency comb has been widely used in precision measurement. In this study, a multi-peak fitting approach is first proposed to fit the two-photon transition spectrum which overlaps with the neighboring transition in Rb-87. The multi-peak fitting approach is used to eliminate the frequency shift affected by the neighboring transition. With locking the carrier envelope offset frequency at 1/4 repetition frequency, the transition frequency is measured to be 770569132739.9 +/- 5.8 kHz, which agrees well with the previous result recommended by Comite International des Poids et Mesures.

Frequency Domain Approach for Face Recognition Using Optical Vanderlugt Filters

In this paper human face machine identification is experienced using optical correlation techniques in spatial frequency domain. This approach is tested on ORL dataset of faces which includes face images of 40 subjects, each in 10 different positions. The examined optical setup relies on optical correlation based on developing optical Vanderlugt filters and its basics are described in this article. With the limitation of face database of 40 persons, the recognition is examined successfully with nearly 100% of accuracy in matching the input images with their respective Vanderlugt synthesized filters. Software simulation is implemented by using MATLAB for face identification.

Controllable Fabrication of GeSi Nanowires in Diameter of About 10 nm Using the Top-Down Approach

Ordered GeSi nanowires with a ～ 10nm cross section are fabricated utilizing top-down and Ge condensation techniques. In transmission electron microscopy measurements, the obtained GeSi nanowires exhibit a single-crystal structure and a smooth Ge/SiO2 interface. Due to the linear relationship between the cross-section area and the initial pattern size under the self-limited oxidation condition, the cross-section size of GeSi nanowires can be precisely controlled. The Raman spectra reveal a high Ge fraction （up to 97%） and a biaxial strain of the GeSi nanowires. This top-down technique is promising for fabrication of high-performance GeSi nanowire based optoelectronic devices.

Calculation of the Duration of the Atomic Tunneling Ionization in a Strong Electrostatic Field by Using Bohmian Trajectories Approach

The duration of a bound electron tunneling through the barrier formed by atomic potential and electrostatic field is calculated by the Bohmian trajectories scheme. The time of the tunneling ionization decreases with the increase of the amplitude of the electrostatic field. By using the information about the position, velocity and force of the Bohmian trajectories, the dynamical process of tunneling through the barrier is investigated.

A Web-Based CAL System Constructing Tool Using Case-BasedReasoning Approach

It seems that a big problem in applying the WWW to education fields is that teachershave difficulty directly developing and managing a web-based intelligent CAL (Computer AidedLearning) system, because of the shortage of funds and teachers who are skilled in both AI (ArtificialIntelligence) and computer information technologies. Focusing on solving the problems we havedeveloped a general-purpose tool called WWW-CALIST (WWW-based Computer Aided LearningIndividual-adaptive System Tool), which helps teachers build up a web-based individualized adaptivecomputer aided learning environment called 'test→search for information using an adaptivekowledge map→adaptive learning'. By using easy-to-use interfaces equipped with the tool, ateacher who knows only the HTML can develop and manage web-based individualized adaptive CAIsystems for various education domains.

经口腔前庭腔镜手术与颈部开放手术治疗甲状腺乳头状癌的临床研究

目的探讨经口腔前庭入路腔镜甲状腺切除术(endoscopic thyroidectomy using the oral vestibular approach,ETOVA)与传统颈部开放手术治疗女性甲状腺乳头状癌的安全性、有效性及美容效果。方法回顾性分析2019年1~12月行甲状腺乳头状癌根治术的120例女性患者的临床资料,分为经口腔前庭入路腔镜甲状腺手术组(腔镜组,n=60)和传统颈部开放手术组(开放组,n=60),对比两组患者术中及术后相关临床资料。结果两组患者年龄、肿瘤直径、中央区淋巴结清扫时间、中央区淋巴结清扫总数、中央区转移淋巴结数量、术后并发症、术后24 h疼痛评分、术后6个月疼痛评分均无统计学差异(P均>0.05)腔镜组手术总时长、术中失血量、术后引流量均大于开放组(P均<0.001),腔镜组术后满意度高。结论ETOVA在治疗甲状腺乳头状癌是安全、有效的,具有更好的美容效果,患者满意度高,可以考虑作为部分患者,尤其是年轻女性甲状腺乳头状癌患者的首选手术方案。

