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The unbalanced barrel pitching system is a typical electro-hydraulic coupling servo control system, the performance of which determines the response speed and hit probability of vehicle mounted weapon equipment. However, in the actual service process, its core component, the high precision jet pipe servo valve, will produce the gradual erosion of the pilot stage’s receivers and the power stage’s throttling edges, which will induce the performance degradation of the unbalanced barrel pitching system, and finally greatly reduce the performance of barrel weapons. Therefore, a pressure and position double loop state space model of unbalanced barrel pitching system including the core parameters of performance degradation is established. The erosion behavior mechanism model of jet pipe servo valve is constructed, and the performance degradation characteristics of the unbalanced barrel pitching control system under the condition of erosion are further analyzed. Finally, aiming at the double loop structure of internal pressure loop and external position loop, the RBF Network Adaptive Robust Sliding Mode-Proportional Integral Derivative two-stage controller of barrel system is designed, based on which the experimental platform of unbalanced barrel pitching control is built. The experimental results are in good agreement with the theoretical results, so the proposed control method can effectively suppress the degradation of internal structural parameters induced by erosion, that is, it can better compensate the performance degradation of barrel pitching system induced by gradual erosion behavior.

The construction of microporous organic polymers (MOPs) with sustainable building blocks is essential for their scale-up preparation and practical applications.

Based on the principle of two-phase hydrodynamics and the mechanism of cavitation generation, this paper uses the finite volume method (FVM) in computational fluid dynamics (CFD) to analyse the features of fluid flow in jet amplifier, i.e., the pilot stage of jet pipe servo valve, and designs a lab bench to experimentally prove the accuracy of this numerical method. On this basis, the author discussed how four structural parameters influence the amplification efficiency of the jet amplifier. The amplification efficiency of the jet pipe servo valve can be maximized by setting the distance between nozzle and receiving holes of 0.1 mm, the diameter of receiving holes of 0.2 mm, the inclination angle of 22.5°, and the spacing between the two receiving holes of 0 mm (if possible). The research methods and results provide a solid basis for the design and performance prediction of the jet pipe servo valve.

The prevalence, clinical features, and outcomes of patients with systemic lupus erythematosus (SLE) complicated with or without aortic aneurysm (AA) were compared in a Chinese single-center cohort.Included in this study were SLE patients who received treatment at Shanghai Changhai Hospital between 2000 and 2020. The prevalence, clinical features, and outcomes of these SLE patients with or without AA were compared by Student's t-tests or Fisher's exact tests as appropriate. Risk factors associated with AA occurrence in SLE were evaluated by univariable and multivariable logistic regression analyses. The survival analysis between SLE patients with or without AA was conducted by the Kaplan-Meier method.Of the 1843 SLE patients included in this study, 16 (0.86%) were identified as having AA, and 160 of the remaining 1825 SLE patients without AA were selected as a simple random sample for comparison. The SLE patients with AA showed a higher proportion of smoking and hypertension as compared with those with no AA. Multivariable logistic regression analysis showed that a long SLE duration and anti-RNP positivity were two independent risk factors associated with AA occurrence in SLE patients. The log rank test showed that SLE patients with AA had a significantly higher risk of progression to death. Renal disorder was associated with an even poorer outcome in SLE patients with AA.The incidence of AA in SLE patients may be underestimated. The association between AA and SLE, especially in patients with multiple risk factors, should not be ignored. Key Points • The risk of SLE patients developing AA may be higher than that previously estimated. • The risk of SLE patients especially with multiple risk factors developing AA should not be ignored. • The diagnosis of AA should not be forgot when SLE patients present with chest, back, or abdominal symptoms with unexplained causes.

Continuous optimization of diagnosis and treatment of malignant tumors has led to significantly prolonged survival in cancer patients. Despite the recent increase in the incidence of multiple primary malignant tumors (MPMT), it remains rare in clinical practice; therefore, normative guidance on its etiology, diagnosis, and treatment is insufficient. Here we describe the case of a patient with three primary malignant tumors, namely breast cancer, diffuse astrocytoma, and hepatic malignant perivascular epithelioid cell tumors (PEComa) and discuss relevant literature.

