Mechanical Property and Microstructure of Cement Mortar with Carbonated Recycled Powder

Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect.

Impact of W alloying on microstructure, mechanical property and corrosion resistance of face-centered cubic high entropy alloys: A review

Face-centered cubic (f.c.c.) high entropy alloys (HEAs) are attracting more and more attention owing to their excellent strength and ductility synergy, irradiation resistance, etc. However, the yield strength of f.c.c. HEAs is generally low, significantly limiting their practical applications. Recently, the alloying of W has been evidenced to be able to remarkably improve the mechanical properties of f.c.c. HEAs and is becoming a hot topic in the community of HEAs. To date, when W is introduced, multiple strengthening mechanisms, including solid-solution strengthening, precipitation strengthening (μphase,σphase, and b.c.c. phase), and grain-refinement strengthening, have been discovered to be activated or enhanced. Apart from mechanical properties, the addition of W improves corrosion resistance as W helps to form a dense WO_(3) film on the alloy surface. Until now, despite the extensive studies in the literature, there is no available review paper focusing on the W doping of the f.c.c. HEAs. In that context, the effects of W doping on f.c.c. HEAs were reviewed in this work from three aspects, i.e., microstructure,mechanical property, and corrosion resistance. We expect this work can advance the application of the W alloying strategy in the f.c.c. HEAs.

Assessment of Lubrication Property and Machining Performance of Nanofluid Composite Electrostatic Spraying(NCES)Using Different Types of Vegetable Oils as Base Fluids of External Fluid

The current study of minimum quantity lubrication(MQL)concentrates on its performance improvement.By contrast with nanofluid MQL and electrostatic atomization(EA),the proposed nanofluid composite electrostatic spraying(NCES)can enhance the performance of MQL more comprehensively.However,it is largely influenced by the base fluid of external fluid.In this paper,the lubrication property and machining performance of NCES with different types of vegetable oils(castor,palm,soybean,rapeseed,and LB2000 oil)as the base fluids of external fluid were compared and evaluated by friction and milling tests under different flow ratios of external and internal fluids.The spraying current and electrowetting angle were tested to analyze the influence of vegetable oil type as the base fluid of external fluid on NCES performances.The friction test results show that relative to NCES with other vegetable oils as the base fluids of external fluid,NCES with LB2000 as the base fluid of external fluid reduced the friction coefficient and wear loss by 9.4%-27.7%and 7.6%-26.5%,respectively.The milling test results display that the milling force and milling temperature for NCES with LB2000 as the base fluid of external fluid were 1.4%-13.2%and 3.6%-11.2%lower than those for NCES with other vegetable oils as the base fluids of external fluid,respectively.When LB2000/multi-walled carbon nanotube(MWCNT)water-based nanofluid was used as the external/internal fluid and the flow ratio of external and internal fluids was 2:1,NCES showed the best milling performance.This study provides theoretical and technical support for the selection of the base fluid of NCES external fluid.

Effect of Water Absorption on the Mechanical Property and Failure Mechanism of Hollow Glass Microspheres Composite Epoxy Resin Solid Buoyancy Materials

To study the water absorption of hollow glass microspheres(HGMs)composite epoxy resin solid buoyancy materials in the marine environment and its effect on the mechanical properties,the water absorption was measured by immersing the material in distilled water for 36 days at ambient temperature and fitted to Fick’s second law.The strength of materials before and after water absorption were tested by uniaxial experiments,and the effects of the filling ratio and water absorption on the mechanical properties of the materials were analyzed and explained.Finally,the failure modes and mechanism of the hollow glass microspheres composite material were explicated from the microscopic level by scanning electron microscope(SEM).This research will help solve the problems of solid buoyancy materials in ocean engineering applications.

