Generalized variation iteration solution of an atmosphere-ocean oscillator model for global climate

A box model of the interhemispheric thermohaline circulation (THC) in atmosphere-ocean for global climate is considered. By using the generalized variational iteration method, the approximate solution of a simplified nonlinear model is studied. The generalized variational iteration method is an analytic method, and the obtained analytic solution can be operated sequentially. The authors also diversify qualitative and quantitative behaviors for corresponding physical quantities.     

Temperature-induced fractionation of oxygen isotopes of diatom frustules and growth water in Lake Sihailongwan in Northeast China

Diatom oxygen isotopes have been widely applied in quantitative reconstruction of the paleoclimate and paleoenvironment, but have rarely been reported in China. In the present study, Lake Sihailongwan in Northeast China was selected for detailed investigation of oxygen isotopic fractionation between diatom frustules and lake water induced by growth temperature. This study involved a 2-year period of field monitoring of the lake water temperature at multiple depths and biweekly collections of traps for both sediment and water at shallow and bottom depths (7 and 49 m below the lake surface, respectively), diatom separation and purification of the trap sediments, and oxygen isotope measurement for diatom silica and lake water samples. The conditioned experiment conducted herein demonstrated that the laboratory device, methods and techniques used in this study were capable of generating reliable data for the typical oxygen isotope composition of diatom frustules. The data obtained revealed a prominent linear relationship between the oxygen isotope composition of the modern diatom and lake temperature during growth. The fractionation coefficient was about −0.185‰/°C−0.238‰/°C in the temperature range of 3.6–24°C, which is consistent with the observations from various aquatic environments and laboratory culture with different diatom taxa. These findings provide strong support for the dominant control of the growth temperature on the oxygen isotope fractionation between the diatom frustules and ambient water. A notable difference in the fractionation coefficient was observed between the surface and bottom diatom oxygen isotopes, suggesting that various depositional processes and taphonomic effects influenced the surface and bottom trap samples. Another factor leading to this difference may be that enrichment by evaporation and dilution by rainfall have a stronger influence on the surface. Overall, the results presented here demonstrate significant progress in evaluation of diatom oxygen isotopes in China and draw attention to the differences between surface and bottom diatom oxygen isotope compositions.     

Application of surface plasmon resonance in screening adsorbents and explaining adsorption phenomena using model polymers

A surface plasmon resonance (SPR) technique was developed as an online screening method to identify effective adsorbents for the peptide NH₂-Cys-Thr-Trp-Trp-COOH (CW-4). To validate the SPR technique, several linear polymers containing amino acid residues were synthesized as models of their corresponding adsorbents. SPR screening of all the linear polymers demonstrated that the linear polymer containing phenylalanine residues (PPhe) exhibited the highest affinity for CW-4 among the polymers tested. In accordance with the screening results from SPR, the adsorbent containing phenylalanine (APhe) exhibited the highest adsorption capacity for CW-4. An interesting observation was that the amounts of CW-4 adsorbed on 3 adsorbents were quite small, even though both SPR and isothermal titration calorimetry (ITC) experiments indicated the presence of interactions between CW-4 and the three polymers. A kinetic analysis performed using SPR technology suggested such a phenomenon was ascribed to the poor stability of the CW-4/polymer complexes; that is, CW-4 associates with the polymers quickly, but it also dissociated quickly. The combined results suggested that SPR was a promising tool to identify the optimal adsorbent for peptides, analyze the interactions contributing to adsorption and explain adsorption phenomena using polymer models.     

板式无砟轨道CA砂浆工艺研究及抗冻性应用

通过技术指标和试验材料比较，提出了板式无砟轨道CA砂浆配合比及配制工艺。并加以实践利用，在普通CA砂浆的基础上开发研制出抗冻性CA砂浆，适用于寒冷地区的板式无砟轨道，对于我国东北地区铁路的发展提出了研究方向。     

高桥墩翻升模板施工方法

文章从高桥墩翻升模板的装置组成、设计、模板的选择和施工方法等方面，对高桥墩翻升模板的施工方法进行了介绍。     

基于有限元技术的背压活塞的模态分析与疲劳寿命计算

背压活塞是钻井中途油气层测试器的重要零件之一.其工作环境恶劣,受到各种干扰力的作用,容易发生断裂,造成重大事故.利用ANSYS软件,采用区块Lanczos法对背压活塞进行了模态分析,求出了其前六阶固有频率和相应的振型.分别采用兰德格拉夫损伤公式和ANSYS软件中疲劳寿命计算模块对背压活塞进行疲劳分析,计算疲劳寿命分别为1.90年和1.88年,验证了结果的正确性.     

DCB—偶氮胂与钙显色反应的研究及应用

本文首次研究了DCB—偶氮胂与钙的显色反应。在PH9.18—10.0的条件下,钙与DCB—偶氮胂形成1:2蓝色络合物,表观摩尔吸光系数为2.20×10~4l.mol~(-1)cm~(-1)。用乙酰丙酮作掩蔽剂,成功地测定了合成试样及水样中的钙。     

一种物理参数识别的时域频域混合法

本文论述了在状态空间中应用复模态理论对粘性阻尼系统的物理参数进行识别的一种方法,提出了从测得的时域、频域数据计算质量、阻尼和刚度矩阵的一个过程。文中采用了双最小二乘逼近来识别系统的模态参数。在识别物理参数时,采用了不同测点的数据进行计算,以求达到更好的精度。     

重点钢铁厂铁矿石还原及焦炭气化的藕合反应

通过在模拟高炉温度和煤气成分变化的条下,对我国重点钢铁厂铁矿石还原及焦炭气化的藕合反应研究,阐明了焦炭气化与铁矿石还原与反应历程有关。分析预测高炉冶炼效果除考虑恒定温度和恒定煤气成分下焦炭与铁矿石冶金性能外,还应考虑焦炭与铁矿石藕合反应过程CO过剩量。研究表明宝钢、首钢、本钢、鞍钢CO过剩系数ηc较小,煤气利用好;包钢、重钢和梅山冶金公司ηco较大,煤气利用较差。     

Cu—Zn—Al合金热循环相变的电镜观察

利用电镜高温台,直接观察Cu-Zn-Al合金在热循环过程中电子衍衬及电子衍射像的动态变化。低温马氏体M18R呈板条状,内部有厚度为5～10nm的层错亚结构。在热循环中,衍衬像不发生明显改变,但观察到可逆的电子衍射图变化,分析表明这是可逆的DO_3M18R型相变。在母相向马氏体转变之前,还出现“预马氏体效应”特征的漫散射条纹和额外衍射斑点。