Role of processing parameters on relative density,microstructure and mechanical properties of selective laser melted titanium alloy

The relationships between the selective laser melting(SLM)processing parameters including laser power,scanning speed and hatch space,the relative density,the microstructure,and resulting mechanical properties of Ti-6Al-2Zr-1Mo-1V alloy were investigated in this work.The result shows that laser power acts a dominant role in determining the relative density in comparison with scanning speed and hatch space.The optimal SLM process window for fabricating relative density>99%samples is located in the energy density range of 34.72 J·mm^(-3)to 52.08 J·mm^(-3),where the laser power range is between 125 W and 175 W.An upward trend is found in the micro-hardness as the energy density is increased.The optimum SLM processing parameters of Ti-6Al-2Zr-1Mo-1V alloy are:laser power of 150 W,scanning speed of 1,600 mm·s^(-1),hatch space of 0.08 mm,and layer thickness of 0.03 mm.The highest ultimate tensile strength,yield strength,and ductility under the optimum processing parameter are achieved,which are 1,205 MPa,1,099 MPa,and 8%,respectively.The results of this study can be used to guide SLM production Ti-6Al-2Zr-1Mo-1V alloy parts.

Relative Content of Phenoxyethanol and p-Hydroxyacetophenone in Water Phase of Oil-water Systems and Teir Relevant Control Parameters

In emulsion system, micro-organisms survive in water phase, thus concentration of preservative in water phase directly reflects to anti-fungi efficacy. As preservative easily migrates into oil phase, it reduces preservative efficacy. A common solution is to increase preservative amount in the whole system. However this way always brings safety issues as preservative is a major allergen. Another effective but safety way is to prohibit preservative migrating into oil phase. In cosmetic research area, phenoxyethanol （PE） and p-Hydroxyacetophenone （p-HAP） pair gradually emerges to be a popular preservative candidate. Thus this new preservative system has been focused as the research object in this work. The relative contents （C） of both PE （CPE） and p-HAP （Cp-HAP） in water phase has been carefully determined. Eight commonly used oils have been further employed to check CPE and Cp-HAP in different oil-water system. The other infuence parameters such as polyols, processing parameters are also investigated. Results shows squalane, petrolatum, silicone oil and hydrogenated polyisobutene might be good oil phase candidates for formulation when using PE and p-HAP preservative system. In these oil systems, PE and p-HAP are mainly located in water phase. Besides, increasing percentage of 1, 3-butylene glycol, shortening homogenization time or adding preservatives at the end of processing under lower temperature could effectively increase effective content preservatives in water phase, either.

Relative peripheral refractive errors in Chinese children with myopic anisometropia

AIM:To compare relative peripheral refractive errors(RPREs)in Chinese children with and without myopic anisometropia(MAI)and to explore the relationship between RPRE and myopia.METHODS:This observational cross-sectional study included 160 children divided into two groups according to the interocular spherical equivalent refraction(SER)difference≥1.0 D in the MAI group(n=80)and<1.0 D in the non-MAI group(n=80).The MAI group was further divided into two subgroups:ΔSER<2.0 D group and ΔSER≥2.0 D group.Basic ocular biometric parameters of axial length(AL),average keratometry(Ave K),cylinder(CYL),surface regularity index(SRI),and surface asymmetry index(SAI)were recorded.In addition,multispectral refraction topography was performed to measure RPRE,and the parameters were recorded as total refraction difference value(TRDV),refraction difference value(RDV)0-10,RDV10-20,RDV20-30,RDV30-40,RDV40-53,RDV-superior(RDV-S),RDV-inferior(RDV-I),RDV-temporal(RDV-T)and RDV-nasal(RDV-N).RESULTS:In the non-MAI group,the interocular differences of all parameters of RPRE were not significant.In the MAI group,the interocular differences of TRDV,RDV10-53,RDV-S,RDV-I,RDV-T,and RDV-N were significant.In subgroup analysis,the interocular differences of TRDV,RDV30-53,RDV-I,and RDV-T were significant in ΔSER<2.0 D group and ΔSER≥2.0 D group,but the interocular differences of RDV10-30,RDV-S and RDV-N were only significant in the ΔSER≥2.0 D group.In correlation analysis,ΔTRDV,ΔRDV 10-53,ΔRDV-S,and ΔRDV-N were negatively correlated with ΔSER but positively correlated with ΔAL.CONCLUSION:The more myopic eyes have larger hyperopic RPRE in Chinese children with MAI in certain retinal range,and partialΔRPRE is closely associated with ΔSER and ΔAL.

