Investigations of the mechanical response of dummy HTPB propellant grain under ultrahigh acceleration overload conditions using onboard flight-test measurements

In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.

An integrated split and dummy gates MOSFET with fast turn-off and reverse recovery characteristics

A power MOSFET with integrated split gate and dummy gate(SD-MOS) is proposed and demonstrated by the TCAD SENTAURUS.The split gate is surrounded by the source and shielded by the dummy gate.Consequently,the coupling area between the split gate and the drain electrode is reduced,thus the gate-to-drain charge(Q_(GD)),reverse transfer capacitance(C_(RSS)) and turn-off loss(E_(off)) are significantly decreased.Moreover,the MOS-channel diode is controlled by the dummy gate with ultra-thin gate oxide t_(ox),which can be turned on before the parasitic P-base/N-drift diode at the reverse conduction,then the majority carriers are injected to the N-drift to attenuate the minority injection.Therefore,the reverse recovery charge(Q_(RR)),time(T_(RR)) and peak current(I_(RRM)) are effectively reduced at the reverse freewheeling state.Additionally,the specific on-resistance(R_(on,sp)) and breakdown voltage(BV) are also studied to evaluate the static properties of the proposed SD-MOS.The simulation results show that the Q_(GD) of 6 nC/cm^(2),the C_(RSS) of 1.1 pF/cm^(2) at the V_(DS) of 150 V,the QRR of 1.2 μC/cm^(2) and the R_(on,sp) of 8.4 mΩ·cm^(2) are obtained,thus the figures of merit(FOM) including Q_(GD) ×R_(on,sp) of50 nC·mΩ,E_(off) × R_(on,sp) of 0.59 mJ·mΩ and the Q_(RR) × R_(on,sp) of 10.1 μC·mΩ are achieved for the proposed SD-MOS.

Detecting the One-Shot Dummy Attack on the Power Industrial Control Processes With an Unsupervised Data-Driven Approach

Dear Editor,Dummy attack(DA), a deep stealthy but impactful data integrity attack on power industrial control processes, is recently recognized as hiding the corrupted measurements in normal measurements. In this letter, targeting a more practical case, we aim to detect the oneshot DA, with the purpose of revealing the DA once it is launched.Specifically, we first formulate an optimization problem to generate one-shot DAs. Then, an unsupervised data-driven approach based on a modified local outlier factor(MLOF) is proposed to detect them.

基于SPH方法的二维液舱晃荡特性研究

本文基于流固耦合动力学理论,建立二维液舱晃荡的光滑粒子流体动力学模型,并引入Dummy边界处理固定边界问题。首先,与实验结果对比验证模型的有效性;随后,分析不同横摇激励、多种载液率下自由液面的运动规律,研究液体抨击舱壁产生的压力特性;在此基础上,设计单一隔板和组合隔板等不同制荡结构,探究共振频率、30%载液率下,自由液面形态和壁面冲击压力的特性。结果表明:在共振频率下,横摇幅值对压力峰值的影响最大;随着载液率的增加,壁面抨击压力双峰特性逐渐消失;当隔板尺度较小时,T型隔板更有利于降低压力的整体水平;双T型隔板可有效降低舱底冲击。

BIOSID Dummy撞击实验的计算机模拟研究

给出了一个BIOSIDdummy侧撞有限元模拟结果 ,和实验结果比较验证后可知该模型是可靠有效的。这一模型不仅可以用于任何侧撞情况下车辆乘员损伤防护模拟的研究 。

Hybrid-Ⅲ型Dummy刚性有限元模型的研究改进

Hybrid-Ⅲ型Dummy刚性有限元模型因具有独特的优点已被广泛地用于评定汽车乘员安全系统有效性的模拟研究中。在汽车安全带的模拟中发现现有模型存在较大的缺陷。本文提供了一个改进模型,利用实验结果验证,改进模型是合理有效的。该模型可为乘员安全保护系统的评估提供更为精确的模拟结果。