The adoption of new synthesis strategy and monomers significantly promotes the construction of porous organic polymers (POPs) and their promising applications. A fabricating method of porous polyimides is developed via sequential imidization and cross-linking reaction among self-condensable building blocks, as reported in the authors' previous manuscript. Here, porous polyureas (A-POPs) are prepared starting from 4-ethynylaniline and diisocyanate monomers, while porous polyamides (B-POPs) are synthesized from 4-ethynylbenzoic acid and diisocyanate monomers. It is found that decreasing the monomer content in solvent can effectively inhibit the premature phase separation and facilitate the evolution of integrated network. Eventually, a maximum surface area of 425 m

This paper discusses the problem of fault estimation for two-dimensional (2-D) Fornasini-Marchesini (FM) dynamical systems. The objective of this paper is to design a fault estimation filter to reconstruct the characteristics of faults in low-frequency domain and satisfy different performance levels. Utilizing the generalized Kalman-Yakubovich-Popov (GKYP) lemma, this problem is transformed into a multi-objective optimization problem, which is non-convex in essence. On this basis, an optimization algorithm is proposed to solve the non-convex optimization problem. Sufficient conditions are derived for the proposed fault estimation filter. Finally, simulation results show the effectiveness of the theoretical results.

The development of simple and highly effective desulfurization technology is attracting more and more interest in both industrial and academic fields. Here, a new family of precursors was prepared based on hyper-cross-linked asphalt and coal tar building blocks. Thanks to the preintroduced porous structure, the precursors were converted into carbons with high surface area and large micropore volume via a uniform carbonization process. The synergistic effects of high surface area, abundant microporous structure, and the introduced polar functional groups endow the carbon materials with high desulfurization performance. The results of repeated experiments show that the adsorption capacities of five carbonized samples are higher than 40 mg S g-1, and the theoretical maximum adsorption capacity reaches 44.7 mg S g-1. Particularly, the adsorption equilibrium of all the carbonized samples can be reached in 5 min. Moreover, the recycle adsorption performance was also studied. Toluene exhibits the best elution effect among three eluents (iso-octane, para-xylene, and toluene) and the adsorption capacity remains 89% of the initial adsorption capacity after two adsorption-desorption cycles. It is believed that both innocent treatment of byproducts from petroleum industry and their high-value application for deep desulfurization in liquid hydrocarbon fuels benefit environmental protection and sustainable development.

This paper investigates the robust controller design for polytopic-type uncertain linear systems disturbed by external disturbances in restricted frequency ranges. The primary goal is to design a state-feedback controller, ensuring that the closed-loop system is robustly stable and keeps a prescribed finite-frequency (FF) disturbanceattenuation performance. For this purpose, a robust generalized Kalman-Yakubovich-Popov (KYP) lemma is applied to describe the finite-frequency specification, aiming at improving the disturbance-attenuation performance over the given frequency range. In this setting, more relaxed analysis conditions for robust stability and finitefrequency specifications are derived by introducing additional slack variables, which contain some existing conditions as special cases. Based on the homogeneous polynomially parameter-dependent (HPPD) technique, new controller design conditions in terms of linear matrix inequalities (LMIs) are developed. It is shown that the proposed finite-frequency design scheme can achieve a better disturbance- suppression performance in restricted frequency ranges than the existing ones, which is illustrated by an example about the satellite system.