Energy Balance-related Behaviors Are Related to Cardiometabolic Parameters and Predict Adiposity in 8-14-year-old Overweight Chinese Children One Year Later

To identify target energy balance-related behaviors（ERBs）,baseline data from 141overweight or obese schoolchildren（aged 8-14years old）was used to predict adiposity[body mass index（BMI）and fat percentage]one year later.The ERBs included a modified Dietary Approach to Stop Hypertension diet score（DASH score）,leisure-time physical activity（PA,days/week）,and leisure screen time（minutes/day）.Several cardiometabolic variables were measured in the fasting state, including systolic blood pressure （SBP）, diastolic blood pressure （DBP）, blood glucose （GLU）, total cholesterol （TC）, triglycerides （TG）, low-density lipoprotein （LDL-C）, and high-density lipoprotein （HDL-C）.

Using Grey Relational Analysis to Evaluate Different Influencing Factors on Aquifer Parameters Variations with Groundwater Source Heat Pump Operation

The influence of particle migration induced by groundwater source heat pump( GWSHP) operation on aquifer parameters was theoretically analyzed. Then the sensitivity analysis of different influencing factors,which influenced aquifer parameters with GWSHP operation,was evaluated by using grey relational analysis method through a case study. The present study indicated that the erosion parameter, hydraulic conductivity and initial concentration were critical influencing factors which affected the aquifer parameters and the suitability of GWSHP. It also indicated that the discharge of single well should be controlled and the diameter of single well should be selected appropriately in order to decrease particle migration.

A Relation of the Noncommutative Parameters in Generalized Noncommutative Phase Space

We introduce the deformed boson operators which satisfy a deformed boson algebra in some special types of generalized noncommutative phase space. Based on the deformed boson algebra, we construct coherent state representations. We calculate the variances of the coordinate operators on the coherent states and investigate the corresponding Heisenberg uncertainty relations. It is found that there are some restriction relations of the noncommutative parameters in these special types of noncommutative phase space.

Characterization of Source Parameters and Some Empirical Relations between Them for Kachchh Region, Gujarat, India: Implication of January 26, 2001 Bhuj Earthquake and Its Aftershock Sequence

Study of source parameters of small to moderate and large earthquakes is important to understand the differences and similarities between dynamic ruptures of different earthquakes and clarifying the scaling relations. In the present study, we have characterized source parameters and presented new and revised empirical relationships between various source parameters for Kachchh region of Gujarat, India to facilitate to draw first-order conclusions regarding the trends in the region. We have studied total 202 aftershocks of shallow-focus (hypo central depth less than 40 km) and moderate magnitude recorded over the Kachchh region during January 2001 to December 2012 by different seismological observatories of India Meteorological Department. We have adopted the spectral technique for source parameter estimation, where S-wave displacement spectra are considered and applied Fast Fourier Transform (FFT) to compute displacement spectra. We have followed the Brune’s source model for our estimation and the estimated values of source parameters show close approximation to the global values. While derived empirical relations between different source parameters, they demonstrate direct or inverse proportion to linear or power scale. Interrelation between seismic moment, rupture parameters, corner frequency and radiated seismic energy can be summarized as , , and ER μ M0 and ER μ Mw for our analysis. Stress drop distribution over the Kachchh region is very scattered and due to its peculiar behavior, it is difficult to derive its empirical relation with other source parameters. Sufficient accuracy on measuring source parameters like corner frequency stress drop, rupture dimensions, radiated seismic energy etc. helps to understand earthquake processes in the region. This is the first ever attempt to establish empirical relation between different source parameters for Kachchh region for longer aftershock sequence and they are useful to assess future earthquake potential over the region.

Calculation of reverse-fault-related parameters using topographic profiles and fault bedding

Fault-related parameters are critical for studying tectonic evolution, deformation character- istics, active tectonism, and seismic hazards. A new method of calculating reverse-fault- related parameters has been developed, which uses systematic analysis of the geometrical characteristics of normal and reverse scarps of reverse faults together with measurements of topographic profiles and fault bedding. The results show that the most suitable method of calculating fault parameters heavily relies on the specific type of fault scarp. For a reverse scarp, the size of the vertical displacement （VD） of the fault, the vertical separation （VS） of the hanging wall and the footwall, and the fault scarp height （SH）how the relationship VD ≥VS ≥ SH; conversely, for normal scarps, VD ≤ VS ≤ SH. The theoretical equations were used to study fault deformation in the Southwest Tianshan Mountain foreland basin. The results showed that, for every fault, VD ≥ VS ≥SH, which is consistent with our predicted relationship. This finding demonstrates that this method is suitable to explore structural information of reverse faults. In the study area, the vertical displacement is 1.4 times the horizontal displacement, suggesting that fiexural-slip faults may play an important role in transferring local deformation from horizontal shortening to vertical uplift. Therefore, one of the most important steps in correct calculation of reverse-fault-related parameters is selection of the proper equations by identifying the specific type of fault scarp and the corresponding calculation method.

