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Effect of dietary with Zhibai dihuang pills and gonadotropinreleasing-hormone-analogue on girls with precocious and rapidly progressive puberty
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作者 Xue-Mei Wang Wei Li +2 位作者 Liu-Qing Yang Rui Luo Chen-Chen Zhang 《World Journal of Clinical Cases》 SCIE 2024年第24期5534-5541,共8页
BACKGROUND At present,the clinical mechanisms underlying precocious puberty remain unclear,making effective intervention for children experiencing this condition and rapidly progressive puberty essential.AIM To explor... BACKGROUND At present,the clinical mechanisms underlying precocious puberty remain unclear,making effective intervention for children experiencing this condition and rapidly progressive puberty essential.AIM To explore the effects of Zhibai dihuang pills and gonadotropin-releasing hormone analogue(GnRHa)on growth and ovarian function in girls with precocious puberty.METHODS The clinical data of 84 adolescent girls with precocious puberty and rapidly progressive puberty from February 2017 to August 2023 were retrospectively analyzed.Girls were divided into a control group and an observation group,with 42 cases in each group.The control group received diet intervention combined with GnRHa treatment,while the observation group received diet intervention combined with Zhibai dihuang pills+GnRHa treatment.Outcomes such as clinical efficacy,growth indicators,ovarian function,and adverse reactions were compared between the two groups.RESULTS The observation group showed superior clinical efficacy compared to the control group(P<0.05).Prior to the intervention,no significant differences were found in growth or ovarian function between the groups(P>0.05).Post-intervention,the observation group exhibited significantly lower rates in growth,height,and bone age,along with reduced levels of progesterone,testosterone,estradiol,prolactin,luteinizing hormone,and follicle-stimulating hormone compared to the control group(P<0.05).The incidence of adverse reactions was similar across both groups(P>0.05).CONCLUSION Combining Zhibai dihuang pills with GnRHa and dietary intervention effectively improves growth,enhances ovarian function,and minimizes adverse reactions in adolescent girls with precocious and rapidly progressive puberty. 展开更多
关键词 Zhibai dihuang pills Gonadotropin-releasing hormone analogue Dietary intervention Precocious puberty rapidly progressive puberty Ovarian function
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Formulation Study for Rotundine Rapidly Disintegrating Tablet
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作者 王小琼 柯学 +1 位作者 平其能 许伯慧 《Journal of Chinese Pharmaceutical Sciences》 CAS 2005年第2期100-104,共5页
Aim The aim of the present study was to prepare tablets which can rapidlydisintegrate in saliva, containing active ingredient in high dose (37.5% W/W). Methods Rapidlydisintegrating tablets containing rotundine were p... Aim The aim of the present study was to prepare tablets which can rapidlydisintegrate in saliva, containing active ingredient in high dose (37.5% W/W). Methods Rapidlydisintegrating tablets containing rotundine were prepared by direct compression, wet granulation andmoulding, respectively . Different disintegrants and excipients were decided by single factor test.The typical disintegration time measurement and a new method of wetting time measuring wereintroduced for assessing rapidly disintegrating tablets. Results The tablets (80 mg) prepared bydirect compression have the crushing strength of 4.0 kg ?mm^(-2) and rapidly disintegratewithin 15 s in the saliva of healthy volunteers; the tablets prepared by wet granulation also havesufficient strength, a little longer but acceptable disintegration time (within 25 s in saliva) ;and the tablets obtained by moulding show disintegration within 40 s in saliva but low strength (2kg·mm^(-2)) . Disintegration time profiles of tablets are similar to those of wetting time, and thedisintegration and wetting times in vitro are similar to the disintegration time in vivo, thelatter having higher correlation with that in oral cavity. Conclusion The rapidly disintegratingtablets can be prepared by using these three techniques and excipients. Both in vitro disintegrationtime and wetting time are necessary indexes for judgment of in vitro disintegration profile. 展开更多
关键词 ROTUNDINE rapidly disintegrating tablets disintegration time wetting time
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The usefulness and significance of assessing rapidly progressive spermatozoa 被引量:15
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作者 Lars Bjorndahl 《Asian Journal of Andrology》 SCIE CAS CSCD 2010年第1期33-35,共3页
