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Andrographolide inhibits chikungunya virus infection by up-regulating host innate immune pathways

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Asian Pacific Journal of Tropical Medicine 2018年第3期11卷 214-221页

作者： Swati Gupta Kamla Prasad Mishra Paban Kumar Dash Manmohan Parida Lilly Ganju Shashi Bala Singh defence Institute of Physiology & Allied Sciences defence Research and Development Establishment

Objective: To investigate the therapeutic efficacy of andrographolide, a plant derived compound, against chikungunya virus(CHIKV) infection. Methods: Using flow cytometry and immunoblotting assay, in vitro viral protein expression was studied in THP-1 cells line. In Balb/c mouse neonates, viral RNA copy number was determined by real time PCR. Results:The results showed reduced CHIKV protein expression on andrographolide treatment in CHIKV-infected human peripheral blood mononuclear cells, Vero cells and THP-I cell *** vivo, andrographolide treatment to CHIKV-infected neonates reduced viral RNA copy number. Further. andrographolide also increased cytotoxic T lymphocytes both in vitro and in vivo. Andrographolide also activated host innate immune pathways, viz., protein kinase *** eukaryotic initiation factor 2 α, retinoic acid inducible gene-Ⅰ and interferon regulatory factor 3/7, thereby increasing IFN-a secretion. CHIKV-induced nuclear factor κlight chain enhancer of activated B cells and tumor necrosis factor-a was also reduced on andrographolide treatment. Conclusion: Andrographolide inhibits CHIKV by suppressing viral protein expression and up-regulating host innate immunity and hence could be an effective therapeutic agent against CHIKV infection.

关键词： Chikungunya virus Andrographolide Interferon α Protein kinase R Retinoic acid inducible gene-I Tumor necrosis factor α

Effect of tidal currents on the transport of saline water from the North Branch in the Changjiang River estuary

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Journal of Oceanology and Limnology 2018年第6期36卷 2085-2097页

作者：丁坚邵雨辰吴德安 Key Laboratory of Coastal Disaster and defence Ministry of EducationHohai UniversityNanjing 210098China Nanjing Water Planning and Design Institute Corp.Ltd. Nanjing 210022China

Based on the MIKE 21 numerical model combined with measured data, a numerical model for the coupling of water and salinity in the Changjiang(Yangtze) River estuary was established, and based on good verification, the influence of the tidal current intensity on the transport and variations of salinity concentrations in saline water from the North Branch to the South Branch was numerically evaluated. The time and space mean root mean square of the tidal current velocity can be expressed as a parabolic function of an adjustment coefficient for the amplitude of the M2 tidal constituent along the open boundaries of the model. Under the advection of runof f and tidal currents, the saline pool is transported downstream in an oscillatory pattern. With the enhancement of tidal current intensity, the oscillatory motion of the saltwater pool is increasingly significant in a tidal cycle forced by rising and falling tides. Along four set paths, the daily average concentrations of the saline core were generally similar, and in the process of transportation downstream, the concentrations of saltwater declined. The decay of the tidal-period-averaged salinity of the saltwater was linearly related to the square of the tidal current. Thus, the tidal current has a significant and direct impact on saltwater transport and diffusion in the Changjiang River estuary.

关键词： Changjiang River estuary saltwater intrusion numerical simulation transport and diffusion attenuation

Electroless nickel fabrication on surface modified magnesium substrates

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defence Technology（防务技术） 2019年第4期15卷 636-644页

作者： Ayushi Thakur Swaroop Gharde Balasubramanian Kandasubramanian Department of Metallurgical and Materials Engineering National Institute of Technology Hazratbal Srinagar Jammu & Kashmir 190006 India Department of Metallurgical & Materials Engineering DIAT (DU) Ministry of Defence Girinagar Pune 411025 Maharashtra India

In recent years,magnesium(Mg)has evolved as a salient material,in affiliation with electroless nickel(Ni)coating,which have found applications in automobiles,aerospace and confederate fields attributing to its excellent inherent weight sensitive ***,being acknowledged for its remarkable auxiliary properties like flexible machining,appreciable weight sensitivity and ability to be patently diecast into mesh constructs,magnesium is prejudiced by aeronautical standards predominantly for its inferior corrosion resistance *** this sense,electroless nickel plating on magnesium and its alloys has been suggested to extricate it from corrosion problem and make it more competitive in industrial and defence *** fixation of metal ions onto respective substrates accrues and alters their mechanical,electrochemical and tribological properties,destitute of any electric current *** proficiently identified technique is prosecuted with the assistance of a series of sequenced operations involving a prior pretreatment,which corresponds to the chemical cleaning of the substrate surface;electroless coating;and a later activation process which is a mild etching of the electroless coated *** susceptibility of magnesium to this methodology has advanced and propagated its exercise and applicability in aircraft,satellites and allied aeronautical ***,researchers have proposed various eco-friendly and modified duplex and composite coatings which have transmuted properties of these appendages by tailoring alloy compositions and reagents *** review article systematically colligates various considerations and evaluations on electroless nickel applications of magnesium and its alloys and explicates how it anchors its practice in the respective ***,a comprehensive analysis is devised based on the pre-existing treatment methods for accomplishing the same.