EUROSID-I Dummy的结构及有限元模型

描述了ＥＵＲＯＳＩＤ－Ｉ型ｄｕｍｍｙ的结构及有限元模型，以便对该ｄｕｍｍｙ进行计算机模拟。该模型不仅可用于各种侧向撞击的研究，也可用于ｄｕｍｍｙ的改进和发展。

EUROSID-Ⅰ型Dummy的计算机模拟

在介绍了ＥＵＲＯＳＩＤ－Ｉ型Ｄｕｍｍｙ的有限元模型的基础上，给出了对ＥＵＲＯＳＩＤ－Ｉ型Ｄｕｍｍｙ的计算机数值模拟结果及分析。通过对有关试验结果的验证，可知该模型是合理有效的。

Synthesis and Solid Phase Extraction Performance Study of NNAL-specific Molecularly Imprinted Polymers Using Dummy Templates

Dummy molecularly imprinted polymers （DMIPs） for 4-（methylnitrosamino）-1-（3-pyridyl）-1-butanol （NNAL） were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-（acetymethylamino）-1-（3-pyridyl）-butanol, 4- （methylamino）-1-（3-pyridyl）-1-butanol, and 1-（3-pyridyl）-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy （XPS） and Fourier transform infrared spectroscopy （FT-IR）. Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-（acetymethylamino）-1-（3-pyridyl）-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction （DMISPE） was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.

Effect coding与dummy coding赋值方法及其医学研究应用

目的介绍effect coding的变量赋值方法及其在医学研究中的应用,并与dummy coding方法比较。方法将2005年调查中搜集到西部10省40个县的村医20125张处方作为分析资料,省作为分类变量,分别采用dummy coding与effect coding两种编码方式纳入模型,分析处方费用的影响因素,并做比较。结果分类变量的编码方式不同,不会影响回归分析的结果。疾病种类、村医的文化程度、患者年龄、在治疗中是否使用注射剂以及处方所开出的药物个数都是村医处方费用的影响因素。结论 Effect coding在回归的系数的解释方面有其独到的优点,各省份的回归系数之间可以直接进行大小的比较,回归系数的正负表示该省的处方费用较平均水平的高低。

Effect of temperature on formability of glass mat reinforced thermoplastic sheets with ductile dummy sheets

Given the increasing use of glass mat-reinforced thermoplastic(GMT)composites,the formability of GMT sheets is currently a topic of research.A new sheet forming process for solidified GMT was developed.In this process,a GMT sheet was sandwiched by dummy metallic sheets during deep drawing.The dummy metallic sheets acted as protective materials and media for heating the GMT sheet.In this study,tensile tests of GMT specimens were carried out under different temperature conditions.The effect of temperature on the tensile deformation was analyzed.The effect of temperature on the deep drawing process of GMT sheets with dummy sheets was further investigated.Finite element method(FEM)was conducted to simulate the deep drawing process.In the drawing force rising stage,the law of drawing force with the depth of the drawing was analyzed using FEM and experiments.

Fluorescent competitive assay for melamine using dummy molecularly imprinted polymers as antibody mimics

A fluorescent competitive assay for melamine was first developed utilizing dummy molecularly imprinted polymers（DMIPs） as artificial antibodies. This method is based on the competition between fluorescent substances and the unlabeled analyte for binding sites in synthesized DMIPs and the decreased binding of fluorescent substances to DMIPs due to increased concentrations of melamine in the solutions. DMIPs for melamine were synthesized under a hot water bath in the presence of the initiator azobisisobutyronitrile（AIBN） using 2,4-diamino-6-methyl-1,3,5-triazine（DAMT） as a dummy template, methacrylic acid（MAA） as a functional monomer, and ethylene glycol dimethacrylate（EGDMA） as a crosslinking agent. The adsorption capacity and selectivity of DMIPs for melamine were evaluated by the isothermal adsorption curve and Scatchard analysis. The evaluation results showed that the synthesized DMIPs had specific recognition sites for melamine and the maximum adsorption amount was 1 066.33 μg g^（-1）. Later, 5-（4,6-d ichlorotriazinyl） amino fluorescein（DTAF） with a triazine ring, which s lightly resembles m elamine, w as selected as the fluorescent substance. The fluorescent competitive assay using DMIPs as t he antibody mimics was finally established by selecting and optimizing the reaction solvents, DMIPs amount, DTAF concentration, and incubation time. The optimal detection system showed a linear response w ithin range of 0.05-40 mg L^（-1） and the limit of detection（LOD） was 1.23 μg L^（-1）. It was successfully applied to the detection of melamine in spiked milk samples wi th satisfactory recoveries（71.9 to 86.3%）. According to the comparative analysis, the result of optimized fluorescent competitive assay re vealed excellent agreement with the HPLC-MS/MS result for melamine.

