含碱掺铒磷酸盐玻璃光谱性质的研究

以72P2O5-8Al2O3-20R2O(R=Li，Na、K)和(77-x)P2O5-8Al2O3-(15 x)Na2O(x=0，5，10，15，20)掺铒磷酸盐玻璃系统为研究对象，测量和计算了掺铒磷酸盐玻璃的各种光谱参数，探讨了不同碱金属氧化物及其含量对掺铒磷酸盐玻璃光谱性质的影响。结果表明，积分吸收截面∑abs、峰值发射截面σemi、J-O强度参量Ωt以及自发辐射几率AR有较强的成分依赖性，并且主要决定于Er^3 离子周围结构和Er-O键共价性的变化；减小Er-O键的共价性可得到较高的∑abs、σemi以及AR。     

The effect of OH~- groups on the spectroscopic properties of erbium-doped tellurite glasses

With the rapid development of computer networks and other data-transmitting ser-vices, the demand for the increase of transmission capacity of the long distance trans-mission system is urgent. However, the conventional SiO2-based EDFA is limited for its small bandwidth. The Er3+-doped tellurite glass exhibits a larger stimulated-emission cross section and a broader emission bandwidth at the third communication window (1.55 μm) than that of silicate, phosphate, and germanate glasses, which c…     

Optimization of spectroscopic properties of ytterbium-doped laser glasses

Four laser glasses with high emission cross sections are experimentally obtained. The laser performance parameters are determined from the spectroscopic parameters of these glasses and compared with those of developing laser glasses abroad. It is shown that Yb~(3-)-doped telluorogermanate, Yb~(3 )-doped niobosilicate glasses have the highest emission cross section and gain coefficient, the smallest minimum pumping intensity and saturation pumping intensity, and the lowest minimum fraction of excited ions. Yb~(3 )-doped borate glass follows just behind them. These glasses have some spectroscopic advantages over laser glasses developed recently elsewhere. Yb~(3 )-doped phosphate glass is comparable to phosphate laser glass which had high emission cross section and was developed recently by HOYA Corporation in Japan.The domestic glasses with optimum spectroscopic properties may be promising candidates for applications in high-average power and high-peak power solid state lasers, especially laser for the ne     

Microstructure and Thermal Properties of the GeS2-In2S3-CsI Glasses

The-homogeneous GeS2-In2 S3-CsI glassy samples were prepared by conventional melt-quenching method. When the molar ratio of In2 S3 to Csl remains 1, the non-crystalline region can extend to the composition 0.4GeS2-0.3In2S3-0.3 CsI. And with the addition of CsI, the glass-forming ability of this serial glass reaches its maximum at the composition 0.8GeS2-0.1 In2 S3 -0.1CsI. According to the Raman spectra, the microstructure of these glasses is mainly constituted by [ GeS4 ] and [ InS4-xIx ] tetrahedra, which are interconnected by the bridging sulfur atoms ; meanwhile, the ethane-liked structural units [ S3 Ge-GeS3 ] can be formed because of the lacking of sulfur ; Cs ^＋ ion, which is added from CsI , exists as the nearest neighbor of I-ion in the glassy network.     

Effects of Zn/P ratio on structures and properties of zinc-iron phosphate glasses

Effects of Zn/P ratio on the structures and properties of glasses with the general composition of (80-x)ZnO-20Fe2O3 -xP2O5 (x=40, 45, 50, 55,60) (molar fraction, %) were investigated. Glass structure was measured by infrared absorption spectrum. Glass density (ρ) was measured by the Archimedes method. Coefficients of thermal expansion (α) and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate(DR )in water at 90 C for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. (80-x)ZnO-20Fe2O3 -xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with α<8.0×10-6C-1 .     

Effects of SnO on structure and properties of borosilicate glasses

Tin was found in the bottom of float borosilicate glasses. To simulate the enriched amounts of SnO found on the surface of the float borosilicate glasses, a series of glasses were produced in which the stannous concentration was varied from 0.1 wt% to 9.0 wt%, while the relative concentration of other components were held constant. Infrared spectra were obtained to probe the effect of increased amounts of SnO on the structure of the glass samples. The results show that SnO plays the role of an intermediate in glasses studied. When FO/SnO〉1.0, SnO takes the role of network-former. And when FO/SnO〈1.0, SnO can give the free oxygen as network-modifier. Besides, SnO has intensive effect on thermal performance of borosilicate glasses.     

