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Blast wave characteristics of multi-layer composite charge:Theoretical analysis,numerical simulation,and experimental validation

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Defence Technology（防务技术） 2023年第1期19卷 91-102页

作者： jun-bao li Wei-bing li Xiao-wen Hong Jia-xin Yu Jian-jun Zhu ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing210094China Inner Mongolia Metal Material Research Institute Yantai264003China China Ship Development and Design Center Wuhan 430064China

This article investigates the characteristics of shock wave overpressure generated by multi-layer composite charge under different detonation *** dimensional analysis and the explosion mechanism of the charge,a peak overpressure prediction model for the composite charge under singlepoint detonation and simultaneous detonation was *** effects of the charge structure and initiation method on the overpressure field characteristics were investigated in AUTODYN *** accuracy of the prediction model and the reliability of the numerical simulation method were subsequently verified in a series of static explosion *** results reveal that the mass of the inner charge was the key factor determining the peak overpressure of the composite charge under single-point *** peak overpressure in the radial direction improved apparently with an increase in the aspect ratio of the *** overpressure curves in the axial direction exhibited a multi-peak phenomenon,and the secondary peak overpressure even exceeded the primary peak at distances of 30D and 40D(where D is the charge diameter).The difference in peak overpressure among azimuth angles of 0-90°gradually decreased with an increase in the propagation distance of the shock *** coupled effect of the detonation energy of the inner and outer charge under simultaneous detonation improved the overpressure in both radial and axial *** difference in peak overpressure obtained from model prediction and experimental measurements was less than 16.4%.

关键词： Blast wave characteristics Multi-layer composite charge Dimensional analysis AUTODYN mapping Model Explosion experiment

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Blast performance of layered charges enveloped by aluminum powder/rubber composites in confined spaces

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Defence Technology（防务技术） 2022年第4期18卷 583-592页

作者： jun-bao li Wei-bing li Jia-xin Yu Wei Xiao He-yang Xu ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing210094China School of Chemical Engineering Nanjing University of Science and TechnologyNanjing210094China

A layered charge composed of the JH-2 explosive enveloped by a thick-walled cylindrical casing(active aluminum/rubber and inert lithium fluoride/rubber composites) was designed and explosion experiments were conducted in a 1.3 m3tank and a 113 *** blast parameters,including the quasistatic pressure(ΔpQS),special impulse(I),and peak overpressure(Δpmax),and images of the explosion process were recorded,and the influence of the Al content(30% and 50%) and Al particle size(1,10,and 50 μm) on the energy release of aluminum/rubber composites were *** results revealed that the use of an active layer increased the peak overpressure generated by the primary blast wave,as well as the quasistatic pressure and special impulse related to fuel burning within tens of milliseconds after *** the Al content was increased from 30% to 50%,the increases of ΔpQS and I were not obvious,and Δpmaxeven decreased,possibly because of decreased combustion efficiency and greater absorption of the blast wave energy for layers with 50% *** with the pure JH-2charge,the charge with 1 μm Al particles produced the highest Δpmax,indicating that better transient blast performance was generated by smaller Al ***,the charge with 10 μm Al particles showed the largest ΔpQSand I,suggesting that a stronger destructive effect occurred over a longer duration for charges that contained moderate 10 μm Al.

关键词： Confined explosion Aluminum powder/rubber composites Layered charge Blast parameters

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Predisposing factors, diagnosis, treatment and prognosis of cerebral venous thrombosis during pregnancy and postpartum： a case-control study

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Chinese Medical Journal 2011年第24期124卷 4198-4204页

作者： GAO Hui YANG bao-jun JIN li-ping JIA Xiao-fang Department of Obstetrics ＆ Gynecology Beijing Tiantan HospitalCapital Medical University Beijing 100050 China