Using dummy data for RFID tag and reader authentication

Radio-Frequency IDentification(RFID)technology is an essential enabler of a multitude of intelligent applications.The robust authentication of RFID system components is critical in providing trustworthy data delivery from/to tags.In this paper,we propose an authentication protocol based on monitoring the transmissions between readers and tags in the system.The proposed authentication scheme is based on injecting decoys within the exchanged communications(between RFID readers and tags)and is used in the authentication process.Furthermore,the proposed authentication scheme is mathematically modeled and validated using extensive simulation.The simulations results show that the proposed scheme provides a 100%confidence level in the authentication of tags and detection of compromised readers.

Study of a 105 GHz short-pulse dummy load for the electron cyclotron resonance heating system with the quasi-optical method

The accurate power measurement is important for an ECRH system in tokamak.The dummy load is designed and developed for the measurement of the millimeter wave power.This work analyzes the dummy load based on the quasi-optical method and the ray tracing method.The reflectivity and thermal deposition of the dummy load have been considered to ensure the safety of the entire system.High-power tests have been carried out at a 105 GHz/500 kW ECRH system.The results of the tests indicate that the designed dummy load is stable and valid.

DUMMY ROV试验平台的设计及应用

DUMMY ROV用于模拟ROV,它是拥有工作级ROV的尺寸、远程操作模式和甲板操作功能的试验平台。在深水工程项目通常会使用尚未参加海上施工项目的ROV设备进行相关操作测试。但由于ROV水下作业环境与水上的差别,用于水下生产设备的ROV系统的陆地测试的效果往往不理想。以ROV使用操作要求及ROV硬件设备为基础搭建的DUMMYROV具备了工作级ROV的陆地操作能力,而且在陆地操控的耐受性上强于工作级ROV。

Influence of platform position on stray grain nucleation in Ni-based single-crystal dummy blade clusters

Stray grains are the most severe of the solidification defects that occur in the industrial single-crystal blade preparation process.In this study,a single-crystal dummy blade cluster with different crystal orientations controlled by the seeding method was prepared,and the influence of the position of the circular platform(relative to the sample and furnace body)on stray grain nucleation was investigated.Results show that the microstructure of the circular platforms could be divided into the center,expansion,and stray grain regions.The inside of the circular platform facing the center of the cluster is more prone to stray grain formation than the outside of the circular platform facing the furnace body.With an increase in the distance between the circular platform and the bottom of the dummy blade cluster,the stray grain region expands,whereas the expansion region narrows.The stray grain is slightly aggravated with increase of the misorientation.Finally,the mechanism underlying the influence of platform position on the formation of stray grains in single-crystal dummy blade clusters is discussed based on the temperature evolution during directional solidification.

Mechanism of single-event transient pulse quenching between dummy gate isolated logic nodes

As integrated circuits scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes.The so-called single-event transient（SET） pulse quenching induced by single-event charge sharing collection has been widely studied. In this paper, SET pulse quenching enhancement is found in dummy gate isolated adjacent logic nodes compared with that isolated by the common shallow trench isolation（STI）. The physical mechanism is studied in depth and this isolation technique is explored for SET mitigation in combinational standard cells. Three-dimensional（3D） technology computer-aided design simulation（TCAD） results show that this technique can achieve efficient SET mitigation.

