Researches show thatthere is a strong correlation between the spectral lag of flare and flare characteristic parameters (peak time, width, rise time, decay time), as time goes on, the flare becomes wider and the spectral lag becomes larger. We use the discrete-correlation function (DCF) to study the spectral lag of a multi-flare GRB (GRB 051117A)with 10 flares, it is found that within GRB 051117A, the spectral lag is also strongly correlated with the peak time, width, rise time and decay time of the flares. this is, lag∝t_peak, ω, t_rise, t_decay. The flares will also evolve over time within a GRB. This work extends the relationship between the spectral lag between GRBs and the characteristic parameters of flares to the interior of GRBs, which can help us have a deeper understanding of multi-flare GRBs. Moreover, the correlation between the flare characteristic parameters within GRB 051117A is highly similar to that between multiple GRBs and even prompt emission pulses. This also supports that X-ray flares and prompt emission pulses may have the same physical origin.

The jet radiation mechanism of fermi blazars is a very important problem. 442 groups of blazar data are collected, including 215 flat-spectrum radio quasars (FSRQ) and 227 BL Lac. Based on the data, the correlation between jet power and multi-wave luminosity is studied. The results are as follows:(1) for FSRQ, jet power is strongly correlated with the luminosity of radio, optical band, X-ray and gamma rays. And the order of luminosity distrbution is:logL_γ > logL_O > logL_X > logL_R. (2) For BL Lac, jet power is strongly correlated with the luminosity of radio, optical bands and gamma-rays. But there is only a weak correlation between jet power and X-ray luminosity. And the order of luminosity distrbution is:logL_O > logL_γ > logL_X > logL_R. Moreover, the luminosity of each band of BL Lac is less than that of FSRQ. We believe that these differences are due to differences in the intrinsic properties of FSRQ and BL Lac, i.e., differences in accretion modes and jet radiation mechanisms, etc.

To verify dominating processes in the inverse Compton mechanism and the origin of soft photons in the dominating processes, we collected multi-wavelength (quasi-) simultaneity data of 75 flat-spectrum radio quasars from the literature. We fitted the spectral energy distribution using logarithmic parabolic functions, then analyzed three correlations for the whole sample, the subsamples of two bins, respectively. The research results are summarized as follows. (1) We find significant correlations of log[U_B(νF_ν)_EC/U_ext(νF_ν)_syn] and logδ for the whole sample and subsamples of two bins, respectively. Our results show that the inverse Compton mechanism of the flat-spectrum radio quasar is preferentially dominant by the external Compton process under the leptonic model. (2) Based on the Bootstrap to calculate observed seed factor distribution, we apply this method to constrain the origin of soft photons of the dominant process of inverse Compton mechanism. The observed seed factor distribution suggests that soft photons are likely to be dominated by dust torus for populations with relatively low synchrotron peak frequencies. But, we cannot determine the origin of soft photons of the dominant process of inverse Compton mechanism for populations with relatively high synchrotron peak frequencies.

The spectral energy distributions (SEDs) of 29 states of 3C 279 are collected as samples, and the steady-state broken power-law electron energy distribution (EED) is applied.Then the relationship between the external observation and the internal physical properties of the source light is studied. Our main results are as follows:(1) Our results support the shock wave interpretation of photovariation (but require oblique shock) or magnetic reconnection interpretation. (2) There is a significant inverse correlation between EC peak luminosity logν_EC^pkL_EC^pk and magnetic field logB. There is a positive correlation between Doppler factor logδ and EC peak luminosity logν_EC^pkL_EC^pk, which means that the increase of Doppler factor is one of the reasons for the increase of EC peak luminosity. (3) There is no significant positive correlation between the synchronous peak frequency logν_syn^pk and peak luminosity logν_syn^pkL_syn^pk, which means that the sequence of flares may not be valid for all flares. (4) The parameter U_e/U_B (the ratio of relativistic electron energy density to magnetic field energy density) is far from 1, indicating that the equipartition trend between relativistic electron and magnetic field is not obvious, and 86% of parameters U_e/U_B have a ratio greater than 1, which means that most of the jets in 3C 279 are dominated by particles. From the relation of P_B (magnetic field power)< P_r (radiation power)< P_e (relativistic electron power)< P_p (cold proton power), P_p/P_jet (ratio of cold proton power to jet power) > 0.5, it indicates that the energy in 3C 279 jet is also carried by cold protons. Meanwhile, we find that the gamma-ray dissipation region in 3C 279 is located at 0.1-1.8 PC from the black hole center, suggesting that they are located outside the broad-line region (BLR) and within the dusty Torus (DT).

