Redundancy elimination techniques are extensively investigated to reduce storage overheads for cloud-assisted health systems.Deduplication eliminates the redundancy of duplicate blocks by storing one physical instance...Redundancy elimination techniques are extensively investigated to reduce storage overheads for cloud-assisted health systems.Deduplication eliminates the redundancy of duplicate blocks by storing one physical instance referenced by multiple duplicates.Delta compression is usually regarded as a complementary technique to deduplication to further remove the redundancy of similar blocks,but our observations indicate that this is disobedient when data have sparse duplicate blocks.In addition,there are many overlapped deltas in the resemblance detection process of post-deduplication delta compression,which hinders the efficiency of delta compression and the index phase of resemblance detection inquires abundant non-similar blocks,resulting in inefficient system throughput.Therefore,a multi-feature-based redundancy elimination scheme,called MFRE,is proposed to solve these problems.The similarity feature and temporal locality feature are excavated to assist redundancy elimination where the similarity feature well expresses the duplicate attribute.Then,similarity-based dynamic post-deduplication delta compression and temporal locality-based dynamic delta compression discover more similar base blocks to minimise overlapped deltas and improve compression ratios.Moreover,the clustering method based on block-relationship and the feature index strategy based on bloom filters reduce IO overheads and improve system throughput.Experiments demonstrate that the proposed method,compared to the state-of-the-art method,improves the compression ratio and system throughput by 9.68%and 50%,respectively.展开更多
The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the mult...The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the multi hypothesis prediction stage is a challenging task.To resolve this problem,this paper constructs a novel compressed sensing-based high-quality adaptive video reconstruction optimizationmethod.Itmainly includes the optimization of prediction blocks(OPBS),the selection of searchwindows and the use of neighborhood information.Specifically,the OPBS consists of two parts:the selection of blocks and the optimization of prediction blocks.We combine the high-quality optimization reconstruction of foreground block with the residual reconstruction of the background block to improve the overall reconstruction effect of the video sequence.In addition,most of the existing methods based on predictive residual reconstruction ignore the impact of search windows and reference frames on performance.Therefore,Block-level search window(BSW)is constructed to cover the position of the optimal hypothesis block as much as possible.To maximize the availability of reference frames,Nearby reference frame information(NRFI)is designed to reconstruct the current block.The proposed method effectively suppresses the influence of the fluctuation of the prediction block on reconstruction and improves the reconstruction performance.Experimental results showthat the proposed compressed sensing-based high-quality adaptive video reconstruction optimization method significantly improves the reconstruction performance in both objective and supervisor quality.展开更多
In this paper, we investigate the elastic wave full-waveform inversion (FWI) based on the trust region method. The FWI is an optimization problem of minimizing the misfit between the observed data and simulated data. ...In this paper, we investigate the elastic wave full-waveform inversion (FWI) based on the trust region method. The FWI is an optimization problem of minimizing the misfit between the observed data and simulated data. Usually</span><span style="font-family:"">,</span><span style="font-family:""> the line search method is used to update the model parameters iteratively. The line search method generates a search direction first and then finds a suitable step length along the direction. In the trust region method, it defines a trial step length within a certain neighborhood of the current iterate point and then solves a trust region subproblem. The theoretical methods for the trust region FWI with the Newton type method are described. The algorithms for the truncated Newton method with the line search strategy and for the Gauss-Newton method with the trust region strategy are presented. Numerical computations of FWI for the Marmousi model by the L-BFGS method, the Gauss-Newton method and the truncated Newton method are completed. The comparisons between the line search strategy and the trust region strategy are given and show that the trust region method is more efficient than the line search method and both the Gauss-Newton and truncated Newton methods are more accurate than the L-BFGS method.展开更多
A number of synergistic solvent extraction (SSX) systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia....A number of synergistic solvent extraction (SSX) systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in- clude (1) Versatic 10/CLXS0 system for the separation of Ni from Ca in sulphate solutions, (2) Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (3) Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, (4) Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, (5) Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (6) Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, (7) Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, (8) Versatic 10/LIX63fFBP system to recover Cu/Ni from strong chloride solutions, and [9) Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported.展开更多
