A novel immiscible high entropy alloy strengthened via L1_(2)-nanoprecipitate

The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.

UGS模式下县城高中《数学文化》校本课程的实践探究

《数学文化》校本课程在高中应用中的重要性体现在培养数学兴趣、拓宽数学视野、培养数学思维和培养数学素养等方面。文章以UGS模式下县城高中《数学文化》校本课程的实践探究为研究对象,从高二数学老师的角度出发,结合理论和实际,详细深入地探讨了该校本课程的实施情况、措施和效果。通过对学生的学习成绩和学习动机的调查分析,得出了一些有益的结论和建议,以期待为学校提供借鉴和参考。

化学专业课程设置改革构想

为了适应国家经济建设的需要,高等学校面临进一步的教学改革。化学专业原有的课程设置,缺少课程之间的有机联系,难以适应现代科技高速发展、多学科之间紧密联系、相互渗透的发展趋势,也不能适应通才教育的要求。为了让学生在四年的学习过程中,既能系统、牢固地掌握化学的基础理论,又尽可能多的了解化学最新前沿知识,化学专业课程的设置必须改革。

高血压脑出血术后再出血的原因及防治对策

目的重点研究和探讨高血压脑出血术后再出血的原因及防治对策。方法利用回顾性分析的方法研究和比较对我院于2010年1月-2012年12月收治的172例高血压脑出血术后再出血的患者的临床资料进行回顾性对照分析。随机分为两组，观察组86例采用综合防治手段，对照组86例采用常规处理。结果出血量〉90ml的时候术后再出血患者的比率为最高，达到45．5％。观察组的术后再出血情况明显好于对照组，治疗后恢复情况也有显著改善。结论手术时机的选择、止血治疗、术中止血、术后保持血压平稳等综合治疗是减少患者高血压脑出血术后再出血的关键因素。

Reaction kinetics of roasting high-titanium slag with concentrated sulfuric acid

A novel method of roasting high-titanium slag with concentrated sulfuric acid was proposed to prepare titanium dioxide, and the roasting kinetics of titania was studied On the basis of roasting process. The effects of roasting temperature, particle size, and acid-to-ore mass ratio on the rate of roasting reaction were investigated. The results showed that the roasting reaction is fitted to a shrinking core model. The results of the kinetic experiment and SEM and EDAX analyses proved that the reaction rate of roasting high-titanium slag with concentrated sulfuric acid is controlled by the internal diffusion on the solid product layer. According to the Arrhenius expression, the apparent activation energy of the roasting reaction is 18.94 kJ/mol.

Biomechanical Characteristics of Rape Stalks

[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of maximum stem bearing ca- pacity, maximum compressive strength, elastic modulus and moment of inertia along plant height were analyzed, as well as the effect of different varieties and water contents on the biomechanical property indices of rape stalks. [Result] The maximum loads of rape stalks presented liner decrease trend along with the increase of stem height, and all reached the maximums below the height of 50 cm. The maximum stem compressive strength and elastic modulus of the 4 varieties were increased with ascending height, but in a slow rate with small change, thus the modulus of e- lasticity could be considered as unchanged. The maximum bearing capacity, maxi- mum compressive strength and elastic modulus of dry rape stalks were higher than wet stalks, indicating that the water contents of rape stalks had significant effect on their mechanical properties. According to the actual lodging situations in filed, stalks of variety No. 1 owned the worst biomechanical properties and lodging degree, while the biomechanical properties of No. 6 and F5 were better than No. 1 and No. 9, and they also had stronger lodging-resistance. [Conclusion] The study provides parameters and bases for the design of mechanized production and mechanical deep processing of crops, and can better reveal the physical natures of organisms. The methods used in this study can also be used to screen excellent crop stalks.

Chunk approach for English teaching

This paper suggests a chunk approach to solve the plateau problem among advanced English learners. The paper first discusses the extant problems and then provides a definition of the chunk approach. Based on some research results in cognitive psychology, it analyses the important role that chunks play in language acquisition and production and thus provides a cognitive foundation for implementing the chunk approach in English teaching. The paper also offers a set of classroom activities which can be easily adopted or adapted by other teachers.

