bluuebunny/crossref_metadata_2025 huggingface dataset:
European Bats as Carriers of Viruses with Zoonotic Potential
Authors: Kohl Claudia , Kurth Andreas
Published: August 2014

Bats are being increasingly recognized as reservoir hosts of highly pathogenic and zoonotic emerging viruses (Marburg virus, Nipah virus, Hendra virus, Rabies virus, and coronaviruses). While numerous studies have focused on the mentioned highly human-pathogenic bat viruses in tropical regions, little is known on similar human-pathogenic viruses that may be present in European bats. Although novel viruses are being detected, their zoonotic potential remains unclear unless further studies are conducted. At present, it is assumed that the risk posed by bats to the general public is rather low. In this review, selected viruses detected and isolated in Europe are discussed from our point of view in regard to their human-pathogenic potential. All European bat species and their roosts are legally protected and some European species are even endangered. Nevertheless, the increasing public fear of bats and their viruses is an obstacle to their protection. Educating the public regarding bat lyssaviruses might result in reduced threats to both the public and the bats.
A protocol for the creation of useful geometric shape metrics illustrated with a newly derived geometric measure of leaf circularity
Authors: Krieger Jonathan D.
Published: August 2014

• Premise of the study: I present a protocol for creating geometric leaf shape metrics to facilitate widespread application of geometric morphometric methods to leaf shape measurement.

• Methods and Results: To quantify circularity, I created a novel shape metric in the form of the vector between a circle and a line, termed geometric circularity. Using leaves from 17 fern taxa, I performed a coordinate‐point eigenshape analysis to empirically identify patterns of shape covariation. I then compared the geometric circularity metric to the empirically derived shape space and the standard metric, circularity shape factor.

• Conclusions: The geometric circularity metric was consistent with empirical patterns of shape covariation and appeared more biologically meaningful than the standard approach, the circularity shape factor. The protocol described here has the potential to make geometric morphometrics more accessible to plant biologists by generalizing the approach to developing synthetic shape metrics based on classic, qualitative shape descriptors.
L'ethnicité, un levier d'action pertinent du management interculturel des ressources humaines ?
Authors: Apitsa Suzanne Marie , Amine Abdelmajid
Published: August 2014

Cet article vise à mettre en lumière la pertinence du concept d’ethnicité comme levier du management interculturel des ressources humaines. Il part d’un ancrage du concept d’ethnicité dans le champ du management interculturel et mobilise les travaux en management de la diversité pour saisir les enjeux liés à l’ethnicité dans la gestion des ressources humaines. L’étude empirique, fondée sur une étude de cas de trois FMN françaises implantées au Cameroun, montre que l’ethnicité, qui reste largement occultée dans les dispositifs de GRH, gagnerait à être mobilisée de manière plus formalisée et contrôlable comme outil du management interculturel des hommes en vue de générer une meilleure implication des acteurs dans l’organisation.
Âge, absence-maladie et présentéisme au travail : le cas d'un établissement de santé régional
Authors: Huver Benjamin , Richard Sébastien , Vaneecloo Nicolas , Bierla Ingrid
Published: August 2014

Notre article explore le lien entre l’âge et deux évènements de la vie au travail : l’absence-maladie de courte durée et le présentéisme. Ce dernier caractérise la situation d’un salarié se rendant à son travail, alors que son état de santé justifierait une absence. Pour cela, nous étudions le cas d’un centre hospitalier régional employant environ 4 000 salariés. La technique statistique utilisée repose sur l’hypothèse que les valeurs nulles d’absence (aucune absence enregistrée) peuvent s’expliquer soit par une bonne santé, soit par le présentéisme. Sur la base d’un modèle de comptage permettant un traitement différencié de ces deux processus (un modèle binomial négatif à inflation de zéros), nous estimons conjointement une espérance d’absence et une probabilité de présentéisme pour chaque individu. Cette méthode économétrique est ensuite appliquée à une analyse en catégories d’âge. Nos résultats montrent que deux effets jouent parallèlement et s’annulent en apparence dans une analyse statistique générale. D’une part, on s’aperçoit que pour les individus appartenant aux classes d’âge supérieures, la durée moyenne de l’absence est plus importante que pour les autres, comme le montre la littérature. Lorsqu’ils s’absentent, les salariés séniors connaissent des périodes d’absence plus longues, pouvant s’expliquer par un état de santé plus fragile et une guérison plus lente. D’autre part, ces salariés sont aussi ceux dont les probabilités de présentéisme sont les plus élevées. Ainsi, les séniors sont-ils également davantage présents au travail lorsqu’ils sont malades.
La représentation de la performance des entreprises dans un contexte de faillite de la normalisation, le cas du Cameroun
Authors: Pigé Benoît , Sangué-Fotso Robert
Published: August 2014

Dans des territoires où les réglementations s’avèrent conflictuelles, détournées ou non appliquées, les facteurs annexes au bon fonctionnement d’une économie de marché tendent à devenir prépondérants pour évaluer la performance d’une entreprise vis-à-vis de ses parties prenantes. En effet, les externalités générées par les entreprises sont souvent déterminantes dans la réalisation d’opérations financièrement profitables. Dès lors, la mesure de la performance par le seul profit comptable apparaît manifestement inadaptée aux besoins des acteurs de l’économie. À partir d’entretiens réalisés au Cameroun auprès de dirigeants ou de personnels d’encadrement, nous soulignons l’importance de redéfinir la représentation comptable de la performance comme un ensemble multi-dimensionnel qui doit permettre de rendre compte de la performance de l’entreprise à la totalité des parties prenantes.
Comportements proactifs de socialisation : à la recherche des déterminants individuels communs
Authors: Perrot Serge , Jaidi Yasmina
Published: August 2014

