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In synchrotron radiation field, the apertures of optical components increase gradually and their surface figure precisions have been demanded to be a nano-radian level. This paper researches the modern surface figure measurement methods in this field, stitching interferometry, to realize the high resolution two-dimensional measurement of optical components. The basic principles of the stitching interferometry are introduced. Then, a series of common optical surface shape measurement instruments in the synchrotron radiation field are overviewed, such as long trace profilers based on laser beams, high precision and auto-collimation measuring machines for nanometer optical components and stitching interferometers. It describes their development history and working characteristics and compares their shortcomings and advantages. Finally, this paper analyzes the main error sources involved in the stitching interferometry, and points out that the application and development trends of the technology are mainly the innovation of the stitching algorithm, the improvement of measuring speeds of interferometers, the commercialization of interferometers and the integration of the interferometry and other science technologies. 漏 2016, Science Press. All right reserved.

The genetic diversity of 10 Pinus tabulaeformis natural secondary forest populations in northern China and the correlation with environmental factors were analyzed by using ISSR molecular marker techniques.250 individuals were amplified 137 bands by using 13 ISSR primers.The average percentage of polymorphic loci is 60.72%,and there is significant difference between different populations with the highest value in BTM group(71.53%) and the lowest value in YLG group(51.09%).Expected heterozygosity index and Shannon′s information index(I) individually range from 0.2824—0.3702 and 0.1923—0.2490 respectively between different geographic populations,and their average values are 0.3210 and 0.2165 respectively.The genetic variety between different populations are 37.53% of total genetic diversity.Among 10 P.tabulaeformis natural populations,genetic distances range from 0.083(LKS to CJC) to 0.2939(SDC to DWP),geographic distances range form 110.9252 km(LKS to SDC) to 1741.0933 km(YWL to YLG).Genetic distance and geographic distance are uncorrelated in the Mantel test(r=0.069,P=0.360).UPGMA clustering analysis showed that YWL,LKS,CJC,YLGY and SDC populations were a group,and MS population was clearly separated from other populations,and the other four populations were clustered into a group.The populations located in the boundary of the second and the third topography steps of China(YWL、BTM、YLGY) have a high level of genetic diversity,and the populations in critical distribution areas have a low level.The correlation analysis of genetic diversity and environmental factors showed that allele number and polymorphic percentage of natural populations were a significant positive correlation with the annual average temperature,the average temperature in January,the extreme minimum temperature,and were significant negative correlation with altitude.With increasing annual maximum temperature and the altitude,decreasing in annual rainfall,Shannon′s information index rises.Finally,get a result that the molecular variation of P.tabulaeformis natural secondary forest population have partly geographical variation.

An image test system using a CCD and a standard target was established to measure the stabilization accuracy of a gun control system.The principle and structures of the system were introduced.and its key algorithms such as image pretreatment,template matching,the orientation of target cross center and system calibration were investigated.In order to remove the disturbance of the reticle of graduation board on the target cross,the algorithm of the switching median filter was presented.After choosing the grayscale transformation to improve the image contrast,the algorithms for fabricating and matching the template were analyzed and chosen.Then,the orientation algorithms of pixel and subpixel for target cross center were presented.Finally,the angle resolution of the system pixel was confirmed using a calibration method based on active vision.The result indicates that the test accuracy has been better than 0.07 mil,which meets the practical test requirement and implements the stabilization accuracy measurement of modern fire-control systems with stabilized guns in firing ranges.

The primary tube of a visible zoom lens and its mounting are designed by UG advanced simulation according to the characteristcs of a wide temperature range(-40-+55 ℃) and little optical axis variation(≤0.2 mrad),and the deformation patterns in different conditions are gotten by using finite element analysis.An estimation way to get the optical axis variation is proposed,by which the more reasonable structure type is obtained.The results from the lens transfer function test and vibration test show that the Modulation Transfer Function(MTF) is above 0.2 and the fundamental frequency is 117 Hz.The practical image is stable and clear,which indicates that the optimized design of zoom lens is reasonable.

Based on the measurement principle of laser hatched method,an equipment for measure plasma shield was set up.The shielding of NS pulse laser induced breakdown in water was studied.Laser induced plasma shield images were recorded.Linear relation between the effect and laser energy was found.Linear break phenomenon by the NS pulse laser was observed for the first time.These research results will provide the theoretical and experimental references for laser processing underwater,laser medicine and corresponding hydromechanics.

Aiming at measurements of glass material inner-stress,a new high precision measurement method is proposed using the Magnetic-Optic Modulation technique for the stress birefringence.The proposed method has the strong points that simple theory,high precision and so on.The theory derivation is also given using the Jones Matrix,and the results show that the two methods to improve measurement efficiency are feqsible when the testing sample is much bigger.

Based on femtosecond laser inscription technology,a novel method for femtosecond laser micromachining system is proposed to fabricate a microfiber Fabry-Perot (F-P) cavity on the fiber end surface.This technique can solve the parallelism problem of the traditional fiber F-P sensors inscribed by femtosecond laser.The F-P interferometric sensor made by the proposed technique shows over 20 dB fringe visibility.This technique is parameter-controllable and easy to implement.It is a promising candidate of strain measurement in the case of extreme temperature circumstances.

The development of a novel push-type ultrasonic endoscope is described in which probe rotation is accomplished by a small motor situated near the transducer. A digital FPGA-based ultrasound imaging system is implemented which uses coded excitation to increase the SNR and penetration depth, with probe rotation accomplished by a small motor situated near the transducer replacing the external motor and the long steel wire used in other ultrasonic endoscopes. The apparatus is tested continuously for 300 hours with no obvious problems. The coded excitation, digital quadrature demodulation imaging system can obtain ultrasonic images of higher quality and more information of the echo is preserved compared with the analog imaging system, because the analog digital conversion is moved to the first step of the signal processing.The digital imaging system possesses a higher SNR resulting in a sharp image. Locating the motor near the probe improves the consistency of rotational speed in comparison with external guide-wire rotation, and increases the image quality and life-span of these devices.