It is possible and clinically relevant to distinguish between slow and rapid progressive spermatozoa in basic semen analysis. This is discussed in light of the different purposes of semen analysis for the subfertile c... It is possible and clinically relevant to distinguish between slow and rapid progressive spermatozoa in basic semen analysis. This is discussed in light of the different purposes of semen analysis for the subfertile couple and the male patient. The two groups of progressive spermatozoa should be distinguished to help ensure that pertinent information available in the semen sample is not neglected. 展开更多
关键词 male factor infertility manual sperm motility assessment quality control rapidly progressive spermatozoa referencevalues semen analysis staff training
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Effect of cooling rates on clustering towards icosahedra in rapidly solidified Cu_(56)Zr_(44) alloy 被引量:1
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作者 胡艳军 文大东 +2 位作者 蒋元祺 邓永和 彭平 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期533-543,共11页
The rapid solidification processes of liquid Cu56Zr44 alloys at different cooling rates (γ) were simulated by a molecular dynamics (MD) method. In order to assess the influence of cooling rate on the clustering t... The rapid solidification processes of liquid Cu56Zr44 alloys at different cooling rates (γ) were simulated by a molecular dynamics (MD) method. In order to assess the influence of cooling rate on the clustering tendency and degree towards icosahedrons, a ten-indices' cluster-type index method was suggested to characterize the local atomic structures in the super-cooled liquid and the rapidly solidified solid. And their clustering and ordering degrees as well as the packing density of ieosahedral clusters were also evaluated by an icosahedral clustering degree (fI), the chemical order parameter (ηαβ) and densification coefficients (D0, DI and DIS), respectively. Results show that the main local atomic configurations in Cu56Zr44 alloy system are Z12 clusters centered by Cu, and most of which are (12 0 12 0 0 0 0 0 0 0) standard icosahedra and (12 0 8 0 0 0 2 2 0 0) as well as (12 2 8 2 0 0 0 0 0 0) defective icosahedra. Below glass transition temperature (Tg), these icosahedral clusters will be coalesced to various icosahedral medium-range orders (IMROs) by IS linkages, namely, icosahedral bond, and their number N, size n, order parameter ηαβ as well as spatial distributions vary with y. As the cooling rate exceeds the critical value (γc) at which a glassy transition can take place, a lower cooling rate, e.g., γ1=10^1K/ns, is demonstrated to be favorable to uplift the number of icosahedra and enlarge the size of IMROs compared with the higher cooling rates, e.g., γ5=10^5 K/ns, and their packing density and clustering degree towards icosahedra in the rapidly solidified solid can also benefit from the slow cooling process. 展开更多
关键词 rapid solidification Cu-Zr alloy cooling rate CLUSTERING ICOSAHEDRON
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Microstructure and Properties of Cu-Cr-Zr Alloy after Rapidly Solidified Aging and Solid Solution Aging 被引量:14
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作者 Ping LIU Juanhua SU +1 位作者 Qiming DONG Hejun LI 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第4期475-478,共4页
The structure and properties of Cu-Cr-Zr alloy were studied after rapidly solidified aging and solid solution aging.At the early stage of aging (500℃ for 15 rain), the hardness and the conductivity of the alloy rap... The structure and properties of Cu-Cr-Zr alloy were studied after rapidly solidified aging and solid solution aging.At the early stage of aging (500℃ for 15 rain), the hardness and the conductivity of the alloy rapidly solidified are 143 HV and 72% IACS, respectively. Under the same aging condition, the hardness and electrical conductivity of the alloy solid solution treated can reach 86 HV and 47% IACS, respectively. The microstructure was analyzed, and the grain size after rapid solidification is much smaller than that after solid solution treatment. By rapidly solidified aging the fine precipitates distribute inside the grains and along the grain boundary, while by solid solution aging there are large Cr particles along the grain boundary. 展开更多
关键词 Cu-Cr-Zr alloy PROPERTIES Solid solution aging rapidly solidified aging
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Microstructure and thermal stability behavior of a rapidly solidified Al-Ti-Fe-Cr alloy 被引量:3
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作者 CHEN Yiqing, CAO Qingping, and SU YongSchool of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China 《Rare Metals》 SCIE EI CAS CSCD 2002年第3期207-212,共6页
