基于Arduino与Processing的心率检测计设计研究

随着社会经济的高速发展,人们的物质生活也有了极大的提高,但同时也伴随着各种疾病的到来,身体健康已经成为人们普遍关注的焦点,因此,心率检测仪、血压计、血糖仪等各种家用医疗监测仪器已经逐渐融入日常生活。心脏病是人们难以预防的突发致命疾病之一,本文介绍的是一款基于Arduino【是基于易用硬件和软件的原型开源平台,包由可编程的电路板(简称微控制器),以及集成开发环境(称为Arduino IDE)的现成软件组成】Processing(开源编程语言,包括编辑器、编译器、展示器)的简易心率检测计系统,其功能实用、操作简单,可以测量心率,当超出正常心率范围时及时预警,是一款便携的实时心率测试仪。

Structure and electrochemical properties of hypo-stoichiometric hydro-gen storage alloys prepared by twin-roller rapid quenching process

The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show that both of the alloys have a typical single-phase hexagonal CaCus-type structure. The cell volume of the hylpo-stoichiometric alloy M1B4.85 is slightly larger than that of the stoichiometric alloy M1B5.0, although its lattice constant cla is smaller. Under 2 C discharging rate, i.e. 640 mA/g, the M1B4.85 has a discharge capacity of 320 mAh/g, which is higher than that of the M1Bs.o, 312 mAh/g. Nevertheless, the capacities of the M1B4.85 and the M1Bs.o decline 24.7% and 20.2% after 400 cycles, respectively. The relationship of electrochemical performances of the alloys with their structures is discussed.

Dynamic tensile behaviors of AZ31B magnesium alloy processed by twin-roll casting and sequential hot rolling

The dynamic tensile behavior of twin-roll cast-rolled and hot-rolled AZ31B magnesium alloy was characterized over strainrates ranging from 0.001 to 375 s^-1 at room temperature using an elaborate dynamic tensile testing method, and the relationshipbetween its mechanical properties and microstructures. It is observed that the sheet has a strong initial basal fiber texture andmechanical twinning becomes prevalent to accommodate the high-rate deformation. The yield strength and ultimate tensile strengthmonotonically increase with increasing the strain rate, while the strain hardening exponent proportionally decreases with increasingthe strain rate due to twinning-induced softening. The total elongation at fracture distinctly decreases as the strain rate increasesunder quasi-static tension, while the effect of strain rate on the total elongation is not distinct under dynamic tension. Fractographicanalysis using a scanning electron microscope reveals that the fracture is a mixed mode of ductile and brittle fracture.

Bonding strength of Invar/Cu clad strips fabricated by twin-roll casting process

Based on traditional twin-roll casting process,Invar/Cu clad strips were successfully fabricated by using solid Invar alloy strip and molten Cu under conditions of high temperature,high pressure and plastic deformation.A series of tests including tensile test,bending test,T-type peeling test and scanning electron microscope(SEM)and energy dispersive spectrometer(EDS)measurements were carried out to analyze the mechanical properties of Invar/Cu clad strips and the micro-morphology of tensile fracture surfaces and bonding interfaces.The results indicate that no delamination phenomenon occurs during the compatible deformation of Invar/Cu in bending test and only one stress platform exists in the tensile stress-strain curve when the bonding strength is large.On the contrary,different mechanical properties of Invar and Cu lead to delamination phenomenon during the uniaxial tensile test,which determines that two stress platforms occur on the stress-strain curve of Invar/Cu clad strips when two elements experience necking.The average peeling strength can be increased from13.85to42.31N/mm after heat treatment at800℃for1h,and the observation of the Cu side at peeling interface shows that more Fe is adhered on the Cu side after the heat treatment.All above illustrate that heat treatment can improve the strength of the bonding interface of Invar/Cu clad strips.