Preparation of ultrafine rhenium powders by CVD hydrogen reduction of volatile rhenium oxides

A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials. In the process, volatile rhenium oxides, such as ReO4 and Re2O7, were vaporized under a controlled oxidizing atmosphere via the pyrolysis of ammonium perrhenate, and carried into reduction zone by carrier gas, and there reduced into rhenium powders by hydrogen gas. Thermodynamic calculations indicated that Re207 could be prevented from further decomposition through controlling the oxygen partial pressure higher than 10 1.248 Pa in the pyrolysis of ammonium perrhenate. This result was further validated via DSC-TGA analysis of ammonium perrhenate. The typical rhenium powders prepared by the CVD method proposed show irregular polyhedron morphology with particle size in the range of 100-800 nm and a Ds0 of 308 nm. The specific surface area and oxygen content were measured to be 4.37 m^2/g and 0.45%, respectively.

Thermodynamic calculation of high zinc-containing Al-Zn-Mg-Cu alloy

Phase fraction and solidification path of high Zn-containing Al-Zn-Mg-Cu series aluminum alloy were calculated by calculation of phase diagram （CALPHAD） method. Microstructure and phases of Al-9.2Zn-1.7Mg-2.3Cu alloy were studied by X-ray diffraction （XRD）, differential scanning calorimetry （DSC） and scanning electron microscopy （SEM）. The calculation results show that η（MgZn2） phase is influenced by Zn and Mg. Mass fractions of η（MgZn2） in Al-xZn-1.7Mg-2.3Cu are 10.0%, 9.8% and 9.2% for x=9.6, 9.4, 8.8 （mass fraction, %）, respectively. The intervals of Mg composition were achieved for θ（Al2Cu）＋η（MgZn2）, S（Al2CuMg）＋η（MgZn2） and θ（Al2Cu）＋S（Al2CuMg）＋η（MgZn2） phase regions. Al3Zr, α（Al）, Al13Fe4, η（MgZn2）, α-AlFeSi, Al7Cu2Fe, θ（Al2Cu）, Al5Cu2MgsSi6 precipitate in sequence by no-equilibrium calculation. The SEM and XRD analyses reveal that α（Al）, η（MgZn2）, Mg（Al,Cu,Zn）2, θ（Al2Cu） and Al7Cu2Fe phases are discovered in Al-9.2Zn-1.7Mg-2.3Cu alloy. The thermodynamic calculation can be used to predict the major phases present in experiment.

Pharmacokinetics of Scutellarin in Dogs

Aim To establish an RP-HPLC method for the determination of scutellarin in plasma and study its pharmacokinetics in dogs. Methods Scutellarin was given to dogs by intravenous injection and determined by RP-HPLC, the mean plasma concentration-time curve was plotted and pharmacokinetic parameters were calculated by program 3p87. Resu;ts The concentration-time curve of scutellarin could be fitted to three-compartment model with T1/2 pi, T1/2 α and T1/2 β being 1.05 ± 0.80 min, 6.99 + 2.76 min and 51.61 + 28.78 min, respectively, Vc being 880.1 + 508.3 mL, CL being 189.6 + 53.8 mL@ min- 1, and AUC0-90 and AUC0-∞ being 574.43 + 133.95 μg@ min@ mL - 1 and 599.34 ± 132.00μg@ min@mL- 1, respectively. Conclusion The fact that the concentrations of scutellarin in plasma declined rapidly after the medication suggested that the T1/2 of scutellarin should be taken into account in drug administration and preparation development.

Preparation and mechanical properties of carbon/carbon composites with high textured pyrolytic carbon matrix

Short carbon fiber felts with an initial porosity of 89.5% were deposited by isobaric, isothermal chemical vapor infiltration using natural gas as carbon source. The bulk density of the deposited carbon/carbon （C/C） composites was 1.89 g/cm3 after depositing for 150 h. The microstructure and mechanical properties of the C/C composites were studied by polarized light microscopy, X-ray diffraction, scanning electron microscopy and three-point bending test. The results reveal that high textured pyrolytic carbon is deposited as the matrix of the composites, whose crystalline thickness and graphitization degree highly increase after heat treatment. A distinct decrease of the flexural strength and modulus accompanied by the increase of the toughness of the C/C composites is found to be correlated with the structural changes in the composites during the heat treatment process.