Les comportements individuels proactifs de socialisation constituent l’un des moyens essentiels par lesquels les individus s’intègrent dans une organisation. Notre recherche s’intéresse à l’analyse des déterminants individuels de ces comportements, en particulier aux antécédents dispositionnels. Nous avons obtenu l’accord d’une grande compagnie d’assurance française pour l’envoi d’un questionnaire aux nouveaux collaborateurs embauchés en 2010, nous permettant d’obtenir 218 questionnaires remplis et utilisables. Nous montrons, d’une part, qu’il existe un déterminant dispositionnel commun aux différents comportements proactifs et, d’autre part, que la personnalité proactive jusqu’ici mobilisée dans la littérature a un pouvoir explicatif nettement plus faible que l’initiative personnelle. Nous appelons donc les chercheurs à utiliser le concept d’initiative personnelle plutôt que celui de personnalité proactive dans les futures recherches.
Validation d'une échelle de mesure de la justice interorganisationnelle dans un contexte « Donneur d'Ordre/Sous-Traitant » français
Authors: Bergon Gwenaëlle
Published: August 2014

Dans le contexte économique et industriel actuel, la problématique des relations inter-entreprises dans la chaîne de sous-traitance représente un enjeu majeur et d’actualité. Dans ce cadre, la justice interorganisationnelle prend toute son importance. A partir d’une étude quantitative auprès de 101 fournisseurs français, nous présentons la validation d’une échelle de mesure de la justice développée par Colquitt (2001), traduite et adaptée au contexte particulier des chaînes de sous-traitance.
L'opportunité des poursuites du procureur international : du pouvoir arbitraire au contrôle insuffisant
Authors: Le Gall Élise
Published: August 2014

Tenter un bilan des vingt années d’existence de la justice pénale internationale dans sa lutte contre l’impunité nécessite de porter un regard appuyé sur son centre de gravité qu’est le Procureur international. Son action fait l’objet de critiques de plus en plus insistantes, pointant du doigt les risques qu’elle fait encourir à l’impartialité de la justice. C’est pourquoi il est judicieux de porter une analyse poussée de son action et plus particulièrement de l’opportunité des poursuites telle qu’il l’applique pour y déceler les impairs et tenter de dégager des améliorations structurelles. Cette dernière s’ancre dans la phase préliminaire du procès qui, en tant qu’étape décisive de la procédure judiciaire à venir, sous-tend l’aboutissement de la lutte contre l’impunité. Il est donc essentiel d’y consacrer une attention particulière notamment au travers d’une meilleure prise en considération de la victime qui rendra à l’impartialité toutes ses lettres de noblesse.
Persuasive Technology and Users Acceptance of E-commerce
Authors: Alhammad Muna M. , Gulliver Stephen R.
Published: August 2014

Persuasive technologies have been extensively applied in the context of e-commerce for the purpose of marketing, enhancing system credibility, and motivating users to adopt the systems. Recognising that persuasion impacts on consumer behaviour to purchase online have not been investigated previously. This study reviews theories of technology acceptance, and identifies their limitation in not considering the effect of persuasive technologies when determining user online technology acceptance. The study proposes a theoretical model that considers the effect of persuasive technologies on consumer acceptance of e-commerce websites; with consideration of other related variables, i.e. trust and technological attributes. Moreover the paper proposes a model based on the UTAUT2, which contains relevant contributing factors; including the concept of perceived persuasiveness.
Fresh Food Online Supermarket Development Study
Authors: Xiang Xie , Jiashi Liu , Zhongliang Guan , Xinsheng Ke
Published: August 2014

The preservation of fresh food is difficult, so the problems of food safety and the waste of it are very serious. The development of Fresh food online supermarkets will contribute to solve the problem. On the basis of describing the concept, scope and development status of fresh food, the development advantage and disadvantage of fresh food online supermarket is analyzed by SWOT method, future development analysis of the fresh food online supermarkets is been done. Predictive analysis of the future development of the fresh food online supermarkets mainly includes the spread of the fresh food online supermarkets, price transparency, food quality changes, fresh food cold chain logistics improvement and goods consumption evaluation. The relevant suggestions could promote the rapid and healthy development of the fresh food online supermarkets.
Synthesis of Dendritic Silver Nanostructures on Al Foil by Galvanic Displacement for Catalytic Degradation of Methylene Blue
Authors: Fu Li , Matsunaka Sokiransky Mika , Yu Ai Min
Published: August 2014

Silver dendrites were synthesized via a simple and straightforward strategy based on the galvanic displacement between Ag ions and aluminum foil in the room temperature. Because the presence of Al2O3 thin layer on the surface of aluminum foil, the NaCl was added to accelerates the reaction rate. The formed Ag dendrites was characterized by UV-vis spectroscopy, SEM and XRD. The as-prepared Ag dendrites were developed as a catalyst by mixed with reduced graphene oxide and used for degradation of methylene blue when the presence of NaBH4. Moreover, the optimal conditions of degradation were also investigated.
Study on the Regeneration of Quaternary Ammonium Heteropolyphosphatotungstate Catalyst
Authors: Lu Xiao Zhu , Liu Guo Qin , Liu Xin Qi , Jing Lu
Published: August 2014