低温磷酸镁水泥混凝土的力学性能

基于响应曲面法设计试验,研究不同环境温度（0、-20 ℃）下水胶比（W/C）、集胶比（G/C）、氧化镁与磷酸盐质量比（M/P）对磷酸镁水泥（MPC）混凝土抗压强度和抗折强度的影响。使用Design-Expert软件对数据进行分析处理,得到的回归模型反映了3个因素对低温环境下MPC混凝土力学性能的影响规律。3个因素对低温环境下混凝土强度的影响程度为：W/C>M/P>G/C,MPC混凝土抗压强度和抗折强度随W/C的增大而降低。-20 ℃环境下MPC混凝土抗压强度和抗折强度随G/C的增大而降低,随M/P的增大而增大;0 ℃环境下抗压强度随G/C的增大而增大,随M/P的增大而降低;抗折强度随G/C的增大而降低,随M/P的增大而降低。-20 ℃环境温度下MPC混凝土7 d抗压强度和抗折强度在W/C为0.14、M/P为5.0、G/C为2.0时达到最大值。0 ℃环境温度下MPC混凝土7 d抗压强度在W/C为0.14、M/P为3.0、G/C为3.0时达到最大值;7 d抗折强度在W/C为0.14、M/P为3.0、G/C为2.0时达到最大值。模型预测强度值与试验实际强度值之间偏差不超过10%,模型显著性良好。     

磷酸铁的湿法磷酸制备及其对合成的磷酸铁锂性能的影响

以湿法磷酸和硫酸亚铁分别为磷源和铁源,通过合成、沉淀过程制备磷酸铁,研究了不同摩尔投料比对合成磷酸铁质量的影响,并以制备的磷酸铁为磷源和铁源采用溶胶凝胶法制备了磷酸铁锂材料.采用了X射线衍射、扫描电子显微镜等手段对合成的磷酸铁锂材料结构和微观形貌进行表征,同时考察了其电化学性能.结果表明：在湿法磷酸和硫酸亚铁摩尔比为1∶1时合成出的磷酸铁中磷质量分数为16.38％,铁质量分数为29.30％,得到的产物最为接近二水磷酸铁;用该磷酸铁制备的磷酸铁锂正极材料在0.1C倍率下充放电,其首次放电比容量达144.4 mAh/g,40次充放电循环后放电容量能达到141.6 mAh/g,衰减率为1.94％,循环倍率性能优良.     

高折射率光色玻璃性能的研究

在普通光色玻璃的基础上,加入用于提高光色玻璃折射率的高价氧化物,制得了折射率大于1 60的光色玻璃.实验发现,高价氧化物的加入,明显提高了光色玻璃的折射率,并对玻璃的光色性能产生影响;同时讨论了热处理温度高低和热处理时间长短对高折射率光色玻璃光色性能的影响.结果表明:高价氧化物含量较高时,使得光色玻璃的光色性能变劣;热处理温度对高折射率光色玻璃光色性能的影响要比对普通光色玻璃的影响显著得多,玻璃的饱和透光率随着热处理时间的不同而不同.     

Frequency up-conversion luminescence properties and mechanism of Tm<Superscript>3+</Superscript>/Er<Superscript>3+</Superscript>/Yb<Superscript>3+</Superscript> co-doped oxyfluorogermanate glasses

Oxyfluoride glasses were developed with composition 60GeO 2 ·10AlF 3 ·25BaF 2 ·(1.95-x)GdF 3 · 3YbF 3 ·0.05TmF 3 ·xErF 3 (x=0.02,0.05,0.08,0.11,0.14,0.17)in mole percent.Intense blue(476 nm),green(524 and 546 nm)and red(658 nm)emissions which identified from the 1G 4 →3H 6 transition of Tm3+and the(2H 11/2 ,4S 3/2 )→4I 15/2 ,4F 9/2 →4I 15/2 transitions of Er3+,respectively,were simultaneously observed under 980 nm excitation at room temperature.The results show that multicolor luminescence including white l...     

神经网络用于三元不对称有机磷酸酯杀虫剂的 QSAR 研究

在０乙基Ｎ烷基（取代硫脲基）硫代磷酰胺酯类杀虫剂的定量构效关系（ＱＳＡＲ）研究中，用Ｒ型聚类分析提取特征结构参数，结合多元线性回归和神经网络方法研究构效关系。回归方法为ＱＳＡＲ研究提供变量的物理解释，改进的神经网络方法———广义误差反传神经网络（ＧＢＰ）建立了更加精确的构效关系模型。研究表明神经网络在ＱＳＡＲ研究中具有良好的预测和非线性处理功能。     

激光强化处理参数对轧辊表面性能的影响

通过试验，研究了激光功率、光斑直径、扫描速度、搭接量和合金粉含量等激光处理工艺参数对轧辊表面性能的影响，结果表明，轧辊表面经激光淬火处理后。性能稳定，耐磨性和抗疲劳性均有所提高，达到了生产要求．     

Microstructure and mechanical properties of calcium phosphate cement/gelatine composite scaffold with oriented pore structure for bone tissue engineering

The macroporous calcium phosphate(CPC) cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede’s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this work might be a potential scaffold for bone tissue engineering.     