Constraints on Characteristics and Distribution of Gas Hydrate and Free Gas Using Broad-Band Processing of Three-Dimensional Seismic Data

Gas hydrate drilling expeditions in the Pearl River Mouth Basin,South China Sea,have identified concentrated gas hydrates with variable thickness.Moreover,free gas and the coexistence of gas hydrate and free gas have been confirmed by logging,coring,and production tests in the foraminifera-rich silty sediments with complex bottom-simulating reflectors(BSRs).The broad-band processing is conducted on conventional three-dimensional(3D)seismic data to improve the image and detection accuracy of gas hydratebearing layers and delineate the saturation and thickness of gas hydrate-and free gas-bearing sediments.Several geophysical attributes extracted along the base of the gas hydrate stability zone are used to demonstrate the variable distribution and the controlling factors for the differential enrichment of gas hydrate.The inverted gas hydrate saturation at the production zone is over 40% with a thickness of 90 m,showing the interbedded distribution with different boundaries between gas hydrate-and free gas-bearing layers.However,the gas hydrate saturation value at the adjacent canyon is 70%,with 30-m-thick patches and linear features.The lithological and fault controls on gas hydrate and free gas distributions are demonstrated by tracing each gas hydrate-bearing layer.Moreover,the BSR depths based on broad-band reprocessed 3D seismic data not only exhibit variations due to small-scale topographic changes caused by seafloor sedimentation and erosion but also show the upward shift of BSR and the blocky distribution of the coexistence of gas hydrate and free gas in the Pearl River Mouth Basin.

NUMERICAL SIMULATION OF MOLTEN POOL AND CONTROL STRATEGY OF KISS POINT IN A TWIN-ROLL STRIP CASTING PROCESS

Coupled turbulent flow, temperature fields of the twin-roll casting strip process were simulated by three-dimensional finite element method. Based on the heat balance calculation and using inverse methods between the simulations and real experiments, the relational models among casting speed, location, and coefficient of heat transfer between molten metal and rolls in different regions are given. In the simulation, the calculated surface temperatures are in good agreement with the measured values. An on-line model of kiss point is derived by simulations and the geometry of molten pool, corresponding control strategy is also proposed.

Design and optimization of a greener sinomenine hydrochloride preparation process considering variations among different batches of the medicinal herb

The current methods used to industrially produce sinomenine hydrochloride involve several issues,including high solvent toxicity,long process flow,and low atomic utilization efficiency,and the greenness scores of the processes are below 65 points.To solve these problems,a new process using anisole as the extractant was proposed.Anisole exhibits high selectivity for sinomenine and can be connected to the subsequent water-washing steps.After alkalization of the medicinal material,heating extraction,water washing,and acidification crystallization were carried out.The process was modeled and optimized.The design space was constructed.The recommended operating ranges for the critical process parameters were 3.0–4.0 h for alkalization time,60.0–80.0℃ for extraction temperature,2.0–3.0(volume ratio)for washing solution amount,and 2.0–2.4 mol·L^(-1) for hydrochloric acid concentration.The new process shows good robustness because different batches of medicinal materials did not greatly impact crystal purity or sinomenine transfer rate.The sinomenine transfer rate was about 20%higher than that of industrial processes.The greenness score increased to 90 points since the novel process proposed in this research solves the problems of long process flow,high solvent toxicity,and poor atomic economy,better aligning with the concept of green chemistry.

Simulation of critical cooling rate and process conditions for metallic glasses in vertical type twin-roll casting

Critical cooling rates for producing metallic glasses were evaluated based on a calculated continuous cooling transformation(CCT)diagram.Temperature distributions of the melt in molten pool in the vertical type twin-roll casting(VTRC)process of metallic glasses were simulated,and cooling rates under different casting conditions were calculated with the simulated results.By comparing the results obtained by CCT diagrams and simulation,the possibility of producing metallic glasses by the VTRC method and influences of casting conditions on cooling rate were discussed.The results reveal that cooling rate with3or4orders of magnitude by the VTRC process can be attained in producing Mg-based metallic glasses,which is faster than the critical cooling rate calculated by the CCT diagram.One side pouring mode can improve the temperature distributions of casting pool.VTRC process has a good ability in continuous casting metallic glassy thin strips.