The quaternary ammonium heteropolyphosphatetungstate compound is proved as a promising catalyst to accelerate the synthesis of epoxidized soybean oil (ESO). As to enhance the efficiency of the catalyst, this paper investigated the process of regeneration of deactivated catalyst (DC) from reaction system of ESO. The single factor experiments were carried out to optimize the regeneration conditions and the optimize process conditions were as follows: acid solution at pH 3, m (deactivated catalyst):m (H2O2):m (H3PO4):m (cetylpyridiniumammonium chloride)=10:5:1:1,and stirred via mechanical and ultrasound agitation . Under above conditions, the epoxy value (≥6.0 %) of ESO which were catalyzed by generated catalyst and yield (≥92 %) were achieved.The results indicate that the activity of regenerated catalysts remain the same as that of the fresh catalysts and certify the economic feasibility of the process.
Study of Thermal and Wet Reclamation Technology of Used Sodium Silicate Bonded Sand
Authors: Sun Qing Zhou , Du Hang , Zhang Pu Qing , Zhao Zhong Kui , Yan Jing Guang
Published: August 2014

This paper makes an experimental research of the thermal and wet reclamation technology of used sodium silicate bonded sand, determines the technological process of thermal and wet reclamation of used sodium silicate bonded sand, and found that the larger the size of sand lump is, the longer the granulation will take; the higher the water temperature is, the shorter time the granulation of sand lump will need; and the stirring of water can significantly reduce the granulating time of sand lump. The quality of sodium silicate bonded sand reclaimed by a combination of stirring scrubbing and flushing overmatches the sand reclaimed by pure flushing; and as the water temperature goes up, with the same conditions of reclamation, the content of residual Na2O in the reclaimed sand will drop, and the ratio of removed binder film will increase. Compared to raw sand, the tensile strength of ester-hardened sodium silicate bonded sand mixed by reclaimed sand is slightly lower.
Comparation of Calix[6]arene and its Phosphorus Derivative for Complexation of Na+, Cu2+, Ni2+, Pb2+, Fe3+, Cr3+ and 2+ UO22+ Ions
Authors: Mo Hui Yan , Wang Jing Song , Zhang Heng Yuan , Guo Qing Wei , Pi Yin An
Published: August 2014

The calix [6] arene and 5,11,17,23,29,35-butyl-25,26,27,28,29,30-diethyl phosphates calix [6] arene (EtPO6) were synthesized and their complexation with different metal ions were investigated. The calix [6] arene and EtPO6 were characterized by IR spectrum. The complexation between the host (calix [6] arene and EtPO6) and the guest (metal ions) were investigated by UV-VIS spectrum and extraction experiments. The results show that the complexation of metal ions by calix [6] aren ranked as Na+ > Cu2+ > Pb2+ > UO22+ > Fe3+ > Cr3+ > Ni2+, and the complexation of metal ions by EtPO6 ranked as UO22+ > Cu2+ > Fe3+ > Pb2+ > Na+ > Cr3+ > Ni2+. Compared with calix [6] aren, the extraction capacity of UO22+, Cu2+, Fe3+, Pb2+, Cr3+ and Ni2+ ions by EtPO6 increased by 37.6%, 10.2%, 10.6%, 9.6%, 2.2%, 4.4%, respectively, while that of Na+ ion decreased by 22.3%.
Synthesis and Magnetic Properties of LaMnO3/α-Al2O3 Magnetic Nanocomposites
Authors: Wang Shi Fa , Sun Guang Ai , Ding Q.P. , Zu Xiao Tao
Published: August 2014

In this paper, LaMnO3/α-Al2O3 magnetic nanocomposites were synthesized through using a soft-chemistry route. The synthesis strategy in this work is based on a soft-chemistry process using a polyacrylamide gel route in which citric acid is employed as the chelating agent. The composites were characterized by thermogravimetric and differential scanning calorimetry analyses, X-ray diffraction, scanning electron microscope, energy dispersive x-ray spectroscopy and vibrating sample magnetometer. Scanning electron microscope observation reveals that the content of α-alumina decreases with the increase of number of sample surface particle in the composites. Magnetic hysteresis loop measurement shows that the LaMnO3 sample exhibit paramagnetism at room temperature. Interestingly, the weak ferromagnetism at room temperature was observed for a composition of 0.7 α-Al2O3 / 0.3 LaMnO3. The forming mechanisms and magnetic properties of α-Al2O3 / LaMnO3 composites have been discussed based on the experimental results.
Microstructure and Mechanical Properties of Permanent Mold Low-Pressure Casting and Sand Mold Gravity Casting of A357 Alloy
Authors: Li Qiang , Wu Hai Jun , Lu Shao Ping , Kong Ling Jiao , Hao Qi Tang
Published: August 2014

The microstructure and mechanical properties of permanent mold low-pressure casting (PMLPC) and sand mold gravity casting (SMGC) of A357 alloy were studied. The grain size of alloys formed by PMLPC is finer than that formed by sand mold gravity casting because of higher freezing rate of the former. The secondary dendrite arm spacing of PMLPC is approximately 15.2 μm (SD=4) while that of SMGC is 33.2 μm (SD=6). The ultimate tensile strength of PMLPC has a wider range from 350 MPa to 299.9 MPa and an elongation from 1.2 to 4.9. In comparison, the ultimate tensile strength of SMGC ranges from 307 MPa to 315 MPa and its elongation ranges from 2.1 to 3.7. These differences may be attributed to various factors, such as filling speed, filling pressure, and cooling rate, that affect the quality of permanent molds during the filling process.
Morphology and Phase Diagram of Cyclic ABCB Tetrablock Copolymer
Authors: Liu Lan , Zhang Shi Jie , Shi Bo , Mai Dong Dong , Du Xiao Qing , Lin Bo
Published: August 2014

