催化裂解Ⅱ型装置首次应用MGD技术的工业试验

对催化裂解Ⅱ(DCC-Ⅱ)型装置进行多产液化气和柴油裂化技术(MGD)改造。根据装置特点,分别进行了提升管的预提升段和反应床层的稳定汽油回炼改造。改造前后进行了标定。标定结果显示,丙烯产率提高1.5～1.7个百分点,总轻烃液收增加1.0～1.2个百分点。汽油的烯烃体积分数降低6～10个百分点,芳烃体积分数增加4～5个百分点,辛烷值提高约1个单位。改造后的DCC装置可以根据不同季节、不同的市场需求和产品价格变化情况灵活生产。     

Decentralized coordinated control of elastic web winding systems without tension sensor

In elastic web winding systems, precise regulation of web tension in each span is critical to ensure final product quality, and to achieve low cost by reducing the occurrence of web break or fold. Generally, web winding systems use load cells or swing rolls as tension sensors, which add cost, reduce system reliability and increase the difficulty of control. In this paper, a decentralized coordinated control scheme with tension observers is designed for a three-motor web-winding system. First, two tension observers are proposed to estimate the unwinding and winding tension. The designed observers consider the essential dynamic, radius, and inertial variation effects and only require the modest computational effort. Then, using the estimated tensions as feedback signals, a robust decentralized coordinated controller is adopted to reduce the interaction between subsystems. Asymptotic stabilities of the observer error dynamics and the closed-loop winding systems are demonstrated via Lyapunov stability theory. The observer gains and the controller gains can be obtained by solving matrix inequalities. Finally, some simulations and experiments are performed on a paper winding setup to test the performance of the designed observers and the observer-base DCC method, respectively.     

DCC汽油全馏分选择性加氢脱硫技术（CDOS-FRCNⅡ）的工业应用

介绍了CDOS-FRCNⅡ工艺技术生产超低硫汽油的优越性，该工艺省去了催化裂化汽油轻重馏分（LCN/HCN）切割过程，具有流程简单、操作灵活、投资省、耗能低的特点。该工艺配套的新型纳米钛基催化剂HDDO-100/HDOS-200/HDMS-100具有高脱硫活性、高选择性和稳定性，适用于全馏分加氢脱硫工艺，在处理高二烯烃、高烯烃含量的FCC汽油及DCC汽油中表现出优异的活性和稳定性，在新建的 500 kt/a DCC汽油加氢装置，采用CDOS-FRCNⅡ工艺技术及配套催化剂，实现了DCC汽油的产品升级，生产出符合国Ⅴ排放标准的汽油。     

Conserved Conformational Hierarchy across Functionally Divergent Glycosyltransferases of the GT-B Structural Superfamily as Determined from Microsecond Molecular Dynamics

It has long been understood that some proteins undergo conformational transitions en route to the Michaelis Complex to allow chemistry. Examination of crystal structures of glycosyltransferase enzymes in the GT-B structural class reveals that the presence of ligand in the active site triggers an open-to-closed conformation transition, necessary for their catalytic functions. Herein, we describe microsecond molecular dynamics simulations of two distantly related glycosyltransferases that are part of the GT-B structural superfamily, HepI and GtfA. Simulations were performed using the open and closed conformations of these unbound proteins, respectively, and we sought to identify the major dynamical modes and communication networks that interconnect the open and closed structures. We provide the first reported evidence within the scope of our simulation parameters that the interconversion between open and closed conformations is a hierarchical multistep process which can be a conserved feature of enzymes of the same structural superfamily. Each of these motions involves of a collection of smaller molecular reorientations distributed across both domains, highlighting the complexities of protein dynamic involved in the interconversion process. Additionally, dynamic cross-correlation analysis was employed to explore the potential effect of distal residues on the catalytic efficiency of HepI. Multiple distal nonionizable residues of the C-terminal domain exhibit motions anticorrelated to positively charged residues in the active site in the N-terminal domain involved in substrate binding. Mutations of these residues resulted in a reduction in negatively correlated motions and an altered enzymatic efficiency that is dominated by lower K_m values with k_cat effectively unchanged. The findings suggest that residues with opposing conformational motions involved in the opening and closing of the bidomain HepI protein can allosterically alter the population and conformation of the “closed” state, essential to the formation of the Michaelis complex. The stabilization effects of these mutations likely equally influence the energetics of both the ground state and the transition state of the catalytic reaction, leading to the unaltered k_cat. Our study provides new insights into the role of conformational dynamics in glycosyltransferase’s function and new modality to modulate enzymatic efficiency.     

N-(4-羟基-L-脯氨酰基)-L-丝氨酸的合成

以N-叔丁氧羰基-O-苄基-L-丝氨酸和N-叔丁氧羰基-4-羟基-L-脯氨酸为原料,经由羟基保护,二环己基碳二亚胺(DCC)缩合,脱保护基等步骤合成了4-羟基-L-脯-L-丝二肽。     

某科研楼净化空调设计

以某电子科研楼为工程实例,介绍了洁净室的空调设计,从新风的处理、空调机房、回风夹道的布置以及自动控制方面进行了阐述和讨论。     

丙烯的需求及增产丙烯的技术进展

因丙烯需求旺盛,从而促使增产丙烯的技术得以发展。本文介绍了丙烯脱氢的Ｏｌｅｆｌｅｘ、Ｃａｔｏｆｉｎ及ＬｉｎｄｅＰＤＨ工艺,ＩＦＰ联产丙烯的Ｍｅｔａ－４工艺。     

级联型有源电力滤波器控制技术研究

在高压大容量场合,传统的级联型有源电力滤波器(APF)需要对谐波和无功电流进行检测,算法复杂,且检测精度影响APF的电流补偿效果.提出一种直接电流控制(DCC)和倍频载波相移SPWM(FDCPS-SP-WM)相结合的级联型APF控制技术,具有易于实现、谐波补偿效果好等优点.首先构建了直流侧电压、网侧电流双闭环控制方案;然后对双闭环控制系统的具体实现进行了分析;最后通过一台1kV·A,10 kHz两H桥级联APF的原理样机进行了实验验证.     

不同SDH设备混合组环的网管信息透传分析

由于不同厂家技术及其他原因,造成光通信设备在互联互通上存在一定的困难,这也一直是业界关注的重要问题之一。为了使华为的OptiX Metro5000和NEC的WBM光设备混合组网后,其各自的网管信息能到达通信调度的网管终端,文章简单介绍了通过华为OptiX光设备SDH的D字节的映射、还原处理,实现了各自网管信息的透传。     

缬氨酸薄荷酯制备及生物活性研究

以L-缬氨酸和薄荷为原料,以二环己基碳二亚胺(DCC)及4-二甲氨基吡啶(DMAP)为催化剂合成了缬氨酸薄荷酯,利用核磁、质谱及红外对产物进行表征。利用电休克惊厥实验及抑制HeLa细胞增殖实验分别对缬氨酸薄荷酯的抗癫痫及体外抑制肿瘤活性进行了初步研究。在最大电休克惊厥实验中,小鼠腹腔注射给药,当缬氨酸薄荷酯给药量为100mg/kg时,与生理盐水组及卡马西平组相比, 4只预筛选过的小鼠,在0.5 、1、2、3、4 h后出现的惊厥数分别为2、2、1、0、0只,显示出了与对照品卡巴列平类似的抗癫痫活性;在体外抗肿瘤活性实验中,与对照组相比,抑制率最高达到52.5%,显示出了明显的抑制肿瘤细胞增殖的能力。