Assessment of active tectonics from geomorphic indices and morphometric parameters in part of Ganga basin

Ganga river basins exposed to active erosional and deformational processes. The recurrence of landslides, floods, and seismic activities makes it more susceptible to deformational activities. The tectonic analysis using geomorphic indices and morphometric parameters will help in determining the hazard-prone area of the river basin. Geomorphic indices and morphometric parameters are calculated to investigate the role of neotectonic activities, as it acts as a controlling factor in the development of landforms in the tectonically active terrains. Neotectonic activities influence the terrain topography, which significantly affects the drainage system and geomorphological setup of the area. In this study, the assessment of active tectonics of study area was determined using Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER) Global Digital Elevation Model(GDEM) based on Geomorphic Indices(Stream Length Gradient index, Hypsometric integral, Asymmetry factor, Basin shape, Valley floor width to Valley height ratio, Mountain front sinuosity index) cumulatively with Linear, Areal and Relief morphometric parameters on 27 delineated basins of the study area. The combined classification of Relative Tectonic Activity Index(Iat) and morphometric parameters of 27 basins categorized all the zones into four different classes:Class 1 – Very High(<1.97;410 km^2);Class 2 – High(1.97 – 2.05;275 km^2);Class 3 – Moderate(2.05 – 2.21;273 km^2),and Class 4 – Low(>2.21;299 km^2). The basins with tectonic activities have a consistent relationship with structural disturbances, basin geometry, and field studies. The tectonically active zonation of a part of Ganga basin using geomorphic indices and morphometric parameters suggest that it has significant influence of neotectonic activities in a part of Ganga basin.

Impacts of parameter uncertainties on deep chlorophyll maximum simulation revealed by the CNOP-P approach

Parameter uncertainty is a primary source of uncertainty in ocean ecosystem simulations.The deep chlorophyll maximum(DCM)is a ubiquitous ecological phenomenon in the ocean.Using a theoretical nutrients-phytoplankton model and the conditional nonlinear optimal perturbation approach related to parameters,we investigated the eff ects of parameter uncertainties on DCM simulations.First,the sensitivity of single parameter was analyzed.The sensitivity ranking of 10 parameters was obtained by analyzing the top four specifi cally.The most sensitive parameter(background turbidity)aff ects the light supply for DCM formation,whereas the other three parameters(nutrient content of phytoplankton,nutrient recycling coeffi cient,and vertical turbulent diff usivity)control nutrient supply.To explore the interactions among diff erent parameters,the sensitivity of multiple parameters was further studied by examining combinations of four parameters.The results show that background turbidity is replaced by the phytoplankton loss rate in the optimal parameter combination.In addition,we found that interactions among these parameters are responsible for such diff erences.Finally,we found that reducing the uncertainties of sensitive parameters could improve DCM simulations remarkably.Compared with the sensitive parameters identifi ed in the single parameter analysis,reducing parameter uncertainties in the optimal combination produced better model performance.This study shows the importance of nonlinear interactions among various parameters in identifying sensitive parameters.In the future,the conditional nonlinear optimal perturbation approach related to parameters,especially optimal parameter combinations,is expected to greatly improve DCM simulations in complex ecosystem models.

Performances of the cotton bollworm,Heliothis armigera (Hubner) at different temperatures and relative humidities

The cotton bollworm, Heliothis armigera (Hubner) is an important insect species at-tacking many crops. Their performances have been examined at temperatures from 15℃ to 35℃ and relative humidities (RH) between 22.5% and 100%, respectively, in order to assess possible effect of climate in future on its occurrence and infestation. Durations of all developmental stages of the insect shortened with increasing temperature. The temperature favoring population growth ranged from 25℃ to 30℃.Larval duration and adult longevity decreased as relative humidity increased, but development of other stages was independent of RH. At RH of over 64%, their survival rate, egg production and oviposition rate varied a little, and all the population parameters of the insect remained at a relative constant level.