Microphases and triangle phase diagrams of cyclic ABCB tetrablock copolymer melts have been investigated by a combinatorial screening algorithm based on self-consistent field theory (SCFT) in two-dimensional space. Eight main stable ordered morphologies have been observed in the intermediate-segregation regime. SCFT simulation experiments reveal that the compositions of block chain in the cyclic polymer are comparable, the cyclic architecture of polymer chain has a strong topological constraint on the geometry of microphases. The morphologies and phase diagrams are helpful to control and design the suitable ordered microstructure of cyclic copolymer systems.
Probabilistic Analysis of Gun Barrel Ablation Life Based on the Modified Response Surface Model
Authors: Zhou Wei , Fang Jun
Published: August 2014

The randomness of structural and material parameters needs to be considered in the reliability analysis of gun barrel ablation life. However, the traditional method, like Stochastic FEM sampling, results in huge computing workload and low efficiency. This paper proposed a modified response surface model for estimating the gun barrel ablation life. In which, the estimation error of the response surface model is the optimization goal. Gauss-Newton method (GNM) is used to get the optimal solution whose initial value is solved by Genetic-algorithm (GA). After that, ablation life can be calculated by the optimized response surface model. GA is effective in global solution space searching, while GNM is effective in local searching. The new method takes full advantages of both GA and GNM in parameters estimation. The simulation result shows that the combination of GA and GNM obtains a higher precision of ablation estimation and greatly improves the computational efficiency.
Research Summary on Nanostructured Ceramic Coating Grinding Surface Residual Stress
Authors: Liu Wei Xiang , Wang Yao , Gao Li
Published: August 2014

After precise grinding n-WC/12Co coatings with diamond wheel , there is residual stress on the surface of parts ,the paper drawn conclusions about this study,it Pointed out the contents of further study ,the direction of farther study was prospected in this study too. The interaction between the abrasive grains and the workpiece was approximately regarded as ideal small-scale indentation phenomenon, it was used to evaluate the surface quality in ceramic machined processing that formation of grinding crack and its propagation process, the material removed process and the surface defects of the ceramic grinding, the cutting model proved that although the removed material is usually brittle removal, most of the grinding energy consumption was related with plastic deformation.
The Simulation Analysis of the Influence of Grinding Point Position on Grinding Wheel
Authors: Li Li Jun , Bai Wei Tao , Wei Sun , Bai Guang Hua
Published: August 2014

the process of the wheel style grinding wheel grind concave surface of rotors has been simulated in this paper,through changing of the location of grinding point, the qualitative change of the strain and stress has been simulated and analyzed, obtaining that when the grinding point is at the midpoint of wheel grinding arc, the strain and stress of grinding wheel are the smallest, when at other locations, strain presents parabolic and spreads to the edge, the maximum and minimum stress are in the process of gradually decreasing as grinding dot moving from the edge to the halfway point , and the maximum stress and strain are occurred in a neighborhood of the grinding point.
Calculation and Analysis of Tandem Cold Rolling Force Parameters
Authors: Bai Jin Lan , Pan Hong Zhi
Published: August 2014

In order to improve the accuracy of rolling force parameters,the elastic deformation and pressure between rolls of tandem cold rolling are calculated using divided element method in this paper. Bland-Ford model is used to calculate the rolling force, and the lengths of flattening contact arcs of each element are calculated. Considering the flattening contact arc lengths and tensile stress synthetically, rolling force parameters are calculated iteratively. Then the corresponding procedure is developed, and the distribution of rolling force, pressure between rolls and tensile stress are calculated with this procedure. The results are basically consistent with the measured data, and it will be useful to thermal crown calculation and strip flatness control.
Characteristics of Inconel 625 Filler Metal Affecting to Weld and Deposited Metal Zones in the Case of Welded to Forged Steel for Piston Crown Material
Authors: Lee Sung Yul , Moon Kyung Man , Won Jong Pil , Jeong Jae Hyun , Baek Tae Sil
Published: August 2014

Recently, wear and corrosion of the engine parts surrounded with combustion chamber is more serious compared to the other parts of the engine due to using of heavy oil of low quality. Therefore, an optimum repair welding for these parts is very important to prolong their lifetime in a economical point of view. In this study, Inconel 625 filler metal was welded with GTAW method in the forged steel which would be generally used with piston crown material. In this case, the mechanical and corrosion properties between weld metal zone (WM) welded to the groove which were artificially made in the base metal and deposited metal zone (DM) only welded by Inconel 625 filler metal on the surface of the base metal were investigated using electrochemical methods, such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% H2SO4 solution. The deposited metal zone exhibited a better corrosion resistance compared to the weld metal zone, furthermore, its corrosion potential was a nobler value rather than that of the weld metal zone. However, the hardness indicated more or less higher value in the weld metal zone. The corrosive products after measurement of anodic polarization curves was hardly observed both in the weld and deposited zones, while, the morphologies of the corroded surfaces exhibited general and pitting corrosion in the weld and deposited metal zones respectively. The fine pearlite microstructure was a little observed in the weld metal zone, moreover, the microstructure of ferrite with elliptical pattern was significantly increased in the deposited metal zone. As a result, it is considered that the amount of Cr, Mo and Ni having a high corrosion resistance diffuse and migrate from the weld metal zone to the base metal zone, thus, the deposited metal zone indicated a better corrosion resistance than the weld metal zone because the amount of Cr, Mo and Ni were much involved in deposited metal zone compared to the weld metal zone.
Effect of Process Parameters on Warpage of Printer Board with Metal-Insert
Authors: Liu Cheng Juan , Huang Xian Kun , Wu Qiu Ping , He Hai Qin , Li Yan Ping
Published: August 2014