A rapidly solidified Al-2.5Ti-2.5Fe-2.5Cr (mass fraction in percent) alloywas prepared by melt spinning. As-quenched and as-annealed microstructures were studied by X-raydiffractometry (XRD), transmission electron mic... A rapidly solidified Al-2.5Ti-2.5Fe-2.5Cr (mass fraction in percent) alloywas prepared by melt spinning. As-quenched and as-annealed microstructures were studied by X-raydiffractometry (XRD), transmission electron microscopy (TEM), high-resolution transmission electronmicroscopy (HREM) and energy dispersive spectrum (EDS) analysis. The microhardness of the alloy atdifferent annealing temperatures was measured. The results obtained indicate that the microhardnessof the rapidly solidified Al-2.5Ti-2.5Fe-2.5Cr alloy does not vary with different annealingtemperatures. The as-quenched microstructure of the alloy includes two kinds of dispersed primaryphases: Al_3Ti and Al_(13)(Cr, Fe)_2. After annealing at 400 deg C for 10 h, the stable phaseAl_(13)Fe_4 appears in the microstructure. 展开更多
关键词 rapidly solidified Al-Ti-Fe-Cr alloy MICROHARDNESS as-quenchedmicrostructure as-annealed microstructure
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Effect of heat treatment on the microstructure and micromechanical properties of the rapidly solidified Mg61.7Zn34Gd4.3 alloy containing icosahedral phase 被引量:2
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作者 Wen-bo Luo Zhi-yong Xue Wei-min Mao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第7期869-877,共9页
In this paper, the microstructure evolution of the rapidly solidified (RS) Mg61.7Zn34Gd4.3 (at%, atomic ratio) alloy at high temperatures was investigated. The hardness and elastic modulus of the main precipitated pha... In this paper, the microstructure evolution of the rapidly solidified (RS) Mg61.7Zn34Gd4.3 (at%, atomic ratio) alloy at high temperatures was investigated. The hardness and elastic modulus of the main precipitated phases were also analyzed and compared with those of the α-Mg matrix on the basis of nanoindentation tests. The results show that the RS alloy consists of either a petal-like icosahedral quasicrystal (IQC) phase (~20 μm) and block-shaped H1 phase (~15 μm) or IQC particles with an average grain size of ~107 nm as well as a small proportion of amorphous phase, which mainly depends on the holding time at the liquid temperature and the thickness of the ribbons. The IQC phase gradually transforms at 400?C to a short-rod-shaped μ-phase (Mg28.6Zn63.8Gd7.7) with a hexagonal structure. The hardness of the IQC phase is higher than that of H1 phase, and both phases exhibit a higher hardness than the α-Mg matrix and the μ-phase. The elasticity of the H1 phase is superior to that of the α-Mg matrix. The IQC phase possesses a higher elastic modulus than H1 phase. The easily formed H1 phase exhibits the poorest plastic deformation capacity among these phases but a higher elastic modulus than the α-Mg matrix. 展开更多
关键词 magnesium ALLOY ICOSAHEDRAL phase rapidly SOLIDIFICATION NANOINDENTATION MICROMECHANICAL properties
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Effects of Additional Elements on Microstructure and Precipitation Behaviour in Rapidly Solidified Al-Ti Base Alloys 被引量:3
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作者 Won-Wook Park Chul-Jin Choi and Bong-Sun You (Dept. of Materials Processing, Korea Institute of Machinery and Metals, 66 Sangnam-Dong,Changwon, Kyungnam, Korea 641-010)(To whom correspondence should be addressed) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1996年第3期195-198,共4页
Rapidly solidified Al-Ti base alloys were prepared by melt spinning at the cooling rate about 107 K/s. The melt-spun ribbons were used to observe the dricrostructures after heat treatment.In the supersaturated Al-Tl-S... Rapidly solidified Al-Ti base alloys were prepared by melt spinning at the cooling rate about 107 K/s. The melt-spun ribbons were used to observe the dricrostructures after heat treatment.In the supersaturated Al-Tl-Si alloy, age hardening occurred after 1 h anneal in the temperature range of 4000~500℃, which seems to be attributed to the precipitation of metastable Ll2- (Al,Si)3Ti phase. However. the microhardness was relatively low because of the low v/o and the insufflcient stability of precipitates. Thus. Cr was added to Al-Ti-Si alloys in order to stabilize the microstructures and to increase the v/o of precipitate5. As a result. the alIoys containing Cr were evaluated to possess the improved properties at the service temperature. 展开更多
关键词 Ti BASE Al Effects of Additional Elements on Microstructure and Precipitation Behaviour in rapidly Solidified Al-Ti Base Alloys
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Rugate filters prepared by rapidly alternating deposition 被引量:1