Parameterization of Sheared Entrainment in a Well-developed CBL.PartⅡ:A Simple Model for Predicting the Growth Rate of the CBL

Following the parameterization of sheared entrainment obtained in the companion paper, Liu et al. （2016）, the present study aims to further investigate the characteristics of entrainment, and develop a simple model for predicting the growth rate of a well-developed and sheared CBL. The relative stratification, defined as the ratio of the stratification in the free atmosphere to that in the entrainment zone, is found to be a function of entrainment flux ratio （Ae）. This leads to a simple expression of the entrainment rate, in which Ae needs to be parameterized. According to the results in Liu et al. （2016）, Ae can be simply expressed as the ratio of the convective velocity scale in the sheared CBL to that in the shear-free CBL. The parameterization of the convective velocity scale in the sheared CBL is obtained by analytically solving the bulk model with several assumptions and approximations. Results indicate that the entrainment process is influenced by the dynamic effect, the interaction between mean shear and environmental stratification, and one other term that includes the Coriolis effect. These three parameterizations constitute a simple model for predicting the growth rate of a well-developed and sheared CBL. This model is validated by outputs of LESs, and the results show that it performs satisfactorily. Compared with bulk models, this model does not need to solve a set of equations for the CBL. It is more convenient to apply in numerical models.

INFLUENCES OF MOLECULAR WEIGHT AND BRANCHING PARAMETER OF LACQUER POLYSACCHARIDE ON THE GROWTH OF LEUCOCYTES

A method of determining branching parameter of lacquer polysaccharide wasestablished by acid-base back-titration of terminal uronic acid of branches. The branchingfactors obtained are in agreement with the values determined by colorimetric method withcarbazole and the results estimated by using Zimm-Stockmayer equation from viscositydata. Influences of molecular weights and branching factors of five fractions of lacquerpolysaccharide on the bioactivities were studied. The results show that the polysaccharideshave bioactivities in motivating the growth of leucocytes, and the effect increases with thedecrease of molecular weight and branching factor in the range studied (17×10~4 >M_w>4×10~4).

Effect of sintering parameters on powder injection molded Ti(C, N)-based cermets

Effect of two-stage sintering parameters such as heating rate, top sintering temperature and holding time, sintering temperature and holding time at the second stage on relative density, transverse rupture strength(TRS) and microstructures of powder injection molded Ti(C, N)-based cermets were investigated, by means of Archimedes’s method, three-point bending test and micrographic analysis. The results show that the optimum sintering cycle for powder injection molded Ti(C, N)-based cermets comprises rapid heating (10℃/min) at low temperatures, slow heating (5℃/min) at intermediate temperatures, holding at the highest sintering temperature (1420℃) for a short time (10min), and holding at the second stage (1360℃) for a longer time (6h) to avoid grain coarsening, and that its TRS reaches 624MPa, and there are little pores in their microstructures.

Effects of <i>Nigella sativa</i>L. Seed Extract on Fatigue, Blood Biochemical Parameters and Thyroid Function in Male Mice

Nigella sativa L. (Black seed), is a traditional herbal medicine that has been used for many purposes. The present study was designed to investigate the effects of hydro-alcoholic extract of nigella sativa L. (NS) on performance of Forced Swimming Test (FST), blood biochemical parameters related to fatigue and thyroid functions. Therefore, Blood Urea Nitrogen (BUN), Creatine Kinase (CK), Lactic Dehydrogenase (LDH), and Total Protein (TP), triiodothyronine T3, thyroxin T4 and TSH tests were investigated. Thirty five male adult mice were randomly divided into five groups: three NS-fed groups, one fluoxetine treated group and one control group. Three NS experimental groups received hydro-alcoholic extract of NS at doses of 50, 100 and 200 mg/kg orally for two weeks. Immobility time decreased in all NS groups compared with control group. Administration of NS significantly increased the concentration of T3 and T4 of the treatment groups. On the contrary, the amount of BUN, CK, LDH, TP and TSH decreased. In conclusion, black seed extract at the experimented doses showed anti-depressant, anti-fatigue and hyperthyroid effects.

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions

This study deals with the climatic parameters and the climatic differences in Elazig and its close regions (cities of Malatya, Tunceli, Bing?l, Erzincan). Data on mean monthly temperature, daily maximum-minimum temperature, rela-tive humidity, pressure, wind speed, rainfall, solar radiation and sunshine duration were analyzed and modeled for 10-year period, from 1994 to 2003. Malatya city was the hottest area whole period, while the Erzincan city was the coldest area. Maximum temperatures were at highest values in Tunceli. Minimum temperatures reached the warmest values in the Malatya. Erzincan city was the most humid area almost throughout the period while Malatya was the least humid area. Wind speed reached the highest values in the Elazig and the lowest values in the Tunceli. Pressure reached the highest values in the Malatya and the lowest values in the Erzincan. Direct solar radiation reached the highest val-ues in the Tunceli and the lowest values in the Erzincan. Sunshine duration reached the highest values in the Malatya and the lowest values in the Erzincan. A regression analysis was carried out by using the linear regression technique to model the climatic parameters. The models developed can be used in any study related to climatic and its effect on the environment and energy. The models developed in this study can be used for future predictions of the climatic parame-ters and analysing the environmental and energy related issues in Elazig and its close regions (cities of Malatya, Tun-celi, Bing?l, Erzincan).