In order to study the influence of process parameters on forming quality of printer board with metal-insert,shorten the development cycle,reduce the enterprise cost,the warp trend and reasons of injection process parameters,including packing time,hold pressure,mold temperature,melt temperature,on the warpage of the part were analyzed by means of software moldflow. The results show that warpage amounts decreases with packing time and hold pressure increasing,larger packing time and longer hold pressure is advantageous to the injection parts molding;And warpage amounts increases with mold temperature and melt temperature increasing,the lower mold temperature and melt temperature is advantageous to the injection parts molding;Among the four parameters,the melt temperature had the greatest influence,followed by the mold temperature and the hold pressure,packing time had the minimal influence on the warpage.
Effects of Grain Size on Crack Tip Mechanical Fields of Intergranular Cracking
Authors: Wang Wei Bing , Xue He , Yang Fu Qiang , Liu Kun
Published: August 2014

Intergranular stress corrosion cracking is one of important failure form of structural materials in nuclear power plants, and the initiation and development of crack at grain boundary are affected by the grain size of materials. The macroscopic model and mesoscopic model of crack propagation was established by using finite element method, and the effects of grain size on fracture parameters such as Mises stress, the maximum principal stress and equivalent plastic strain nearby crack tip were studied. The results indicate that the distribution of Mises stress and equivalent plastic strain are discontinuity at grain boundary, and the maximum principal stress locates at grain boundary. The Mises stress, maximum principal stress and equivalent plastic strain nearby crack tip increase with the increasing of grain size.
Foundry Technique Designing of the Nodular Cast Iron Casting
Authors: He Bin Feng
Published: August 2014

The traditional method has been used to the foundry technique for the melt block mobile plate. The pouring position,the parting face and some of the casting parameters were determined, such as the allowance for finish, stripping taper, the rate of shrinkage and soon on. The commercial casting simulation software was introduced into the casting process, the filling and solidification process were calculated by it. The results shown that there are some shrinkage exists in the original technique and the filling process were inordinate. The gating system was optimized and according to the simulation results, the shrinkages in the original technique were eliminated and the filling process is smoothly which could help the designer to make a correct determination.
Research on Al Particles Reinforced Thermal Stress Aging Treatment Behavior of Composite Lead-Free Solder
Authors: Zhang Kai Feng , Zhou Ye Ping , Zeng Xian Zuo
Published: August 2014

Studying Al particles reinforced composite lead-free solder by experiments of constant temperature thermal stress aging treatment. Scanning electron microscope was used to observe the micro-structure of composite solder. The results show that composite lead-free solder after constant 125°C aging treatment for 24 hours, Al particles has two types of morphologies: one is small amount of solid solution,another type is a large number of aluminum particles structure.The existence of Al particles slowed down the coarsening rate of the Bi Phase grain, and obtained uniform refined the Bi Phase grain.
Study on Overburden under Temperature Loading Coal Seam Outcrop Fire Area Heat Damage Mechanics Characteristics Experiment
Authors: Jin Yong Fei , Guo Jun , Yue Ning Fang
Published: August 2014

Maglev uses MTS815.02 rock mechanics experimental electro-hydraulic systems and NM-4A nonmetallic ultrasonic testing analyzer for coal fire area overlying rock outcrop samples were heated fracture mechanics properties of experimental studies of rock samples reveal the strength and deformation characteristics with temperature the variation. The results showed that: rock microstructure changes at high temperatures on the mechanical properties have a significant effect, the higher the temperature, the greater the sandstone porosity, fissures, the more velocity is smaller; fire zone in the role of coal outcrops, rocks and mineral composition and structure has changed, the internal expansion of initial damage evolution, a large amount of leakage fissures, heat pressure increases, resulting in the upper part of the coal temperature of natural convection of air through the crack, thereby maintaining the vicinity of the coal to maintain a certain concentration of oxygen. Dynamic evolution of coal seam outcrop fire mechanism provides a theoretical basis.
Effects of Pulsed Magnetic Field on the Microstructure and Mechanical Properties of Mg97Y2Zn1 Alloy
Authors: Yin Jian , Ma Xiu Jun , Yao Jun Ping , Zhou Zhi Jian
Published: August 2014

Effect of pulsed magnetic field treatment on the microstructure and mechanical properties of Mg97Y2Zn1 alloy has been investigated. When the pulsed magnetic field is applied on the alloy in semi-solid state, the α-Mg was modified from developed dendrite to fine rosette, resulting in a refined solidification microstructure with the grain size decreased from 4 mm to 0.5 mm. The volume fraction of the second phase ( X phase) increased by about 10 %. The yield strength, fracture strength and plasticity were improved by 21 MPa, 38 MPa and 2.4 %, respectively. The improvement of mechanical properties was attributed to the refined grain size and increased volume fraction of X phase.
Charpy Impact Properties of Grain Boundary Allotriomorphic Ferrite and Granular Bainite Duplex Microstructure
Authors: Luo Ping , Gao Gu Hui , Gui Xiao Lu , An Bai Feng , Tan Zhun Li , Bai Bing Zhe
Published: August 2014