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作者 张俊超 方明 +2 位作者 邵宇川 晋云霞 贺洪波 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第9期258-261,共4页
A methodology for the fabrication of composite (Nb205)l-x(SiO2)~ thin-film rugate filters by using pulsed direct current magnetron sputtering is presented. The two materials are mixed using rapidly alternating dep... A methodology for the fabrication of composite (Nb205)l-x(SiO2)~ thin-film rugate filters by using pulsed direct current magnetron sputtering is presented. The two materials are mixed using rapidly alternating deposition technol- ogy. The optical properties of the composite films varying with the composition of the material are studied in detail, Refractive indices between 1.50 and 2.14 can be realized in our coating system. Two designed rugate filters with a re- flection band at the wavelength of 532 nm are fabricated using an automatic deposition process. The microstructure of the rugate filter is investigated by using scanning electron microscopy. The calculated and the measured transmittance spectra axe in good agreement with each other, The causes of the slight differences between them are also analysed. 展开更多
关键词 rapidly alternating deposition rugate filter magnetron sputtering mixed oxides
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Positron Annihilation Study on the Microstructural Stability in Rapidly Solidified Al_(92.3)Fe_(4.3)V_(0.7)Si_(1.7)Mm_(1.0) Alloy 被引量:1
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作者 Wei JIA Meikuang Tseng and Jianqiang WANG(Dept. of Material Science, Northeastern University Shenyang 110006, China)Liangyue XIONG and Yelong CHU(International Ceoter for Materials Physics, Institute of Metal Research, Chinese Academy of Sciences,Shenyan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1998年第2期179-181,共3页
Rapidly solidified Al92.3Fe4.3V0.7Si1.7Mm1.0 alloy has been studied by positron lifetime spectroscopy and the variations on the intedecial defects with the annealing temperature were revealed by an analysis of the lif... Rapidly solidified Al92.3Fe4.3V0.7Si1.7Mm1.0 alloy has been studied by positron lifetime spectroscopy and the variations on the intedecial defects with the annealing temperature were revealed by an analysis of the lifetime results. The intedece characteristics derived from the positron-lifetime results could be used to give a satisfactory interpretation of the dependence of mechanical properties on the annealing temperature 展开更多
关键词 FE Positron Annihilation Study on the Microstructural Stability in rapidly Solidified Al MM SI
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TEM microstructure of rapidly solidified Mg-6Zn-1Y-1Ce alloy
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作者 杨文朋 郭学锋 卢正欣 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第4期786-792,共7页
Rapidly solidified(RS) Mg-6Zn-1Y-1Ce ribbons were prepared by single roller melt-spinning technique.Transmission electron microscopy and energy dispersive X-ray spectroscopy were employed to characterize the microst... Rapidly solidified(RS) Mg-6Zn-1Y-1Ce ribbons were prepared by single roller melt-spinning technique.Transmission electron microscopy and energy dispersive X-ray spectroscopy were employed to characterize the microstructure of RS ribbons.The results show that there is high density of particles distributed within grains and at grain boundaries in the region near wheel side.The particle density is decreased in the middle region and free surface region.The alloy is predominantly composed of supersaturated--Mg solid solution,T phase and W phase;meanwhile,a few icosahedral quasicrystalline and Mg4Zn7 particles are also observed.The T phase is confirmed having a body-centered orthorhombic structure that is transformed from the body-centered tetragonal structure Mg12Ce phase due to the partial substitution of Mg atoms by Zn. 展开更多
关键词 Mg-6Zn-1Y-1Ce alloy rapid solidification T phase icosahedral quasicrystalline Mg4Zn7 phase W phase
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Distinct protein kinase C isozymes mediates inhibitory effects of different G-protein coupled receptors on cardiac rapidly activating delayed rectifier K ~ current
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《中国药理学通报》 CAS CSCD 北大核心 2015年第B11期165-166,共2页
