绿松石品质与水耦合关系及变温光谱学表征

绿松石作为一种含水的铜、铝磷酸盐矿物,其矿物中的吸附水、结晶水以及结构水含量,与其结构的致密程度密切相关,对其质地具有一定的表征作用,进而对其颜色品质产生一定的影响。因此,在红外曲线拟合技术基础上,通过研究绿松石中"水"的变化情况作为绿松石品质研究的切入点,对绿松石质地及颜色的分类作半定量分析,进而为后续开展的绿松石品质分类提供科学理论依据。选取产自马鞍山的不同质地和颜色的绿松石原矿样品,通过25~400℃范围内变温加热实验,对绿松石中吸附水、结晶水和结构水的渐变逸出过程中的红外及紫外-可见吸收光谱进行测试,并采用曲线拟合法,分别对红外吸收光谱中结晶水及结构水的吸收谱带进行积分计算,结合绿松石的颜色坐标数值的变化情况,分析研究绿松石品质与其水分子之间的耦合关系及影响因素。结果表明,质地疏松绿松石中"水"峰的相对吸收强度及积分面积比质地致密绿松石明显偏高,并且质地疏松绿松石中结晶水和结构水的稳定性明显低于质地致密绿松石;蓝色调的绿松石往往较蓝绿色调及绿色调绿松石结构致密,低温环境下更不容易因失"水"而产生颜色变化。

基于变温模具的无纺织物热模压成型

为了解决传统热模压过程中无纺织物受热不均匀的问题,文章通过对热模压加热结构和变温模具进行改进与理论分析,根据实际需要设计并选择合理可行的变温模具加热装置,即采用可控热风加热方式。采用ANSYS软件对变温模具进行热场分析,并仿真了变温模具的温度场状况。结果表明,采用可控热风加热方式,可以提高无纺织物的拱度,改善无纺织物的手感和柔软度;采用有限元分析,对确定和验证模具工艺参数具有指导性的作用。

High temperature deformation behavior and optimization of hot compression process parameters in TC11 titanium alloy with coarse lamellar original microstructure

The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.

Microwave Preparation of SiO2-B2O3-Na2O-K2O-CaO-Fe2O3-TiO2 Glass System

This study reports preparation of glass composition （54.50 wt.%） SiO2, （10.80 wt.%） B2O3, （14.20 wt.%） Na2O, （1.20 wt.%） K2O, （6.00 wt.%） CaO, （4.00 wt.%） Fe2O3 and （9.30 wt.%） TiO2 by melt quenching method using direct microwave heating and conventional resistive heating. Study of dielectric loss factor of the glass as function of temperature illustrated increasing loss factor above 370 ℃, 550 ℃, 650 ℃ and 900 ℃, indicating enhanced microwave absorption by the glass at above these temperatures. Chemical analysis results of both the glasses depicted more volatilization loss of volatile ingredients in conventional heating. The study of chemical durability was performed from leachate analysis describing less leaching of Na2O, K2O and other constituents from glass melted in microwave furnace. Glass transition temperatures （Tg） were found to be 576.3 ℃ and 569.5 ℃ for glass melted in conventional and microwave heating route, respectively. Laboratory experiment of glass melting utilizing microwave energy as an alternate heating source demonstrated 70%-75% electrical power saving.

Influence of Holding Time on Hot Deformation Behavior of Hard-Deformed Superalloy U720Li

To improve the hot workability of hard-deformed superalloy U720Li,the effect of holding time before deformation(5 and 10 min)on hot deformation behavior was investigated by hot compression tests.Results show that the flow stress increases with increase in strain rate,while decreases with increase in deformation temperature and holding time.Based on the obtained Arrhenius-type constitutive models,the calculated peak stresses are in good agreement with experimental values,indicating that this model can accurately predict the hot deformation behavior of U720Li alloy,and the deformation activation energies for the holding time of 5 and 10 min were calculated to be 992.006 and 850.996 kJ·mol^(-1),respectively.Moreover,processing maps of U720Li alloy with these two holding durations were constructed.Through observation of deformation microstructures in each domain of the processing maps,the optimal hot working conditions for the holding time of 5 min are determined to be 1090‒1110℃/1‒10 s^(-1) and 1146‒1180℃/1‒10 s^(-1),and the optimal hot working conditions for the holding time of 10 min are 1080‒1090℃/1‒10 s-1 and 1153‒1160℃/1‒10 s^(-1),indicating that the safe processing window can be obviously enlarged by shortening the holding time reasonably.In the absence of cracking,the dynamic recrystallization(DRX)grain size increases gradually with increasing the deformation temperature and holding time,but it first decreases and then increases with the increase in strain rate.When the deformation temperature is below 1100℃,the DRX mechanism is mainly the particle-induced continuous DRX.As the temperature is raised to above 1130℃,the main DRX mechanism changes to discontinuous DRX.

Use of laser speckle contrast imaging to reveal changes in temperature and blood perfusion in the skin of healthy subjects after administration of heated moxa sticks and Daiwenjiu ointment

OBJECTIVE: To investigate the influence of heated moxa sticks( "moxibustion") and Daiwenjiu ointment(DO) on changes in temperature and blood perfusion volume on the skin of the backs of healthy subjects.METHODS: DO was spread on the left side of the body, and the right side of the body was treated with a heated moxa stick. Images denoting blood perfusion and body temperature were collected 7-8 cm lateral to the spinous process of the sixth thoracic vertebra using laser speckle contrast imaging(LSCI). Data obtained from eight-frame images were analyzed and used to calculate the mean blood perfusion volume. Simultaneously,blood-perfusion images were collected from the body surface and used to compare the change in blood flow on the body surface and the actual position of imaging.RESULTS: After moxibustion, a rapid increase in blood perfusion volume and body temperature was noted in the local skin surface. The maximum blood perfusion volume and body temperature was noted at 20 min(P<0.05). At 80-110 min after the spreading of DO, a gradual increase was noted in blood perfusion volume(P<0.05) and body temperature(P<0.05) compared with the baseline level. The maximum blood perfusion volume was at 110 min.CONCLUSION: Using LSCI, these data revealed a rapid and sharp increase in blood perfusion volume and body temperature after treatment with moxibustion, but the respective changes seen in the DO group were gradual and moderate.

A global empirical model for mapping zenith wet delays onto precipitable water vapor using GGOS Atmosphere data

The importance of water vapor in research of global climate change and weather forecast cannot be over emphasized; therefore substantial efforts have been made in exploring the optimal methods to measure water vapor. It is well-established that with a conversion factor, zenith wet delays can be mapped onto precipitable water vapor （PWV）. However, the determination of the exact conversion factor depends heavily on the accurate calculation of a key variable, weighted mean temperature of the trop- osphere （Tin）. AS a critical parameter in Global Positioning System （GPS） meteorology, Tm has recently been modeled into a global grid known as GWMT. The GWMT model only requires the location and the day of year to calculate Tm. Despite the advantages that the GWMT model offers, anomalies still exist in oceanic areas due to low sampling resolution. In this study, we refine the GWMT model by incorporating the global Tm grid from Global Geodetic Observing System （GGOS） and obtain an improved model, GWMT-G. The results indicate that the GWMT-G model successfully addresses the anomaly in oceanic areas in the GWMT model and significantly improves the accuracy of Tm in other regions.