“3+1+1”教学体制改革的尝试

1987年底,为了贯彻面向企业为主,提高学生综合质量的办学思想,院部决定在87级学生中创办首批工程型优秀生试点班,实行“3+1+1”教学体制,即学生在校完成前三年的学习课程后,第四年预分配至用人单位见习工作一年,第五年再回校完成毕业环节。以探索在新形势下如何加强学校与社会共同培养社会主义建设者和接班人的新经验。     

Effect of 18∶1n−9, 20∶5n−3, and 22∶6n−3 on lipid accumulation and secretion by atlantic salmon hepatocytes

We have studied the effects of dietary FA on the accumulation and secretion of [³H]glycerolipids by salmon hepatocytes in culture. Atlantic salmon were fed diets supplemented with either 100% soybean oil (SO) or 100% fish oil (FO), and grew from an initial weight of 113±5 g to a final weight of 338 ±19 g. Hepatocytes were isolated from both dietary groups and incubated with [³H]glycerol in an FA-free medium; a medium supplemented with 0.75 mM of one of three FA—18∶1n−9, 20∶5n−3, or 22∶6n−3—or a medium supplemented with 0.75 mM of the sulfur-substituted FA analog tetradecylthioacetic acid (TTA), which cannot undergo β-oxidation. Incubations were allowed to proceed for 1,2,6, or 24 h. The rate of the secretion of radioactive glycerolipids with no FA added was 36% lower from hepatocytes isolated from fish fed the FO diet than it was from hepatocytes isolated from fish fed the SO diet. Hepatocytes incubated with 18∶1n−9 secreted more [³H]TAG than when incubated with no FA, whereas hepatocytes incubated with 20∶5n−3 or TTA secreted less labeled TAG than when incubated with no FA. This observation was independent of the feeding group. Hepatocytes incubated with 22∶6n−3 secreted the highest amounts of total [³H]glycerolipids compared with the other treatments, owing to increased secretion of phospholipids and mono- and diacylglycerols (MDG). In contrast, the same amounts of [³H]TAG were secreted from these cells as from cells incubated in an FA-free medium. The lipid-lowering effect of FO is thus independent of 22∶6n−3, showing that 20∶5n−3 is the FA that is responsible for the lipid-lowering effect. The ratio of TAG to MDG in lipids secreted from hepatocytes to which 20∶5n−3 or TTA had been added was lower than that in lipids secreted from hepatocytes incubated with 18∶1n−9 or 22∶6n−3, suggesting that the last step in TAG synthesis was inhibited. Morphometric measurements revealed that hepatocytes incubated with 20∶5n−3 accumulated significantly more cellular lipid than cells treated with 18∶1n−9, 22∶6n−3, TTA, or no treatment. The area occupied by mitochondria was also greater in these cells. The present study shows that dietary FO reduces TAG secretion from salmon hepatocytes and that 20∶5n−3 mediates this effect.     

High dietary 18∶3n−3 increases the 18∶3n−3 but not the 22∶6n−3 content in the whole body, brain, skin, epididymal fat pads, and muscles of suckling rat pups

