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1.
Earlier May, China Electricity Council made forecast to the nationwide power supply and demand for the 2nd quarter of 2007 .  相似文献   

2.
The effects of B and Ce on the removal of inclusions, microstructures, and properties of Cu-Fe-P alloys were studied. Certain impurity elements and the microstructures, mechanical properties, and conductivity of four experimental alloys, Cu-0.22Fe-0.06P, Cu-0.22Fe-0.06P-0.05Ce, Cu-0.22Fe-0.06P-0.02B, and Cu-0.22Fe-0.06P-0.05Ce-0. 02B ( %, mass fraction), were tested and analyzed. Results show that on one hand, B and Ce have a remarkable function of removing S, Pb, and Bi from copper alloys ; on the other hand, the recrystallization temperature of the Cu-Fe-P alloy is considerably increased by adding trace B and Ce, resulting in the combined strengthening effect of precipitation hardening and cold work hardening after cold working and aging, while the negative effect of B and Ce on conductivity is slight. Therefore, a good combination of high strength and conductivity is achieved.  相似文献   

3.
ItiswelknownthatthemechanicalpropertiesofgraycastironcanbeimprovedbyaddingsuitableamountofREandN.Tohighcarbonequivalent(CE)gr...  相似文献   

4.
5.
EffectofFluoridesandCeriumDioxideAdditivesonEPandAntiwearPerformanceofGreaseLianYafeng(连亚锋)(GuangzhouMachineToolResearchInsti...  相似文献   

6.
~~Internal Friction and Profile of Property and Structure of PD_3 and PD_3RE Rail Steels  相似文献   

7.
Conclusions We examined the behavior of two materials during high-temperature oxidation: the singlephase -sialon and the material based on -sialon containing up to 8% residual -Si3N4 and the glass phase produced by reaction sintering of the charge based on -modification of silicon nitride. The results show that the maximum oxidation resistance in the temperature range 800–1300°C is exhibited by the single-phase -sialon Si5.5Al0.5O0.5N7.5. The oxidation resistance decreases in the presence of the residual -Si3N4 and the glass phase in the material. The oxidation kinetics are also determined by the structure and composition of the oxide film. The kinetic curves are governed by a parabolic law which indicates that oxidation of the sialons is limited by the diffusion processes. No marked changes were detected in the lattice spacing of the sialon after oxidation.Translated from Poroshkovaya Metallurgiya, No. 6(306), pp. 69–73, June, 1988.  相似文献   

8.
9.
SynthesisandCrystalStructureofHeteronuclearComplexofCopperandYtriumwithGlycineWangRuiyao(王瑞瑶),GaoFeng(高峰),JinTianzhu(金天柱)(...  相似文献   

10.
The present study compares the fatigue and fracture properties of the high-strength β titanium alloy β-Cez with the conventional α+β titanium alloy Ti-6Al-4V, because of increasing interest in replacing α+β titanium alloys with β titanium alloys for highly stressed airframe and jet engine components. This comparison study includes the Ti-6Al-4V alloy in an α+ β-processed condition (for a typical turbine blade application) and the β-Cez alloy in two distinctly different α+β-processed and β-processed conditions (optimized for a combination of superior strength, ductility, and fracture toughness). The comparison principally showed a much lower yield stress for Ti-6Al-4V (915 MPa) than for both β-Cez conditions (1200 MPa). The Ti-6Al-4V material also showed the significantly lower high-cycle fatigue strength (resistance against crack initiation) of 375 MPa (R=−1) as compared to the β-Cez alloy (∼600 MPa, R=−1). Particularly in the presence of large cracks (>5 mm), the fatigue crack growth resistance and fracture toughness of the Ti-6Al-4V material is superior when compared to both β-Cez conditions. However, for small crack sizes, the conditions of both the alloys under study show equivalent resistance against fatigue crack growth. For the β-Cez material, where microstructures were optimized for high fracture toughness (conventional large crack sizes) by thermomechanical processing, maximum K Ic-values of 68 MPa√m of the β-processed β-Cez condition (tested in the longitudinal direction) decreased by ∼50 pct in the presence of small cracks (1 mm). A similar decrease in fracture toughness was obtained by loading the β-processed β-Cez condition perpendicular to the flat surfaces of the pancake-shaped β grain structure (tested in the short transverse direction). These results were discussed in terms of the effectiveness of the crack front geometry in hindering crack propagation. Further, the results of this study were considered for alloy selection and optimized microstructures for fatigue and fracture critical applications. Finally, the advantage of the α+β-processed β-Cez condition in highly stressed engineering components is pointed out because of its overall superior combination of fatigue crack initiation and propagation resistance (especially against small fatigue cracks).  相似文献   

