bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of A New Differential Scanning Calorimeter
Authors: Zhong Xiaoqin , Niu Xiaojian , Lu Baokang , Shen Xiuguo 
Published: August 2020

Abstract
The core component of DSC is a temperature difference sensor used to measure the temperature change of sample and reference material during reaction. Taking temperature difference sensor as the research object, a new DSC is designed, which uses many pairs of thermocouples in series to form a radiating thermocouple stack to improve the calorimetric sensitivity of the temperature difference sensor and reduce the measurement error caused by the uneven temperature distribution on the sensor. Through theoretical analysis, it can be seen that the original signal acquisition volume of the temperature difference sensor with multiple pairs of thermocouples has increased greatly, the calorimetric sensitivity is higher, and the error is smaller. Based on the finite element analysis software ANSYS, the steady state thermal analysis is performed on the high-sensitivity temperature difference sensor and the dumbbell-type temperature difference sensor respectively. The results show that the temperature difference of the high-sensitivity temperature difference sensor is 40.8% ∼ 52.3% lower than that of the dumbbell-type temperature difference sensor under different working temperatures, which greatly reduces the measurement error caused by the uneven temperature distribution.
An Experiment Method of Choosing Structure of shrouded power turbine blade
Authors: Tiancai Guo , Youliang Xu , Yanong Chen , Yunqiu Zhang 
Published: August 2020

Abstract
The turbine blade presents various failure modes in service. The stress concentration located near the shroud can result in fracture failure, thus the structural optimization of the shroud is the main focus for mechanical engineers. Stress concentration is difficult to accurately evaluate by calculation and needs to be verified by experiment. Three-dimensional photoelastic test is an important method of program preference. This paper conducts three-dimensional photoelastic tests on shrouded turbine blades with different structures to select structures with minimum concentrated stress. It is shown in the experiment results that the stress fringe pattern clearly shows the stress distribution trend and stress concentration area of the blades, which shows the quality of design intuitively. It shows that photoelastic test can provide a reliable test basis for the design and model selection of small aeroengine shrouded turbine blades. The advantage of this method is that it is a fast, economical and intuitive method of program preference. The method has been successfully applied in a self-developed small aeroengine shrouded turbine blades.
Effects of strain paths on the fracture forming limit of high strength structural steel sheets
Authors: Xu Teng , Xia Qin-xiang , Qi Zhen-jie , Wu Xiao-yu , Ran Jia-qi , Gong Feng 
Published: August 2020

Abstract
The cruciform two-axial tensile specimen was designed and the two-axial tensile test scheme for different strain paths was developed. The effect of strain paths on the forming limit of high strength structural steel plates was obtained by the DIC method. The results show that for the unidirectional alternating loading test scheme, the equivalent strain of the ultimate strain is less than the sum of the equivalent strains from each step. When the main strain direction of the specimen pre-strain is perpendicular to the final strain path, the forming limit decreases with the increase of the pre-strain.
Study on the design of internal flash cleaning device in long diameter drill pipe used in coal mine
Authors: Fei Lan 
Published: August 2020

Abstract
This paper takes the long diameter geological drill pipe used in coal mine as the research object. The internal flash cleaning technology which remains in the drill pipe hole after the internal flash turning is studied. A hand - held pneumatic internal flash cleaning device was designed to replace the original manual way of removing iron filings. It greatly reduces the labor intensity of workers, improves the working environment, and shortens the cleaning time of flash inside a single drill pipe. This device greatly improves the work efficiency and makes it safer and more reliable to use.
Mechanics model and optimum design of PE pellet shell for anti-water-seepage with ease in open
Authors: Gu Lizhi , Huang Ehui , Song Jinling , Liang Fengshun , Huang Lihong , Fang Yongying , Chen Suhang 
Published: August 2020

Abstract
Polyethylene capsule shells are a kind of container for pills with low cost and long-term preservation, after paraffin-sealed. This kind of pellet shell is composed of two hemispheric shells with the seal convex and concave allowances, at which they connect, locate and unify together as a whole by local elastic deformation. However, the water seepage occurs in certain percentage of the pills during paraffin-seal operation. In order to solve the problem of water seepage and further improve the process, the current study presents the tension model under the action of ideal gas in paraffin-sealing, the enhanced cantilever beam model under water cooling, and the simply supported beam model for investigation of the cause of the water seepage. The criterion of impervious water was put forward and developed with anti-inference method. The case analysis shows that the seepage is caused by the unreasonable structure of the seal of PE pellet. On the basis of this, the seal allowance of the shell is improved and optimized in the current design. And the overlap amount of the half shells was increased from 0.15mm to 0.30mm, at least, with protruding and half shot shell with concave is increased and the small Angle of the double V structure is adopted. The results of calculation and test show that the new design is of rational and reliability, and it met the requirements of small force and ease in opening the shell.
A novel test rig development for experimental study of fluid mechanics of hydraulic orifice and/or gaps under high or low temperature conditions
Authors: Wang Wenlin , Xu Jiabing , Kong Xin , Wu Yongming 
Published: August 2020

