Wavelength-tunable L-band mode-locked fiber laser using a long-period fiber grating

We demonstrate an L-band wavelength-tunable passively mode-locked fiber laser using a single long-period fiber grating (LPFG) as a narrow-band optical attenuator (NBOA). Through bending the LPFG, the central wavelength can be continuously tuned from 1582.02 to 1597.29 nm, while the output power only varies from 1.465 to 1.057 mW, approximately a rate of 22 µW/nm variation. This is the first time that LPFG is functioned as a NBOA in mode-locked fiber lasers, showing the great advantage of less impact on output power variation reduction. Besides, the total cavity length is 5.08 m, which is the shortest length yet reported in wavelength-tunable mode-locked fiber lasers. The wavelength tuning could also be realized at harmonic mode locking with tuning range of 14.69 nm under 5th harmonic

Fine mapping and candidate gene analysis of proportion of four-seed pods by soybean CSSLs

Soybean yield, as one of the most important and consistent breeding goals, can be greatly affected by the proportion of four-seed pods (PoFSP). In this study, QTL mapping was performed by PoFSP data and BLUE (Best Linear Unbiased Estimator) value of the chromosome segment substitution line population (CSSLs) constructed previously by the laboratory from 2016 to 2018, and phenotype-based bulked segregant analysis (BSA) was performed using the plant lines with PoFSP extreme phenotype. Totally, 5 ICIM QTLs were repeatedly detected, and 6 BSA QTLs were identified in CSSLs. For QTL (qPoFSP13-1) repeated in ICIM and BSA results, the secondary segregation populations were constructed for fine mapping and the interval was reduced to 100Kb. The mapping results showed that the QTL had an additive effect of gain from wild parents. A total of 14 genes were annotated in the delimited interval by fine mapping. Sequence analysis showed that all 14 genes had genetic variation in promoter region or CDS region. The qRT−PCR results showed that a total of 5 candidate genes were differentially expressed between the plant lines having antagonistic extreme phenotype (High PoFSP > 35.92%, low PoFSP< 17.56%). The results of haplotype analysis showed that all five genes had two or more major haplotypes in the resource population. Significant analysis of phenotypic differences between major haplotypes showed all five candidate genes had haplotype differences. And the genotypes of the major haplotypes with relatively high PoFSP of each gene were similar to those of wild soybean. The results of this study were of great significance to the study of candidate genes affecting soybean PoFSP, and provided a basis for the study of molecular marker-assisted selection (MAS) breeding and four-seed pods domestication

GestureQuery: A Multitouch Database Query Interface

Multitouch interfaces allow users to directly and interactively manipulate data. We propose bringing such interactive manipulation to the task of querying SQL databases. This paper describes an initial implementation of such an interface for multitouch tablet devices called GestureQuery that translates multitouch gestures into database queries. It provides database users with immediate constructive feedback on their queries, allowing rapid iteration and refinement of those queries. Based on preliminary user studies, Gesture-Query is easier to use, and lets users construct target queries quicker than console-based SQL and visual query builders while maintaining interactive performance

Trajectory Tracking Control Using Fourier Series Based Learning Controller with Phase Compensation

In this paper, a Fourier series based learning controller (FLC) with a novel phase compensation method is proposed for the tracking control of a class of uncertain nonlinear systems. Without a priori knowledge of the system model, all the nonlinearities and uncertainties are lumped together and compensated for by FLC. The learning algorithm of FLC is designed in the Fourier space, which converts the tracking problem in the time domain into a number of regulation problems in the frequency domain. Due to the clear physical meaning of FLC, the influence of the phase lags between the system input and output can be reduced by the phase compensation method. Therefore, more frequency components can be employed in FLC and the control performance will be greatly improved. Experiments are conducted on a belt-driven positioning table to verify the effectiveness of the proposed control method