The stability of Au nanoparticles (AuNPs) is easily affected by environmental factors, and the use of expensive disposable AuNP-based probes not only wastes resources but also increases the cost of detection. Therefore, there is an urgent need to develop stable and recyclable AuNP-based probes. Here, highly stable AuNPs were synthesized via an in situ reduction reaction between HAuCl4 and hyperbranched polyethylenimine (HPEI). We used HPEI to replace the small molecule reducing agent as a green reducer and template for the green and facile preparation of AuNPs as well as a good stabilizer and decorator of AuNPs. Due to the good properties (massive amount of amino groups, excellent reduction ability and hyperbranched topology structure) of HPEI, the HPEI–AuNPs are highly stable under high temperatures, strong ionic strength and different pH conditions. Meanwhile, the reductive HPEI was also used as the reducing agent to reduce Ag+ to Ag0; this can combine with AuNPs to form stable Au–Ag core–shell NPs accompanied by a special red-to-brown color change, achieving the colorimetric detection of Ag+ by the naked eye. Moreover, this HPEI–AuNP probe not only exhibits good selectivity and high sensitivity (a LOD of 0.41 μM) towards Ag+ but has also been successfully applied in real water samples (drinking and tap water). More importantly, by taking advantage of an etching reaction of the Ag shell of the Au–Ag core–shell NPs, a recoverable and reusable HPEI–AuNP probe towards Ag+ was developed successfully. This novel colorimetric system shows excellent recyclability and reusability, which is inspirational for the development of low-cost AuNP colorimetric probes and consistent with the idea of green chemistry.

Toxic solvents and catalysts, tedious monomer synthesis, and long reaction time significantly limit the sustainable and large-scale preparation and practical application of microporous polyimides (MPIs). In this work, three kinds of MPIs were successfully prepared through thermal polycondensation in the diphenyl sulfone (DPS) solvent using 1,4,5,8-naphthalenetetracarboxylic dianhydride and triamines as building blocks. The polymerization can be completed in 30 min, and the resultant MPIs exhibit large surface areas up to 1825 m2 g−1. Owing to their abundant microporous structures and plenty of imide rings, MPIs demonstrate excellent ammonia adsorption performance (21.10 wt%, at 303 K and 1.0 bar) and favorable regeneration ability. DPS as a non-volatile solvent can be recovered and recycled three times. In comparison with previous reports, this strategy is more time efficient, environmentally friendly and potentially scalable.

To solve the problem of location service interruption that is easily caused by incomplete visual satellite environments such as occlusion, urban blocks and mountains, we propose an altimeter + inertial navigation system (INS) + giant low earth orbit (LEO) dual-satellite (LEO2) switching integrated navigation algorithm based on a similar ellipsoid model and unscented Kalman filter (UKF). In addition to effectively improving the INS error, for the INS + LEO dual-satellite switching algorithm without altimeter assistance, our algorithm can also significantly suppress the problem of excessive navigation and positioning error caused by this algorithm in a long switching time, it does not require frequent switching of LEO satellites, and can ensure navigation and positioning functions without affecting LEO satellite communication services. In addition, the vertical dilution of precision (VDOP) value can be improved through the clock error elimination scheme, so, the vertical accuracy can be improved to a certain extent. For different altimeter deviations, we provide simulation experiments under different altimeter deviations; it can be found that after deducting the fixed height deviation, the algorithm can also achieve good accuracy. Compared with other typical algorithms, our proposed algorithm has higher accuracy, lower cost and stronger real-time performance, and is suitable for navigation and positioning scenarios in harsh environments.

In challenging environments such as forests, valleys and higher latitude areas, there are usually fewer than four visible satellites. For cases with only two visible satellites, we propose a dual-satellite alternate switching ranging integrated navigation algorithm based on the broadband low earth orbit (LEO) constellation, which integrates communication and navigation (ICN) technology. It is different from the traditional dual-satellite integrated navigation algorithm: the difference is that it can complete precise real-time navigation and positioning without an altimeter and continuous observation. First, we give the principle of our algorithm. Second, with the help of an unscented Kalman filter (UKF), we give the observation equation and state equation of our algorithm, and establish the mathematical model of multipath/non-line of sight (NLOS) and noise interference. Finally, based on the SpaceX constellation, for various scenarios, we analyze the performance of our algorithm through simulation. The results show that: our algorithm can effectively suppress the divergence of the inertial navigation system (INS), in the face of different multipath/NLOS interference and various noise environments it still keeps good robustness, and also has great advantages in various indicators compared with the traditional dual-satellite positioning algorithms and some existing 3-satellite advanced positioning algorithms. These results show that our algorithm can meet the real-time location service requirements in harsh and challenging environments, and provides a new navigation and positioning method when there are only two visible satellites.