Abstract
To meet the demand of ever operating in extreme environments of modern high-end vehicles or machineries, it is meaningful to perform basic research on fluid mechanics of hydraulic orifices and/or gaps under high or low temperature conditions. In this study, a novel compact experimental module which integrates the oil, the oil supply mechanism, the testing damping valve with orifices and/or gaps and several sensors was proposed, the experimental module has avoided the bulky method of using a full hydraulic system for oil supply and can be wholly placed into a high/low temperature chamber to undertake experiments; Based on the integrated experimental module, a test rig employing a variable-frequency-motor-driven ball screw driver to excite the testing module was developed. By using the virtual instrument technology, the hardware and software of automatic measurement and control system was further developed, so the automatic control and data collection of the test rig was realized. Final results show that the test rig can conveniently perform fluid mechanics experiments for various hydraulic orifices and/or gaps under high or low temperature conditions with high efficiency, so the test rig can be a very good platform for pertinent basic research works.
An experimental study on the discharge coefficient of a sharped-edged hydraulic orifice
Authors: Wang Wenlin , Cao Xiaochang , Kong Xin , Wu Yongming 
Published: August 2020

Abstract
Aiming at performing basic research on fluid mechanics of hydraulic orifices under high or low temperature conditions, in this study, a novel compact experimental module, which integrates the oil, the oil supply mechanism, the test valve with orifice and several sensors, was firstly developed, the experimental module can be wholly placed into a high/low temperature chamber to undertake experiments; Based on the integrated experimental module, an automatic measurement test rig was further developed. By using the test rig, experiments on flow characteristics of a sharp-edged hydraulic orifice, which uses the anti-wear hydraulic oil HM46 as the working fluid, were conducted in a temperature range of -10°C∼+80°C, the Flow-Pressure Characteristics and Discharge Coefficient of the hydraulic orifice were obtained by curve fitting, the effects of different temperatures on the Discharge Coefficient and damping force were finally investigated. The results show that in the temperature range up to room temperature of 20°C, the Flow-Pressure characteristics, the Discharge Coefficient and damping force of the sharp-edged orifice are not sensitive to temperature changes, but when the temperature is below room temperatures, the discharge coefficient drops linearly, and the damping force increases with the decreasing of temperatures.
Study on the characteristics of metal magnetic memory signal of X70 pipeline steel
Authors: Zhang Xiyong , Chen Yun , Chen Yonghong 
Published: August 2020

Abstract
In view of the zero crossing phenomenon of the normal component of the magnetic memory signal on the surface of the ferromagnetic component in the crack or stress concentration, many scholars have disputes about it. In this paper, through the simulation of the crack by wire cutting, the normal component of the magnetic leakage signal on the surface of the pipeline component is stretched on the tensile testing machine, and the normal component of the magnetic memory signal on the surface of the pipeline component is analyzed. It is found that the zero crossing phenomenon does exist in the normal component of the crack, but the zero crossing occurs with the pulling when the load increases to a certain extent, it will not drift after passing the zero point. The results show that the normal component cannot be used to judge the crack or stress concentration simply.
Simulation Analysis of Installation Process of Long stern Shaft of Large Ship
Authors: Zhou J H , Shi H 
Published: August 2020

Abstract
Due to the large journal and long length, the installation of the stern shaft on the large ship is very difficult. In view of this situation, the numerical method based on three bending moments is used to analyze the number and arrangement position of temporary support during the installation of the stern shaft, to solve the change of the deflection and stress of the stern shaft and the reaction force of temporary support, and to obtain the influence law of the number and arrangement position of temporary support on the deflection and stress of the stern shaft. The calculation results show that when the stern shaft is pushed into the rear end face of the fore stern bearing, the deflection of the front end of the stern shaft is too large to pass the fore stern shaft tube bearing smoothly, so that a new technology of the guide shaft fixing at the front of the stern shaft was adopted, the structure, size and hoisting mode of the guide shaft were optimized, and the smooth installation of the long stern shaft was realized. The research results can provide a theoretical reference for the installation analysis and calculation of stern shaft section of large ships.