Keywords pregnancy; puerperium; cerebral venous thromboembolism; anticoagulant agents; thrombolysis Background Previous investigations have demonstrated a relatively low incidence of stroke among young women, though both pregnancy and delivery can substantially increase the risk. Cerebral venous thrombosis may manifest different characteristics during pregnancy and postpartum as a result of their specific physiological statuses. This study aimed to identify the clinical manifestations, diagnosis, treatment, and prognosis of cerebral venous thrombosis during pregnancy and postpartum. Methods We conducted a retrospective analysis of 22 patients with cerebral venous thrombosis who were assigned to either group A （during pregnancy） or group B （during postpartum）. The relevant risk factors, initiation and development of the disease, clinical presentations, diagnosis, treatment, and prognosis were compared between the two stages. Results Cerebral venous thrombosis occurred during both pregnancy and postpartum, but was more common postpartum. Patients in group A had a longer hospitalization period than those in group B. Confirmed predisposing factors in 85.7% of patients of group A were dehydration, infection, and underlying cerebrovascular disorders. No obvious predisposing factors were identified in group B. The most frequent symptom was headache, with epileptic seizures, hemiparalysis and aphasia being less frequent symptoms. Focal neurological symptoms （P=0.022） and cerebral infarction （P=0.014） occurred more frequently in group A than in group B. Anticoagulation therapy proved to be safe for cerebral venous thrombosis patients during puerperium, regardless of parenchymal hemorrhage. However, more attention should be paid to spontaneous in-site placental hemorrhage in pregnant patients. Both groups had similar prognoses （P=1.000）, with 36.3% patients suffering from consequential dysfunction or recurrent intracranial hypertension Delayed diagnosis was associated wi

关键词： pregnancy puerperium cerebral venous thromboembolism anticoagulant agents thrombolysis

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Expression of non-structural protein NS3 gene of Bombyx mori densovirus (China isolate)

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Journal of Genetics and Genomics 2008年第4期35卷 239-244页

作者： Huijuan Yin Qin Yao Zhongjian Guo Fang bao Wei Yu jun li Keping Chen Institute of life Sciences Jiangsu University 301# Xuefu Road Zhenjiang 212013 China

The invertebrate parvovirus Bombyx mori Densonucleosis Virus type 3 （China isolate）, named BmDNV-3, is a kind of bidensovirus. It is a new type of virus with unique replication mechanisms. To investigate the effects of the NS3 gene during viral DNA replication, a pair of primers was designed for amplifying NS3 gene of Bombyx mori densovirus （China isolate）. Gene NS3 amplified was cloned into a prokaryotic expression vector pET-30a and the donor plasmid pFastBacHTe, respectively. The NS3 protein was expressed in Escherichia coli BL21. The pFastBacHTe-NS3 was transformed to E. coli DHIOBac. The recombinant bacmid baculoviruses （rBacmid-EGFP-NS3） isolated from the white colonies were transfected into BmN-4 cells using a transfection reagent. BraN-4 cells were infected with recombinant virus to express fusion proteins. The expression of fusion protein around 30 kDa in E. coli BL21 was identified by SDS-PAGE, Western blotting, and mass spectrometry. The expressed NS3 protein by B. mori nucleopolyhedrovirus bacmid system was confirmed by Western blotting using an anti-NS3 polyclonal antibody. And about 45 kDa protein was found. The expressed fusion protein was smaller than the expected size of EGFP-NS3, 55 kDa. Western blotting analysis indicated that EGFP-NS3 protein was expressed in infected larvae with smaller molecular size.

关键词： BmDNV NS3 protein expression

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Synthesis of granulated li_(1.33)Mn_(1.67)O_(4) via two antisolvent methods for lithium adsorption from gas-produced water

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Chinese Journal of Chemical Engineering 2024年第5期69卷 34-46页

作者： jun Qiu Lu-Ri bao Wei Guo Ying Yang Shu-Ying Sun National Engineering Research Center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China

Gas-produced water is an accompanying wastewater in the natural gas extraction process,and it is a potential liquid lithium resource that contains a considerable amount of *** study investigated the feasibility of using manganese-based ion sieves to adsorb and extract lithium from gas-produced *** we focused on the applicability of two different granulation methods,extrusion and droplet,in gas-produced water *** types of H_(1.33)Mn_(1.67)O_(4) particles were prepared by the extrusion method(EHMO)and the droplet method(DHMO).The porosity of DHMO was much higher than that of EHMO,and the adsorption performance of DHMO increased with the decrease of binder *** prepared with a binder concentration of 0.14 g·ml^(-1)exhibited the best adsorption performance in gas-produced water,and the li^(+)adsorption capacity could reach 25.14 mg·g^(-1).In gas-produced water,the adsorption equilibrium of DHMO only took 9 h,and the adsorption process conformed to the Langmuir model and pseudo-second-order kinetic *** pore diffusion model(PDM)could well describe its adsorption ***,DHMO showed a great selectivity to li^(+),and the selectivity order of DHMO in gas-produced water was li^(+)>Ba^(2+)>>Mg^(2+),Ca^(2+),Sr^(2+)>>Na^(+)>>K^(+).After 20 cycles,the li^(+)adsorption capacity was still higher than 17.30 mg·g^(-1),and the rate of manganese dissolution was less than 1%.