In underground mines, visible light communication(VLC) system is a promising method to realize effective communication,which supports communication and illumination at the same time. Therefore, adequate research of un...In underground mines, visible light communication(VLC) system is a promising method to realize effective communication,which supports communication and illumination at the same time. Therefore, adequate research of underlying physical propagation phenomenon should be carried out to realize VLC system in underground mines. To design VLC system and evaluate its performance, accurate and efficient channel models, including large-scale fading and scattering characteristics, are needed to be established. However,the characteristics of the underlying VLC channels about fading and scattering have not been sufficiently investigated yet. In this paper, a path loss channel model, based on the recursive model, is proposed precisely. Its path loss exponent is determined by three different trajectories, which is studied in the mining roadway and working face environment. Besides, the shadowing effect for VLC has been modelled by a Bimodal Gaussian distribution in underground mines. Considering the number of transmitters in line-of-sight(Lo S) as well as non-line-of-sight(NLo S) scenarios,our simulation illustrates the fact that, as the curve fitting technique is employed, the path loss displays a linear behavior in log-domain.The path loss expression is derived, it is related to the distance. Finally, root mean square(RMS) delay spread and Mie scattering in underground mines are analyzed.展开更多
This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 b...This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 batches of market samples in China.The samples were extracted with acetonitrile,cleaned up with primary secondary amine(PSA)and octadecylsilane(C18)and determined by GC-MS/MS in multiple reaction monitoring(MRM)mode.Matrix-matched calibration was recommended to combat the matrix effect.A good linearity was observed in the range of 10−500 ng/mL with correlation coefficients≥0.9950.The mean recoveries for most of the pesticides were in the range of 70%−120%with RSD<20%.The limits of detection ranged 0.28–2.00μg/kg,while the limits of quantification were 0.94–6.65μg/kg.Following the application of“top-down”approach,the expanded measurement uncertainty for all the analytes was<30%.The proposed method was successfully applied to determine pesticide residues in 20 market samples in China,where 9 pesticides were detected and quintozene exceeded the criteria domestically and abroad.展开更多
In this paper, a novel fuzzy sliding mode control(FSMC) guidance law with terminal constraints of miss distance, impact angle and acceleration is presented for a constant speed missile against the stationary or slow...In this paper, a novel fuzzy sliding mode control(FSMC) guidance law with terminal constraints of miss distance, impact angle and acceleration is presented for a constant speed missile against the stationary or slowly moving target. The proposed guidance law combines the sliding mode control algorithm with a fuzzy logic control scheme for the lag-free system and the first-order lag system. Through using Lyapunov stability theory, we prove the sliding surface converges to zero in finite time. Furthermore, considering the uncertain information and system disturbances, the guidance gains are on-line optimized by fuzzy logic technique. Numerical simulations are performed to demonstrate the performance of the FSMC guidance law and the results illustrate the validity and effectiveness of the proposed guidance law.展开更多
Full-waveform velocity inversion based on the acoustic wave equation in the time domain is investigated in this paper. The inversion is the iterative minimization of the misfit between observed data and synthetic data...Full-waveform velocity inversion based on the acoustic wave equation in the time domain is investigated in this paper. The inversion is the iterative minimization of the misfit between observed data and synthetic data obtained by a numerical solution of the wave equation. Two inversion algorithms in combination with the CG method and the BFGS method are described respectively. Numerical computations for two models including the benchmark Marmousi model with complex structure are implemented. The inversion results show that the BFGS-based algorithm behaves better in inversion than the CG-based algorithm does. Moreover, the good inversion result for Marmousi model with the BFGS-based algorithm suggests the quasi-Newton methods can provide an important tool for large-scale velocity inversion. More computations demonstrate the correctness and effectives of our inversion algorithms and code.展开更多
We develop a new full waveform inversion (FWI) method for slowness with the crosshole data based on the acoustic wave equation in the time domain. The method combines the total variation (TV) regularization with the c...We develop a new full waveform inversion (FWI) method for slowness with the crosshole data based on the acoustic wave equation in the time domain. The method combines the total variation (TV) regularization with the constrained optimization together which can inverse the slowness effectively. One advantage of slowness inversion is that there is no further approximation in the gradient derivation. Moreover, a new algorithm named the skip method for solving the constrained optimization problem is proposed. The TV regularization has good ability to inverse slowness at its discontinuities while the constrained optimization can keep the inversion converging in the right direction. Numerical computations both for noise free data and noisy data show the robustness and effectiveness of our method and good inversion results are yielded.展开更多
In this paper, wave simulation with the finite difference method for the Helmholtz equation based on the domain decomposition method is investigated. The method solves the problem by iteratively solving subproblems de...In this paper, wave simulation with the finite difference method for the Helmholtz equation based on the domain decomposition method is investigated. The method solves the problem by iteratively solving subproblems defined on smaller subdomains. Two domain decomposition algorithms both for nonoverlapping and overlapping methods are described. More numerical computations including the benchmark Marmousi model show the effectiveness of the proposed algorithms. This method can be expected to be used in the full-waveform inversion in the future.展开更多
