The IC failures induced by accidental dropping event of modern handheld electronic devices such as mobile phones may result from various failure modes such as cracking of package(PKG), solder joint, etc. Generally, th...
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ISBN:
(数字)9798350353808
ISBN:
(纸本)9798350353815
The IC failures induced by accidental dropping event of modern handheld electronic devices such as mobile phones may result from various failure modes such as cracking of package(PKG), solder joint, etc. Generally, the board level drop test is normally adopted to evaluate the IC failure risk instead of the set level drop test considering cost and efficiency. recently, however, the chip crack/damage failure rate in board level drop is much lower than that of mobile set level free drop. In this paper, a comprehensive study was performed to investigate the dynamic response characteristics of drop test with a customized PCB board when subjected to board level drop test and set level free drop test. The board level drop test was carried out according to JEdEC standard using a drop test apparatus, and the set level free drop test was employed by using the free drop machine. Moreover, two Finite Element models with reference to board level drop and set level free fall drop tests were developed to simulate the actual drop test scenarios based on two simplified FEA methods (Input-G method and impact velocity method, respectively). The simulation data were compared with experimental outputs to identify the FE Models in terms of accuracy of the results extracted. The dynamic key parameters of typical locations in PCB were analyzed to characterize performance difference during two kinds of drops. The measured and simulateddata of corresponding locations in set level drop are all larger than those of board level drop in terms of impact acceleration intensity andduration, the strain response and the simulated chip stress. Comparing with board level drop response, a greater acceleration impact would induce a greater strain response, subsequently, the stress subjecting to chip of IC package is greaterduring set level free drop. Thus, we can conclude that the impact effect of set level free drop is severer than that of board level drop from experiment and simulation results, this
Operational naval ship systems rely on advanced sensors and equipment to detect targets and manage weapon control and engagement. However, their growing complexity, driven by technological advancements and the increas...
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In the process of plugging wellbore with balanced plugging mud, hydration reaction kinetics, heat transfer and fluid mechanics interact with each otherduring the cement plugging stage, forming a complex physical and ...
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Sepsis is a life-threatening organ dysfunction caused by the dysregulatedresponse of the host to an infection, and treatments are limited. recently, a novel selenium source, selenium-enriched Cardamine violifolia(SEC...
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Sepsis is a life-threatening organ dysfunction caused by the dysregulatedresponse of the host to an infection, and treatments are limited. recently, a novel selenium source, selenium-enriched Cardamine violifolia(SEC) has attracted much attention due to its anti-inflammatory and antioxidant properties, but little is known about its role in the treatment of sepsis. Here, we found that SEC alleviated LPS-induced intestinal damage, as indicated by improved intestinal morphology, and increaseddisaccharidase activity and tight junction protein expression. Moreover, SEC ameliorated the LPS-inducedrelease of pro-inflammatory cytokines, as indicated by decreased IL-6 level in the plasma and jejunum. Moreover, SEC improved intestinal antioxidant functions by regulating oxidative stress indicators and selenoproteins. In vitro, TNF-α-challenged IPEC-1 cells were examined and showed that selenium-enriched peptides, which are the main functional components extracted from Cardamine violifolia(CSP), increased cell viability, decreased lactate dehydrogenase activity and improved cell barrier function. Mechanistically, SEC ameliorated LPS/TNF-α-induced perturbations in mitochondrial dynamics in the jejunum and IPEC-1 cells. Moreover, CSPmediated cell barrier function is primarily dependent on the mitochondrial fusion protein MFN2 but not MFN1. Taken together,these results indicate that SEC mitigates sepsis-induced intestinal injury, which is associated with modulating mitochondrial fusion.
distribution networks manage numerous devices, however, their level of automation is relatively low, often resulting in false signals andrelatively low data quality. Therefore, it has become extremely challenging to ...
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Grain size determination is essential in producing and testing iron and steel *** size determination of martensitic steels usually requires etching with picric acid to reveal the prior austenite grain ***,picric acid ...
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Grain size determination is essential in producing and testing iron and steel *** size determination of martensitic steels usually requires etching with picric acid to reveal the prior austenite grain ***,picric acid is toxic and explosive and belongs to hazardous chemicals,which makes it difficult for laboratories and testing institutions to obtain.A new experimental method was developed to use Nital etchant instead of picric *** deep learning method was used to recognize the prior austenite grain boundaries in the etched martensite microstructure,and the grain size could be determined according to the recognition ***,the polished martensite specimen was etched twice with Nital etchant and picric acid,respectively,and the same position was observed using an optical *** images of the martensitic structure and its prior austenite grain boundary label were obtained,and a data set was ***,based on this data set,a convolutional neural network model with a semantic segmentation function was trained,and the accuracy rate of the test set was 87.53%.Finally,according to the recognition results of the model,the grain size rating can be automatically determined or provide a reference for experimenters,and the difference between the automatic determination results and the measuredresults is about 0.5 level.
This research paper presents a comparative study of machine learning (ML) algorithms for the predictive modelling of spot-welding process parameters. The focus is on predicting the nugget diameter (Nd) and nugget heig...
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Lithium all-solid-state batteries (LASSBs) face the challenge of poor performance, interface contact between electrodes, limiting voltage window of solid electrolytes, side reactions between cathode/solid electrolyte,...
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Using K2S2O8-Na2SO3 as the redox initiation system,a hydrogen-bond-association-baseddodecyl methacrylate system associative anti-sheardrag reducer was synthesised by standard emulsion *** reaction process was simple...
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Using K2S2O8-Na2SO3 as the redox initiation system,a hydrogen-bond-association-baseddodecyl methacrylate system associative anti-sheardrag reducer was synthesised by standard emulsion *** reaction process was simple and gentle as well as safe and *** design was carried out using moleculardynamics simulation *** results of infrared spectroscopy,thermogravimetric analysis,differential scanning calorimetry,gel chromatography,and laser light scattering showed that the reaction polymerisation was relatively complete,the product was uniform,the molecular weight distribution was controllable,and the synthesised polymer had good *** donor lauryl methacrylate-styrene-methacrylic acid(LMA-St-MAA)and acceptor lauryl methacrylate-styrene-dimethylaminoethyl methacrylate(LMA-St-dMA)polymers had an associative intermolecular interaction force,which increased the molecular cluster size of the associative system *** complex had good shearresistance,and the test results of the tube pump shear test showed that the synthesised associative oil-soluble polymerdrag reduction system exhibited betterdrag reduction rate performance than poly-α-olefins overrepeated *** research results provide a reference plan for minimising the number of station-to-station inputs,thereby ensuring the stability of oil pipelines andreducing transportation costs.
Thin-film transistors (TFT) and organic light-emitting diodes (OLEd) fordisplay applications involve new materials, structures and processes in the design anddevelopment phase, and these elements can have a signific...
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