聚四氟乙烯对锰系磷化膜抗磨损性能的影响

本文通过对普通锰系磷液中添加聚四氟乙烯（简称ＰＴＦＥ）乳液ＦＬ,使ＰＴＦＥ和磷酸锰盐在钢的表面共同沉积,形成复合膜,实验表明,当溶液中ＦＬ含量达到８ｍＬ／Ｌ,处理温度为６５℃时,表面膜的耐磨性最佳,比之单一锰系磷化膜要提高６倍左右,扫描电镜分析发现ＰＴＦＥ呈束状均匀镶嵌在磷酸锰盐的空隙中,磨损表面仅有轻微擦伤,而在相同磨损条件下,单一锰系磷化膜的磨损表明有明显的粘着撕裂抗,呈典型的粘着麻损形貌特征     

基于神经网络的高强钢管砼柱抗震性能研究

利用人工神经网络的自适应性、容错性、模糊性，建立了一个三层BP神经网络模型对高强钢管混凝土核心柱抗震性能进行了研究.在试验研究的基础上，用30组数据作为学习样本进行训练，模型的误差收敛快，学习效果很好.用另外8组数据作为测试样本，对柱的位移延性进行预测，结果和试验值吻合良好.与其它文献的柱位移延性公式计算值相比，大大提高了预测值的精度.该方法可作为实际结构设计的一种辅助手段.     

An improved neural network model for prediction of mechanical properties of magnesium alloys

An improved neural network model was developed for prediction of mechanical properties in the de-sign and development of new types of magnesium alloys by refining the types of input variables and using a more reasonable algorithm. The results showed that the improved model apparently decreased the prediction errors, and raised the accuracy of the prediction results. Better preprocessing parame-ters were found to be [0.15, 0.90] for the tensile strength, [0.1, 0.9] for the yield strength, and [0.15, 0.90] for the elongation. When the above parameters were used, the relativity for predicition of strength was bigger than 0.95. By using improved ANN analysis, more reasonable process parameters and compo- sition could be obtained in some magnesium alloys without addition of strontoum.     

Influence of addition of B2O3 on properties of Yb^3＋-doped phosphate laser glass

The three host glasses doped with Yb^3＋ were prepared by means of conventional melt quenching technology, and the influence on physical and spectral properties of phosphate glass due to addition of B2O3 was investigated and compared with silicate glass. The results show that due to the existence of OH^- impurities which induce the non-radiative route, the fluorescence lifetime of phosphate glass is shorter, so silicate glass has better spectral properties than phosphate glass. Silicate glass has more excellent thermal-mechanical properties than phosphate glass, but with the addition of B2O3, thermal-mechanical properties of phosphate glass are improved greatly without fluorescence quenching effect, and this kind of borophosphate glass will be the candidate to be used in high average power solid state laser.     

CO_2激光辐照对PZT-4陶瓷压电性能的影响

常温常压下,采用CO2激光辐照带有电极的PZT-4陶瓷片,当激光辐照时间分别为2、5和10 s时,在适当的激光功率密度下可使其压电应变常数d33从380 pC/N下降为零。系统地研究了激光功率密度和激光辐照时间对PZT-4陶瓷压电性能影响的规律。XRD、拉曼光谱和退火实验结果表明:CO2激光辐照使d33下降为零的原因是由于激光热效应导致PZT-4陶瓷的电畴排列失序,极化状态消失;而激光辐照未使其物相发生变化。     

城市公交网络的复杂网络关联性质分析

以国内4个城市公交网络为研究对象,分别在L空间和P空间对这些网络的静态统计特性和关联性质进行计算和分析。结果表明,L空间公交网络节点具有正的度度相关性,节点度与其集聚系数具有负的相关性;P空间公交网络节点k。（是）随度k的变化显示出随机的特征,节点C（是）随度的增长呈幂律下降。研究还发现,L空间公交网络节点权分布为双斜率幂律分布,明显不同于其他的加权复杂网络;节点权随度的增长呈幂律上升。