Battery grade γ-MnO2 powder was investigated as an oxidant and an adsorbent in combination with Fe/Al coagulants for removal of arsenic from contaminated water. Simultaneous oxidation of As(III) and removal by coprec...Battery grade γ-MnO2 powder was investigated as an oxidant and an adsorbent in combination with Fe/Al coagulants for removal of arsenic from contaminated water. Simultaneous oxidation of As(III) and removal by coprecipitation/adsorption (one step process) was compared with pre-oxidation and subsequent removal by coprecipitation/adsorption (two step process). The rate of As(III) oxidation with MnO2 is completed in two stages: rapid initially followed by a first order reaction. As(III) is oxidised to As(V) by the MnO2 with a release of approximately 1:1 molar Mn(II) into the solution. No significant pH effect on oxidation of As(III) was observed in the pH range 4 - 6. The rate showed a decreasing trend above pH 6. The removal of As(V) by adsorption on the MnO2 decreased significantly with increasing pH from 4 to 8. The adsorption capacity of the γ-MnO2 with particle size 90% passing 10 μm was determined to be 1.5 mg/g at pH 7. MnO2 was found to be more effective as an oxidant for As(III) in the two step process than in the one step process.展开更多
BACKGROUND: Propofol has been shown to attenuate neuronal injury in a number of experimental conditions. However, its effect in models of cerebral ischemia after subarachnoid hemorrhage (SAH) remains controversial....BACKGROUND: Propofol has been shown to attenuate neuronal injury in a number of experimental conditions. However, its effect in models of cerebral ischemia after subarachnoid hemorrhage (SAH) remains controversial. OBJECTIVE: To explore the effects of intracisternal injection of HX0507, a water-soluble propofol prodrug, on basilar artery vasospasm and brain tissue injury in a rabbit model of SAH. DESIGN, TIME AND SETTING: A randomized, controlled, in vivo animal experiment based on behavior and morphology. The study was performed at the Laboratory of Anesthesiology and Critical Care Medicine, West China Hospital, Sichuan University from April to December 2007. MATERIALS: HX0507 was provided by the Laboratory of Anesthesiology and Critical Care Medicine, West China Hospital of Sichuan University. METHODS: A total of 30 healthy, male, New Zealand rabbits were randomly assigned to sham-operation, SAH-control, and SAH-HX0507 groups, with 10 animals in each group. The single-hemorrhage SAH model was established by injecting autologous arterial blood (1.0 mL/kg) into the cisterna magna in the SAH-control and SAH-HX0507 groups, while the sham-operation group was injected with normal saline (1.0 mL/kg). Thirty minutes after injection, the sham-operation and SAH-control groups were injected with normal saline (0.1 mL/kg) into the cisterna magna, while the SAH-HX0507 group received an injection of HX0507 (4.8 mg/kg). MAIN OUTCOME MEASURES: The cross-sectional area and corrugation coefficients of basilar arteries and hippocampal CA1 neuronal densities were measured 48 hours after SAH (peak stage of vasospasm) using the Computer-Assisted Stereological Toolbox system. The ultrastructural structure of the basilar artery wall was examined by transmission electron microscopy. In addition, neurological behavioral impairment was evaluated by appetite score at pre-SAH, and 1 and 2 days after SAH. RESULTS: The cross-sectional area of basilar arteries and hippocampal CA1 neuronal densities, as well as ultrastructural structure scores of the SAH-control group were significantly less than the other groups (P 〈 0.01 or P 〈 0.05), while the corrugation coefficients of basilar arteries and appetite score 2 days after SAH were significantly greater than the other groups (P 〈 0.01 or P 〈 0.05). The appetite score 1 day after modeling was remarkably greater than the SAH-control group (P 〈 0.05). However, no significant difference was determined between the sham-operation and SAH-HX0507 groups (P 〉 0.05). CONCLUSION: Intracisternal administration of HX0507 attenuated basilar artery vasospasm and hippocampal ischemic injury in a rabbit model of SAH.展开更多
(+)-Catechin(CE)is mainly found in green and black tea and has many biological effects,such as antiinflammatory,anti-cancer,anti-viral effects,protecting human organs,especially the kidney.This study aims to identify ...(+)-Catechin(CE)is mainly found in green and black tea and has many biological effects,such as antiinflammatory,anti-cancer,anti-viral effects,protecting human organs,especially the kidney.This study aims to identify the circRNAs induced by CE in db/db mice and their roles in diabetic nephropathy progression.After the db/db mice were treated with CE,RNA-seq was performed to identify the differentially expressed circRNA and mRNAs.The ceRNA regulatory network was constructed and analyzed using bioinformatics software and public databases(Cytoscape,Clue GO,Mi RWalk,STRING,et al.).Our results revealed that 6 differentially expressed circRNAs are most associated with the cholinergic synapse,neurotrophin signaling pathway,and insulin signaling pathway.Among these,circRNA.5549 and circRNA.4712 might regulate Cd36,Cyp26 b1,C8 a,Cyp2 j13,Grem2 genes through ceRNA regulatory mechanism in the presence of CE treatment.The expanded network of proteins interacting with these 5 genes shows that the TGF-βsignaling pathway,signaling pathways regulating pluripotency of stem cell,fat digestion and absorption,and PPAR signaling pathway was highly enriched.Overall,circRNA.5549 and circRNA.4712 exhibit a promotive function in CE-treated db/db mice,especially in circRNA.5549/miR-29a-5P/Cd36 regulatory network,and this evidence suggest that their ceRNA regulatory network might be a therapeutic target for DN in humans.展开更多
This paper develops a dual-indicator discrete method(DDM)for evaluating the system reliability performance of long soil subgrade slopes.First,they are segmented into many slope sections using the random finite element...This paper develops a dual-indicator discrete method(DDM)for evaluating the system reliability performance of long soil subgrade slopes.First,they are segmented into many slope sections using the random finite element method,to ensure each section statistically contains one potential local instability.Then,the k-out-of-n system model is used to describe the relationship between the total number of sections n,the acceptable number of failure sections m,the reliability of sections R_(sec),and the system reliability R_(sys).Finally,m and R_(sys)are jointly used to assess the system reliability performance.For cases lacking spatial data of soil properties,a simplified DDM is provided in which long subgrade slopes are segmented by the empirical value of section length and R_(sec)is substituted by that of crosssections taken from them.The results show that(1)DDM can provide the probability that the actual number of local instabilities does not exceed a desired threshold.(2)R_(sys)decreases with increasing n or decreasing R_(sec);that is,it is likely to encounter more local instabilities for longer or weaker subgrade slopes.n is negatively related to the horizontal scale of fluctuation of soil properties and positively related to the total length of subgrade slopes L.(3)When L is sufficiently large,there is a considerable opportunity to meet local instabilities even if R_(sec)is large enough.展开更多