Landscape Aesthetic Characteristics of Wulingyuan World Natural Heritage Property and Realization Path of Aesthetic Education Value

Wulingyuan is a world natural heritage property mainly dominated by rare quartz sandstone peak forest landscape at home and abroad and supplemented by karst landscapes,with a large number of geological and historical sites,biological and ecological landscape and unique cultural landscapes.Preserving the secluded and beautiful scenery environment,biological environment and ecosystem of subtropical zone,Wulingyuan presents a splendid and magnificent landscape,with high aesthetic value,and becomes an important practice base of aesthetic education.The aesthetic education value of Wulingyuan World Natural Heritage Property can be realized by systematically studying and presenting the aesthetic education value of Wulingyuan World Natural Heritage Property,developing a series of aesthetic education courses to lead tourists into the world of Wulingyuan aesthetic education,carrying out a series of popular science activities of“Wulingyuan World Natural Heritage Property Entering Campus”,and incorporating into the aesthetic education curriculum system of schools,etc.This paper analyzes the landscape aesthetic characteristics of Wulingyuan World Natural Heritage Property thoroughly,which indicates the direction for realizing the aesthetic education value of the property,and also provides a reference for realizing the aesthetic education value of similar world natural heritage property.

Effect of temperature on dielectric property and microwave heating behavior of low grade Panzhihua ilmenite ore

The permittivity of low grade Panzhuhua ilmenite ore at 2.45 GHz in the temperatures from 20 ℃ up to 100 ℃ was measured using the technology of open-ended coaxial sensor combined with theoretical computation. The results show that both the real （ε′） and imaginary （ε′） part of complex permittivity （ε′-jε′） of the ilmenite significantly increase with temperature. The loss tangent （tanδ） is a quadratic function of temperature, and the penetration depth of ilmenite decreases with temperature increase from 20 ℃to 100 ℃ The increase of the sample temperature under microwave radiation displays a nonlinear relationship between the temperature （T） and microwave heating time （t）. The positive feedback interaction between complex permittivity and sample temperature amplifies the interaction between ilmenite and the microwave radiation. The optimum dimensions for uniform heat deposition vary from 10 cm to 5 cm （about two power penetration depths） in a sample being irradiated from both sides in a 2.45 GHz microwave field when temperature increases from room temperature to 100 ℃

Mixed grain structure and mechanical property anisotropy of AZ40 magnesium alloy bar with diameter of 160 mm

The mixed grain structure and mechanical property anisotropy of AZ40 magnesium alloy bar with a diameter of 160 mm manufactured by ＂multi-direction forging（MDF） ＋ extrusion ＋ online cooling＂ technique were investigated by optical microscopy（OM）, scanning electron microscopy（SEM）, X-ray diffraction macro-texture measurement and room temperature（RT） tensile test. The results show that mixed grain structure is caused by the micro-segregation of Al in semi-continuous casting ingot. Homogenization of（380 °C, 8 h） ＋（410 °C, 12 h） cannot totally eliminate such micro-segregation. During MDF and extrusion, the dendrite interiors with 3%-4% Al（mass fraction） transform to fine grain zones, yet the dendrite edges with about 6% Al transform to coarse grain zones. XRD macro-textures of the outer, R/2 and center show typical fiber texture characteristics and the intensity of [0001]//Ra D orientation in the outer（11.245） is about twice as big as those in the R/2（6.026） and center（6.979）. The as-extruded AZ40 magnesium alloy bar has high elongation（A） and moderate ultimate tensile strength（Rm） in both extrusion direction（ED） and radius direction（Ra D）, i.e., A of 19%-25% and Rm of 256-264 MPa; however, yield strength（Rp0.2） shows anisotropy and heterogeneity, i.e., 103 MPa in Ra D, 137 MPa in ED-C（the center） and 161 MPa in ED-O（the outer）, which are mainly caused by the texture.（155 °C, 7 h） ＋（170 °C, 24 h） aging has no influence on strength and elongation of AZ40 magnesium bar.

Relationship between Bending Property and Density of Wheat Stem

[ Objective] The aim is to research the relationship between bending property and density of wheat stem. [ Method ] The bending properties such as elastic modulus, bending strength, flexural rigidity, moment of inertia, density and water content of the second base internodes of Zhengmai 9023 and Yumai 25 were determined. [ Result] The results show that during filling stage, there are significant differences in the elastic modulus, moment of inertia, flexural rigidity and density among wheat varieties, while there are no significant differences in the bending strength and water content among wheat varieties. The moment of inertia, flexural strength and flexural rigidity have positive relationship to density but negative relationship to water content. [ Conclusion] The study results provide some references for the research on high yield cultivation and lodging resistance of wheat.