Determination of Piperazine Ferulate in Human Plasma by HPLC and Its Pharmacokinetic Study

Aim To establish a sensitive HPLC method for determination of piperazine ferulate and to study its pharmacokinetics in healthy volunteers. Methods Piperazine ferulate was separated on a Shimadzu C_ 18 column with acetic acid (0.1%)-methanol (60 ∶ 40, V/V) as mobile phase after liquid-liquid extraction, and detection was performed at 310 nm. Piperazine ferulate pharmacokinetic parameters after a single oral dose of 200 mg of piperazine ferulate dispersible tablets in 20 healthy male volunteers were calculate...

Pharmacokinetics of Ferulic Acid in Rabbits with BloodStasis

To test and study the Syndrome and Treatment Pharmacokinetics (S & TRK),we studied the pharmacokinetics of ferulic acid in healthy and blood stasis (microcirculation dysfunction)rabbits by RP-HPLC. After a single intravenous injection offenilic acid(5mg/kg)to healthy and blood stasis rabbits, compartment model of ferulic acid serum concentration was fitted and then pharmacokinetic parameters were calculated with a MCPKP program on a COMPAQ 386 compute Important parameters are as follows: In healthy rabbits V_B=0.9525±0.0211 L/kg,V_1=0.2462±0.0381 L/kg, CL_B=1.8133±0.9512 L/h·kg, T_(1/2β)=0.3639±0913, AUC=2.7566±0.8232 μg·h/ml; In blood stasis rabbits V_B=0.7882±0.0321 L/kg,V_1=0.1966±0.0537 L/kg,CL_B=0.8820±0.5481 L/h·kg,T_(1/2β)=0.6193±0.1216 h, AUC=5.6690±2.3541μg·h/ml.Through this experiment we found the sig-nificant differences in the FA's pharmacokinetic parameters between healthy and blood stasis rabbits.The results obtained correspond with S & TPK.

胶州湾北部软底大型底栖动物丰度和生物量的研究

1995年3～11月对胶州湾北部软底海域进行了 两月一次的大型底栖动物调查。调查期间，大型底栖动物总平均丰度和总平均生物量分别为 1891.3 inds./m2和41.9 g.w.w/m2。与该海域有关大型底栖动物丰度和生物量的历史 资料相比较，本研究所得到的大型底栖动物丰度值显著增加，生物量值则有较明显的下降， 初步分析了发生这些变化主要原因。丰度和生物量比较曲线表明，所研究海域底栖生物群落 处于中等干扰(即污染的影响 )状态。

Research on Yield and Quality of Hybrid Rice under Efficient Application Amount of Phosphorus and Potassium

[Objective] Application of P and K was not reasonable in southwest rice producing area, with no effective method for guiding application of P and K. This study aimed to conduct experiments with the same N application and different P and K application in different ecological points, to explore a scientific and efficient management method of P and K nutrients and provide guidance for application of P and K in rice production. [Method] Hybrid rice Chuanxiang9838 was used as experimental material to study the relationship among application amount of P and K, utilization rates of P and K, rice yield and rice quality in seven ecological points of four provinces （municipalities） including Sichuan, Chongqing, Yunnan and Guizhou. The application amount per hectare of P was 37.5, 75, 112.5 and 150 kg, respectively; the application amount per hectare of K was 45, 135 and 180 kg, respectively. A total of 10 treatments were set for split-plot design with three replications. [Result] Yield of Chuanxiang9838 significantly varied in different experimental locations and under different levels of P and K, interaction of ecological point and different P and K treatments varied significantly. Yield had reached the maximum in ecological point of Yunnan Binchuan and in treatment with application of N 150 kg P 75 kg K 90 kg. Efficient utilization rates of P and K varied in each ecological point, efficient application amount of P and K in Sichuan Dongpo, Sichuan Luxian, Guizhou Xiaohe and Chongqing Yongchuan was the same, while that in Sichuan Guanghan, Sichuan Zhongjiang and Yunnan Binchuan was different. The main objective of high-yield rice production was to increase the number of effective panicles per hectare and seed setting rate. Rice quality was clustered into 2 categories by locations and 6 categories by treatments. [Conclusion] Prediction models of efficient application of P and K in rice production were established, which provided guidance for high-yield rice production and rational and efficient utilization of P and K in southwest rice area.

