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Constraining the non-Einsteinian polarizations of gravitational waves by pulsar timing array

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Science China(Physics,Mechanics & Astronomy) 2019年第7期62卷 63-75页

作者： rui Niu Wen zhao CAS Key Laboratory for Researches in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China School of Astronomy and Space Science University of Science and Technology of China

Pulsar timing array(PTA) provides an excellent opportunity to detect the gravitational waves(GWs) in nanoHertz frequency *** particular, due to the larger number of "arms" in PTA, it can be used to test gravity by probing the non-Einsteinian polarization modes of GWs, including two spin-1 shear modes labeled by "sn" and "se", the spin-0 transverse mode labeled by "b" and the longitudinal mode labeled by "l". In this paper, we investigate the capabilities of the current and potential future PTAs, which are quantified by the constraints on the amplitudes parameters(c_b, c_(sn), c_(se), c_l), by observing an individual supermassive black hole binary in Virgo cluster. We find that for binary with total mass M_c= 8.77 × 10~8 M_⊙ and GW frequency f = 10^(-9) Hz, the PTA at current level can detect these GW modes if c_b> 0.00106, c_l> 0.00217, c_(se)> 0.00271, c_(sn)> 0.00141, which will be improved by about two orders if considering the potential PTA in SKA era. Interesting enough, due to effects of the geometrical factors, we find that in SKA era, the constraints on the l, sn, se modes of GWs are purely dominated by several pulsars, instead of the full pulsars in PTA.

关键词： gravitational waves pulsar timing array

Catalytic mechanism of manganese ions and visible light on chalcopyrite bioleaching in the presence of Acidithiobacillus ferrooxidans

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Chinese Journal of Chemical Engineering 2022年第1期35卷 457-465页

作者： Chunxiao zhao Baojun Yang rui Liao Maoxin Hong Shichao Yu jun Wang Guanzhou Qiu Key Laboratory of Biohydrometallurgy of Ministry of Education School of Minerals Processing&BioengineeringCentral South UniversityChangsha 410083China

The bioleaching of chalcopyrite is low cost and environmentally friendly,but the leaching rate is *** explore the mechanism of chalcopyrite bioleaching and improve its leaching rate,the effect and mechanism of manganese ions(Mn^(2+))and visible light on chalcopyrite mediated by Acidithiobacillus ferrooxidans(***)were *** experiments showed that when both Mn^(2+)and visible light were present,the copper extraction was 14.38%higher than that of the control system(without Mn^(2+)and visible light).Moreover,visible light and Mn^(2+)promoted the growth of *** electron microscopy(SEM)and energy dispersive spectrometer(EDS)analysis revealed that Mn^(2+)promoted the formation of extracellular polymeric substance(EPS)on the surface of chalcopyrite,changed the morphology of ***,enhanced the adsorption of bacteria on chalcopyrite surface with light illumination,and thus promoted the bioleaching of ***–vis absorbance spectra indicated that Mn^(2+)promoted the response of chalcopyrite to visible light and enhanced the catalytic effect of visible light on chalcopyrite *** on X-ray photoelectron spectroscopy(XPS),the relevant sulfur speciation of chalcopyrite before and after bioleaching were analyzed and the results revealed that visible light and Mn^(2+)promoted chalcopyrite bioleaching by reducing the formation of passivation layer(S_(n)^(2-)/S0).Investigation into electrochemical results further indicated that Mn^(2+)and visible light improved the electrochemical activity of chalcopyrite,thus increasing the bioleaching rate.

关键词： Acidithiobacillus ferrooxidans Mn^(2+) Electrochemistry Catalysis Dissolution

Obstacle avoidance for multi-missile network via distributed coordination algorithm

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Chinese Journal of Aeronautics 2016年第2期29卷 441-447页

作者： zhao Jiang Zhou rui School of Automation Science and Electrical Engineering Beihang University

A distributed coordination algorithm is proposed to enhance the engagement of the multi-missile network in consideration of obstacle avoidance. To achieve a cooperative interception, the guidance law is developed in a simple form that consists of three individual components for tar- get capture, time coordination and obstacle avoidance. The distributed coordination algorithm enables a group of interceptor missiles to reach the target simultaneously, even if some member in the multi-missile network can only collect the information from nearest neighbors. The simula- tion results show that the guidance strategy provides a feasible tool to implement obstacle avoid- ance for the multi-missile network with satisfactory accuracy of target capture. The effects of the gain parameters are also discussed to evaluate the proposed approach.