The objective of this study was to test the hypothesis that increasing maternal dietary 18∶3n−3 by decreasing the 18∶2n−6/18∶3n−3 ratio will increase the 18∶3n−3 and 22∶6n−3 content of the whole body, liver, skin (epidermis, dermis, and subcutaneous tissue), epididymal fat pads, and muscles (arms and legs) of 2-wk-old rat pups. Sprague-Dawley dams at parturition were fed semipurified diets containing either a low (18∶2n−6 to 18∶3n−3 ratio of 24.7∶1) or a high (18∶2n−6 to 18∶3n−3 ratio of 1.0∶1) 18∶3n−3 fatty acid content. During the first 2 wk of life, rat pups received only their dams' milk. Fatty acid composition of the pups' stomach contents (dams' milk), whole body, brain, liver, skin, epididymal fat pads, and muscles was determined. The stomach fatty acid composition of 18∶3n−3 reflected the dams' diet. The content of 18∶3n−3 in whole body, brain, liver, skin, epididymal fat pads, and muscles was significantly (P<0.05) greater in rat pups fed the high compared with the low 18∶3n−3 fatty acid diet. The 22∶6n−3 content of the whole body, brain, skin, epididymal fat pads, and muscles was not quantitatively different in rat pups fed either the low or high 18∶3n−3 fatty acid diet. The 20∶5n−3 and 22∶5n−3 content of the whole body, skin, and epididymal fat pads was significantly increased in rat pups fed the high compared with the low 18∶3n−3 fatty acid diet. High content of 18∶3n−3 was found in the skin of rat pups fed either a low or high 18∶3n−3 fatty acid diet. These findings demonstrate that high maternal dietary 18∶3n−3 significantly increases the 18∶3n−3 but not the 22∶6n−3 content of the whole body, brain, skin, epididymal fat pads, and muscles with approximately 39 and 41% of the whole body 18∶3n−3 content being deposited in the skin of suckling rat pups fed either the low or high 18∶3n−3 diet, respectively.     

派翠西雅,个性SPA1+1

也许你没有太多的时间;也许你不想太大的投入;也许你家的浴室还不够放下一只浴缸;也许……这些都没有关系,因为有一盒派翠西雅的SPA GEL 加一杯花草茶就已经足够。享受 SPA,更多的是一份创意的快乐和香氛的体验。     

Structural and optical properties of 2D Ruddlesden-Popper perovskite (BA)2(FA)n−1PbnI3n+1 compounds for photovoltaic applications

2D-3D–structured formamidine perovskite composites are highlighted due to their enhanced stability in solar cell applications. However, the structural and optical properties of 2D formamidine perovskites remain unclear. In this work, we developed new formamidine-based Ruddlesden-Popper perovskite compounds (BA)₂(FA)_n−1Pb_nI_3n+1 (n ≤ 4) using hot-spin coating. Orthorhombic 2D-layered perovskites were formed with a mixture of 3D formamidine perovskite from (BA)₂(FA)_n−1Pb_nI_3n+1 precursors. Their formation highly depended on the solvent used in the precursors, in which dimethyl sulfoxide benefited from the b-axis oriented growth and improved the crystallization of the compounds. The formamidine-based Ruddlesden-Popper perovskites were direct bandgap materials, with the experimental bandgaps of over 1.7 eV, and whose average photoluminescence lifetimes were affected by their chemical components and crystal structures. In addition, planar perovskite solar cells were fabricated by employing these films as absorbing layers. The initial devices from the (BA)₂(FA)₃Pb₄I₁₃ precursors exhibited an efficiency of 2.88% and an open voltage of 0.93 V. These results indicated that the formation and stability of 2D-structured perovskites were strongly related to the A-site cations, thus offering new insights into the structures of 2D perovskites and their applications for 2D-3D–structured perovskite solar cells.     

