多元化教学模式在大学物理教学中的探索与实践

大学物理课是理工科高等院校的一门重要公共基础课,它对于培养学生的科学素养、提高学生分析问题和解决问题的能力、协调理论知识与提高动手能力具有其他课程不能替代的重要作用,以往的教学中存在“重理论、轻应用”“重模型、轻推导”的传统倾向,同时高考课改使得受教育群体的物理知识体系多元化.为此,本文探索了新的有效的教学模式,首先分析了大学物理的教学现状,然后根据大学物理的教学目标,讨论了基于多元化教学模式的大学物理的教学改革途径.     

基于极化-空间模超纠缠的量子网络多跳纠缠交换方法研究

基于纠缠交换方法进行多跳量子信息传输,是实现远距离量子网络通信的基本方式之一.传统的多跳量子网络通常使用单自由度极化光子纠缠态作为量子信道,信息传输容量较低且容易受到噪声的干扰.本文提出一种基于超纠缠的高效量子网络多跳纠缠交换方法,利用极化-空间模式两自由度的纠缠光子,建立超纠缠量子多跳信息传输通道.以远程超纠缠隐形传态的信道建立需求为例,首先给出了基础的逐跳超纠缠交换方案,为降低该方案的端到端超纠缠建立时延,提出在中间量子节点进行同时测量的并行超纠缠交换方案.在此基础上,为降低并行超纠缠交换的经典信息开销,进一步提出一种分级并行超纠缠交换方案.理论分析及仿真结果表明该方案的纠缠建立时延接近于并行超纠缠交换方案,但可以减少经典信息传输量,在一定程度上实现两者的平衡.相比传统的纠缠交换方法,本文方案有利于解决远程超纠缠通信的需求,对未来构建更高效率的量子网络有积极意义.     

MARKOV SKELETON PROCESS IN PERT NETWORKS

In this article, we investigate Programming Evaluation and Review Technique networks with independently and generally distributed activity durations. For any path in this network, we select all the activities related to this path such that the completion time of the sub-network （only consisting of all the related activities） is equal to the completion time of this path. We use the elapsed time as the supplementary variables and model this sub-network as a Markov skeleton process, the state space is related to the subnetwork structure. Then use the backward equation to compute the distribution of the sub-network＇s completion time, which is an important rule in project management and scheduling.     

《无机化学学报》投稿须知(NOTICE TO AUTHORS)

<正>《无机化学学报》是中国化学会主办的学术期刊,面向国内外发行。主要报道我国无机化学领域的基础理论和应用基础理论研究成果,促进国内外学术交流,繁荣无机化学学科。它涉及的内容有固体无机化学、     

Broadband Convergence of 40 GHz-ROF and 10-Gb/s WDM-PON Systems in the Duplex Access Network

A broadly converged 40G-ROF and 10-Gb/s WDM-PON multi-service access system is proposed and exper- imentally demonstrated. This scheme consists of an integrated system of 40G-ROF and 10-Gb/s WDM-PON simultaneously transmitting independent 2.5-Gb/s wireless and 10-Gb/s wire signal. At the base station, it employs a remodulation scheme, which is achieved by remodulating the upstream OOK signal on the DPSK downstream signal, to reduce the cost of the base station. The transmission experiment is carried out over a 25-km-long single mode fiber （SMF-28）. The results show that the sensitivities of downstream PON and ROF signal are -14.5 dBm and -21.5 dBm, respectively, and the sensitivity of upstream signal is -25.3 dBm.     

全国首家DHI标准物质制备实验室启动

不久前,农业部畜牧业司组织召开全国奶牛生产性能测定标准物质制备实验室（二期）建设项目验收会,并取得圆满成功。DHI标准物质是DHI测定中对乳成分快速分析仪进行校准的标准牛奶样品。标准物质生产和定期使用是DHI测定体系的关键控制点。     

TS3000总硫分析仪分析低压力硫化氢的研究

通过时TS3000 总硫分析仪气体进样模块的简单改装,利用仪器的富集功能,使其可以分析由质量流量控制器原理发生的低含量、低压力的硫化氢气体,解决了TS3000 总硫分析仪不能检测压力较低样品的难题.对不同含量硫化氢样气体的分析结果表明,改装后的仪器仍具有很好的线性及准确度,同时验证了仪器改装方法的可行性.     

A 2D Lanthanide-organic Framework Based on Inorganic Lanthanum（Ⅲ） Sulfate Skeletons：Synthesis,Structure,and Luminescence and Thermal Properties

A new lanthanum coordination polymer formulated as {[La2(pyda) 2(μ4-SO4) ·5H2O]· 2H2O}n(1,H2pyda = 2,6-pyridine-dicarboxylic acid) has been synthesized from the reaction of H2pyda with lanthanide nitrate in the presence of sulfate as a counter anion. The compound was characterized by elemental analysis,IR spectroscopy and X-ray single-crystal diffraction. It crystallizes in the orthorhombic system,space group Pna21,with a = 18.8558(19) ,b = 6.5831(7) and c = 18.7543(19) . The compound is a 2D hybrid,in which the La(Ⅲ) ions were doubly connected by the carboxylic group of pyda2-ligand to form the La(Ⅲ) dimer followed by being grafted into 1D zig-zag chains which are further connected into a 2D network containing {[La(SO4) ]+}n helical chains. The interchain hydrogen bonding and π-π stacking interactions extended the 2D networks into a 3D supramolecular edifice.     

A Novel Inorganic-organic Hybrid Borate with Unique One-dimensional Infinite Aluminium-oxygen Chains

A novel inorganic-organic hybrid borate,[Al2(fum)(H3BO3)(OH) 4]n·n(H3BO3) (1,H2fum = fumaric acid) ,has been synthesized and characterized by single-crystal X-ray diffraction,FTIR and elemental analysis. Crystal data for compound 1: orthorhombic,space group Pnma,a = 14.108(3) ,b = 6.9412(14) ,c = 14.995(3) ,V = 1468.3(5) 3,Z = 4,Mr = 359.72,Dc = 1.627 g/cm3,μ = 0.254 mm-1,F(000) = 736,the final R = 0.0492 and wR = 0.1650 with I > 2σ(I) . In compound 1,each AlⅢ ion is coordinated by six oxygen atoms to adopt a distorted octahedral geometry. Both fumarate anion and the coordinated boric acid act as bidentate bridging ligands to link two neighboring AlⅢ centers simultaneously. Each AlⅢ ion is bridged by two μ2-hydroxyl ligands to construct an infinite wave-like [Al2(fum)(H3BO3)(OH) 4]n chain. These one-dimensional chains form hydrogen bonds with free boric acid molecules giving rise to a three-dimensional supramolecular network.     

Synthesis and Crystal Structure of a Zinc（II） Complex with 2-（4＇-Chlorine-benzoyl）- benzoic Acid and 1,10-Phenanthroline

A new metal-organic complex Zn2（cbba）4（phen）2 （Hcbba = 2-（4＇chlorine-ben- zoyl）benzoic acid, phen = 1,10-phenanthroline） 1 has been hydrothermally synthesized and structurally characterized by elementa...