关键词： Cooperative guidance Distributed algorithms Impact time Missile guidance Multiple missiles Obstacle avoidance Proportional navigation

Multi‑level autonomous integrity monitoring method for multi‑source PNT resilient fusion navigation

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Satellite Navigation 2023年第3期4卷 210-226页

作者： rui Chen Long zhao School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

For the integrity monitoring of a multi-source PNT(Positioning,Navigation,and Timing)resilient fusion navigation system,a theoretical framework of multi-level autonomous integrity monitoring is *** to the mode of multi-source fusion navigation,the framework adopts the top-down logic structure and establishes the navigation source fault detection model based on the multi-combination separation residual method to detect and isolate the fault source at the system level and subsystem *** isolated non-redundant navigation sources,the system level recovery verification model is *** the isolated multi-redundant navigation sources,the sensor fault detection model optimized with the dimension-expanding matrix is used to detect and isolate the fault sensors,and the isolated fault sensors are verified in ***,according to the fault detection and verification results at each level,the observed information in the fusion navigation solution is dynamically *** this basis,the integrity risk dynamic monitoring tree is established to calculate the Protection Level(PL)and evaluate the integrity of the multi-source integrated navigation *** autonomous integrity monitoring method proposed in this paper is tested using a multi-source navigation system integrated with Inertial Navigation System(INS),Global Navigation Satellite System(GNSS),Long Baseline Location(LBL),and Ultra Short Baseline Location(USBL).The test results show that the proposed method can effectively isolate the fault source within 5 s,and can quickly detect multiple faulty sensors,ensuring that the positioning accuracy of the fusion navigation system is within 5 m,effectively improving the resilience and reliability of the multi-source fusion navigation system.

关键词： Autonomous integrity monitoring Fault detection and isolation Multi-source PNT resilient fusion navigation Protection level

Distributed three-dimensional cooperative guidance via receding horizon control

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Chinese Journal of Aeronautics 2016年第4期29卷 972-983页

作者： zhao Jiang Zhou rui School of Automation Science and Electrical Engineering Beihang University

The paper presents a new three-dimensional (3D) cooperative guidance approach by the receding horizon control (RHC) technique. The objective is to coordinate the impact time of a group of interceptor missiles against the stationary target. The framework of a distributed RHC scheme is developed, in which each interceptor missile is assigned its own finite-horizon optimal control problem (FHOCP) and only shares the information with its neighbors. The solution of the local FHOCP is obtained by the constrained particle swarm optimization (PSO) method that is integrated into the distributed RHC framework with enhanced equality and inequality constraints. The numerical simulations show that the proposed guidance approach is feasible to implement the cooperative engagement with satisfied accuracy of target capture. Finally, the computation efficiency of the distributed RHC scheme is discussed in consideration of the PSO parameters, control update period and prediction horizon. (C) 2016 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.

关键词： Distributed algorithms Impact time Missile guidance Multiple missiles Particle swarm optimization (PSO) Receding horizon control (RHC) Three-dimensional (3D)

Particle swarm optimization applied to hypersonic reentry trajectories

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Chinese Journal of Aeronautics 2015年第3期28卷 822-831页

作者： zhao Jiang Zhou rui School of Automation Science and Electrical Engineering Beihang University

Abstract This paper presents the novel use of the particle swarm optimization （PSO） to generate the end-to-end trajectory for hypersonic reentry vehicles in a quite simple formulation. The velocity- dependent bank angle profile is developed to reduce the search space of unknown parameters based on the constrained PSO algorithm. The path constraints are enforced by setting the fitness function to be infinite on condition that the particles violate the maximum allowable values. The PSO algo- rithm also provides a much easier means to satisfy the terminal conditions by adding penalty terms to the fitness function. Furthermore, the approximate reentry landing footprint is fast constructed by incorporating an interpolation model into the standardized bank angle profiles. Numerical sim ulations demonstrate that the PSO method is a feasible and flexible tool to generate the end-to-end trajectory and landing footprint for hypersonic reentry vehicles.

关键词： Footprint Hypersonic vehicles Particle swarm optimization(PSO) Reentry Trajectories

Effect of nano TiO_(2) and SiO_(2) on gelation performance of HPAM/PEI gels for high-temperature reservoir conformance improvement

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Petroleum Science 2023年第6期20卷 3819-3829页

作者： Yang Liu Hong-jun Zhang Dao-Yi Zhu Zi-Yuan Wang jun-Hui Qin Qi zhao Yu-Heng zhao Ji-rui Hou China University of Petroleum Beijing102249China

Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects on their gelation performance, which has been little researched. In this study, the high-temperature gelation performance, chemical structure, and microstructure of polymer gels prepared from two nanomaterials (i.e., nano-SiO_(2) and nano-TiO_(2)) were measured. The conventional HPAM/PEI polymer gel system was employed as the control sample. Results showed that the addition of nano-TiO_(2) could significantly enhance the gel strength of HPAM/PEI gel at 80 ℃. The gel strength of the enhanced HPAM/PEI gel with 0.1 wt% nano-TiO_(2) could reach grade I. The system also had excellent high-temperature stability at 150 ℃. The enhanced HPAM/PEI gel with 0.02 wt% nano-TiO_(2) reached the maximum gel strength at 150 ℃ with a storage modulus (G′) of 15 Pa, which can meet the need for efficient plugging. However, the nano-SiO_(2) enhanced HPAM/PEI polymer gel system showed weaker gel strength than that with nano-TiO_(2) at both 80 and 150 ℃ with G′ lower than 5 Pa. Microstructures showed that the nano-TiO_(2) enhanced HPAM/PEI gel had denser three-dimensional (3D) mesh structures, which makes the nano-TiO_(2) enhanced HPAM/PEI gel more firmly bound to water. The FT-IR results also confirmed that the chemical structure of the nano-TiO_(2) enhanced HPAM/PEI gel was more thermally stable than nano-SiO_(2) since there was a large amount of –OH groups on the structure surface. Therefore, nano-TiO_(2) was more suitable as the reinforcing material for HPAM/PEI gels for high-temperature petroleum reservoir conformance improvement.