Aim Evidence has shown that stimulation of alA-adrenorecetors receptor (alA-AR) or angiotensin II type 1 receptor (AT1R) acutely down-regulates the rapid component of the delayed rectifier K + current (IKr) via... Aim Evidence has shown that stimulation of alA-adrenorecetors receptor (alA-AR) or angiotensin II type 1 receptor (AT1R) acutely down-regulates the rapid component of the delayed rectifier K + current (IKr) via protein kinase C (PKC). This study was designed to investigate which PKC isozymes mediate down-regulations of IKr by alA-AR and AT1R. Method The whole-cell patch-clamp technique was used to record IKr in native cardio- myocytes and in human embryonic kidney (HEK) 293 cells co-transfected with human ether-a-go-go related gene (hERG) encoding α-subunit of IKr and human alA-AR or AT1R gene. Result In isolated guinea-pig ventricular cardiomyocytes the inhibitory action of Ang II on IKr was little affected by Go6976 (selectively inhibiting PKCα, β and γ) and Go6983 (selectively inhibiting PKCα, β, γ , δ, and ζ), but was significantly antagonized by an inter- nal dialysis with PKCe-selective inhibitory peptide εV1 -2. In contrast, the inhibitory action of alA-AR agonist A61603 on IKr was remarkably attenuated by Go6976 or Go6983, but not affected by peptide εV1 -2. Moreover, specific PKC-selective inhibitory peptide antagonized the effect of A61603. The results suggested that PKCe and PKCα isoform respectively mediated the inhibitory effect of AT1R and a1A-AR. In heterologous expression system, both PKCα and e-selective activator peptides down regulated hERG current with different manner. PKCα activator peptide shifted the activation curve of the channel to the right, but PKCe-selective activator peptide did not. Simi- larly, A61603 shifted the activation curve to the right, whereas Ang Ⅱ had no effect. In addition, both A61603 and PKCα activator peptide showed inhibitory action on bERG A PKC current (an bERG mutant in which 17 of the 18 ROSITE-predicted PKC acceptor serines/threonines were changed to alanine) with a similar potency to wild type bERG current. But, both Ang Ⅱ and PKCe-selective activator peptide exhibited no effects on bERG △ PKC cur- rent. The results indicated that PKCα and PKCe isoforms down-regulated bERG current through different mecha- nism. Conclusion PKCα and PKCe isoform respectively mediates the inhibition on IKr by stimulation of AT1R and alA-AR via different molecular mechanism. 展开更多
关键词 rapidly ACTIVATING delayed rectifier K + CURRENT protein KINASE C AT1R alA-AR
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Microstructure Evolution and Tensile Properties of Pure Ti Subjected to Rapidly Heating and Quenching
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作者 Weisong ZHAO Wei ZHANG Jinyu GUO Boquan WANG Jingdong GUO Ke LU 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第2期190-194,共5页
The pure α-Ti samples were heated at an extremely high rate (~10^6 K/s) to the temperature of β phase zone followed by a rapidly quenching in an electro-pulsing treatment. After the treatment, micrometer-thick la... The pure α-Ti samples were heated at an extremely high rate (~10^6 K/s) to the temperature of β phase zone followed by a rapidly quenching in an electro-pulsing treatment. After the treatment, micrometer-thick lamellar substructures were generated within the original equiaxed α-Ti coarse grains. Misorientations across adjacent lamellae are of a few degrees. The ultrafine lamellar substructures originated from a non-equilibrium α-β-α’ phase transformation during rapidly heating-quenching process with a short exposure time at high temperatures. Tensile strength was increased by about 100 MPa due to the formation of the ultrafine lamellar substructure while the same tensile plasticity (elongation-to-failure) was maintained relative to the original sample. The strengthening effect could be attributed to the effective blockage of dislocation motions by a high density of sub-boundaries. 展开更多
关键词 Pure Ti MICROSTRUCTURE Properties rapidly heating
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Diffraction and luminescence analysis of extremely rapidly cooled molten system(LiF-CaF)-xLnF(Ln=Sm and Gd)
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作者 Miroslav BOČA Jarmila MLYNÁRIKOVÁ +3 位作者 Iveta MACKOVÁ Dušan JANIČKOVIČ Adriana CZÍMEROVÁ Zhong-ning SHI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第4期1151-1164,共14页
Samples of(LiF-CaF2)eut-x SmF3(-x GdF3)(x=0.03-0.50) were prepared by spontaneous cooling as well by very fast cooling(using the rapid solidification processing(RSP) method) which provide two types of sample morpholog... Samples of(LiF-CaF2)eut-x SmF3(-x GdF3)(x=0.03-0.50) were prepared by spontaneous cooling as well by very fast cooling(using the rapid solidification processing(RSP) method) which provide two types of sample morphology: riffle-like and sphere-like fragments. All types of samples were studied by XRD, optical absorption and fluorescence spectroscopy. The presence of LiF stabilises the cubic cell dimension, and the content of lanthanide fluorides presents influence on phases formed, as well as the crystallinity