Chinese library classification no. : U662.2
DEKA VII Multipoint Fuel Injector Application Study
Authors: Li Fu , Suli Feng , Weidong Xiang 
Published: August 2020

Abstract
Injectors must be capable of metering and delivering the fuel in the form of an optimized spray into the engine. That is to meet increasing requirements of emission related legislations and better engine running conditions. Every engine has unique requirements, technical background, parameters, etc. In order to determine the optimized injector characteristics, communications and joint efforts are necessary between the customer system engineering and the DEKA VII injector application. The study will provide general technical guidance.
A Thermal Conductivity Predictive Method of Graphene Epoxy Nanocomposites
Authors: Wang Danyong , Zhang Haiyun , Wei Huazhen , Li Shuhu 
Published: August 2020

Abstract
Interfacial interaction between flaked graphene and epoxy was the key element of effecting whether graphene as nanofillers could improve some of the properties of epoxy. Based on really materials and applied manufacturing process, a new kind of a thermal conductivity predictive method for graphene epoxy nanocomposites which could compute and analyze thermal conductivity of any content ratio of graphene in the epoxy with only one content ratio was built in order to provide theoretical foundations for design and property of graphene epoxy nanocomposites. According to practically different materials system and corresponding manufacturing processes, few experiments which only needed thermal conductivity of one random content-ratio graphene epoxy nanocomposites were made to predict effective thermal conductivity of any other content ratio of graphene epoxy nanocomposites under the same manufacturing processes by obtaining experimental constants based on numerical progressive iterative approximation method and compute the above experimental constants as basic materials parameters so as to build the whole analysis model in the next step. An excellent agreement was found between data obtained from this study and the experiment.
Effect of cold rolling process on microstructure and properties of T1 Copper sheet
Authors: Sun Shuo , Li Ting-qu 
Published: August 2020

Abstract
The 8mm thick T1 state copper plate was cold rolled into 3mm, 2mm and 1mm thin plate sections, and its microstructure and texture were analyzed by optical metallographic microscope and X-ray diffraction (XRD). The mechanical properties were tested by cupping machine and micro-hardness tester. The results show that with the increase of cold rolling deformation, the grain size decreases and a strong (220) diffraction surface texture appears. The highest tensile strength is 421.76MPa, and the microhardness is 129.9HV, all of which are greatly improved, but the elongation decreases from 40% to 5%, and the fracture morphology changes from ductile fracture to quasi cleavage fracture.
A Study on the Microstructure Strengthening Phase of the TC4 strengthened Layer by powder-mixed near-dry EDM
Authors: Junling Zhao , Lanrong Cai , Min Li 
Published: August 2020

Abstract
The surface of TC4 titanium alloy was strengthened by powder-mixed near-dry EDM. In the research, the experimental investigation analyzed the influence of pulse on time and electrode polarity on strengthened layer microstructure of TC4 titanium alloy. The wear of the substrate surface and the strengthened layer was measured. The results showed that the number of corrosion pits and petal-like tissues of the strengthening layer increases first and then decreases with the increase of pulse on time. The more petals and pit tissues were obtained by negative electrode than positive electrode. When the pulse on time is 100μs and the electrode polarity is negative, it is beneficial to produce the petal-like and pit-like tissues. The petal-like strengthening phase is the key factor affecting the wear resistance of the strengthened layer. The experimental revealed that the wear resistance of the strengthened layer is about 3.5 times as much as that of the substrate.
The effect of laser surface treatment on the adhesive bonding performance of aluminum alloy
Authors: Wang W , Xu J W , Chen X , Liang Y J , Zhu L Z 
Published: August 2020

Abstract
For the purpose of convenient treatment before gluing and improving the adhesive bonding performance, we compared the tensile shear strengths of epoxy adhesive bonding to 2A12 aluminum with preferred pre-treatments. Taking advantages on both convenience and pre-treatment quality, we investigated the influences of duration of laser treatment on the adhesive bonding strength to obtain the optimized extents of laser treatment. With the analysis of scanning electron microscopy, laser confocal scanning microscopy and contact angle measurements adopted to characterize the surface morphology, roughness and wettability, respectively, we discussed the effects of pre-treatments on the surface status and adhesive bonding. As a result, we proposed a pre-treatment with laser treatment on aluminum to improve adhesive bonding performance, by which the removal of oxide layer, surface roughening and cleaning were easily accomplished before gluing.
Effect of polypropylene fiber content on compressive and flexural performance of recycled concrete
Authors: Hongbing Zhu , Bei Han , Na Zhang 
Published: August 2020

Abstract
Recycled concrete was a kind of green, environmental protection and energy-saving building material, and its mechanical properties can be improved by adding polypropylene fiber. Taking the polypropylene fiber content as a parameter, experiment of cube compressive strength and bending strength on polypropylene fiber recycled aggregate concrete (PFRAC) and natural aggregate concrete were done, among which the PFRAC has 50% replacement rate of recycled aggregate. Through the comparison of strength and fracture mode of specimens, the influence of polypropylene fiber content on the pressure resistance and fracture resistance of recycled concrete were studied, and the recycled concrete’s appropriate amount of polypropylene fiber which strength can reach to natural aggregate concrete were obtained. The results were as follows: the compressive strength and bending strength of recycled concrete with polypropylene fiber were obviously intensified and the strength continuously intensifies along with the adding of fiber content. The compressive strength and bending strength of PFARC exceed that of natural aggregate concrete when fiber content was up to 1.0kg/m3. The recycled concrete with polypropylene fiber can still maintain the property of crack without breaking after damage, and the britttle fracture morphology wouldn’t occur in it.
Electrochemical Synthesis of Al-Sm Metal by Coreduction of Sm(III) and Al(III) in a K3A1F6 Melt
Authors: Zhang Zhen , Zhang Xiao-Lian 
Published: August 2020