A 600-m Jacketing Line of Cable-In-Conduit Conductor (CICC) and the First 600-m Dummy Cable

A cable-in-conduit conductor(CICC ) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0. 1×20.8±0.1, 20.4±0. 1×20.4± 0.1 and 18.6±0.1×18.6±0.1mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and X-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.

The Reliability of the Anaerobic Power Dummy Throw Test in High School Wrestlers:A Pilot Study

AP(anaerobic power)output is an important physical characteristic that is required to succeed in sports such as wrestling.The Wingate test is considered the Gold Standard for assessing AP but is not specific to the sport of wrestling.The purpose of this study was to examine the reliability of a novel field test known as the LWAPT(Lopez wrestling anaerobic power test)for the assessment of AP.The participants were male high school wrestlers(n=10,age:17.0±0.8 yrs,mass:70.9±10.2 kgs).The participants met on one occasion in order to complete the testing protocol.The protocol initiated with the participants completing a 10-15 minute dynamic WU(warm-up)that included three practice dummy throw attempts(dummy mass=31.75 kgs).Following the dynamic WU(≈5 minutes),the participants performed two trials of the LWAPT.In order to perform the LWAPT,wrestlers stood behind the wrestling dummy in a squat position with legs bent at 45-90 degrees.Next the wrestlers wrapped their arms around the waist of the dummy and on the signal“go”the wrestlers quickly exploded up,lifting the dummy by getting triple extension with the ankles,knees and hips as one would in a power clean.After the wrestler was fully extended,he turned in midair in order to drive the dummy onto its stomach on the ground,where the wrestler was on top of the back of the dummy(a common position after an opponent has been thrown).The participant then repositioned the dummy to the original position to execute another throw.The participants completed as many dummy throws as possible during the one minute trials.The LWAPT trials were separated by 15 minutes.The trial scores were 15.6±2.5 and 17.2±1.5 throws respectively.The interclass and intraclass reliability coefficients were r=0.84 and ICC=0.80.The standard error of the measure was SEm=1.0 throws with 90%confidence limits of UL:1.7,LL:0.7.The mean difference between trials was 1.6±1.4 throws(90%confidence limits of UL:2.4,LL:0.8).Bland-Altman plots suggested agreement between trials with no evidence of heteroscedasticity.The LWAPT exhibits moderate to high reliability as an assessment of AP.The inclusion of additional dummy throw trials to the assessment protocol may enhance the degree of reliability of the dummy throw test as a measure of AP.

Investigation on vehicle occupant dummy applicability for under-foot impactloading conditions

Purpose:Under-foot impact loadings can cause serious lower limb injuries in many activities,such asautomobile collisions and underbody explosions to military vehicles.The present study aims to comparethe biomechanical responses of the mainstream vehicle occupant dummies with the human body lowerlimb model and analyze their robustness and applicability for assessing lower limb injury risk in underfoot impact loading environments.Methods:The Hybrid III model,the test device for human occupant restraint(THOR)model,and a hybridhuman body model with the human active lower limb model were adopted for under-foot impactanalysis regarding different impact velocities and initial lower limb postures.Results:The results show that the 2 dummy models have larger peak tibial axial force and highersensitivity to the impact velocities and initial postures than the human lower limb model.In particular,the Hybrid III dummy model presented extremely larger peak tibial axial forces than the human lowerlimb model.In the case of minimal difference in tibial axial force,Hybrid III's tibial axial force(7.5 KN)isstill 312.5%that of human active lower limb's(2.4 KN).Even with closer peak tibial axial force values,thebiomechanical response curve shapes of the THOR model show significant differences from the humanlower limb model.Conclusion:Based on the present results,the Hybrid III dummy cannot be used to evaluate the lowerlimb injury risk in under-foot loading environments.In contrast,potential improvement in ankle biofidelity and related soft tissues of the THOR dummy can be implemented in the future for betterapplicability.