三元体系AlCl_3+CaCl_2+H_2O,AlCl_3+FeCl_3+H_2O和CaCl_2+FeCl_3+H_2O在35℃时的相平衡

缺少含AlCl_3、CaCl_2和FeCl_3的溶液相平衡,使通过蒸发结晶从粉煤灰盐酸浸取液中制备纯净的AlCl_3?6H_2O变得比较困难。采用等温溶解法研究了三元体系AlCl_3+CaCl_2+H_2O,AlCl_3+FeCl_3+H_2O和CaCl_2+FeCl_3+H_2O在35℃时的相平衡关系,测定了相应的溶解度及密度,并绘制了相应相图及密度-组成图。实验结果表明:三元体系AlCl_3+CaCl_2+H_2O和AlCl_3+FeCl_3+H_2O分别有两条溶解度曲线,两个单盐结晶区,无复盐和共溶体产生,同离子效应导致增加溶液中CaCl_2和FeCl_3浓度会有效降低AlCl_3的溶解度;CaCl_2+FeCl_3+H_2O体系会形成复盐CaCl_2·2FeCl_3·7H_2O;所得35℃相图与25℃相图相比,三元体系AlCl_3+CaCl_2+H_2O和AlCl_3+FeCl_3+H_2O中AlCl_3·6H_2O结晶区增大,CaCl_2·6H_2O结晶区转变成CaCl_2·4H_2O结晶区,CaCl_2+FeCl_3+H_2O体系中CaCl_2·2FeCl_3·8H_2O结晶区转变为CaCl_2·2FeCl_3·7H_2O结晶区。     

"1+1"模式炼焦煤选煤厂投产3年回顾

介绍了以"1 1"模式炼焦煤选煤厂设计的文峰选煤厂投产3年多的运行状况:实现了清水选煤;做到小于0.6kg/t的国际先进水平的低介耗,各项生产技术经济指标总体上好于设计指标。     

掺杂Eu3+或Tb3+的(Gd,Lu)2O3粉体的发光性能

采用高温固相法在空气中合成了(Od,Lu)2O3,(Gd,Lu)2O3:Eu3+和(Gd,Lu)2O3:Tb3+系粉体.研究了二元系中Lu2O3的摩尔分数对抑制Gd2O3高温相变、粉体的发光性质和光谱性质的影响.结果表明:在(Gd,Lu)2O3系粉体中,当Lu2O3的摩尔分数(下同)大于40%时,能在煅烧温度不低于1 700℃情况下,抑制Gd2O3的相变得到利于制备透明陶瓷的立方相结构.而且随着Lu3+离子的浓度增加,先后观察到红移和蓝移现象;在(Gd,Lu)203:Eu3+系粉体中,粉体的发光强度随着Lu3+掺杂量增加而减小,Eu3+的最佳掺杂量为7%;在(Gd,Lu)2O3:Tb3+系粉体中,Tb3+离子的最佳掺量为1%.     

呋喃与(HF)n(n=1-3)分子间氢键相互作用研究

采用MP2/6-311++G(d,P)方法对单体HF、呋喃(C_4H_4O),以及它们形成的复合物C_4H_4O与(HF)_n(n=1-3)的结构和相互能量等进行了研究。结果显示复合物C_4H_4O与(HF)_n(n=1-3)中随着HF分子的增多,复合物结合能增大,但C_4H_4O与HF形成的单个氢键键能减小,且当n=3时C_4H_4O已不能同时与3个HF形成三个分子间氢键。自然轨道(NBO)显示,C_4H_4O与(HF)_n(n=1-2)中随着n值的增大,C_4H_4O中的O原子与FH形成的单个氢键相互作用显著减小。C_4H_4O与(HF)_n(n=1-2)中形成的氢键具有一定的方向性和饱和性。     

Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷的光学性能

以Ca(NO3)2、Er(NO3)3、Yb(NO3)3、KF和NaF为原料,采用热压烧结方法制备出Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷。测试了样品室温吸收光谱和发射光谱。利用Judd-Ofelt理论分析了样品的光学性能,并对吸收光谱进行计算拟合,得到光谱参数?t (t=2,4,6),根据光谱参数?t计算出Er3+某些能级的的跃迁几率、荧光分支比、辐射寿命和品质因子,讨论并比较了Er3+-Yb3+和Er3+-Na+共掺对CaF2透明陶瓷光学性能的影响。结果表明：掺杂Yb3+和Na+改变了Er3+光谱参数;Er3+-Yb3+共掺有利于提高样品的荧光强度;Er3+-Na+共掺有利于提高荧光寿命。     

Fatty acids,the immune response,and autoimmunity: A question of n−6 essentiality and the balance between n−6 and n−3