Heat transfer analysis and experimental study of unequal diameter twin-roll casting process for fabricating Cu/Al clad strips

Unequal diameter twin-roll casting(UDTRC)can improve the formability,surface conditions,and production efficiency during the fabrication of clad strips.Using Fluent software,a numerical simulation is used to study the asymmetric heat transfer characteristics of Cu/Al clad strips fabricated by UDTRC.The effects of roller velocity ratio,Cu strip thickness,and inclination angle on the kissing point position,as well as the entire temperature distribution are obtained.The heat transfer model is established,and the mechanism is discussed.The Cu strip and rollers are found to be the main causes of asymmetric heat transfer,indicating that the roller velocity ratio changes the liquid zone proportion in the molten pool.The Cu strip thickness determines the heat absorption capacity and the variations in thermal resistance between the molten Al and the big roller.The inclination angle of the small roller changes the cooling time of big roller to molten Al.Moreover,the microstructure of Al cladding under different roller velocity ratios is examined.The results show significant grain refinement caused by the shear strain along the thickness direction of Al cladding and the intense heat transfer at the moment of contact between the metal Al cladding and Cu strip.

Investigation of the solute transportation coupled with heat transfer and fluid flow during twin-roll strip casting process

Mathematical model of solute [C] distribution in twin-roll strip casting process has been setup successfully with Calcosoft for the first time. Simulation result shows that in the center of the molten steel pool between the two rolls there is a vortex flow, which is a solute enriched area. But the highest solute concentration position is at the solidification front of the columnar grain zone near the cooling roll surface. Another solute enriched position is in the back flow above the nip point. Combined with the formation mechanism of microstruoture in final as cast strip, analysis shows that solute enriched area is in the transitional area between columnar and equiaxed grain zone.

Investigation on taste characteristics and sensory perception of soft-boiled chicken during oral processing based on electronic tongue and electronic nose

The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.

Mathematical modeling of fluid flow and level profile during twin-roll strip casting process

In twin-roll strip casting process,transport phenomena of fluid in the molten pool directly affect the process stability and the quality of products.In order to elucidate the fundamental transport phenomena in twin-roll casting,a commercial software called ProCAST was employed to simulate the transient fluid flow and level profile behaviors during the early stage of the process in this study.The coupled set of governing differential equations for mass,momentum and energy balance were solved with the finite element method and the transient free surface problem was treated with a volume of fluids(VOF) approach.The effect of different delivery systems configuration on flow pattern,level profile in the pool was studied and analyzed in this paper. The new wedge metal delivery systems have been optimized for the twin-roll strip caster.It was shown that new type metal delivery systems had a preferable effect on the uniform distribution of fluid and level fluctuation in the pool.The simulation results also provide a valuable basis for the optimization of delivery system and process parameters during the initial pouring stage.

A new insight into LPSO phase transformation and mechanical properties uniformity of large-scale Mg-Gd-Y-Zn-Zr alloy prepared by multi-pass friction stir processing

A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was investigated.Moreover,a quantitative relationship between the microstructure and tensile yield strength was established.The results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were broken.In IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute atoms.The severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO phase.After MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% respectively.Grain refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP sample.In particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in IZ.This result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate.

Recent developments in selective laser processes for wearable devices

Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to develop original solutions to such challenging technological problems due to their remote,sterile,rapid,and site-selective processing of materials.In this review,recent developments in relevant laser processes are summarized under two separate categories.First,transformative approaches,such as for laser-induced graphene,are introduced.In addition to design optimization and the alteration of a native substrate,the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors,or the sequential addition of functional layers coupled with other electronic elements.In addition,the more conventional laser techniques,such as ablation,sintering,and synthesis,can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new mechanisms.Later,various wearable device components developed through the corresponding laser processes are discussed,with an emphasis on chemical/physical sensors and energy devices.In addition,special attention is given to applications that use multiple laser sources or processes,which lay the foundation for the all-laser fabrication of wearable devices.

Effect of bubble morphology and behavior on power consumption in non-Newtonian fluids’aeration process

Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm.