BackgroundPrevious studies have revealed the key functions of N6-methyladenosine (m6A) modification in breast cancer (BC). MALAT1 as a highly m6A modified lncRNA associated with cancer development and metastasis, but the functional relevance of m6A methyltransferase and MALAT1 in BC is still unknown. Here, our study investigated the effects of the novel m6A methyltransferase METTL3 on epithelial-mesenchymal transition (EMT) in BC via the MALAT1/miR-26b/HMGA2 axis.MethodsFirstly, we collected clinical BC samples and cultured BC cells, and detected mRNA and protein levels in the human samples and human cell lines by RT-qPCR and Western blot, respectively. Then, the binding of MALAT1 and miR-26b and the targeting relationship between miR-26b and HMGA2 were examined by dual-luciferase assay. Moreover, the binding of MALAT1 and miR-26b was tested by RNA pull down and RNA immunoprecipitation (RIP) assays. Methylated-RNA immunoprecipitation (Me-RIP) was used to detect the m6A modification level of MALAT1. The interaction of METTL3 and MALAT1 was detected by photoactivatable ribonucleoside-crosslinking immunoprecipitation (PAR-CLIP). Finally, effects on invasion and migration were detected by Transwell.ResultsIn BC, the level of miR-26b was consistently low, while the levels of METTL3, MALAT1 and HMGA2 were high. Further experiments showed that METTL3 up-regulated MALAT1 expression by modulating the m6A modification of MALAT1, and that MALAT1 could promote the expression of HMGA2 by sponging miR-26b. In BC cells, we found that silencing METTL3 could inhibit EMT and tumor cell invasion by suppressing MALAT1. Furthermore, MALAT1 mediated miR-26b to target HMGA2 and promote EMT, migration, and invasion. In summary, METTL3 promoted tumorigenesis of BC via the MALAT1/miR-26b/HMGA2 axis.ConclusionsSilencing METTL3 down-regulate MALAT1 and HMGA2 by sponging miR-26b, and finally inhibit EMT, migration and invasion in BC, providing a theoretical basis for clinical treatment of BC.

In this work, two hyperbranched polyethyleneimine (HPEI) based gels were prepared and employed as adsorbents for the removal of dyes. HPEI-MBA gel was obtained by a cross-linking reaction between HPEI and N, N′-methylene-bis-acrylamide (MBA). And HPEI-MBA gel was further treated with isobutyric anhydride to form thermoresponsive HPEI-MBA-IBAm gel having important application in aspect of desorption of dyes. The structure and morphology of gels were characterized by FTIR, XPS, SEM and BET. Many different affecting factors for adsorption capacity of gel, such as contact time, pH, concentration of dyes and adsorptive selectivity, were investigated. The HPEI-MBA gel demonstrated a satisfactory adsorption capacity for methyl orange (MO) and xylenol orange (XO) as high as 1552.76 mg/g and 3312.06 mg/g, respectively. Interestingly, the HPEI-MBA gels had a considerable adsorption capacity for mixed system of anionic and cationic dyes by regulating the value of pH. In the MO/methylene blue (MB) mixture system, the adsorption capacities of gels for MO and MB were all higher than that of single-dye system, and in the MO/basic fuchsin (BF) mixture, the adsorption capacity for MO and BF can be improved under neutral condition. In the MO adsorption process, the adsorption/desorption kinetic of HPEI-MBA and HPEI-MBA-IBAm gels exhibited a good fit to the pseudo-second-order model. Meaningfully, the adsorption efficiency of HPEI-MBA gel for MO was still as high as 93.52% after 11 cycles of adsorption/desorption. More importantly, we developed a general and facile method to achieve dye desorption by adjusting temperature which relies on the temperature-sensitive properties of HPEI-MBA-IBAm. Therefore, the HPEI-MBA gels and HPEI-MBA-IBAm gels, as a new recycle adsorbent, could have comprehensive application in the removal of dyes from wastewater.