A new type of high strength and low cost bainitic steel with ultra-low carbon content and high Si content has been developed on the basis of Mn-series air-cooling bainitic steels. The tensile properties of YS>690MPa and the impact toughness of AKV>60J at-40°C were obtained by controlling the processing parameters. This was attributed to the formation of the grain boundary allotriomorphic ferrite (FGBA) and the granular bainite (GB) with different shape of M/A islands. The high strength due to the inter-lath lamellar M/A islands or retained austenite companying with high dislocated bainitic ferrite laths of average 300nm width. The effect of microstructure on the impact crack initiation and propagation was studied. The results showed that crack initiation occurred in two different types of sites: at interphase boundaries of bainite ferrite (BF) and M/A islands, at grain boundaries. The FGBA and bainite ferrite (BF) both had blunting effect on microcrack tip to reduce the crack propagation path. Because of the presence of FGBA, the unit crack path was short, at less than 5μm. The blunting effect of BF could be enhanced by the M/A islands, which force the cracks change the propagation path and reduce the unit crack path to less than the size of bainite packets. The mechanism of low temperature microcrack origin of the ultra-low carbon bainitic (ULCB) steel with the microstructure of the FGBA and GB was also discussed.
Hot Radial Upset-Extruding Process for Tube Structure with a Nozzle of 316LN Stainless Steel
Authors: Wang Xin , Feng Xiao , Zhang Lei , Lin Feng , Pan Ji Luan
Published: August 2014

AP1000 nuclear power main pipe, a type of complicated thick-walled tube structure with both high and thick-walled nozzles, is one of the key parts in nuclear island. It is required to be manufactured by integral plastic forming technique. Up to now, no economical and efficient plastic forming process for AP1000 main pipe has been reported. To aim for forming the tube structure with a nozzle such as AP1000 main pipe, a radial upset-extruding (RUE) process was developed, in which the initial billet is an extruded tube with a hole. RUE process is an extrusion method which realizes radial outflow of the metal around the hole of tube billet through an axial upsetting force and restriction of dies. Thick-walled tube structure with a nozzle derived from AP1000 main pipe was simplified to be a thick-walled three-way pipe, on which RUE process was analyzed based. Combined with reduced scale model experiments, thermomechanical coupled finite element analysis integrated with recrystallization models of 316LN was performed to investigate RUE process. Metal flow, deformation distribution, recrystallization distribution, and extrusion load and clamping load in RUE process was analyzed. The experimental workpiece of pure lead based on reduced scale model validate metal flow behavior predicted by using numerical simulation. The results indicate that the essence of RUE process is to deflect the flow of the material around the orifice of the tube billet. The loads of dies are significantly sensitive to the initial forming temperature and the friction coefficient, while the impact of the extrusion velocity is negligible. RUE process could be used to form thick-walled tube structure with a nozzle, and it has a potential for solving the manufacture of AP1000 main pipe.
Numerical Simulation of Extrusion Process to Produce Complex Aluminum Profiles Using the ALE Approach
Authors: Cheng Lei , Huang Guo Jie , Wang Jian Wei , Xiao Wei , Xie Shui Sheng
Published: August 2014

Although still having certain limitations, the numerical simulation technology has been increasingly applied to aid in optimizing the aluminum extrusion process and die design. In the present research, numerical simulations of the profiles extrusion process were performed, using the Finite Volume Method (FVM) and Finite Element Method (FEM) to make use of the individual merits of the Euler approach and Lagrange approach, respectively. The application of the simulation technology to produce large, complex profiles has, however, been quite limited. In order to solve the limited, numerical simulation of aluminum profiles with large and complicated cross-section in extrusion process was achieved using Arbitrary Lagrangian-Eulerian (ALE) approach, and non-uniform velocities at the die exit, leading to extrudate distortions, were predicted. Extrusion experiments proved that the die with the optimized design could circumvent the distortion problem. The numerical simulation technology can indeed be effectively used to reduce the number of die trials and offer the potential to realize zero die trial.
Impact Strength Behavior and Fracture Morphologies of Tungsten Alloy with High Deformation
Authors: Tian Kai Wen , Zhu Li Jun , Jia Wan Ming , Zou Min Ming , Feng Hong Wei , Shi Hong Gang
Published: August 2014

High strength tungsten alloys with different deformation of 20%, 40%, 50% and 60% were prepared by swaging, and the impact strength and impact fracture morphologies were tested and observed respectively by Charpy tester and SEM to study the influence of deformation degree on fracture behavior. The results show that with the deformation degree increasing from 20% to 40%, 50% and 60%, the toughness reduces from 99J to 51J, 43J and 29J. The fracture mode of impact changes from intergranular to cleavage fracture.
Simultaneous Determination of Ruthenium and Zinc in Catalysts for Hydrogenation of Benzene to Cyclohexene Using Sodium Peroxide Fusion Sample Digestion and ICP-OES
Authors: Wei Xiao Juan , Tian Zhi Quan
Published: August 2014