关键词： Electroless nickel plating Magnesium Magnesium alloys Corrosion-resistance Micro arc oxidation(MAO)

An experimental study of impact loading on deck of shore-connecting jetties exposed to oblique waves and current

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Journal of Hydrodynamics 2014年第2期26卷 216-225页

作者：孟艳秋陈国平严士常童朝锋 Key Laboratory of Coastal Disaster and defence Ministry of Education Hohai University College of Harbour Coastal and Offshore Engineering Hohai University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

The impact pressure from waves is an important issue to be considered in the design of coastal structures. In this paper, the waves acting on the deck of a shore-connecting jetty on a slope exposed to oblique waves and in the presence of current are examined based on laboratory experiments. The impact pressures are measured on a 1：50 scale model of a jetty head with down-standing beams and berthing members. The relations of the impact pressure with the incident wave angle and the current velocity are examined. It is shown that the impact pressure is sensitive to the wave angle and the current velocity. A computational model for the impact load on the deck of shore-connecting jetties exposed to oblique waves and current is developed.

关键词： wave current impact pressure shore-connecting jetty on a slope

Assimilating operational SST and sea ice analysis data into an operational circulation model for the coastal seas of China

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Acta Oceanologica Sinica 2015年第7期34卷 54-64页

作者： JI Qiyan ZHU Xueming WANG Hui LIU Guimei GAO Shan JI Xuanliang XU Qing Key Laboratory of ministry of Education for Coastal Disaster and defence Hohai University Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting CenterState Oceanic Administration

The prediction of sea surface temperature （SST） is an essential task for an operational ocean circulation model. A sea surface heat flux, an initial temperature field, and boundary conditions directly affect the accuracy of a SST simulation. Here two quick and convenient data assimilation methods are employed to improve the SST simulation in the domain of the Bohai Sea, the Yellow Sea and the East China Sea （BYECS）. One is based on a surface net heat flux correction, named as Qcorrection （QC）, which nudges the flux correction to the model equation; the other is ensemble optimal interpolation （EnOI）, which optimizes the model initial field. Based on such two methods, the SST data obtained from the operational SST and sea ice analysis （OSTIA） system are assimilated into an operational circulation model for the coastal seas of China. The results of the simulated SST based on four experiments, in 2011, have been analyzed. By comparing with the OSTIA SST, the domain averaged root mean square error （RMSE） of the four experiments is 1.74, 1.16, 1.30 and 0.91~C, respectively; the improvements of assimilation experiments Exps 2, 3 and 4 are about 33.3%, 25.3%, and 47.7%, respectively. Although both two methods are effective in assimilating the SST, the EnOI shows more advantages than the QC, and the best result is achieved when the two methods are combined. Comparing with the observational data from coastal buoy stations, show that assimilating the high-resolution satellite SST products can effectively improve the SST prediction skill in coastal regions.

关键词： sea surface temperature data assimilation ensemble optimal interpolation quick correction Bohai Sea Yellow Sea East China Sea

Influence of welding consumables on tensile and impact properties of multi-pass SMAW Armox 500T steel joints vis-a-vis base metal

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defence Technology（防务技术） 2018年第3期14卷 188-195页

作者： Ambuj Saxena A.Kumaraswamy G.Madhusudhan Reddy Vemuri Madhu defence Institute of Advanced Technology(DU) Pune 411025India defence Metallurgical Research Laboratory KanchanbaghHyderabad 500048India

In this investigation, comparative study of tensile and impact properties of multi-pass SMAW Armox500 T steel joints fabricated by austenitic stainless steel(ASS) and low hydrogen ferritic steel(LHF)consumables vis-a-vis base metal was carried out. The tensile tests were conducted on computer controlled Walter t Bai Ag UTM at a nominal strain rate of 10à3 sà1. Subsequently, charpy impact tests were carried out on an instrumented Zwick-Roell test setup to obtain load vs. displacement and maximum energy absorbed vs. displacement of the specimen. It was observed that, the joint efficiency of weldment processed by LHF consumable was 41.7% and weldment processed by ASS was 30.6% of its base metal indicating the influence of electrode consumable on tensile properties of the joints. On the contrary, impact toughness of weldment processed by ASS was 20% more and weldment processed by LHF was 12% less than that of base metal. Microstructural studies also revealed that, ASS can be considered as a candidate welding consumable for good strain hardening and toughness of the welding joint in impact applications. However, LHF steel consumable is recommended for welding joints that requires higher joint efficiency under tensile loading conditions.