11.
A series of Eu(Ⅲ) complexes of α-thenoyltrifluoroacetone(HTTA) with trioctylphosphine oxide(TPPO) and benzoic acid(BA) or its two derivatives, p-toluic acid(PTA) and p-methoxybenzoic acid(POA) were synthesized and were characterized with elemental analysis, IR spectroscopy, scanning electronic microscopy and fluorescent spectra. The complexes were revealed to be Eu(BA)(TTA)2TPPO2, Eu(PTA)(TTA)2TPPO2 and Eu(POA)(TTA)2TPPO2. The excitation and absorption spectra of the complex Eu(POA)(TTA)2TPPO2 in MeOH solution were investigated in detail. The experimental result showed that relatively cheap materials with sharp red luminescence could be pre-pared, when benzoic acid or its two derivatives were added in Eu(Ⅲ) complexes of α-thenoyltdfluoroacetone with trioctylphosphine oxide. The relative fluorescence intensity of the Eu(Ⅲ) complexes decreased in the following order: Eu(POA)(TTA)2TPPO2> Eu(PTA)(TTA)2TPPO2>Eu(BA)(TTA)2TPPO2.  相似文献   

12.
Two kinds of Eu-complexes, Eu(TTA)2(Phen)(AA) and Eu(TTA)2(Phen)(MA) (HTTA=2-Thenoyltrifluoroacetone, Phen=1,10- phenanthroline, AA=acrylic acid, MA=Maleic anhydride), which combined the excellent fluorescence properties of Eu(TTA)2(Phen)(H2O) and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared (IR) spectra, and X-ray photoelectron spectroscopy (XPS). Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the ?λ (λ=2 and 4) experimental intensity parameters were calculated. The results demonstrated that the ?2 intensity parameters for the two complexes were smaller than those for the Eu(TTA)2(Phen)(H2O) complex, indicating that a less symmetri- cal chemical environment existed in the complexes. It implied that the radiative efficiency of the 5D0 of these two complexes could be en- hanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA (τ=7.26×10–4 s) or Eu-MA complex (τ=8.12×10–4 s) was higher than that of the Eu(TTA)2(Phen)(H2O) complex, which was attributed to the substitution of the water molecule (H2O) in Eu(TTA)2(Phen)(H2O) by the MA or AA ligand.  相似文献   

13.
Eu(OA)3(TTA) (OA=cis-9-octadecenoic acid, TTA=4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione) complexes (Eu- complexes) containing the ligand OA with long molecular chains were synthesized. The Eu(OA)3(TTA) complexes and peroxide were added into nitrile-butadiene rubber (NBR) by mechanical shearing to get the uncured composites. The cured composites were obtained by vulcanizing the uncured composites at high temperature. The in-situ reaction including polymerization and grafting of Eu-complex took place at the curing process, which was verified by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed the fine dispersion of Eu(OA)3(TTA) complex (Eu-complex) in the cured composites compared with the uncured ones. Fluorescent spectra and Judd-Ofelt parameters analysis revealed that the fluorescent intensity increased approximate linearly with the content of Eu- complex increasing due to the in-situ reaction and long molecular chains of OA. The fluorescent lifetime of composites was longer than that of original Eu-complexes.  相似文献   

14.
A novel pyrazolone pyridine-containing ligand,2,6-bis(1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl)pyridine (H2L) was de-signed and synthesized from pyridine-2,6-dicarboxylic acid (1),and its Eu(III) and Tb(III) complexes were prepared.The ligand and com-plexes were characterized in detail based on FT-IR spectra,1H NMR,elemental analysis and thermal analysis,and the formula of Ln2L3·4H2O (Ln=Eu or Tb) of rare earth complexes was confirmed.The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated,which showed that the Eu(III) and Tb(III) ions could be sensitized efficiently by the ligand (H2L) and emit the photolumi-nescence with high intensity,narrow half-peak width,and monochromic light.The results indicated that the complexes showed potential as excellent luminescent materials.  相似文献   

15.
A novel rare earth complex Eu(TTA)2(N-HPA)Phen (TTA = thenoyltrifluoroacetone, N-HPA = N-phenylanthranilic acid, and phen = 1,10-phenathroline ), which contains three different ligands, was synthesized. The Eu complex was blended with poly N-vinylcarbazole (PVK) in different weight ratios and spin coated into films. The luminescence properties of films were investigated and energy transfer between PVK and the complex was discussed. Multilayer structural devices consisting of ITO/PVK: Eu (TTA)2 (N-HPA) phen/BCP/Alq3/Al were fabricated with PVK : Eu (TTA)2(N-HPA) as light-emitting layer. Increasing the concentration of Eu in the PVK thin film would inhibit the emission of PVK to different degrees. Finally, the pure red luminescence of europium( Ⅲ ) was observed when the doping weight ratio was approximately 1 : 5, which indicated an effective energy transfer from PVK to rare earth complex.  相似文献   