In this paper, we firstly derive the stability conditions of high-order staggered-grid schemes for the three-dimensional (3D) elastic wave equation in heterogeneous media based on the energy method. Moreover, the plan...In this paper, we firstly derive the stability conditions of high-order staggered-grid schemes for the three-dimensional (3D) elastic wave equation in heterogeneous media based on the energy method. Moreover, the plane wave analysis yields a sufficient and necessary stability condition by the von Neumann criterion in homogeneous case. Numerical computations for 3D wave simulation with point source excitation are given.展开更多
A new wave simulation technique for the elastic wave equation in the frequency domain based on a no overlapping domain decomposition algorithm is investigated. The boundary conditions and the finite difference discrim...A new wave simulation technique for the elastic wave equation in the frequency domain based on a no overlapping domain decomposition algorithm is investigated. The boundary conditions and the finite difference discrimination of the elastic wave equation are derived. The algorithm of no overlapping domain decomposition method is given. The method solves the elastic wave equation by iteratively solving sub problems defined on smaller sub domains. Numerical computations both for homogeneous and inhomogeneous media show the effectiveness of the proposed method. This method can be used in the full-waveform inversion.展开更多
Background:Postoperative pulmonary complications often lead to increased mortality and financial burden.Residual paralysis plays a critical role in postoperative pulmonary complications.This meta-analysis was performe...Background:Postoperative pulmonary complications often lead to increased mortality and financial burden.Residual paralysis plays a critical role in postoperative pulmonary complications.This meta-analysis was performed to determine whether sugammadex overmatches neostigmine in reducing postoperative pulmonary complications.Methods:PubMed,Embase,Web of Science,Medline through Ovid,Cochrane Library,Wanfang,China National Knowledge Infrastructure,and Chinese BioMedical Literature Databases were searched from their inception to 24 June,2021.Random effects models were used for all analyses.Cochrane risk of bias tool was used to assess the quality of RCTs,while Newcastle Ottawa Quality Assessment Scale was used to assess for the quality of cohort studies.Results:Seventeen studies were included in the meta-analysis.Pooled data from cohort studies showed reversing neuromuscular blocking with sugammadex had less risk of compound postoperative pulmonary complications(relative risk[RR]:0.73;95%confidence interval[CI]:0.60-0.89;P=0.002;I^(2)=81%),pneumonia(RR:0.64;95%CI:0.48-0.86;I^(2)=42%)and respiratory failure(RR:0.48;95%CI:0.41-0.56;I^(2)=0%).However,pooled data from RCTs did not show any difference between the two groups in pneumonia(RR:0.58;95%CI:0.24-1.40;I^(2)=0%)and no respiratory failure was reported in the included RCTs.The difference was not found between sugammadex and neostigmine about atelectasis in pooled data from either RCTs(RR:0.85;95%CI:0.69-1.05;I^(2)=0%)or cohort studies(RR:1.01;95%CI:0.87-1.18;I^(2)=0%).Conclusion:The evidence of superiority of sugammadex was limited by the confounding factors in cohort studies and small scale of RCTs.Whether sugammadex precedes neostigmine in preventing pulmonary complications after surgery is still unknown.Well-designed RCTs with large scale are needed.Registration:PROSPERO(https://www.crd.york.ac.uk/PROSPERO/);CRD 42020191575.展开更多
A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement dista...A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement distance, the accuracy, the space resolution, the ability of multi-parameter measurements, and the intelligence of full distributed fiber sensor systems, a new generation fiber sensor technology based on the optical fiber nonlinear scattering fusion principle is proposed. A series of new generation full distributed fiber sensors are investigated and designed, which consist of new generation ultra-long distance full distributed fiber Raman and Rayleigh scattering photon sensors integrated with a fiber Raman amplifier, auto-correction full distributed fiber Raman photon temperature sensors based on Raman correlation dual sources, full distributed fiber Raman photon temperature sensors based on a pulse coding source, full distributed fiber Raman photon temperature sensors using a fiber Raman wavelength shifter, a new type of Brillouin optical time domain analyzers (BOTDAs) integrated with a fiber Raman amplifier for replacing a fiber Brillouin amplifier, full distributed fiber Raman and Brillouin photon sensors integrated with a fiber Raman amplifier, and full distributed fiber Brillouin photon sensors integrated with a fiber Brillouin frequency shifter. The Internet of things is believed as one of candidates of the next technological revolution, which has driven hundreds of millions of class markets. Sensor networks are important components of the Internet of things. The full distributed optical fiber sensor network (Rayleigh, Raman, and Brillouin scattering) is a 3S (smart materials, smart structure, and smart skill) system, which is easy to construct smart fiber sensor networks. The distributed optical fiber sensor can be embedded in the power grids, railways, bridges, tunnels, roads, constructions, water supply systems, dams, oil and gas pipelines and other facilities, and can be integrated with wireless networks.展开更多