Identification and Cloning of Differentially Expressed Genes Involved in the Interaction Between Potato and Phytophthora infestans using a Subtractive Hybridization and cDNA-AFLP Combinational Approach

Using a subtractive hybridization （SH）/cDNA-AFLP combinational approach, differentially expressed genes involved in the potato-Phytophthora infestans interaction were identified. These included genes potentially controlling pathogenesis or avr genes in P. infestans as well as those potentially involved in potato resistance or susceptibility to this pathogen. Forty-one differentially expressed transcript, derived fragments （TDFs）, resulting from the interaction, were cloned and sequenced. Two TDFs, suggested as potential pathogenicity factors, have sequence similarity to N-succinyl diaminopimelate aminotransferase and a transcriptional regulator, TetR family gene, respectively. Two other TDFs, suggested as potential avr genes, have sequence similarity to an EST sequence from Avr41Cf.41Avr91Cf- 9 and a P. infestans avirulence-associated gene, respectively. Genes＇ expression and origin were confirmed using Southern blots, Northern blots and qRT-PCR, he., potential resistance gene DL81 was induced at 12 hpi in the moderately resistant cultivar, whereas it was down-regulated as early as 6 hpi in the susceptible cultivar. On the other hand, DL21 was induced at 6 hpi （3.38-fold） in response to the highly aggressive isolate （US8） and strongly up-regulated thereafter （25.13-fold at 120 hpi.）, whereas it was only slightly up-regulated in response to the weakly aggressive isolate US11 （3.82-fold at 96 hpi）, suggesting its potential involvement as a susceptibility gene.

Intuitive approach towards detection of attention tunneling while using a head-up display

Head-up display （HUD）, a primary cockpit display, helps in optimizing a pilot＇s attention towards aircraft and outside events. Slight mismatch in the balance may cause missed events; this phenomenon is called attention tunneling and affects the situational awareness of the pilot. This work reports an intuitive approach to detect attention tunneling while use of HUD in aircrafts. Texture analysis of a composite HUD camera video provided three distinguishing parameters, viz., contrast, correlation, and homogeneity. These three texture parameters are used as inputs for a fuzzy inference-based assistive detection system which could be used for distinguishing tunneled and nontunneled HUD operation.

A proposed approach for detecting terahertz pulses by using double few-cycle laser pulses with opposite carrier envelope phases

Previous research shows that few-cycle laser（FCL） pulses with low energy and without a bias field can be used to coherently detect terahertz（THz） pulses. As we know, it is very difficult to stabilize the carrier envelope phase（CEP） of FCL pulses, i.e., there are some random fluctuations for the CEP. Here we theoretically investigate the influence of such instability on the accuracy of THz detection. Our results show that although there is an optimum CEP for THz detection, the fluctuations of the CEP will lead to terrible thorns on the detected THz waveform. In order to solve this problem, we propose an approach using two few-cycle laser pulses with opposite CEPs, i.e., their CEPs are differed by π.

Hybrid approach used for extended image-based wavefront sensor-less adaptive optics

The stochastic paralld gradient descent （SPGD） algorithm is widely used in wavefront sensor-less adaptive optics （WSAO） systems. However, the convergence is relatively slow. Modal-based algorithms usually provide much faster convergence than SPGD; however, the limited actuator stroke of the deformable mirror （DM） often prohibits the sensing of higher-order modes or renders a closed-loop correction inapplicable. Based on a comparative analysis of SPGD and the DM-modal-based algorithm, a hybrid approach involving both algorithms is proposed for extended image-based WSAO, and is demonstrated in this experiment. The hybrid approach can achieve similar correction results to pure SPGD, but with a dramatically decreased iteration number.