Water Relations on Alhagi sparsifolia in the Southern Fringe of Taklamakan Desert

Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.

腰椎退行性侧弯矫正后颈椎和胸椎的代偿性对齐变化

背景:目前关于腰椎退变性侧弯患者矫形术后颈胸椎矢状面参数的代偿性改变及其内在联系,以及上述改变对生活质量的影响,尚缺乏相关研究。目的:评估腰椎退行性侧弯矫正术后颈椎和胸椎的代偿性对齐变化。方法:纳入接受腰椎退行性侧弯矫正治疗的患者103例,评估患者的人口统计学特征和脊柱矢状面参数,并尝试建立颈椎矢状面参数变化与腰椎畸形矫正后的预测方程。同时,采用SRS-22量表评估患者的生活质量,探究矫正术后颈椎和胸椎代偿性变化与患者健康相关生活质量之间的关系。结果与结论:①术后3个月及2年,颈椎、胸椎各指标与术前相比均显著改善(P<0.05),但术后3个月与术后2年相比变化不显著(P>0.05);术后3个月及2年,腰椎参数中腰椎前凸角、C_(7)-S_(1)矢状面垂直轴、骨盆入射角-腰椎前凸角与术前相比有显著变化(P<0.05),但术后3个月与术后2年相比变化不显著(P>0.05);②相关性分析显示,腰椎前凸角与C_(3)-C_(7)颈椎前凸角、C_(1)-C_(7)颈椎前凸角、C_(2-7)矢状面垂直轴、胸廓入口角和C_(7)-S_(1)矢状面垂直轴高度相关(|r|≥0.5,P<0.0001);腰椎前凸角与胸椎后凸角也有显著的相关性(r=-0.280);③建立了2个颈椎代偿性变化的预测公式:颈椎前凸角=0.524×腰椎前凸角-6.612,C_(2-7)矢状面垂直轴=-0.263×腰椎前凸角-5.436(P<0.05,R^(2)>0.6);④术后C_(2-7)矢状面垂直轴在14.4-26.8 mm之间,颈椎前凸角在9°-41°之间,腰椎前凸角在42.7°-68.7°之间,矢状面垂直轴在-40-40 mm之间的患者,生活质量恢复更好;⑤提示腰椎退行性侧弯矫正术后可以观察到显著的颈椎矢状面代偿性变化,发现腰椎前凸每增加1°,颈椎前凸相应增加约0.5°,C_(2-7)矢状面垂直轴相应减少约0.3 mm;如果代偿性变化更接近于正常矢状面,患者满意度更高。

Parametric sensitivity analysis of bearing characteristics of single DOF autonomous system of magnetic-liquid double suspension bearing

The mathematical model of single degree of freedom(DOF)nonlinear autonomous bearing system under constant flow supporting model is deduced.The single DOF nonlinear autonomous bearing system is transformed with the method of linear and nonlinear treatment,the mathematical expression and parameters sensitivity of relative error of stiffness and damping are presented.Finally,the main factors of magnetic-liquid double suspension bearing(MLDSB)are analyzed,and the influence on bearing performance indicators of single DOF nonlinear autonomous bearing system of main factors is revealed.The results show that linear stiffness/damping is the first part of equivalent stiffness/damping,and the second and third parts are high order minor term of Tayor series transform.The film thickness,the magnetic-liquid proportionality coefficient,the mass of rotor are the major influence factor of the bearing performance.The research can provide the theoretical reference for the design and nonlinear analysis of MLDSB.

Static and Dynamic Scaling Relationships for Moderate and Small Earthquakes in the Yunnan Region

Source spectra for moderate and small earthquakes are obtained after removing the path effect, site effect, and instrument response, etc. in the observed S-wave spectra. Based on the Brune source model and by means of genetic algorithm, the source parameters including seismic moment, stress drop, source dimension, etc. are determined, the radiated seismic energy for small-to-moderate earthquakes is measured with consideration of underestimation and compensation brought forth by limited bandwidth of the instrument, and the scaling relationships of static and dynamic parameters for earthquakes