Multistate transition and coupled solid-liquid modeling of motion process of long-runout landslide

The recognition,repetition and prediction of the post-failure motion process of long-runout landslides are key scientific problems in the prevention and mitigation of geological disasters.In this study,a new numerical method involving LPF3D based on a multialgorithm and multiconstitutive model was proposed to simulate long-runout landslides with high precision and efficiency.The following results were obtained:(a)The motion process of landslides showed a steric effect with mobility,including gradual disintegration and spreading.The sliding mass can be divided into three states(dense,dilute and ultradilute)in the motion process,which can be solved by three dynamic regimes(friction,collision,and inertial);(b)Coupling simulation between the solid grain and liquid phases was achieved,focusing on drag force influences;(c)Different algorithms and constitutive models were employed in phase-state simulations.The volume fraction is an important indicator to distinguish different state types and solid‒liquid ratios.The flume experimental results were favorably validated against long-runout landslide case data;and(d)In this method,matched dynamic numerical modeling was developed to better capture the realistic motion process of long-runout landslides,and the advantages of continuum media and discrete media were combined to improve the computational accuracy and efficiency.This new method can reflect the realistic physical and mechanical processes in long-runout landslide motion and provide a suitable method for risk assessment and pre-failure prediction.

Efficient stochastic parallel gradient descent training for on-chip optical processor

In recent years,space-division multiplexing(SDM)technology,which involves transmitting data information on multiple parallel channels for efficient capacity scaling,has been widely used in fiber and free-space optical communication sys-tems.To enable flexible data management and cope with the mixing between different channels,the integrated reconfig-urable optical processor is used for optical switching and mitigating the channel crosstalk.However,efficient online train-ing becomes intricate and challenging,particularly when dealing with a significant number of channels.Here we use the stochastic parallel gradient descent(SPGD)algorithm to configure the integrated optical processor,which has less com-putation than the traditional gradient descent(GD)algorithm.We design and fabricate a 6×6 on-chip optical processor on silicon platform to implement optical switching and descrambling assisted by the online training with the SPDG algorithm.Moreover,we apply the on-chip processor configured by the SPGD algorithm to optical communications for optical switching and efficiently mitigating the channel crosstalk in SDM systems.In comparison with the traditional GD al-gorithm,it is found that the SPGD algorithm features better performance especially when the scale of matrix is large,which means it has the potential to optimize large-scale optical matrix computation acceleration chips.

Cascading multi-segment rupture process of the 2023 Turkish earthquake doublet on a complex fault system revealed by teleseismic P wave back projection method

In this study,the vertical components of broadband teleseismic P wave data recorded by China Earthquake Network are used to image the rupture processes of the February 6th,2023 Turkish earthquake doublet via back projection analysis.Data in two frequency bands(0.5-2 Hz and 1-3 Hz)are used in the imaging processes.The results show that the rupture of the first event extends about 200 km to the northeast and about 150 km to the southwest,lasting~90 s in total.The southwestern rupture is triggered by the northeastern rupture,demonstrating a sequential bidirectional unilateral rupture pattern.The rupture of the second event extends approximately 80 km in both northeast and west directions,lasting~35 s in total and demonstrates a typical bilateral rupture feature.The cascading ruptures on both sides also reflect the occurrence of selective rupture behaviors on bifurcated faults.In addition,we observe super-shear ruptures on certain fault sections with relatively straight fault structures and sparse aftershocks.

Management and classification of the fracture of lateral process of talus:An overview and literature update

Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research on FLPT,there has been a breakthrough in the classification,and the methods and principles of clinical management have changed accordingly;however,there is still no standardized guideline for the diagnosis and management of FLPT,and there have been few relevant literature review articles related to this kind of fracture in the past at least 5 years.In this article,we review the clinical classification,classification-based therapeutic recommendations,and prognosis of FLPT,with the aim of providing a reference for the clinical diagnosis and management of this infrequent fracture.

Reinforcement Learning in Process Industries:Review and Perspective

This survey paper provides a review and perspective on intermediate and advanced reinforcement learning(RL)techniques in process industries. It offers a holistic approach by covering all levels of the process control hierarchy. The survey paper presents a comprehensive overview of RL algorithms,including fundamental concepts like Markov decision processes and different approaches to RL, such as value-based, policy-based, and actor-critic methods, while also discussing the relationship between classical control and RL. It further reviews the wide-ranging applications of RL in process industries, such as soft sensors, low-level control, high-level control, distributed process control, fault detection and fault tolerant control, optimization,planning, scheduling, and supply chain. The survey paper discusses the limitations and advantages, trends and new applications, and opportunities and future prospects for RL in process industries. Moreover, it highlights the need for a holistic approach in complex systems due to the growing importance of digitalization in the process industries.