A novel method for simultaneous determination of ruthenium and zinc in catalysts for hydrogenation of benzene to cyclohexene was established by inductively coupled plasma optical emission spectrometry after sample digestion by high temperature fusion with Na2O2. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of Na2O2 and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru and Zn for tested solutions were 11 and 13 ng mL-1, respectively. The relative standard deviations (RSDs) for Ru and Zn were 2.01 and 2.35 % (CRu, Zn = 1 mg L-1, n = 7), respectively. The linear ranges of calibration graphs for Ru and Zn were 0.05 ~ 100.00 mg L-1 and 0.04 ~ 50.00 mg L-1, respectively. The proposed method was applied to determine catalyst samples with good recoveries and satisfactory results.
Study on Hot Rolling Process of Mg-Gd-Y-Nd-Zr Alloy Bar
Authors: Guo La Feng , Li Zhi Heng , Chen Pan Yu , Li Bao Cheng , Zhang Zhi Min
Published: August 2014

A hot rolling method to produce Mg-Gd-Y-Nd-Zr alloy bars through oval-vertical elliptical-round pass system is put forward. The mechanical model of Mg-Gd-Y-Nd-Zr alloy has been established. Using Deform-3D software, the rolling process of Mg-Gd-Y-Nd-Zr alloy bar is simulated at rolling temperature 450°C, rolling speed 0.4m/s. And equivalent stress distribution and load variation has been obtained. It provides a theoretical basis for the hot rolling bars of magnesium alloy. The experiment verifies that the hot rolling process is feasible. The organizational structure is analyzed with metallographic microscope, and the results show that dynamic recrystallization is occurred, the grain size is obviously refined, and the mechanical property of the material is improved in hot rolling process.
Superhydrophobic Structure Fabricated by Femtosecond Laser on Nickel Surface
Authors: Zhang Lei , Cao Xiao Wen , Xiang Ru Yi , Li Shun Guang , Wang Lei , Sun Hui Chao
Published: August 2014

Fabrication of superhydrophobic structure by femtosecond laser become more and more popular in recent years, because it’s inexpensive and micro/nanostructure can be controlled compared with other methods. This paper proposes an approach to fabricate large scale superhydrophobic structure directly on nickel (Ni) surface by femtosecond laser and the apparent contact angle (CA) on the Ni surface can reach 134° without further coating any low surface energy materials. With low laser power, typical laser-induced periodic surface structures (LIPSS) at the submicron level can be observed. With high laser power, periodic ripples with microstructure covered by LIPSS can be observed. The micro/nanostructure on Ni surface is directly replicated onto PDMS and after replication the CA on PDMS surface can be improved to 153° obviously from CA of 120° on PDMS surface without micro/nanostructure. The higher laser power can results in the larger CA. This replication method can be applied for fabricating large scale superhydrophobic structure and the replication master can be used many times.
Talk from the Perspective of Petrology Carving Stone
Authors: Liu Qi Xia , Zhu Tan Qing , Zou Xin , Bo Cao , Li Zhuo Yu
Published: August 2014

This article selects the typical carving stone as the research object. We make an discuss about the factors affecting the effect of seal cutting art of using saber from the perspective of petrology through the conditions of seal cutting stone material, color, hardness, transparency and so on. Making an analyze about the adaptability to seal cutting stone and the stone material impact bit broken seal treatment , in order to select material of seal cutting lovers with reference.
The Portable Measurement Instrument of Dynamic Magnetic Properties for the Soft Magnetic Materials
Authors: Hou Rui Fen , Fan Wen , Zhang Zhi Gao , Gong Wen Jie , Lin An Li
Published: August 2014

The portable measurement instrument is designed and built to measure the dynamic magnetic properties of the soft magnetic materials. The measurement principle and sampling method are presented. The study shows the instrument can measure the different types of soft materials accurately at frequencies in the range of 20 Hz – 200 kHz. The standard deviations of the specific total loss (Ps) and amplitude permeability (μa) are less than 0.3%. The errors of Ps and ua are not larger than 0.3% between the measurement results of the instrument and the standard measurement device of National Institute of Metrology (NIM) of China NIM.
The Study of Large Deformation Upsetting for TC16 Titanium Alloy
Authors: Zhuang Bao Tong , Liu Feng Lei , Huang Hong
Published: August 2014

The microstructure transformation in large deformation upsetting process of TC16 is studied by means of optical microscope and microhardness measuring. The results show that the rolled and annealed TC16 titanium alloy presents tiny isometric crystal grain structure of α+β. When the deformation of the plate nut head is up to 94%, the upsetted shank is overexpansion and the edge of the head laps. The specimen is scrapped due to the widmannstatten structure at the upsetting temperature of 900°C. An adiabatic shear band, the hardness of which is higher than the matrix and surrounding, is observed and widens as the heated temperature rises. Both the size and microstructure of the specimen meet the requirements at the upsetting temperature of 850°C.
Ultrasonic Vibration Dressing Technology on CBN Grinding Wheel and its Grinding Performance on K9 Glass
Authors: He Quan Mao , Zhao Jie , Shen Fei Ling
Published: August 2014

CBN wheel grinding performance on K9 glass is experimentally analyzed, which is using ultrasonic vibration assisted mechanical dressing, and dressing modes have different influences on grinding performance on the basis of the grinding surface morphology characteristics of K9 glass. The experimental results show that the CBN grinding wheel of vibration dressing mode has relatively large grinding ratio compared with ordinary dressing, and its microstructure on the grinding surface is strongly influenced by dressing modes and grinding speed.
Calculation of Axial Rolling Force in Radial-Axial Ring Rolling Process
Authors: Wang Tao , Wang Qiang
Published: August 2014