In this paper, a robust control based on disturbance observer is proposed to improve the tracking accuracy of the Risley prism system (RPS). Applying the flexible thin-wall ring mechanism in the RPS causes a series of tracking and pointing challenges. Disturbances such as friction, shaft deformation, and model perturbation significantly deteriorate the tracking and pointing accuracy of the RPS. Two different observer-based control methods are proposed to guarantee the tracking precision of the RPS. Moreover, the disturbance observation and compensation (DOC) performance of the proposed methods is analyzed and compared. Finally, simulation and experiment results indicate that the proposed control methods, especially the DOC-expanded state observer control mode, obtain the best performance for disturbance rejection in the RPS.

Background Breast cancer is a malignant tumor with high incidence in females. Burgeoning studies have analyzed the relationship between long non-coding RNA (lncRNA) and breast cancer. However, the role of LncRNA UAC1 in the pathogenesis of breast cancer remains unclear. Methods LncRNA-UCA1 levels were detected in breast cancer tissues and cells while correlation between LncRNA-UCA1 expression and patient survival was analyzed by the Kaplan-Meier. The proliferation, invasion and apoptosis of cells were measured by CCK-8 assay, Transwell test and flow cytometry, respectively. Protein levels of apoptosis-related factors were assessed by Western blots. RIP test detected the combination of LncRNA-UCA1 and DNA methyltransferases whereas RNA pull-down test showed the interaction of DNA methyltransferases and LncRNA UCA1. Enrichment of DNA transferase of METTL14 promoter in T47D was assessed by ChIP. Interaction between miR-375 and SOX12 was confirmed via dual-luciferase reporter assay. Tumorigenesis was observed in vivo. Results LncRNA-UCA1 levels were increased in breast cancer and a high LncRNA-UCA1 level was a risk factor of the poor breast cancer prognosis. Silencing LncRNA-UCA1 inhibited the proliferation and invasion but promoted apoptosis of breast cancer cells. LncRNA-UCA1 recruited DNA methyltransferase to the METTL14 promoter region to inhibit METTL14 expression in breast cancer. Low METTL14 levels were associated with stronger proliferation and invasion abilities, whereas weaker proliferation and invasion abilities were related to low LncRNA-UCA1 levels. METTL14 mediated the low expression of miR-375 by m6A modification in breast cancer. Conclusion Depleted LncRNA-UCA1 inhibited breast cancer growth by regulating the METTL14-miR-375-SOX12 axis in vitro and in vivo.

Breast cancer, a multifactorial disease, represents one of the leading causes of cancer-related morbidity and mortality in women. This study set out to elucidate the underlying mechanism by which lncRNA UCA1 affects the m

Coherent beam combination (CBC) with Actively Phase-Controlling is a key method to many applications. The core challenge of achieving a Diffraction-Limited output laser of CBC is to correct and lock the phase errors quickly between the sub-beams. A phase prediction method based on the convolutional neural network with a MSE-NPCD loss function is proposed to solve this problem. By using the proposed method, the phase errors can be predicted by a pair of far-field images in one-step. We also demonstrate the robustness and scalability by adding additional disturbance and expanding the scale of the sub-beams. The result shows that our method can achieve high accuracy and high speed combining effect in a tiled aperture CBC system.

A colorimetric sensor, based on the synergistic coordination effect on a gold nanoparticle (AuNP) platform has been developed for the determination of creatinine. The sensor selects citrate stabilized AuNPs as a platform, polyethylene glycol (PEG) as a decorator, and Hg2+ as a linkage to form a colorimetric probe system (PEG/Hg2&minus, &ndash, AuNPs). By forming hydrogen bond between the oxygen-containing functional groups of PEG and citrate ions on the surface of AuNPs, this probe shows good stability. PEG coordinated with Hg2+ synergistically and specifically on the surface of dispersed AuNPs, and the existence of creatinine could induce the aggregation of AuNPs with a corresponding color change and an obvious absorption peak shift within 5 min. This PEG/Hg2+&ndash, AuNPs probe towards creatinine shows high sensitivity, and a good linear relationship (R2 = 0.9948) was obtained between A620&ndash, 522 nm and creatinine concentration, which can achieve the quantitative calculations of creatinine. The limit of detection (LOD) of this PEG/Hg2+&ndash, AuNPs probe was estimated to be 9.68 nM, lower than that of many other reported methods (Supplementary Materials Table S3). Importantly, the sensitive probe can be successfully applied in a urine simulating fluid sample and a bovine serum sample. The unique synergistic coordination sensing mechanism applied in the designation of this probe further improves its high selectivity and specificity for the detection of creatinine. Thus, the proposed probe may give new inspirations for colorimetric detection of creatinine and other biomolecules.