基金National Key R&D Program of China,Grant/Award Number:2018AAA0102100National Natural Science Foundation of China,Grant/Award Numbers:62177047,U22A2034+6 种基金International Science and Technology Innovation Joint Base of Machine Vision and Medical Image Processing in Hunan Province,Grant/Award Number:2021CB1013Key Research and Development Program of Hunan Province,Grant/Award Number:2022SK2054111 Project,Grant/Award Number:B18059Natural Science Foundation of Hunan Province,Grant/Award Number:2022JJ30762Fundamental Research Funds for the Central Universities of Central South University,Grant/Award Number:2020zzts143Scientific and Technological Innovation Leading Plan of High‐tech Industry of Hunan Province,Grant/Award Number:2020GK2021Central South University Research Program of Advanced Interdisciplinary Studies,Grant/Award Number:2023QYJC020。
文摘Redundancy elimination techniques are extensively investigated to reduce storage overheads for cloud-assisted health systems.Deduplication eliminates the redundancy of duplicate blocks by storing one physical instance referenced by multiple duplicates.Delta compression is usually regarded as a complementary technique to deduplication to further remove the redundancy of similar blocks,but our observations indicate that this is disobedient when data have sparse duplicate blocks.In addition,there are many overlapped deltas in the resemblance detection process of post-deduplication delta compression,which hinders the efficiency of delta compression and the index phase of resemblance detection inquires abundant non-similar blocks,resulting in inefficient system throughput.Therefore,a multi-feature-based redundancy elimination scheme,called MFRE,is proposed to solve these problems.The similarity feature and temporal locality feature are excavated to assist redundancy elimination where the similarity feature well expresses the duplicate attribute.Then,similarity-based dynamic post-deduplication delta compression and temporal locality-based dynamic delta compression discover more similar base blocks to minimise overlapped deltas and improve compression ratios.Moreover,the clustering method based on block-relationship and the feature index strategy based on bloom filters reduce IO overheads and improve system throughput.Experiments demonstrate that the proposed method,compared to the state-of-the-art method,improves the compression ratio and system throughput by 9.68%and 50%,respectively.
基金supported by the National Natural Science Foundation of China under Grant No.61806138KeyR&DProgram of Shanxi Province(International Cooperation)under Grant No.201903D421048+1 种基金National Key Research and Development Program of China under Grant No.2018YFC1604000School Level Postgraduate Education Innovation Projects under Grant No.XCX212082.
文摘The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the multi hypothesis prediction stage is a challenging task.To resolve this problem,this paper constructs a novel compressed sensing-based high-quality adaptive video reconstruction optimizationmethod.Itmainly includes the optimization of prediction blocks(OPBS),the selection of searchwindows and the use of neighborhood information.Specifically,the OPBS consists of two parts:the selection of blocks and the optimization of prediction blocks.We combine the high-quality optimization reconstruction of foreground block with the residual reconstruction of the background block to improve the overall reconstruction effect of the video sequence.In addition,most of the existing methods based on predictive residual reconstruction ignore the impact of search windows and reference frames on performance.Therefore,Block-level search window(BSW)is constructed to cover the position of the optimal hypothesis block as much as possible.To maximize the availability of reference frames,Nearby reference frame information(NRFI)is designed to reconstruct the current block.The proposed method effectively suppresses the influence of the fluctuation of the prediction block on reconstruction and improves the reconstruction performance.Experimental results showthat the proposed compressed sensing-based high-quality adaptive video reconstruction optimization method significantly improves the reconstruction performance in both objective and supervisor quality.
文摘In this paper, we investigate the elastic wave full-waveform inversion (FWI) based on the trust region method. The FWI is an optimization problem of minimizing the misfit between the observed data and simulated data. Usually</span><span style="font-family:"">,</span><span style="font-family:""> the line search method is used to update the model parameters iteratively. The line search method generates a search direction first and then finds a suitable step length along the direction. In the trust region method, it defines a trial step length within a certain neighborhood of the current iterate point and then solves a trust region subproblem. The theoretical methods for the trust region FWI with the Newton type method are described. The algorithms for the truncated Newton method with the line search strategy and for the Gauss-Newton method with the trust region strategy are presented. Numerical computations of FWI for the Marmousi model by the L-BFGS method, the Gauss-Newton method and the truncated Newton method are completed. The comparisons between the line search strategy and the trust region strategy are given and show that the trust region method is more efficient than the line search method and both the Gauss-Newton and truncated Newton methods are more accurate than the L-BFGS method.
文摘A number of synergistic solvent extraction (SSX) systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in- clude (1) Versatic 10/CLXS0 system for the separation of Ni from Ca in sulphate solutions, (2) Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (3) Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, (4) Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, (5) Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (6) Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, (7) Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, (8) Versatic 10/LIX63fFBP system to recover Cu/Ni from strong chloride solutions, and [9) Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported.