A mechanical model of axial ring rolling is established. According to the analytical method, the calculation formula of axial ring rolling contact area and unit rolling force is derived. On this basis the calculation formula of axial rolling force is derived. The influence of processing parameters on the axial rolling force is investigated. It is found that the axial rolling force increases with the increase of the outer diameter of ring, and the axial rolling force decreases with the increase of the inside diameter of ring. The greater the feed in axial direction, the greater the axial rolling force.
Experimental Technique for Ice under Dynamic Compressive Loading
Authors: Liu Chuan Xiong , Hu Zhi Jun
Published: August 2014

Experiments on the dynamic behavior of ice in compression were carried out by means of SHPB apparatus. The specimens were to-10°C~-25°C and the tested strain rate ranged from 700/s to 1000/s. Strain-rate effects and the influence of freezing preserve time were studied. It was observed that the dynamic compressive strength of ice has an effect of strain-rate enhancement and the freezing preserve time has no influence to its dynamic compressive strength. In addition, a Pulse shaping technique to avoid the specimen failing before stress uniformity in ice specimen was presented.
Fracture Analysis of Pneumatic Control Valve Rod Used for Nuclear Power Plants
Authors: Yang Lei , Li Yan , Zhang Lu , Lai Yun Ting , Luo Zhi Feng , Yu Wei Wei
Published: August 2014

The fracture of a carbon steel pneumatic control valve rod used for Nuclear Power Plants was analyzed in terms of the microstructure, inclusions and fractogragh by means of tensile test, charpy V-Notch impact test, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The results indicated that the fracture of the rod is induced by the unqualified chemical composition: a large number of inclusions which distribute in grain boundaries reduce the material plasticity and toughness, and eventually cause fracture.
Influence of Relative Clearance to Hole Quality in Punching Process
Authors: Zhang Kai , Wang Qiang , Ding Zhong
Published: August 2014

Influence of relative clearance to hole quality is investigated by numerical simulation and experiment. The numerical simulation in punching process of sheet metal is conducted by using ANSYS/LS-DYNA.The relative clearances in two sizes are selected to investigate the difference of holes cross section. Influence regularity of the relative clearance to hole quality is obtained by experimental investigation.
The Press and Mold for Bonded NdFeB Magnet Molding
Authors: Qin Wan Zhong , He Jie
Published: August 2014

Bonded NdFeB is a high performance composite magnetic materials which developed in recent years. Compression molding is the most important making method of bonded NdFeB magnets. The Characteristics of bonded NdFeB magnets are introduced. Based on test, research and lot production practice, the important effects of mould structure, press structure and compression molding actions on magnets’ quality are analyzed, The key techniques that controlling the quality of bonded NdFeB magnets are summarized.
Titanium Alloy Ultrasonic Vibration Micro Deep Holes Drilling
Authors: Liu Zhang Feng , Yang Pei Xuan
Published: August 2014

Through analyzing and comparing the ultrasonic drilling and general drilling, exported from cutting dosage and burr , etc, using the ultrasonic vibration drilling device to carry out the TC4 titanium alloy micro-hole drilling test. The ultrasonic vibration drilling more suitable than general drilling for the processing of Titanium Alloy, and solve Φ 2.0 x 20 TC4 Titanium Alloy drilling of small diameter deep hole problem. Fully embodies the advantages of ultrasonic vibration drilling.
Diatomite Experimental Study on New Wet Purification Process
Authors: Zhang Kai Yong , Yu Hong Mei
Published: August 2014

Wet centrifugal separation process is used to purify diatomite by analyzing the properties of diatomite raw ore in Linjiang city, Jilin province. Experimental results determine the affecting sorting important indicators, including scrubbing agent and dosage, sieving mesh, centrifugal separation. The concentration of SiO2 in the final diatomite is 86.76%, reaching primary soil standard. Compared with gravity sedimentation purification process, new technology method saves much time and achieves the ideal separation effect.
Study on Squitter Pulse Argon-Arc Welding Technology for Repairing Balance Shaft Parts
Authors: Meng Ling Dong , Di Yue Lan , Shen Wei , Zhang Qing , Tan Jun
Published: August 2014

Squitter pulse argon-arc welding technology due to its unique way of energy output, has the quick repairing speed, low heat input and high bonding strength on the repairing process. The results of balance shaft parts after repairing by squitter pulse argon-arc welding technology showed that there was no significant micro–pore but closed combination between the substrate and repaired layer. The width of HAZ was 350μm, the average hardness of repaired layer was 420HV, and the wear-resisting property was improved about 36.4%, compared to the substrate. The squitter pulse argon-arc welding technology is a simple, reliable new repair techniques.
Application Research Development of Smart Materials on Personnel Armor Protective Materials
Authors: Liu Jun , Xiong Dang Sheng , Li Bin
Published: August 2014

Integration of smart materials such as field-responsive fluid, i.e. Electro-rheological (ER) , magneto-rheological (MR) and shear thickening fluids (STFs), into armor protective materials, may probably solve the problem between its portability and protective performance. The wide applications of three fluids are described in brief in this paper, and research developments (especially STFs’ in detail) of armor protective materials strengthened by utilizing three fluids or chemical reaction material are summarized. Analysises are made of the questions faced by these composites researches. The foreground is talked about in the end.