of the system, in both the spontaneously and rapidly-cooled systems. The photoluminescence properties of the investigated systems are dependent on the lanthanide fluoride content. The intensity of the emission bands, corresponding to the Sm3+ ion, reaches the maximum when the Sm content is x(SmF3)=0.03. An even stronger dependence is observed of optical properties on the morphology of the samples, i.e. whether the samples are spontaneously cooled or processed by the RSP method followed by mechanical grinding. Mechanical grinding enhances the luminescent properties and leads to higher emission intensities. It is also shown that the photoluminescent spectroscopy is suitable for detection/approval of lowered local symmetry via significant splitting of spectral bands. 展开更多
关键词 molten salts rapidly cooled molten system SmF3 GdF3 absorption spectra fluorescence spectra luminescence properties
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Investigation on Rapidly Solidified T15 High Speed Steel Powder and Its Bulk Microcrystalline Material
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作者 Yu Hui Ding Fuchang +2 位作者 Wang Enke V.N.DiGiambattista Qi Jiazhong 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 1996年第1期24-28,共5页
Authors produced rapidly solidified T15 high speed steel powders by high pressure(5~ 6MPa) N_a atomization and liquid N_2 cooling,observed and analyzed the morphology and structure of the powders;at the same time,prep... Authors produced rapidly solidified T15 high speed steel powders by high pressure(5~ 6MPa) N_a atomization and liquid N_2 cooling,observed and analyzed the morphology and structure of the powders;at the same time,prepared bulk microcrystalline T15 high speed steel materials by hot extruding or HIPing and hot rolling of the powders,observed and measured the microstructure and performance of the bulk materials.It was shown that rapid solidification may change the solidification characteristics and structure of T15 high speed steel powder and improve the qualities and properties of T15 high speed steel materials. 展开更多
关键词 rapidly solidified powder high speed steel bulk microcrystalline material microstructure performance
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MICROSTRUCTURE AND DUCTILITY OF RE DOPED RAPIDLY SOLIDIFIED NiAl
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作者 SUN Baode LIN Dongliang +1 位作者 YANG Gencang ZHOU Yaohe 1)Shanghai Jiao Tong University, Shanghai,China)2)Northwesten Polytechnic University,Xi’an,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1995年第2期106-109,共4页
The paper investigated the effects of RE on the microstructure and ductility of melt-spun Al-63.3at.%Ni and Al-66.4at%Ni.For Al-63.3at.%Ni without RE the microstructure is a mixture of equiaxed martensitic grains and ... The paper investigated the effects of RE on the microstructure and ductility of melt-spun Al-63.3at.%Ni and Al-66.4at%Ni.For Al-63.3at.%Ni without RE the microstructure is a mixture of equiaxed martensitic grains and B2 NiAl grains,but after addition of 0.2wt% RE a complete supersaturated B2 NiAl results,and its elongation is enhanced from 0.9%(without RE) to 1.4%(with 0.2wt%RE).For Al-66.4at.%Ni without RE the microstructure is coarse equiaxed martensitic grains with Ni3Al precipitated at the GBs.But complete martensitic grains and supersaturated single phase,B2 NiAl,would result with addition of 0.05wt%RE and 0.2-0.8wt%RE respectively.The elongation of Al-66.4at.%Ni without RE is only 0.8%.With the addition of 0.05, 0.2 and 0.8wt%RE.the elongation can reach 2.6,3.0 and 3.2% respectively.The addition of RE can change the fracture mode from intergranular fracture(without RE) to a mixture of intergranular and transgranular fracture or entirely transgranular fracture.The mechanisms of microstructure formation and ductility enhancement are analyzed. 展开更多
关键词 NIAL rare earth element rapidly solidified alloy DUCTILITY
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Second-order two-scale analysis and numerical algorithms for the hyperbolic–parabolic equations with rapidly oscillating coefficients
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作者 董灏 聂玉峰 +1 位作者 崔俊芝 武亚涛 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第9期40-53,共14页
We study the hyperbolic–parabolic equations with rapidly oscillating coefficients. The formal second-order two-scale asymptotic expansion solutions are constructed by the multiscale asymptotic analysis. In addition, ... We study the hyperbolic–parabolic equations with rapidly oscillating coefficients. The formal second-order two-scale asymptotic expansion solutions are constructed by the multiscale asymptotic analysis. In addition, we theoretically explain the importance of the second-order two-scale solution by the error analysis in the pointwise sense. The associated explicit convergence rates are also obtained. Then a second-order two-scale numerical method based on the Newmark scheme is presented to solve the equations. Finally, some numerical examples are used to verify the effectiveness and efficiency of the multiscale numerical algorithm we proposed. 展开更多