The low-frequency radio spectrometer carried by Chang'E-4 lander has successfully carried out observation. The observational data are continuously sent back to the ground data center monthly. After certain pretreatment, the 2C level spectrum data is released to scientific teams. The main purpose of this article is to evaluate whether this level of data meets the requirements for detecting the sky-averaged 21 cm global spectrum of the cosmic dark ages. We make a long-term integration of the 2C level data, and simulate the reception of the Galactic foreground radio radiation by the lander. Through the comparison and analysis of the two sets of data, we find that the 2C data has been reduced by 40-50 dB, which almost does not contain the far-field radiation signal of the Galactic foreground. Such a large reduction will affect the detection ability of the payload for the dark ages.

The W-band receiver system can effectively receive many important spectral lines for radio astronomy observations, which is of great significance for astronomical observations and scientific research. As a crucial component of the receiver system, the W-band ortho-mode transducer is important to achieve polarization separation and it has a considerable impact on the overall performance of the receiver system. We design a W-band broadband OMT based on the Boifot junction and introduce the working principle and designing process of OMT. The simulation results show that the relative bandwidth of OMT reaches 49.4%, the return loss is better than 18.7 dB, the cross-polarization is better than 55.8 dB, and the port isolation is better than 54 dB in the 70-116 GHz band.

Edge detection is a basic problem in image processing and computer vision. Its purpose is to identify points with obvious brightness changes in digital images. Laser ranging is an important technical method with the highest accuracy in the field of ranging. Before laser ranging data can be used in scientific research, a series of preprocessing of the original data is required. According to the distribution characteristics of the target signal and noise signal on the image, this paper proposes a method to extract the target signal based on edge detection, which converts the original data into the residual image of distance measurement, and then recognizes the signal position after edge detection. It has been used to process the measured data that the algorithm proposed in this paper has a certain feasibility and versatility.

Aiming at problems of massive signals real-time transmission and processing in ultra-wideband and multi-beam receiving systems, we tested and analyzed the related software of the mainstream backend system based on FPGA + GPU. The ultra-wide band receiving equipment required the backend system software to be capable of wider bandwidth and higher time resolution and higher frequency resolution conditions, as well as the realization of real-time data stream transmission and processing. Combined with the future development direction of large aperture radio observation equipment, it was proposed to use high-speed parallel ring buffers to achieve data stream caching, GPU clusters to achieve data stream real-time processing, and distributed parallel data storage based on BeeGFS, modular construction of data stream transmission pipelines software design ideas.

In order to further improve the real-time performance of the existing real-time lucky imaging system, and in the case of lucky imaging observation through the EMCCD camera with the USB2.0 interface, this paper proposes a real-time lucky imaging technology scheme based on USB2.0 bus data listening. The hardware design and digital logic design of the listening circuit have been carried out and a lucky imaging system with real-time listening, transmission, processing, dynamic update and display has been built. This system inserts the front end of the listening circuit into the USB2.0 bus connecting the camera with a PC. When the camera captures astronomical images and transfers the images to the PC via USB2.0 bus, the special USB2.0 bus data listening system realizes non-intrusive data listening on the bus. After analysis and processing, only valid astronomical image data are sent to a bottom FPGA development board, in which a FPGA lucky imaging system transplanted from an existing Ethernet-based system is embedded. When the development board receives the image data sent by the listening circuit, the embedded lucky imaging system performs image preprocessing, dynamic image selection, real-time registration and superimposition processing, and finally uses 9 adjustable thresholds to binarize high-resolution images and then outputs these images to a VGA displayer. This paper introduces the hardware, logic design method and debugging process of the listening circuit, as well as the transplantation of the lucky imaging system and the experimental situation of the whole system. The experimental results show that the implemented system can perform real-time listening, lucky imaging and dynamic update display for 10 000 frames of 512×512 pixel images continuously transmitted on the USB2.0 bus, and realize the real-time of lucky imaging technology.

At present, speckle interferometry and speckle masking are often used to reconstruct the mode and phase of the target in high-resolution solar image reconstruction. However, due to a large amount of grouped and partitioned data and the complexity of the algorithm, it is difficult to meet the requirements of real-time reconstruction. In order to alleviate the pressure of data processing, based on the existing CPU/GPU hybrid computing method of single block data, a method of allocating multi-component block data to GPU through multi-process and parallel processing is proposed. The experiment shows that the method based on a multi-process parallel acceleration method can improve the utilization efficiency of CPU and GPU resources, enable GPU to process multi-block data at the same time, and significantly improve the speed of image block processing with an acceleration ratio of about 4.7. Relevant studies can provide a reference for the parallel processing of astronomical data.

Wavelet transform de-noising only decomposes and processes the low-frequency part of the signal, neglects the decomposition and processing of the high-frequency part of the signal, which can not effectively extract the whole frequency band information of the signal, thus affecting the denoising effect of pulsar signal. In view of this, this paper proposes to use wavelet packet threshold method to analyze pulse signal, and selects different threshold functions to process the coefficients after wavelet packet decomposition. The experimental results show that the denoising effect of pulsar signal is improved by using this method, and the signal-to-noise ratio, peak signal noise and smoothness index of pulsar signal are improved correspondingly, which provides a new idea for the denoising of pulsar signal.