In this paper, the empirical wavelet transform (EWT) is used to analyze dynamic responses of bridges. In EWT, the Fourier spectrum of the analyzed signal is segmented adaptively to detect the specific frequencies first. And then, the empirical scaling function and the empirical wavelets are defined based on the automatically identified frequencies. Using this tight frame set of empirical wavelets, wavelet transform is applied to the signal to extract the individual modes. The effectiveness of EWT is validated using the vibration signal of a real bridge. The results are compared with those of two common TF methods, namely, the synchrosqueezed wavelet transform (SWT) and Hilbert-Huang transform (HHT). It is demonstrated that EWT is adaptive and can provide accurate frequency representation of the signal.

In free space optical communications, long-distance transmission leads to the attenuation of beacon light, where we adopt a quadrant detector (QD) to receive the weak signal. However, the background light interferes so strongly that the output signal-to-noise ratio (SNR) of QD is at a low level, which causes a decrease in accuracy of the direct detection method. This requires finding a new light spot detection method, so an improved detection method is proposed. Because the dark current noise and the background light noise are both white noise, we adopt a Kalman filter to estimate the real output of four electric signals of QD. Unfortunately, running these through an amplifier introduces some direct current (DC) offsets into the signals. In order to balance the effect of the DC offsets, we consider using the modulation method, where we employ a sine signal to modulate the intensity of the beacon light at the transmitting end, after which we can give an inverse gain to move the center of signals to near zero to eliminate the DC offsets when we calculate the data. In Kalman filtering, we use the peak values of the signals in every period after the analog to digital converter (ADC) as the elements of the measurement matrix. Experimental results show that even when QD output SNR is about &minus, 10 dB, the detection root-mean-square errors decrease by 51.5% using the improved detection method compared with the direct detection method. Moreover, Kalman filtering does not require a large amount of data, which means it works efficiently, can reduce the cost of hardware resources, and is available for the real-time calculation of spot position.

In this paper, a cascade double-loop control (DLC) combined with modeling compensation methods is proposed to improve the tracking precision of the multiaperture imaging system (MAIS). The application of the flexible thin-wall ring mechanism in the coupling rotating prism (CRP) system causes a series of tracking and pointing challenges. Disturbances such as friction, shaft deformation, and model perturbation significantly deteriorate the tracking and pointing accuracy of the CRP. Two different modeling compensation methods that are interfaced with classical DLC are proposed to guarantee the tracking precision of the MAIS. Moreover, the disturbance observation and compensation performance of two different modeling compensation methods are analyzed and compared. Finally, simulation and experiment results indicate that the proposed control methods, especially model compensation based on speed close-loop control, obtain the best performance for disturbance rejection in the MAIS.

Photoelectric angle encoders, working as position sensors, have a great influence on the accuracy and stability of telescope control systems (TCS). In order to improve the tracking precision of TCS, a method based on subdivision error compensation for photoelectric angle encoders is proposed. First, a mathematical analysis of six types of subdivision errors (DC error, phase error, amplitude error, harmonic error, noise error, and quantization error) is presented, which is different from the previously used analysis based on the Lissajous figure method. In fact, we believe that a mathematical method is more efficient than the figure method for the expression of subdivision errors. Then, the distribution law and period length of each subdivision error are analyzed. Finally, an error compensation algorithm is presented. In a real TCS, the elevation jittering phenomenon occurs, which indicates that compensating for the amplitude error is necessary. A feed-forward loop is then introduced into the TCS, which is position loop- and velocity loop-closed, leading to a decrease of the tracking error by nearly 54.6%, from 2.31&rdquo, to 1.05&rdquo, with a leading speed of 0.25&deg, /s, and by 40.5%, from 3.01&rdquo, to 1.79&rdquo, with a leading speed of 1&deg, /s. This method can realize real-time compensation and improve the ability of TCS without any change of the hardware. In addition, independently of the environment and the kind of control strategy used, this method can also improve the tracking precision presumably because it compensates the measuring error inside the photoelectric angle encoder.