Influence of Li addition on mechanical property and aging precipitation behavior of A1-3.5Cu-1.5Mg alloy

The influence of Li addition on mechanical property and aging precipitation behavior of Al-3.5Cu-1.5Mg alloy was investigated by tensile test,scanning electron microscopy（SEM）,transmission electron microscopy（TEM） and high resolution transmission electron microscopy（HRTEM）.The results show that the tensile strength can be significantly improved with the slightly decreased ductility and the form of fracture morphology is converted from ductile fracture into ductile/britde mixed fracture by adding 1.0%Li.Besides,the peak aging time at 185 ℃ is delayed from 12 to 24 h and the main precipitation phase S（Al2CuMg） is converted into S＇（Al2CuMg）＋δ（Al3Li）,while the formation of S＇（Al2CuMg） is delayed.

Rheological property and drying mechanism of thermoresponsive gelcasting of ZnO

To solve the problem of drying gelcast green body, the thermoresponsive gel system which contains macromonomer graft chains was used in gelcasting of ZnO. The effects of the amount and length of graft chains macromonomer PIPAAm, the total amount of organic matters, and the solid loading on the rheological properties of suspensions were investigated, and the drying mechanism of gelcast green body was analyzed. The results show that ZnO suspensions with the gel system still display shear- thinning rheological behavior, but its viscosity increases with increasing the addition amount and relative molecular mass of PIPAAm graft chain, and the total organic matter content. The PIPAAm graft chains inhibit or even eliminate the formation of the ＂dense layer” on the surface of gelcast ZnO green bodies, and accelerate the drying of green bodies. The introduction of PIPAAm graft chains facilitates the shrinkage of the gelcast ZnO green bodies, which is a feasible method to increase the relative density of green bodies.

Property analysis of bistatic forward-looking SAR with arbitrary geometry

Bistatic forward-looking synthetic aperture radar（SAR） has many advantages and applications owing to its twodimensional imaging capability.There could be various imaging configurations because of the geometric flexibility of bistatic platforms,resulting in kinds of models built independently among which there could be some similar even the same motion features.Comprehensive research on such systems in a more comprehensive and general point of view is required to address their difference and consistency.Property analysis of bistatic forwardlooking SAR with arbitrary geometry is achieved including stripmap and spotlight modes on airborne platform,missile-borne platform,and hybrid platform of both.Emphasis is placed on azimuth space variance of some key parameters significantly affecting the subsequent imaging processing,based on which the frequency spectra are further described and compared considering respective features of different platforms for frequency imaging algorithm developing.Simulation results confirm the effectiveness and correctness of our analysis.

Condition Assessment of August A. Busch Bridge Deck Using Portable Seismic Property Analyzer and Ground Penetrating Radar

Ground penetrating radar (GPR) and the portable seismic property analyzer (PSPA) have been extensively used in the past two decades for monitoring, quantifying, and mapping the deterioration of bridge decks. Using PSPA and GPR ensures regular monitoring of bridge conditions, leads to the early detection of deterioration. This research is to address the condition of August A. Busch bridge deck owned by the Missouri Department of Conservation. Visual inspection, GPR, and PSPA data were acquired on the bridge deck. Over 90% of the bridge deck was in fair to good condition with an average compressive strength of over 2500 psi. GPR data showed no indication of significant deterioration. The overall bridge deck was determined to be in fair to good condition.

SYNTHESIS, MAGNETIC PROPERTY AND X-RAY CRYSTAL STUCTURE OF MIXED VALENT COBALT COMPLEX SALT [Co~Ⅲ Cl_2(py)_4][Co~Ⅱ Cl_3(py)]

Complex salt Co_2Cl_5(py)_5 (py=pyridine) was obtained by the reaction of CoCl_2·6H_2O with Bu_4NMnO_4 in pyridine in the presence of benzoic acid. It is monoclinic and crystallizes in space group P2_1/n, fw=690.64, a=28.652(5), b=14.108(4), c=7.424(3) ;β=90.09(1); V=3001(2)~3; Z=4, Dc=1.53g/cm^3. Final R factor is 0.041. The structure consists of a discrete cation [Co~ⅢCl_2(py)_4]^+ and an anion [Co~Ⅱ Cl_3(py)]^-. The Co~Ⅲ ion is coordinated by two Cl^- and four pyridine nitrogen atoms to form an octahedral geometry, and Co~Ⅱ is coordinated by three Cl^- and one pyridine nitrogen atom to form the apices of a tetrahedron. The variable-temperature magnetic susceptility measurement shows no magnet-exchange interaction between Co~Ⅲ and Co~Ⅱ ions.