关键词： Nano-TiO_(2) Nano-SiO_(2) Gel strength Polymer gel High-temperature reservoirs.

Enhanced autophagic clearance of amyloid-βvia histone deacetylase 6-mediated V-ATPase assembly and lysosomal acidification protects against Alzheimer's disease in vitro and in vivo

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Neural Regeneration Research 2025年第9期20卷 2633-2644页

作者： Zhimin Long Chuanhua Ge Yueyang zhao Yuanjie Liu Qinghua Zeng Qing Tang Zhifang Dong Guiqiong He Institute of Neuroscience School of Basic Medical SciencesChongqing Medical UniversityChongqingChina Department of Anatomy Chongqing Medical UniversityChongqingChina Department of Physiology Chongqing Medical UniversityChongqingChina Pediatric Research Institute Children’s Hospital of Chongqing Medical UniversityChongqingChina Ministry of Education Key Laboratory of Child Development and Disorders Children’s Hospital of Chongqing Medical UniversityChongqingChina National Clinical Research Center for Child Health and Disorders Children’s Hospital of Chongqing Medical UniversityChongqingChina Chongqing Key Laboratory of Child Neurodevelopment and Cognitive Disorders Children’s Hospital of Chongqing Medical UniversityChongqingChina

Recent studies have suggested that abnormal acidification of lysosomes induces autophagic accumulation of amyloid-βin neurons,which is a key step in senile plaque ***,resto ring normal lysosomal function and rebalancing lysosomal acidification in neurons in the brain may be a new treatment strategy for Alzheimer's *** acetylation/deacetylation plays a central role in lysosomal ***,we show that inhibiting the classic microtubule deacetylase histone deacetylase 6 with an histone deacetylase 6 shRNA or thehistone deacetylase 6 inhibitor valproic acid promoted lysosomal reacidification by modulating V-ATPase assembly in Alzheimer's *** rthermore,we found that treatment with valproic acid markedly enhanced *** clearance of amyloid-βaggregates,and ameliorated cognitive deficits in a mouse model of Alzheimer's *** findings demonstrate a previously unknown neuroprotective mechanism in Alzheimer's disease,in which histone deacetylase 6 inhibition by valproic acid increases V-ATPase assembly and lysosomal acidification.

关键词： Alzheimer's disease amyloid-β APP/PS1 mice autophagy cognitive impairment histone deacetylase 6 lysosomal acidification microtubule acetylation valproic acid V-ATPase

Salsolinol as an RNA m~6A methylation inducer mediates dopaminergic neuronal death by regulating YAP1 and autophagy

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Neural Regeneration Research 2025年第3期20卷 887-899页

作者： Jianan Wang Yuanyuan Ran Zihan Li Tianyuan zhao Fangfang Zhang Juan Wang Zongjian Liu Xuechai Chen Beijing International Science and Technology Cooperation Base for Antiviral Drugs College of Chemistry and LifeBeijing University of TechnologyBeijingChina Department of Rehabilitation Beijing Rehabilitation HospitalCapital Medical UniversityBeijingChina

Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environmental toxin that causes Parkinson's ***,the mechanism by which Sal mediates dopaminergic neuronal death remains *** this study,we found that Sal significantly enhanced the global level of N~6-methyladenosine(m~6A)RNA methylation in PC12 cells,mainly by inducing the downregulation of the expression of m~6A demethylases fat mass and obesity-associated protein(FTO)and alk B homolog 5(ALKBH5).RNA sequencing analysis showed that Sal downregulated the Hippo signaling *** m~6A reader YTH domain-containing family protein 2(YTHDF2)promoted the degradation of m~6A-containing Yes-associated protein 1(YAP1)mRNA,which is a downstream key effector in the Hippo signaling ***,downregulation of YAP1 promoted autophagy,indicating that the mutual regulation between YAP1 and autophagy can lead to *** findings reveal the role of Sal on m~6A RNA methylation and suggest that Sal may act as an RNA methylation inducer mediating dopaminergic neuronal death through YAP1 and *** results provide greater insights into the neurotoxic effects of catechol isoquinolines compared with other studies and may be a reference for assessing the involvement of RNA methylation in the pathogenesis of Parkinson's disease.

关键词： ALKBH5 autophagy FTO Hippo pathway m~6A Parkinson's disease RNA methylation salsolinol YAP1 YTHDF2