基金support from the National Natural Science Foundation of China (Grant No. 61371110)Key R&D Program of Shandong Province (Grant No. 2016GGX101014)+1 种基金EU H2020 RISE TESTBED project (Grant No. 734325)the Fundamental Research Funds of Shandong University (No. 2017JC029)
文摘In underground mines, visible light communication(VLC) system is a promising method to realize effective communication,which supports communication and illumination at the same time. Therefore, adequate research of underlying physical propagation phenomenon should be carried out to realize VLC system in underground mines. To design VLC system and evaluate its performance, accurate and efficient channel models, including large-scale fading and scattering characteristics, are needed to be established. However,the characteristics of the underlying VLC channels about fading and scattering have not been sufficiently investigated yet. In this paper, a path loss channel model, based on the recursive model, is proposed precisely. Its path loss exponent is determined by three different trajectories, which is studied in the mining roadway and working face environment. Besides, the shadowing effect for VLC has been modelled by a Bimodal Gaussian distribution in underground mines. Considering the number of transmitters in line-of-sight(Lo S) as well as non-line-of-sight(NLo S) scenarios,our simulation illustrates the fact that, as the curve fitting technique is employed, the path loss displays a linear behavior in log-domain.The path loss expression is derived, it is related to the distance. Finally, root mean square(RMS) delay spread and Mie scattering in underground mines are analyzed.
基金the National Key Research and Development Plan of China(2017YFC1702500).
文摘This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 batches of market samples in China.The samples were extracted with acetonitrile,cleaned up with primary secondary amine(PSA)and octadecylsilane(C18)and determined by GC-MS/MS in multiple reaction monitoring(MRM)mode.Matrix-matched calibration was recommended to combat the matrix effect.A good linearity was observed in the range of 10−500 ng/mL with correlation coefficients≥0.9950.The mean recoveries for most of the pesticides were in the range of 70%−120%with RSD<20%.The limits of detection ranged 0.28–2.00μg/kg,while the limits of quantification were 0.94–6.65μg/kg.Following the application of“top-down”approach,the expanded measurement uncertainty for all the analytes was<30%.The proposed method was successfully applied to determine pesticide residues in 20 market samples in China,where 9 pesticides were detected and quintozene exceeded the criteria domestically and abroad.
基金supported by the National Natural Science Foundation of China(6130422461305018+1 种基金61472423)the National Advanced Research Project of China(51301010206)
文摘In this paper, a novel fuzzy sliding mode control(FSMC) guidance law with terminal constraints of miss distance, impact angle and acceleration is presented for a constant speed missile against the stationary or slowly moving target. The proposed guidance law combines the sliding mode control algorithm with a fuzzy logic control scheme for the lag-free system and the first-order lag system. Through using Lyapunov stability theory, we prove the sliding surface converges to zero in finite time. Furthermore, considering the uncertain information and system disturbances, the guidance gains are on-line optimized by fuzzy logic technique. Numerical simulations are performed to demonstrate the performance of the FSMC guidance law and the results illustrate the validity and effectiveness of the proposed guidance law.
文摘Full-waveform velocity inversion based on the acoustic wave equation in the time domain is investigated in this paper. The inversion is the iterative minimization of the misfit between observed data and synthetic data obtained by a numerical solution of the wave equation. Two inversion algorithms in combination with the CG method and the BFGS method are described respectively. Numerical computations for two models including the benchmark Marmousi model with complex structure are implemented. The inversion results show that the BFGS-based algorithm behaves better in inversion than the CG-based algorithm does. Moreover, the good inversion result for Marmousi model with the BFGS-based algorithm suggests the quasi-Newton methods can provide an important tool for large-scale velocity inversion. More computations demonstrate the correctness and effectives of our inversion algorithms and code.
文摘We develop a new full waveform inversion (FWI) method for slowness with the crosshole data based on the acoustic wave equation in the time domain. The method combines the total variation (TV) regularization with the constrained optimization together which can inverse the slowness effectively. One advantage of slowness inversion is that there is no further approximation in the gradient derivation. Moreover, a new algorithm named the skip method for solving the constrained optimization problem is proposed. The TV regularization has good ability to inverse slowness at its discontinuities while the constrained optimization can keep the inversion converging in the right direction. Numerical computations both for noise free data and noisy data show the robustness and effectiveness of our method and good inversion results are yielded.
文摘In this paper, wave simulation with the finite difference method for the Helmholtz equation based on the domain decomposition method is investigated. The method solves the problem by iteratively solving subproblems defined on smaller subdomains. Two domain decomposition algorithms both for nonoverlapping and overlapping methods are described. More numerical computations including the benchmark Marmousi model show the effectiveness of the proposed algorithms. This method can be expected to be used in the full-waveform inversion in the future.
文摘Battery grade γ-MnO2 powder was investigated as an oxidant and an adsorbent in combination with Fe/Al coagulants for removal of arsenic from contaminated water. Simultaneous oxidation of As(III) and removal by coprecipitation/adsorption (one step process) was compared with pre-oxidation and subsequent removal by coprecipitation/adsorption (two step process). The rate of As(III) oxidation with MnO2 is completed in two stages: rapid initially followed by a first order reaction. As(III) is oxidised to As(V) by the MnO2 with a release of approximately 1:1 molar Mn(II) into the solution. No significant pH effect on oxidation of As(III) was observed in the pH range 4 - 6. The rate showed a decreasing trend above pH 6. The removal of As(V) by adsorption on the MnO2 decreased significantly with increasing pH from 4 to 8. The adsorption capacity of the γ-MnO2 with particle size 90% passing 10 μm was determined to be 1.5 mg/g at pH 7. MnO2 was found to be more effective as an oxidant for As(III) in the two step process than in the one step process.