Property A_(UB) of Metric Spaces under Decompositions of Finite Depth

Property AUB is the notion in metric geometry which has applications in higher index problems.In this paper,the permanence property of property AUB of metric spaces under large scale decompositions of finite depth is proved.

ON WEAK CHEBYSHEV SUBSPACES AND THE PROPERTY AWC1 A SURVEY

The property awc1 was used by many authors to obtain results concerning approximation by elements of weak Chebyshev subspaces. In this paper the author studies this property in details, by collecting the scattered results concerning it and by finding new ones.

Electron Donating Property and Catalytic Activity ofPerovskite-type Mixed Oxides (ABO_3) Consisting of Rare Earth and 3d Transition Metals

The catalytic activity of Perovskite-type mixed oxides (LaCoO3, PrCoO3 and SmCoO3) for the reduction of cyclohexanone to cyclohexanol with 2-propanol (Meerwein-PonndorfVerley reduction) has been studied. The data have been correlated with the surface electron donor properties of these mixed oxides

ELECTRIC PROPERTY AND STRUCTURE OF EOSIN B,ROSE BENGAL,EOSIN 10B (PHLOXINE B) AND THEIR RARE EARTH COMPLEXES

The electric property and structure of some fluorescein derivatives and their rare earthcomplexes have been reported before.In order to investigate the effect of differentsubstituents on the electric property,the change of resistivity with temperature of eosin B(disodium salt of dibromodinitrofluorescein),rose bengal (disodium salt of tetrachlorotetraiodofluorescein),eosin 10B (dipotassium salt of dichlorotetrabromofluorescein) andtheir complexes with La(Ⅲ),Ce(Ⅲ),Gd(Ⅲ) and Y(Ⅲ) is studied in this paper.

Property Assessment for Foreign-Funded Enterprises

Along with the further development of China’s openness and continual improvement of its investment environment, more and more foreign investors are coming to China. Foreign capital, advanced technology and equipment and scientific management can boost China’s economic development.

Honey:its medicinal property and antibacterial activity

Indeed,medicinal importance of honey has been documented in the world's oldest medical literatures,and since the ancient times,it has been known to possess antimicrobial property as well as wound-healing activity.The healing property of honey is due to the fact that it offers antibacterial activity,maintains a moist wound condition,and its high viscosity helps to provide a protective barrier to prevent infection.Its immunomodulatory property is relevant to wound repair too.The antimicrobial activity in most honeys is due to the enzymatic production of hydrogen peroxide.However,another kind of honey,called non-peroxide honey(viz.,manuka honey),displays significant antibacterial effects even when the hydrogen peroxide activity is blocked.Its mechanism may be related to the low pH level of honey and its high sugar content(high osmolality) that is enough to hinder the growth of microbes.The medical grade honeys have potent in vitro bactericidal activity against antibiotic-resistant bacteria causing several life-threatening infections to humans. But,there is a large variation in the antimicrobial activity of some natural honeys,which is due to spatial and temporal variation in sources of nectar.Thus,identification and characterization of the active principle(s) may provide valuable information on the quality and possible therapeutic potential of honeys(against several health disorders of humans),and hence we discussed the medicinal property of honeys with emphasis on their antibacterial activities.

First Principles Investigation of Electronic Property and High Pressure Phase Stability of SrnN

An investigation of electronic property and high pressure phase stability of SmN has been conducted using first principles calculations based on density functional theory. The elec- tronic properties of Stun show a striking feature of a half metal, the majority-spin electrons are metallic and the minority-spin electrons are semiconducting. It was found that Stun undergoes a pressure-induced phase transition from NaCl-type （B1） to CsCl-type structure （B2） at 117 GPa. The elastic constants of Stun satisfy Born conditions at ambient pressure, indicating that B1 phase of SmN is mechanically stable at 0 GPa. The result of phonon spectra shows that B1 structure is dynamically stable at ambient pressure, which agrees with the conclusion derived from the elastic constants.