16.
Eu(TTA)2(phen)(MA) complexes were synthesized, in which MA was introduced as the acidic ligand to increase the fluorescent intensity of the complexes. The complexes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and fluorescent spectra, respectively. Different amounts of rare earth complexes were blended with silicon rubber over the melting point of Eu (TTA) 2 (phen) (MA). Next, a definite amount of 2,5-dimethyl-2, 5-di (tert-butylperoxy) hexane was added as a cross linker to the composite, to get the uncured composites. Subsequently, the composites were vulcanized at 160℃, and silicon rubber-based composites with different contents of the complexes were prepared and their fluorescent properties were observed. The contents of rare earth complexes were 0.96 %, 2.83 %, 4.63 % and 6.36 % (mass fraction), respectively. Moreover, the composites of Eu (TTA) 2 (phen) ( MA )/SiR were measured by SEM, XRD, and fluorescent spectra. The measurement result shows that the fluorescent intensity of uncured rubber is similar to one of the pure rare earth complexes. However, there is no marked change of fluorescent intensity in the uncured rubber when the content of rare earth complexes continues to increase.  相似文献   

17.
Exploration of Reactivity of Eu(TTA)2(phen)(MA)   总被引:1,自引:0,他引:1  
The reactivity of Eu(TTA)2(phen)(MA) (HTTA=2-thenoyltrifluoroacetone, MA=maleic anhydride) was studied. A series of products were prepared by direct polymerization, suspension polymerization, and alternate suspension and solution copolymerization with the styrene. And then we reactivity of these products were studied. The complexes were investigated and characterized by X-ray Diffraction (XRD), gel permeation chromatography (GPC) and fluorescence spectrophotometer. Although high polymerization degree is not found in the exploration of reactivity, it is found that the fluorescent intensity of complexes prepared by suspension polymerization increases significantly compared with the original particles, which is five times higher than that of the pure rare earth complex.  相似文献   

18.
Eu(TTA)2(phen)(UAH) (UAH=undecylenic acid)with fine fluorescent property and active group was synthesized. The measurement and characterization of complexes were also carried out. A series of composites based silicon rubber were prepared by blending silicon rubber and Eu(TTA)2(phen)(UAH) rare earth complex with active groups. Next, the effect of vulcanizing time on the property of materials was mainly studied. The results show that the dispersed particle size of rare earth complexes decreases gradually in the vulcanizing process.  相似文献   

19.
Two series of lanthanide-containing metal-organic frameworks(Ln-MOFs) of the general formula{[Ln(HIDA)_2 H_2 O]ClO_4·H_2 O}_n(Ln = La(1),Nd(2),Eu(3),Gd(4),Tb(5),Eu:Tb(6);H_2 IDA=iminodiacetic acid) and [Ln(TT)(HTT)(H_2 O)_3]_n(Ln=Eu(7),Gd(8),Tb(9),Dy(10),and Eu:Tb(11);H_2 TT=tartaric acid)were synthesized by reacting Ln(ClO_4)_3 with iminodiacetic acid and L-tartaric acid,respectively.All compounds were structurally characterized by single-crystal X-ray diffraction.Elemental analyses are co nsistent with the corre sponding crystallographically generated formulas.Mo reover,the luminescence properties of both the single and mixed-lanthanide complexes were studied.Near infrared,red,and green emissions that are characteristic of Nd(Ⅲ),Eu(Ⅲ),and Tb(Ⅲ) are observed for 2,3/7,and 5/9,respectively.For the two mixed-lanthanide complex systems 6 and 11,depending on the relative amount of Eu(Ⅲ) and Tb(Ⅲ),the color of emission can be fine-tuned.It is found that a small amount of Eu(Ⅲ) is adequate for the observation of the most intense transition of Eu(Ⅲ).This is believed to be a result of energy transfer from Tb(Ⅲ) to Eu(Ⅲ) within the same complex-a conclusion supported by the significantly shortened lifetime of Tb(Ⅲ) and the accompanying enhanced lifetime of Eu(Ⅲ) in the mixedlanthanide complex with respect to the corresponding values for the pure Tb(Ⅲ) and Eu(Ⅲ) complexes with the same ligand.  相似文献   

20.
两种新的铕配合物的合成、表征及其光、热、电性质   总被引:1,自引:1,他引:0  
以邻苯二甲酸酐、二苯胺、4-氨基安替吡啉和三氧化二铕为原料合成了Eu(PPA)3Phen和Eu(APA)3Phen.使用核磁和质谱对配体和配合物进行了表征,研究了紫外、荧光光谱、磷光寿命、热稳定性和电化学性质.结果表明,配合物的紫外吸收分别表现出生成它们各自配体的紫外吸收特征,Eu(PPA)3Phen和Eu(APA)3Phen在613nm处有很强的荧光发射,归属于Eu3+的5D0→7F2的特征发射,此外,在590nm处都有荧光发射.测得两种配合物粉末的磷光寿命,它们相差较大,Eu(PPA)3Phen有三个磷光寿命都约为0.0.45μs,Eu(APA)3Phen有两个磷光寿命都为650μs.热重分析表明,Eu(PPA)3Phen在30℃~260℃分解大约10%,而Eu(APA)3Phen在70℃~240℃分解大约5%.使用循环伏安法研究了Eu(PPA)3Phen和Eu(APA)3Phen的电化学性质,结果表明两者都约在0.86V处有不可逆的氧化电位值.  相似文献   

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