关键词 hyperbolic–parabolic equations rapidly oscillating coefficients second-order two-scale numerical method Newmark scheme
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AVERAGING PRINCIPLE FOR QUASI-GEOSTROPHIC MOTIONUNDER RAPIDLY OSCILLATING FORCING
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作者 高洪俊 段金桥 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第1期108-120,共13页
A class of large scale geophysical fluid flows are modelled by the quasi-geostrophic equation. An averaging principle for quasi-geostrophic motion under rapidly oscil-lating ( non-autonomous) forcing was obtained, bot... A class of large scale geophysical fluid flows are modelled by the quasi-geostrophic equation. An averaging principle for quasi-geostrophic motion under rapidly oscil-lating ( non-autonomous) forcing was obtained, both on finite but large time intervals and on the entire time axis. This includes comparison estimate, stability estimate, and convergence result between quasi-geostrophic motions and its averaged motions. Furthermore, the existence of almost periodic quasi-geostrophic motions and attractor convergence were also investigated. 展开更多
关键词 quasi-geostrophic fluid flow almost periodic motion rapidly oscillating forcing averaging principle stable manifold and unstable manifold
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Characterizations of Skeletal Iron Catalysts Prepared from Rapidly and Naturally Quenched Fe-Al Alloys
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作者 LUOGe YANShi-run +4 位作者 QIAOMing-hua ZHANGKai HUHua-rong HEHe-yong FANKang-nian 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第4期452-456,共5页
Surface morphology, physical-chemical properties of skeletal iron catalysts prepared by leaching of the rapidly quenched(RQ) and naturally quenched(NQ) Fe-Al alloys with an aqueous solution of NaOH were characterized... Surface morphology, physical-chemical properties of skeletal iron catalysts prepared by leaching of the rapidly quenched(RQ) and naturally quenched(NQ) Fe-Al alloys with an aqueous solution of NaOH were characterized by using a series of techniques including XRD, BET, XPS, SEM, H_2 and CO-TPD. It was found that the RQ skeletal iron catalyst exhibits a smaller particle size, larger specific surface area and pore volume than the NQ one. The H_2 and CO-TPD experiments showed that the RQ skeletal iron exhibits stronger affinity for H_2 and milder affinity for CO compared with the NQ one. But the NQ skeletal catalyst shows a better thermal stability than the RQ catalyst. 展开更多
关键词 rapidly quenched alloy Skeletal iron catalyst CHARACTERIZATION
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Structural Characteristics of Rapidly Quenched Al-Si Alloys
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作者 Lin LIU(Institute of Solid State Physics, Academia Sinica, Hefei, 230031, China)Yuanda DONG(Dept. of Metallurgy and Materials, Shanghai University of Technology, Shanghai, 200072, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1994年第3期232-234,共3页
The structure of rapldly quenched Al-Si alloys (1 and 4 wt-%Si) was systematically studied by optical and transmission electron microscopy (TEM ) as welI as X-ray djffractjon (XRD). ExperimentaIresults show that rapid... The structure of rapldly quenched Al-Si alloys (1 and 4 wt-%Si) was systematically studied by optical and transmission electron microscopy (TEM ) as welI as X-ray djffractjon (XRD). ExperimentaIresults show that rapid solidification refines the grain size. extends the solid solubility of Si in Al and Introduces a high density ot defects which exist in the forms of vacancies, dislocations and dislocation loops. etc.. The decomposition process of the alloys was fol lowed by using differential scanning calorimeter (DSC) and the activation energy for precipitation of Si was obtained through Kissinger analysis. The precipitation behaviour of Supersaturated Si in both samples was further examined by TEM. It was found that Si mainly precipitated inside the grains in Al-1 wt-%Si alloy. while in Al-4 wt-%Si alloy. nearly all the Si precipitates distributed along the grain boundaries. This may be due to the structure difference between the alloys in as-quenched state 展开更多
关键词 AL SI Structural Characteristics of rapidly Quenched Al-Si Alloys
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