以人力资源市场为导向发展高等职业教育

本文着重论述了高等职业教育作为在市场经济体制下的教育形态，必须遵循市场经济规律，与企业一样进入市场，“生产”能够满足市场需要的“产品”──各类新型人才和劳动者。

Elasticity and Thermodynamic Properties of EuS Related to Phase Transition

First-principles calculations of the crystal structures, phase transition, and elastic properties of EuS have been carried out with the plane-wave pseudopotential density functional theory method. The calculated values are in very good agreement with experimental data as well as some of the existing model calculations. The dependence of the elastic constants, the aggregate elastic modulus, and the elastic anisotropy on pressure have been investigated. Moreover, the variation of the Poisson＇s ratio, Debye temperature, and the compressional and shear elastic wave velocities with pressure have been investigated for the first time. Through the quasi-harmonic Debye model, the thermal expansions, heat capacities, Grneisen parameters and Debye temperatures dependence on the temperature and pressure are obtained in the pressure range from 0 GPa to 60 GPa and temperature range from 0 K to 800 K.

Bending properties and fracture mechanism of C/C composites with high density preform

C/C composites with banded structure pyrocarbon were fabricated by fast chemical vapor infiltration（CVI）,with C3H6 as carbon source,N2 as carrier gas,and three-dimensional（3D） 12K PAN-based carbon fabric with high density of 0.94 g/cm3 as preform.Experimental results indicated that the fracture characteristics of C/C composites were closely related to the frequency of high-temperature treatment（HTT） at the break of CVI process.According to the load？displacement curves,C/C composites showed a pseudoplastic fracture after twice of HTT.After three times of HTT,load？displacement curves tended to be stable with a decreasing bending strength at 177.5 MPa.Delamination failure and intrastratal fiber fracture were observed at the cross-section of C/C composites by scanning electronic microscope.Because the content of pyrocarbon and fibers has a different distribution in layers,the C/C composites show different fracture characteristics at various regions,which leads to good toughness and bending strength.

Pharmacokinetics of Remifentanil in Chinese Patients Undergoing Elective Surgery

Aim To study the pharmacokinetics of remifentanil in Chinese aduh patients undergoing elective surgery and compare the results with the data already published. Methods The pharmacokinetics of remifentanil was determined in 10 aduh patients undergoing elective surgery. Remifentanil 5 - 6 μg·kg^-1 was administered within 1 min after the induction of anesthesia. One point five millilitre of arterial blood samples were collected at 0 （baseline）, 1,2, 3, 5,7, 10, 15, 20, 25, 30, 45, 60, and 90 min after drug administration. Remifentanil concentration was assayed by HPLC/MS/MS. Resuits The concentration-time course of remifentanil was best described by a two-compartment model. Total clearance （CL = 2. 149 ± 0. 431 L·min^-1） of remifentanil was greater than the normal hepatic blood flow. The distribution half-life （t1/2α） [ 1.56 ± 0. 52 min （0.73 - 2.31 ） ] and the elimination half-life （t1/2β） [22.07 ± 10.30 min （9, 71 -36.07）] were similar with those in previous reports. Volume of distribution （ Vd = 65. 766 ± 29. 100 L） was about two times greater than that reported in previous studies of other ethnics. Conclusion In the present study, the volume of distribution is significantly greater than thai reported in previous studies of other ethnics, indicating that there are some differences in the pharmacokinetics of remifentanil among different ethnics.

Dynamics simulation of tertiary amines adsorbing on kaolinite(001) plane

The collecting power of tertiary amines（DRN,DEN and DPN） on kaolinite follows the order of DENDPNDRN.After reacting with DRN,DEN and DPN,the surface potentials of kaolinite increase remarkably,and the recruitments caused by collectors also follow the order of DENDPNDRN.The results of dynamics simulation show that the geometries of substituent groups bonding to N are deflected and twisted,and some of bond angles are changed when tertiary amines cations adsorb on kaolinite（001） surface.Based on the results of dynamics simulations and quantum chemistry calculations,the electrostatic forces between three tertiary amines cations and 4×4×3（001） plane of kaolinite are 1.38×10？7 N（DRN12H＋）,1.44×10-6 N（DEN12H＋）,1.383×10-6 N（DPN12H＋）,respectively.