文摘BACKGROUND: Propofol has been shown to attenuate neuronal injury in a number of experimental conditions. However, its effect in models of cerebral ischemia after subarachnoid hemorrhage (SAH) remains controversial. OBJECTIVE: To explore the effects of intracisternal injection of HX0507, a water-soluble propofol prodrug, on basilar artery vasospasm and brain tissue injury in a rabbit model of SAH. DESIGN, TIME AND SETTING: A randomized, controlled, in vivo animal experiment based on behavior and morphology. The study was performed at the Laboratory of Anesthesiology and Critical Care Medicine, West China Hospital, Sichuan University from April to December 2007. MATERIALS: HX0507 was provided by the Laboratory of Anesthesiology and Critical Care Medicine, West China Hospital of Sichuan University. METHODS: A total of 30 healthy, male, New Zealand rabbits were randomly assigned to sham-operation, SAH-control, and SAH-HX0507 groups, with 10 animals in each group. The single-hemorrhage SAH model was established by injecting autologous arterial blood (1.0 mL/kg) into the cisterna magna in the SAH-control and SAH-HX0507 groups, while the sham-operation group was injected with normal saline (1.0 mL/kg). Thirty minutes after injection, the sham-operation and SAH-control groups were injected with normal saline (0.1 mL/kg) into the cisterna magna, while the SAH-HX0507 group received an injection of HX0507 (4.8 mg/kg). MAIN OUTCOME MEASURES: The cross-sectional area and corrugation coefficients of basilar arteries and hippocampal CA1 neuronal densities were measured 48 hours after SAH (peak stage of vasospasm) using the Computer-Assisted Stereological Toolbox system. The ultrastructural structure of the basilar artery wall was examined by transmission electron microscopy. In addition, neurological behavioral impairment was evaluated by appetite score at pre-SAH, and 1 and 2 days after SAH. RESULTS: The cross-sectional area of basilar arteries and hippocampal CA1 neuronal densities, as well as ultrastructural structure scores of the SAH-control group were significantly less than the other groups (P 〈 0.01 or P 〈 0.05), while the corrugation coefficients of basilar arteries and appetite score 2 days after SAH were significantly greater than the other groups (P 〈 0.01 or P 〈 0.05). The appetite score 1 day after modeling was remarkably greater than the SAH-control group (P 〈 0.05). However, no significant difference was determined between the sham-operation and SAH-HX0507 groups (P 〉 0.05). CONCLUSION: Intracisternal administration of HX0507 attenuated basilar artery vasospasm and hippocampal ischemic injury in a rabbit model of SAH.
基金supported by the National Nature Science Foundation of China(81771152)National Key R&D Plan(No.2017YFC1702500)the Beijing Joint Project for the Central-Affiliated University(2017-01)。
文摘(+)-Catechin(CE)is mainly found in green and black tea and has many biological effects,such as antiinflammatory,anti-cancer,anti-viral effects,protecting human organs,especially the kidney.This study aims to identify the circRNAs induced by CE in db/db mice and their roles in diabetic nephropathy progression.After the db/db mice were treated with CE,RNA-seq was performed to identify the differentially expressed circRNA and mRNAs.The ceRNA regulatory network was constructed and analyzed using bioinformatics software and public databases(Cytoscape,Clue GO,Mi RWalk,STRING,et al.).Our results revealed that 6 differentially expressed circRNAs are most associated with the cholinergic synapse,neurotrophin signaling pathway,and insulin signaling pathway.Among these,circRNA.5549 and circRNA.4712 might regulate Cd36,Cyp26 b1,C8 a,Cyp2 j13,Grem2 genes through ceRNA regulatory mechanism in the presence of CE treatment.The expanded network of proteins interacting with these 5 genes shows that the TGF-βsignaling pathway,signaling pathways regulating pluripotency of stem cell,fat digestion and absorption,and PPAR signaling pathway was highly enriched.Overall,circRNA.5549 and circRNA.4712 exhibit a promotive function in CE-treated db/db mice,especially in circRNA.5549/miR-29a-5P/Cd36 regulatory network,and this evidence suggest that their ceRNA regulatory network might be a therapeutic target for DN in humans.
