增加海底光缆可靠性的无介质激光二极管结构

法国CIT-Alcatel公司的工程师们正忙于完善一种崭新的激光二极管结构，这一新结构用于计划在1985年建成连接科西嘉岛和法国大陆的280兆比特/秒光缆作为光头”。此结构可保证为系统长寿命所必不可少的低电流负载。     

Binuclear Lanthanide Complexes Containing SodiumSyntheses and Crystal Structure of (C_5Me_5)_2Nd(μ-Cl)_2Na(DME)_2 and (C_5Me_5)_2Nd(μ-OCH_3)_2Na(DME)_2

The reaction of NdCl_3 with NaC_5Me_5 generates a novel complex (C_5Me_5)_2Nd(μ-Cl)_2Na(DME)_2 (1).Then (1) reacts with 1 mol ratio Na and a little methyl-naphthalene generating another novel complex(C_5Me_5)_2Nd(μ-OCH_3)_2Na(DME)_2 (2).Complex (1) belongs to orthorhombic crystal system,space groupPbn2_1 with a=1.2635(3) nm,b=1.6127(5) nm,c=1.6543(4J nm,V=3.371(2) nm~3,D_c=1.36 gcm~(-3) andZ=4.The central metal Nd is coordinated by two C_5Me5 ring centroids and two μ-chlorine atoms forming adistorted tetrahedron.The crystal of complex (2) is monoclinic,space group C2/n with a=1.7482(5) nm,b=1.3260(4) nm,c=1.6406(7) nm,β=109.39(3)°,V=3.5874(1) nm~3,D_c=1.26 gcm~(-3) and Z=4,Twofive-membered ring centroids and two p-oxygens of OCH_3 form a distorted tetrahedron around the centralneodymium ion.     

聚合条件对稀土丁二烯-异戊二烯共聚物的分子量及其分布的影响

中国科学院长春应用化学研究所     

Synthesis, Characterization, and Reactivity of Amine Bis（phenolato） Cyclopentadienyl Lanthanide Complexes

（C5H5）3Ln（THF）reacted with amine bis（phenol） LH2 [ L = Me2NCH2CH2N {CH2-（2-O-C6H2-But^1-3-Me- 5）}2 ] in a 1：1 molar ratio in THF to generate the amine bis（phenolato） cyclopentadienyl lanthanide complexes LLn（C5H5） （THF）·（THF）,（Ln = La （1）, n =0; Ln = Sm（2）, n = 1） in high yields. Complexes 1 and 2 were fully characterized by elemental analysis, NMR （for 1） and IR spectra, and X-ray structural determination. The crystal data of complex 1 are monoclinic, P21/c space goup, a= 1.1595（1） nm, b = 1.8588（2） nm, c = 1.6647（1） nm, β = 98.490（2）°, V =3.5486（5） nm^3, Z =4, Dc = 1.338 mg· m^3,μ = 1240 mm^-1, F（000）= 1488, R =0.0249, wR = 0.0568. The crystal data of complex 2 are monoclinic, P21/c sp ace goup, a = 0.9692 （1） nm, b = 1.4583 （2） nm, c = 2.8192 （3） nm, = 96.805 （2）°, V = 3.9584 （7） nm^3, Z=4, Dc =1.340 mg · ma, μ = 1.524 mm^-1, F（000）= 1668, R =0.0346, wR =0.0756. The attempts failed to synthesize the amine bis（phenolate） lanthanide alkoxides by the reactions of complexes 1 and 2 with alcohols. The preliminary results revealed that complex 1 can initiate ε-caprolactone polymerization.     