关键词： SMAW 不锈钢金属相焊接张力关节性质传递

A machine learning method to quantitatively predict alpha phase morphology in additively manufactured Ti-6Al-4V

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npj Computational Materials 2023年第1期9卷 338-352页

作者： Zhuohan Cao Qian Liu Qianchu Liu Xiaobo Yu Jamie J.Kruzic Xiaopeng Li School of Mechanical and Manufacturing Engineering University of New South Wales(UNSW Sydney)SydneyNSW 2052Australia Platforms Division Defence Science and Technology GroupMelbourneVIC 3207Australia

Quantitatively defining the relationship between laser powder bed fusion(LPBF)process parameters and the resultant microstructures for LPBF fabricated alloys is one of main research *** date,achieving the desired microstructures and mechanical properties for LPBF alloys is generally done by time-consuming and costly trial-and-error experiments that are guided by human ***,we develop an approach whereby an image-driven conditional generative adversarial network(cGAN)machine learning model is used to reconstruct and quantitatively predict the key microstructural features(e.g.,the morphology of martensite and the size of primary and secondary martensite)for LPBF fabricated *** results demonstrate that the developed image-driven machine learning model can effectively and efficiently reconstruct micrographs of the microstructures within the training dataset and predict the microstructural features beyond the training dataset fabricated by different LPBF parameters(i.e.,laser power and laser scan speed).This study opens an opportunity to establish and quantify the relationship between processing parameters and microstructure in LPBF Ti-6Al-4V using a GAN machine learning-based model,which can be readily extended to other metal alloy systems,thus offering great potential in applications related to process optimisation,material design,and microstructure control in the additive manufacturing field.

关键词： martensite microstructure alloy

Improved theory of projectile trajectory reference heights as characteristics of meteo-ballistic sensitivity functions

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defence Technology（防务技术） 2017年第3期13卷 177-187页

作者： Vladimir Cech Jiri Jevicky Department of Weapons and Ammunition University of Defence Oprox Inc. Department of Mathematics and Physics University of Defence

Projectile trajectories calculated under non-standard conditions are considered to be perturbed. The tools utilized for the analysis of perturbed trajectories are weighting factor functions(WFFs) which are a special kind of sensitivity functions. WFFs are used for calculation of meteo ballistic elements mB(ballistic wind wB, virtual temperature tB, pressure pB, density rB, speed of sound a) as well. An effect of weapon system parameters can be incorporated into calculations through the reference height of *** are also calculated from WFFs. Methods based on RHT are far more effective than traditional methods that use weighting factors *** have found that the existing theory of RHT has several shortcomings due to we created an improved theory of generalized RHT which represent a special sensitivity parameters of dynamical systems. Using this theory will improve methods for designing firing tables, fire control systems algorithms, and meteo message generation algorithms.

关键词：灵敏度函数气象要素弹道风特征动力系统理论消防控制系统加权因子生成算法

An Overview of High-Performance Aircraft Structural Al Alloy-AA7085

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 909-921页

作者： T.Ram Prabhu CEMILAC Defence R&D Organization

AA7085 Al alloy is a new-generation,high-strength,quench-insensitive alloy that features in airframe applications such as massive bulkhead and wing spars structures in Airbus A380 and Joint Strike Fighter *** alloy has a great potential in replacing currently used high-strength AA7 xxx alloys in many international and national military aircraft programs [Hawk,Su-30,Mi G series,light combat aircraft（Tejas）,Hindustan turbo/jet trainer,light combat helicopter,advanced light helicopter,and fifth-generation fighter aircrafts].An effort has been made to highlight the processing,heat treatment,properties and applications of the AA7085 Al alloy from the existing literature on the AA7085 *** potential applications of this alloy are presented and compared with the currently used AA7075 Al alloy.A typical process cycle involved in the manufacturing of wrought AA7085 alloy products is described in ***,the precipitation mechanisms involved in the different temper conditions are critically reviewed with the supporting *** mechanical properties with a particular emphasis on tensile,fatigue,and fracture toughness properties are discussed in detail based on the analysis of experimental *** effects of temper conditions on the stress corrosion cracking and exfoliation corrosion have also been reviewed critically.

关键词： Al alloys Heat treatment Material processing Mechanical properties Corrosion