One of NVST's scientific goals is to perform two-dimensional spectral scanning observations of solar active regions. Based on NVST's Multi-Band Spectrometer and High Dispersion Spectrometer, this paper proposes a switching and spectral scanning system of the vertical double spectrometer, which can realize the spectral scanning observation tasks of two mutually perpendicular spectrometers and participate in the realization of switching between the two spectrometers. The principle and process of spectral scanning observation is analyzed. Combined with the specific structure of the NVST's terminal instrument system, the optical-mechanical structure design and installation of the system are completed. And the performance test of the system is performed, including system stability, scanning straightness and scanning step accuracy test. The test results meet the expected functional requirements and accuracy requirements. The work can provide support for NVST to perform conventional spectral scanning observations.

Magnetic field is the fundamental driving force of solar eruptions. High precision real-time polarization measurement is a common method to realize magnetic field measurement. However, the commonly used wave plate measurement method needs to be measured many times, and there is a mechanical rotation structure, which can easily cause instrument jitter and reduce the measurement accuracy; the rotation or switching of wave plate also leads to a longer measurement time. At present, the measurement period of solar atmospheric polarization based on DKDP crystal and wave plate is long, and the real-time performance is too low to be applied to the detection of rapidly changing solar active magnetic field. Based on the above background, this paper proposes a real-time polarization detection technology of the solar atmosphere based on the principle of double DKDP crystals. Two DKDP crystals with different fast axis directions are used to realize the polarization modulation of the incident sunlight and obtain the polarization Stokes vector of the solar atmosphere. Compared with the traditional method of combining rotating wave plate and DKDP crystal, the proposed method can increase the single polarization modulation rate from several seconds to millisecond, which greatly improves the real-time performance of solar magnetic field measurement. The simulation results show that the measurement accuracy of the proposed method is 2×10^-3, and the measurement time resolution of single wavelength point is improved by more than 20 times, which can realize the real-time accurate measurement of the polarization information of solar magnetic field.

In this paper, the photometric accuracies of 280 mm whole sky area rotatable photoelectric array which sited in Jilin astronomical observation are studied. A set of photometric standard stars of M67 open star cluster are observed.Firstly, we preprocess the image in IRAF(Image Reduction and Analysis Facility) and the photometry data is acquired by using the method of differential photometry. Then, the data is extracted for least square linear fitting, the fitting results show the main extinction coefficient and the transformation equations from instrument magnitude to standard magnitude. Finally, the root mean square error between transformed magnitude and standard magnitude is calculated to evaluate the photometric accuracy of the equipment. Our results indicate that the photometric precisions of this equipment is 0.13 mag for objects brighter than 13.8 mag under photometric conditions.In order to check this result we match the image with UCAC2 star catalogue and calculated the photometric accuracy. The results are basically similar to the former. The photometry accuracy of this equipment can basically meet the requirements of space debris observation.

There are five lunar eclipses with the heavenly stems-earthly branches dating in the Yin period oracle bone inscription, which are the most conclusive materials known for astronomical dating during the period of the Shang dynasty. The Xia-Shang-Zhou Chronology Project has given the date of occurrence of these lunar eclipses. The authors uses the DE422, modern astronomical planetary ephemeris released by NASA's Jet Propulsion Laboratory (JPL) to calculate main parameters of these lunar eclipses and study their observations on the Earth. The visibility of these lunar eclipses in Anyang, capital of the Shang dynasty, is further confirmed. The results support the date of theses lunar eclipses given by the Xia-Shang-Zhou Chronology Project and provide a certain reference for the in-depth study of the lunar eclipses in Yin period oracle bone inscription.

Using the statistics data of the marching distance during the Spring and Autumn period and Warring States period of China, the stalagmites, tree rings, lake deposits and solar activity data in the Eastern Zhou period in China, the possible relationship between climate change in ancient China and wars during the Spring and Autumn and Warring States period is discussed. The results show that, on the scale of tens to hundreds of years, changes in solar activity, precipitation, temperature and other natural environments may indirectly affect the historical process from the Eastern Zhou period to the unification of China by the Qin Dynasty, which is a factor worthy of attention in historical research. Different from the research inferring that the dry and cold climate led to famines and wars during the monarchy period of the past two thousand years, this paper found that the earlier period in the Eastern Zhou, the intensity of war was mostly positively correlated with temperature and precipitation. Ancient China was based on agriculture, and climate-sensitive agriculture determined the economic foundation of the vassal states, directly affected their national power, and might even affect the evolution and transformation of the political system.