The essentiality of n−6 polyunsaturated fatty acids (PUFA) is described in relation to a thymus/thymocyte accretion of arachidonic acid (20∶4n−6, AA) in early development, and the high requirement of lymphoid and other cells of the immune system for AA and linoleic acid (18∶2n−6, LA) for membrane phospholipids. Low n−6 PUFA intakes enhance whereas high intakes decrease certain immune functions. Evidence from in vitro and in vivo studies for a role of AA metabolites in immune cell development and functions shows that they can limit or regulate cellular immune reactions and can induce deviation toward a T helper (Th)2-like immune response. In contrast to the effects of the oxidative metabolites of AA, the longer-chain n−6 PUFA produced by γ-linolenic acid (18∶3n−6, GLA) feeding decreases the Th2 cytokine and immunoglobulin (Ig)G1 antibody response. The n−6 PUFA, GLA, dihomo-γ-linolenic acid (20∶3n−6, DHLA) and AA, and certain oxidative metabolites of AA can also induce T-regulatory cell activity, e.g., transforming growth factor (IGF)-β-producing T cells; GLA feeding studies also demonstrate reduced proinflammatory interleukin (IL)-1 and tumor necrosis factor (TNF)-α production. Low intakes of long-chain n−3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and th2 responses, proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical role in long-chain n−3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n−3 PUFA from fish oils increase survival and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n−3 PUFA augment disease, whereas n−6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n−6 and n−3 families are clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert their clinical effects are not well understood. Finally, the view that all n−6 PUFA are proinflammatory requires revision, in part, and their essential regulatory and developmental role in the immune system warrants appreciation.     

物理化学3+1模块量化联动考核体系初探

物理化学是化学专业重要的专业基础课程,为了适应应用技术型人才培养模式,对该课程的考核方式改革进行探索,提出3+1模块量化联动考核体系,该体系由平时、综合能力和考试3个课程内考核模块并与实验课程形成联动考核机制。3个考核模块和联动考核模块分别占综合成绩的25%、20%、45%和10%;每个模块包括多个考核小项,进行量化并相互关联;拟构建动态与静态、形成与终结、理论与实践、科学与技术相结合的考核体系。     

“3+1”塔甲醇精馏工艺优化

甲醇是重要的工业原料,制造工艺涉及内容多,专业性强,注重甲醇制造工艺研究,明确甲醇生产中存在的不足,积极优化相关工艺流程,保证甲醇生产品质的同时,更好地提高经济效益,一直是业内人士研究的重要内容。对"3+1"塔甲醇精馏工艺优点及流程做简要阐述,分析甲醇生产中存在的问题,并提出相关的优化措施。     

“3+1”塔甲醇精馏工艺优化

针对甲醇工艺当中的"3+1"塔甲醇精馏工艺系统流程与目前的实际运行状况进行了概述,对该系统在运行过程中所产生的一些问题进行了深入的分析,提出了一些有效的措施在目前的"3+1"塔甲醇精馏工艺基础上进行不断的创新和完善。要想在最大程度上发挥"3+1"塔甲醇精馏工艺的作用,一定要对目前系统中存在的问题进行有效的解决,从而才能保证装置实现安全稳定的运行。     

白光LED用Ca0.5-yWO4∶Eu3+0.25,Li+0.25,Sm3+y红色荧光粉的合成及发光特性

采用固相法制备了白光LED红色荧光粉Ca0.71WO4∶Sm3+0.04,Li+0.25和Ca0.5-yWO4∶Eu3+0.25,Li+0.25,Sm3+y(y=0.00,0.02,0.04,0.06),通过X射线衍射(XRD)、荧光分光光度计以及稳态/瞬态荧光光谱仪研究了荧光粉样品的物相、Sm3+的掺杂量对荧光粉发光性能以及荧光寿命的影响.XRD分析表明,合成的样品均为白钨矿结构.荧光光谱表明,所合成的系列荧光粉均可以被近紫外光(393 nm)和蓝光(464 nm)有效激发,其发射主峰位于615nm处,归属于Eu3+的5D0→7F2跃迁.发光衰减曲线表明,Sm3+的掺杂对荧光粉Ca0.5WO4∶Eu3+0.25,Li+0.25荧光寿命没有影响.实验结果表明,在系列Ca0.5-yWO4∶Eu3+0.25,Li+0.25,Sm3+y荧光粉中Sm3+的最佳掺杂量为4％(摩尔分数).     