关键词： Gas-produced water Granulation li_(1.33)Mn_(1.67)O_(4)

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Feature detection of triangular meshes via neighbor supporting

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第6期13卷 440-451页

作者： Xiao-chao WANG jun-jie CAO Xiu-ping liU bao-jun li Xi-quan SHI Yi-zhen SUN School of Mathematical Sciences Dalian University of TechnologyDalian 116024China State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering Mechanics Dalian University of TechnologyDalian 116024China State Key Laboratory of Structural Analysis for Industrial Equipment School of Automotive EngineeringFaculty of Vehicle Engineering and MechanicsDalian University of TechnologyDalian 116024China Department of Mathematical Sciences Delaware State UniversityDoverDE 19901USA

We propose a robust method for detecting features on triangular meshes by combining normal tensor voting with neighbor supporting. Our method contains two stages： feature detection and feature refinement. Firsts the normal tensor voting method is modified to detect the initial features, which may include some pseudo features. Then, at the feature refinement stage, a novel salient measure deriving from the idea of neighbor supporting is developed. Benefiting from the integrated reliable salient measure feature, pseudo features can be effectively discriminated from the initially detected features and removed. Compared to previous methods based on the differential geometric property, the main advantage of our method is that it can detect both sharp and weak features. Numerical experiments show that our algorithm is robust, effective, and can produce more accurate results. We also discuss how detected features are incorporated into applications, such as feature-preserving mesh denoising and hole-filling, and present visually appealing results by integrating feature information.

关键词： Feature detection Neighbor supporting Normal tensor voting Salient measure

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Latent Local Feature Extraction for Low-Resolution Virus Image Classification

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Journal of the Operations Research Society of China 2020年第1期8卷 117-132页

作者： Zhi-Jie Wen Zhi-Hu liu Yi-Chen Zong bao-jun li Department of Mathematics Shanghai UniversityShanghai 200444China China Information Development Inc.Ltd. Shanghai 200444China School of Automotive Engineering Dalian University of TechnologyDalian 116024China

Virus image classification is a significant and challenging issue in both clinical virology and medical image *** to the low-resolution virus images in the original dataset,there is tricky difficulty in extracting useful features from this kind of poor quality images adopting the traditional feature extraction *** this paper,we propose an effective and robust method,which eliminates the drawbacks of traditional local feature extraction methods and conducts latent local texture feature extraction thus to promote the accuracy of virus image ***,the multi-scale principal component analysis(PCA)filters are learned from all original ***,it establishes a scale space for each PCA-filtered image by 2D Gaussian ***,some typical feature descriptors are employed to extract texture features from all images,which include the original image and its filtered images by PCA and Gaussian *** at the classification of low-resolution images,the proposed method solves the difficulty in extracting the essential feature from the original image and captures its latent and principal texture information from different perspectives in different filtered *** results show that the classification accuracy of the proposed method is much higher than state-of-the-art methods in the same low-resolution virus dataset,reaching 88.00%.

关键词： Low-resolution virus image Principal component analysis Scale space CLBP Support vector machine(SVM)

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Feedback of Efficient Shock Acceleration on Magnetic-field Structure Inside Young Type Ia Supernova Remnants

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Research in Astronomy and Astrophysics 2024年第6期24卷 234-244页

作者： jun-Yu Shen Bi-Wen bao li Zhang Department of Astronomy Key Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China Key Laboratory of Statistical Modeling and Data Analysis of Yunnan Province Yunnan UniversityKunming 650091China