In this paper, a telescope control method to reject ground-based disturb is proposed to enhance the tracking precision of telescope systems. Telescope systems usually suffer some uncertainouter disturbances, some disturbance come from the torque disturb such as friction orwind loads, some of the others may come from the platform. For astronomical telescope, especially relative large volume telescope, disturb from ground istransferred to the telescope via the pier foundation. And the main mount of disturb is the resonance frequency of pier foundation. The frequency is about 10Hz.A complete vibration test was carried out on a quantum satellite-ground communicationground telescope. Some conclusion is achieved. And a control method based on data fusion to rejecting ground-based disturbance is proposed. The test showed that the method could reduce the track error from 1.5 angular second to 0.28 angular second. © 2017 SPIE.

The present report aims to discuss the crystal state variation of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) suffering from thermal cycling process. In this study, in situ X-ray powder diffraction (XRD) was employed to determine thermal expansion and crystal fragmentation, primarily attributed to its crystal state variation. The results showed that the change of crystal volume mainly stemmed from the thermal expansion at the c axis of crystal lattice, and TATB crystal had the same thermal expansion coefficients at a and b axes. It was also demonstrated that crystal fragmentation occurred during this process, and more auto-repair happened in the [002] plane of TATB than other planes. These results will have an implication on the process of TATB-based materials.

Electro-optical stabilization and tracking system is critical and difficult issue in satellite laser communication. Moreover, line-of-sight stabilized system is the kernel of implementing electro-optical stabilization and tracking system, which can be used to isolate the vibration of the moving platform of the satellite and the disturbance of the space environment. In this paper, we propose a new method, which using H∞ mix sensitivity based on generalized internal model controller (GIMC), to design the control system of the electro-optical stabilized platform. It is well known that there is an intrinsic conflict between performance and robustness in the standard feedback framework. Generalized internal model controller is a new architecture which can separate the performance and robustness design in controller design. This architecture has two parts: a high performance controller, say K 0 ,which is designed by PI controller in this paper, and then a robustification controller, say Q, which is designed to improve the ability of the anti disturbance by using H-infinity mix sensitivity controller design method. In this paper, we also present the steps of controller design by using this method to make it easier to use. Based on the proposed method, numerical simulation and experiment are both carried out for a gyro stabilized platform of electro-optical tacking system. Both the numerical simulated and the experimental results show that the electro-optical stabilized platform using the H-infinity mix sensitivity controller design method based on GIMC is accurate and effective. Comparing with the same PI controller in standard feedback framework, the proposed method can guarantee the high tracking performance as same as the PI controller and improve the external disturbance restraining ability a lot. In conclusion, H-infinity mix sensitivity controller design method based on GIMC is a new approach for gyro stabilized platform of electro-optical stabilization and tracking system and might be used easily in practical.

An efficient and low-latency pixel data transmission module for the adaptive optics wavefront processor is presented. A fiber-based custom real-time pixel data transfer protocol is developed, which has the characteristics of long transmission distance, low-latency, and low-protocol overhead. The hardware part of the suite has been verified on different circuit boards with different field-programmable gate arrays. Obtained results demonstrate that the transmission and protocol processing delay are only 413.5 ns, the transmission bandwidth is 3.125 Gbps, and the error rate is less than 10-12. Under the same conditions of 156.25 MHz clock frequencies and length of transmission line, compared with the serial front panel data port protocol adopted by the thirty meter telescope and the european southern observatory, the transmission delay is significantly reduced by 2.82 times and has a remarkably low logic occupancy rate through our solution. Also, the method has been applied in several actual projects. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)