基金supported by the National Natural Science Foundation of China(Nos.52078435 and 51878560)the financial support from the open research fund of MOE Key Laboratory of High-Speed Railway Engineering。
文摘This paper develops a dual-indicator discrete method(DDM)for evaluating the system reliability performance of long soil subgrade slopes.First,they are segmented into many slope sections using the random finite element method,to ensure each section statistically contains one potential local instability.Then,the k-out-of-n system model is used to describe the relationship between the total number of sections n,the acceptable number of failure sections m,the reliability of sections R_(sec),and the system reliability R_(sys).Finally,m and R_(sys)are jointly used to assess the system reliability performance.For cases lacking spatial data of soil properties,a simplified DDM is provided in which long subgrade slopes are segmented by the empirical value of section length and R_(sec)is substituted by that of crosssections taken from them.The results show that(1)DDM can provide the probability that the actual number of local instabilities does not exceed a desired threshold.(2)R_(sys)decreases with increasing n or decreasing R_(sec);that is,it is likely to encounter more local instabilities for longer or weaker subgrade slopes.n is negatively related to the horizontal scale of fluctuation of soil properties and positively related to the total length of subgrade slopes L.(3)When L is sufficiently large,there is a considerable opportunity to meet local instabilities even if R_(sec)is large enough.
文摘In this paper, we firstly derive the stability conditions of high-order staggered-grid schemes for the three-dimensional (3D) elastic wave equation in heterogeneous media based on the energy method. Moreover, the plane wave analysis yields a sufficient and necessary stability condition by the von Neumann criterion in homogeneous case. Numerical computations for 3D wave simulation with point source excitation are given.
文摘A new wave simulation technique for the elastic wave equation in the frequency domain based on a no overlapping domain decomposition algorithm is investigated. The boundary conditions and the finite difference discrimination of the elastic wave equation are derived. The algorithm of no overlapping domain decomposition method is given. The method solves the elastic wave equation by iteratively solving sub problems defined on smaller sub domains. Numerical computations both for homogeneous and inhomogeneous media show the effectiveness of the proposed method. This method can be used in the full-waveform inversion.
基金Sichuan Science and Technology Program(Nos.2020YFS0188 and 2020YJ0283)
文摘Background:Postoperative pulmonary complications often lead to increased mortality and financial burden.Residual paralysis plays a critical role in postoperative pulmonary complications.This meta-analysis was performed to determine whether sugammadex overmatches neostigmine in reducing postoperative pulmonary complications.Methods:PubMed,Embase,Web of Science,Medline through Ovid,Cochrane Library,Wanfang,China National Knowledge Infrastructure,and Chinese BioMedical Literature Databases were searched from their inception to 24 June,2021.Random effects models were used for all analyses.Cochrane risk of bias tool was used to assess the quality of RCTs,while Newcastle Ottawa Quality Assessment Scale was used to assess for the quality of cohort studies.Results:Seventeen studies were included in the meta-analysis.Pooled data from cohort studies showed reversing neuromuscular blocking with sugammadex had less risk of compound postoperative pulmonary complications(relative risk[RR]:0.73;95%confidence interval[CI]:0.60-0.89;P=0.002;I^(2)=81%),pneumonia(RR:0.64;95%CI:0.48-0.86;I^(2)=42%)and respiratory failure(RR:0.48;95%CI:0.41-0.56;I^(2)=0%).However,pooled data from RCTs did not show any difference between the two groups in pneumonia(RR:0.58;95%CI:0.24-1.40;I^(2)=0%)and no respiratory failure was reported in the included RCTs.The difference was not found between sugammadex and neostigmine about atelectasis in pooled data from either RCTs(RR:0.85;95%CI:0.69-1.05;I^(2)=0%)or cohort studies(RR:1.01;95%CI:0.87-1.18;I^(2)=0%).Conclusion:The evidence of superiority of sugammadex was limited by the confounding factors in cohort studies and small scale of RCTs.Whether sugammadex precedes neostigmine in preventing pulmonary complications after surgery is still unknown.Well-designed RCTs with large scale are needed.Registration:PROSPERO(https://www.crd.york.ac.uk/PROSPERO/);CRD 42020191575.
文摘A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement distance, the accuracy, the space resolution, the ability of multi-parameter measurements, and the intelligence of full distributed fiber sensor systems, a new generation fiber sensor technology based on the optical fiber nonlinear scattering fusion principle is proposed. A series of new generation full distributed fiber sensors are investigated and designed, which consist of new generation ultra-long distance full distributed fiber Raman and Rayleigh scattering photon sensors integrated with a fiber Raman amplifier, auto-correction full distributed fiber Raman photon temperature sensors based on Raman correlation dual sources, full distributed fiber Raman photon temperature sensors based on a pulse coding source, full distributed fiber Raman photon temperature sensors using a fiber Raman wavelength shifter, a new type of Brillouin optical time domain analyzers (BOTDAs) integrated with a fiber Raman amplifier for replacing a fiber Brillouin amplifier, full distributed fiber Raman and Brillouin photon sensors integrated with a fiber Raman amplifier, and full distributed fiber Brillouin photon sensors integrated with a fiber Brillouin frequency shifter. The Internet of things is believed as one of candidates of the next technological revolution, which has driven hundreds of millions of class markets. Sensor networks are important components of the Internet of things. The full distributed optical fiber sensor network (Rayleigh, Raman, and Brillouin scattering) is a 3S (smart materials, smart structure, and smart skill) system, which is easy to construct smart fiber sensor networks. The distributed optical fiber sensor can be embedded in the power grids, railways, bridges, tunnels, roads, constructions, water supply systems, dams, oil and gas pipelines and other facilities, and can be integrated with wireless networks.