Using an effective adiabatic index γ_(eff) to mimic the feedback of efficient shock acceleration,we simulate the temporal evolution of a young type Ia supernova remnant (SNR) with two different background magnetic field(BMF) topologies:a uniform and a turbulent *** density distribution and magnetic-field characteristics of our benchmark SNR are studied with two-dimensional cylindrical magnetohydrodynamic *** γ_(eff)is considered,we find that:(1) the two-shock structure shrinks and the downstream magnetic-field orientation is dominated by the Rayleigh–Taylor instability structures;(2) there exists more quasi-radial magnetic fields inside the shocked region;and (3) inside the intershock region,both the quasi-radial magnetic energy density and the total magnetic energy density are enhanced:in the radial direction,with γ_(eff)=1.1,they are amplified about 10–26 times more than those with γ_(eff)=5/*** in the angular direction,the total magnetic energy densities could be amplified about 350 times more than those with γ_(eff)=5/3,and there are more grid cells within the intershock region where the magnetic energy density is amplified by a factor greater than 100.

关键词： methods:numerical ISM:magnetic fields ISM:supernova remnants magnetohydrodynamics(MHD)

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Non-stationary Subdivision for Exponential Polynomials Reproduction

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Acta Mathematicae Applicatae Sinica 2013年第3期29卷 567-578页

作者： bao-jun li Zhi-ling YU Bo-wen YU Zhi-xun SU Xiu-ping liU School of Automotive Engineering Faculty of Vehicle Engineering and MechanicsState Key Laboratory of Structural Analysis for Industrial EquipmentDalian University of Technology School of Mathematical Sciences and LPMC Nankai University School of Mathematical Sciences Dalian University of Technology

In this paper we develop a novel approach to construct non-stationary subdivision schemes with a tension control parameter which can reproduce functions in a finite-dimensional subspace of exponential polynomials. The construction process is mainly implemented by solving linear systems for primal and dual subdivision schemes respectively, which are based on different parameterizations. We give the theoretical basis for the existence, uniqueness, and refinement rules of schemes proposed in this paper. The convergence and smoothness of the schemes are analyzed as well. Moreover, conics reproducing schemes are analyzed based on our theory, and a new idea that the tensor parameter ωk of the schemes can be adjusted for conics generation is proposed.

关键词： Non-stationary subdivision exponential polynomials difference equation tension control

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Interfacial active sites on Co-Co_(2)C@carbon heterostructure for enhanced catalytic hydrogen generation

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Rare Metals 2023年第6期42卷 1935-1945页

作者： Huan-Huan Zhang Yang-Bin Ren Zhen-Luo Yuan Nai-Xin Kang Sehrish Mehdi Cong-Cong Xing Xian-Yun liu Yan-Ping Fan bao-jun li bao-Zhong liu College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo454003China ISM UMR CNRS No 5255Univ.BordeauxTalence Cedex33405France Department of Chemistry The Women University MultanKutchery CampusMultan66000Pakistan Department of Materials Science and Engineering Pennsylvania State UniversityUniversity ParkPA16802USA Research Center of Green Catalysis College of ChemistryZhengzhou UniversityZhengzhou450001China Henan Key Laboratory of Coal Green Conversion Henan Polytechnic UniversityJiaozuo454003China

Designing catalysts with capable dual-active sites to drive catalytic hydrogen generation is necessary for the future hydrogen ***,the interfacial active sites consisting of Co and Co-C on Co-Co_(2)C@carbon heterostructure are designed through annealing and highpressure *** operating temperature during the high-pressure carbonization under a CO-reducing environment is responsible for the construction and regulation of Co-Co_(2)C@C *** optimal catalyst has a high turnover frequency(TOF) of33.1 min^(-1) and low activation energy(E_a) of27.3 kJ-mol^(-1) during the hydrolysis of NH_(3)BH_(3).The catalytic stability of Co-Co_(2)C@C has no dramatic deterioration even after 5 cyclic *** interfacial active sites and the carbon on the catalyst surface enhance hydrogen generation kinetics and catalytic *** construction of interfacial active sites in Co-Co_(2)C@C prompts the dissociation of reactants(NH_(3)BH_(3) and H_(2)O molecules),leading to an enhanced catalytic hydrogen generation from NH_(3)BH_(3) hydrolysis(Co activates NH_(3)BH_(3) and Co-C activates H_(2)O).The construction of hetero-structural catalysts provides theoretical direction for the rational design of advanced transition metal carbide materials in the field of energy catalysis and conversion.

关键词： Interfacial active sites Bimolecular activation Heterostructure Hydrogen generation Catalytic mechanism

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