1+1=2.9

<正> 麦戈(Magog)公司提出在塑料制品工厂中使用挤出机时,轮换使用两根螺杆较为经济。在一根使用750小时后,即换另外一根。使用两根螺杆比一根螺杆的优缺点有:多一根备用螺杆,从价格来看投资多一些;当发现有螺距损坏、尖端破     

PAMAM接枝稻草对Nd3+、Sm3+、La3+的吸附特性

以环氧氯丙烷为交联剂,将聚酰胺胺树状大分子(PAMAM)接枝到稻草基体上,利用FTIR、SEM、XRD、TG等对其结构进行了表征和分析。考察了其对Nd~(3+)、Sm~(3+)、La~(3+)稀土金属离子的吸附性能,探讨了吸附时间、稀土金属离子浓度、吸附温度、溶液pH等因素对吸附性能的影响。同时对吸附过程的动力学、吸附等温线和吸附热力学进行了研究。结果表明,所制备的吸附剂对Nd~(3+)、Sm~(3+)、La~(3+)稀土金属离子的吸附平衡时间约为4 h,平衡吸附量分别为47.14、40.11和50.12 mg/g。吸附过程符合拟二级动力学模型和Freundlich等温线,表明此吸附过程是属于化学吸附过程。吸附热力学研究表明,此吸附过程是自发进行的,同时吸附过程是一个混乱度增加的熵增过程。     

K+掺杂LiNi1/3Co1/3Mn1/3O2材料的制备及电化学性能研究

锂离子电池正极材料LiNi_1/3Co_1/3Mn_1/3O₂具有放电比容量大、热稳定性好、成本低、安全性能好等优点,但其倍率性能有待进一步提升。本文采用水热法制备了K⁺掺杂LiNi_1/3Co_1/3Mn_1/3O₂材料LNCM-xK。通过X射线衍射谱、场发射扫描电镜和X射线光电子能谱表征LNCM-xK的形貌和结构,通过电化学工作站和蓝电测试系统测试其电化学性能。结果表明:K⁺掺杂能有效降低阳离子混排程度,改善LiNi_1/3Co_1/3Mn_1/3O₂材料的电化学性能,其中当x=0.125时K⁺掺杂LiNi_1/3Co_1/3Mn_1/3O₂样品(LNCM-0.125K)阳离子混排程度最低;LNCM-0.125K样品电化学性能最佳,0.2 C下50次循环后容量保持率为96.15%;在不同电流密度(0.2 C,0.5 C,1 C,2 C,5 C)下进行倍率性能测试,连续充放电30次后LNCM-0.125K样品容量保持率为97.00%。     

硫磺制酸装置"3+1"与"3+2"两种转化工艺分析

针对新的国家环保标准要求 ,硫酸装置排放的尾气中SO2 浓度应低于 96 0mg/m3 。分析了常用的“3 1”和“3 2”两种转化工艺的特点 ,结合硫磺制酸工艺指出 :在采用现一种催化剂的情况下 ,“3 2”转化工艺原料气的 φ(SO2 )比“3 1”的更高时 ,仍可获得同样高的最终转化率 ;在原料气中 φ(SO2 )相同的条件下 ,“3 2”转化工艺对达到要求的最终转化率会更有保障。并建议 :采用国产催化剂时宜选用“3 2”五段转化 ;采用进口催化剂时可选用“3 1”四段转化。