Abstract
The electrochemical behaviors of Sm(III) in the molten K3A1F6 system were investigated with a tungsten electrode at 1024 K. By electrochemical tests, including cyclic voltammetry and square wave voltammetry, Sm(III) was reduced to Sm(0) in two steps. The diffusion coefficient of Sm(III) was 1.90*10−5 cm2/s when examined by using cyclic voltammetry in the molten salts. The electrochemical signal of the Al-Sm intermetallic compound was detected at -1.71 V and -2.22 V. AlSm2 and Al3Sm were obtained by potentiostatic electrolysis at -2.3 V for 10 h. These intermetallic compounds were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy with energy.
Preparation and characterization of Salix Psammophila cellulose and Mic-cellulose under the pretreatment of two kinds of acid
Authors: Yuan ZHONG , Ke-bing WANG , Yu-ling LIU , Xue WANG 
Published: August 2020

Abstract
The pretreatment of salix psammophila (SP) with HNO3-ethanol and HC1-ethanol, followed by the treatment with sodium chlorite and KOH, were investigated to obtain SP cellulose. Microcrystalline cellulose was prepared by hydrochloric acid hydrolysis from cellulose treated with nitric acid. The cellulose was characterized by FTIR, XRD, TG, SEM and DSC. The yield of cellulose pretreated with nitric acid and hydrochloric acid were 38.89% and 35.14%, respectively. Infrared spectroscopy showed that lignin and hemicellulose were separated from the extracted cellulose. The SEM photos showed that the width of the extracted cellulose was 5.71 μm and 6.92 μm respectively. XRD analysis showed that the crystallinity of the two groups was 54.13% and 60.86%, respectively. TG analysis showed that the amount of residue showed an increasing trend, and the residual amount extracted from cellulose was 6.67% and 7.90% respectively. In the SEM image of microcrystalline cellulose, a slender structure with a crystallinity of 59.32% was proposed, which had better thermal stability than cellulose.
The characterization and application of chip topside bonding materials for power modules packaging: a review
Authors: Liu Keming , Yang Jinlong , Luo Jian , Wang Li , Huang Quanquan , Chen Fei 
Published: August 2020

Abstract
Bonding material is one weak point in power modules packaging, and can limit the lifetime of power modules. Multiple bonding materials have been manufactured and applied in the power modules such as aluminum wire, copper wire, aluminum ribbon, copper ribbon, Al-clad-Cu wire, direct-bonding-lead. For bonded power modules packging, bonding ability, electrical and thermal conductivity, current carrying capacity, working reliability are the main applying properties of bonding materials. This paper demonstrates the characterization, failure mode & failure mechanism, life-time calculation model of the normal used bonding materials and estimates the developing tendency.
Preparation and properties of polystyrene composites modified by macromolecular antioxidant
Authors: Chen Qi , Xie Zhiwei , Xu Xu , Xu Wei , Huang Yufan , Zhang Yingqiang 
Published: August 2020

Abstract
A macromolecular antioxidant was prepared by copolymerization with styrene and modified A1010-co-PS. Its chemical structure was confirmed by Fourier transform infrared (FTIR). It was added into the formula of PS composite material and the thermal and oxygen aging experiment was carried out on the material. The tensile strength is stable at about 27MPa, the bending strength is stable at about 33MPa, and the impact strength is stable at about 2.3kJ/m2. The results show that it has a more significant effect than antioxidant 1010 and has higher performance stability.
Research Progress of the Preparation and Properties Graphene Cement Composite
Authors: Huang Z L , Qin X T , Mao Z X , Lan H , Tong W H , Zhu S Y 
Published: August 2020

Abstract
Graphehe has extremely great mechanical, electrical and thermal properties that make them ideal reinforcing materials in cement by mixing them homogenously. In this paper, firstly, the dispersion methods of graphene, including physical stirring, surfactant treating and ultrasonication, are presented to obtain stable dispersed surfactant aqueous solution. Then, the mechanical properties of graphene cement composite are studied, such as Young’s modulus, shear modulus, compressive strength, flexural strength and toughness. Moreover, the piezoresistivity of graphene cement composite is researched in comparison with plain cement. At last, the durabilities, especially the resistance to chloride ion permeability, freezing-thawing and carbonization, are summarized and compared.