Synthesis and characterization of lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand

The lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand 3,5-But2-2-(OH)C6H2CH=N-8-C9H6N (HL) were synthesized and characterized. The reaction of anhydrous LnCl3 with NaL formed in situ in a 1:1 molar ratio in THF at room temperature afforded the lanthanide Schiff base dichloride complexes LnLCl2(DME) (Ln=Eu (1);Sm (2)). Complexes 1 and 2 can be used as precursors for the synthesis of the lanthanide cyclopentadienyl Schiff base derivatives. The reactions of complexes 1 and 2 with one equiv of NaCH3C5H4 in THF provided the desired products LnL(CH3C5H4)Cl(THF)·THF (Ln=Eu (3);Sm (4)) in good isolated yields. These complexes were characterized by elemental analysis, IR spectra, and X-ray structural determination, in the case of complexes 3 and 4. The crystal data of complex 3 are monoclinic, P21/c space group, a=1.3370(2) nm, b=1.5190(2) nm, c=1.8910(3) nm, β=109.846(4)°, V=3.6125(8) nm3, Z=4, Dc=1.416 mg/m3, μ=1.847 mm-1, F(000)=1584, R=0.0707, wR=0.1350. The crystal data of complex 4 are monoclinic, P21/c space group, a=1.3383(1) nm, b=1.5210(2) nm, c=1.8960(2) nm, β =109.878(3)°, V=3.6293(7) nm3, Z=4, Dc=1.407 mg/m3, μ=1.728 mm-1, F(000)=1580, R=0.0670, wR=0.1385.     

季冻区温度变化对基坑支护结构影响模拟分析

采用FLAC 3D有限差分软件对基坑悬臂桩支护在冻融循环作用下的影响进行模拟研究.建立基坑模型,采用摩尔-库仑弹塑性本构模型,讨论了正负温水平冻胀力和桩体水平位移的变化规律,以及不同温度冻结深度及冻结速率的变化.通过数值模拟结果表明温度对桩的水平冻胀力和水平位移影响很大,负温情况下温度越低,土体冻结速率越大,其水平冻胀...     

非水相酶促酸解制备类可可脂的工艺研究

在非水相条件下,利用固定化脂肪酶催化棕榈油中熔点分提物(POMF)与硬脂酸(St)进行酸解反应制备类可可脂(CBE).考察了不同固定化酶、酶添加量、反应溶剂、酶的水分活度、底物质量比和反应温度对反应产率、速率以及产物中甘三酯组成的影响.结果表明:Lipozyme RM IM<'IM>添加量8%(以底物质量计),环己烷为溶剂,酶水分活度0.54,St与POMF质量比2:1,反应温度60℃为最佳酸解条件;在此条件下反应150 min,产物中主要甘三酯POP、POS、SOS含量分别达到19.36%、44.17%和25.54%.这与天然可可脂组成(POP 18%、POS 42%、SOS 27%)较为相似,满足CBE指标要求.     

村庄规划编制中的村民自治问题研究

党的十九大报告中乡村振兴战略的提出,充分体现了国家对"三农"问题和乡村发展的高度重视.作为社会振兴目标,"治理有效"强调了自治、法治、德治的"三治合一".加强村庄规划编制中的村民自治有助于创新社会治理格局,实现乡村发展振兴.本文初步分析了我国村庄规划编制行使村民自治权的存在问题及其成因,并据此提出针对性策略,尝试从做好...     

浅议我国健康信息传播

二十一世纪,健康已经逐渐成为社会、政府、大众日益关心的议题,健康传播是大众传播媒介的重要传播内容,这对我国健康传播学者来说,既是机遇也是挑战,本文首先分析了我国健康传播现状,进而就如何推进健康传播提出了建议。     

三相分离法提取生姜油的研究

本文以生姜为原料,采用三相法提取其中的生姜油,考察了叔丁醇的用量、硫酸铵浓度、pH值和温度等因素对提取的影响,并通过正交实验优化了提取工艺。结果表明最佳提取条件为料液与叔丁醇比为1:1.5(w/w),硫酸铵的量为50%,pH值为7.0,提取温度为40℃时,在此条件下生姜油的提取率为3.56%。该研究结果为生姜的深加工提供了新方法。