等离子体引发丙烯酰胺水溶液聚合

用两种等离子体引发丙烯酰胺水溶液聚合的方法 ,制备了线性超高分子量聚丙烯酰胺 .研究了放电时间、放电功率、单体的初始浓度及溶液的pH值等对聚合产物的影响     

澳大利亚H区块中煤阶煤层气储层评价

澳大利亚煤层气资源丰富,尤其是中煤阶的煤层气具有埋藏深度浅、含气量高、渗透率高等易于商业开发的特点。以澳大利亚H区块中煤阶的煤层气为研究对象,在测井识别煤层的基础上,利用测井、录井、岩心分析等数据开展了煤层气储层分布、煤质、物性以及含气性研究,利用取心分析数据获得的动态兰氏体积构建煤层含气量及含气饱和度模型,实现H区块煤层气储层表征。研究结果表明,澳大利亚H区块煤层气储层具有高含气量、低灰分、低挥发分、低湿度、高固定碳、高渗透率的特点,具有较高开发潜力。煤层气储层特征评价将为后续煤层气开发奠定基础,同时为同类型煤层气储层评价提供借鉴。     

基于PCANN的BP神经网络话者识别系统

本文利用主分量神经网络分析法(PCANN)和反向传播神经网络,提出了一种具有较强自适应性和较高识别率的说话人识别方法.在此算法过程中,主分量分析法主要是对语音信号的原始特征作分析以得到更好的特征参数;BP神经网络则是作为一个分类器对说话人进行分类.文章将主分量分析与BP神经网络相结合,提高了识别的正确率,增强了系统抗噪声能力,减少了训练时间和计算量,同时简化了网络结构.     

系统变量对低温环境下超急速爆发沸腾的影响

本文以脉冲激光为热源,以高响应、高精度铂薄膜电阻为测温和加热元件,进行了低温工质(液氮)超急速爆发沸腾的实验研究。利用显微放大摄影系统对不同工况的沸腾过程进行了拍照,发现不同系统变量:如试件表面状况、激光参数对低温工质(液氮)超急速爆发沸腾行为有着重要的影响。     

Synthesis and Crystal Structure of N—（1‘’‘’—Phenyl—2‘’‘’—hydroxyethyl）—2,3—naphthylenedicarboximide

IntroductionThe design and the synthesis of new chiral ox-azoline[1,2 ] and C2 symmetric bis( oxazoline) ligandsand the application of their metal complexes inasymmetric catalytic reactions have inspired manyscientists to great exertions in recent years[3— 8] .Our interest has been focussed on the studies ofenantioselective transition metal catalysis ofhetero-cyclic ligands[9— 11] . In the synthesis of our new de-signed ligands,what is crucial is to select a rigidcyclic backbone. Bis( oxazo…     

Surface-induced orbital-selective band reconstruction in kagome superconductor CsV3Sb5

The two-dimensional (2D) kagome superconductor CsV₃Sb₅ has attracted much recent attention due to the coexistence of superconductivity, charge orders, topology and kagome physics, which manifest themselves as distinct electronic structures in both bulk and surface states of the material. An interesting next step is to manipulate the electronic states in this system. Here, we report angle-resolved photoemission spectroscopy (ARPES) evidence for a surface-induced orbital-selective band reconstruction in CsV₃Sb₅. A significant energy shift of the electron-like band around Γ and a moderate energy shift of the hole-like band around M are observed as a function of time. This evolution is reproduced in a much shorter time scale by in-situ annealing of the CsV₃Sb₅ sample. Orbital-resolved density functional theory (DFT) calculations reveal that the momentum-dependent band reconstruction is associated with different orbitals for the bands around Γ and M, and the time-dependent evolution points to the change of sample surface that is likely caused by the formation of Cs vacancies on the surface. Our results indicate the possibility of orbital-selective control of the band structure via surface modification, which may open a new avenue for manipulating exotic phenomena in this material system, including superconductivity.     

加拿大西加盆地泥盆系页岩气储层特征

西加盆地作为加拿大最重要页岩气产地,其中尤以泥盆纪页岩最为著名,针对该页岩气储层特征的研究对于页岩气富集规律研究、开发方案设计以及有利区优选意义重大。在岩心分析、测井识别、岩心观察以及实验室分析基础上,采用薄片鉴定、XRD全岩分析、储层物性分析、有机地球化学分析、含气量测定以及页岩三轴应力分析等手段,开展岩石学、矿物学、储层物性、有机地球化学、含气性以及岩石力学等页岩气储层特征相关研究。研究结果表明目的页岩气储层为灰色、黑灰色硅质、钙质泥岩;骨架矿物为石英、方解石;孔隙类型则以裂缝、有机孔为主,岩心分析孔隙度为1.32-6.88%;总有机碳含量百分数为0.23%～8.37%;含气量为0.76～2.95 m~3/t;页岩的静态杨氏模量与泊松比分别为32.4～41.2 GPa,0.24～0.28.表明西加盆地泥盆纪页岩储层具有脆性矿物含量高、物性良好、有机质成熟度高、含气量高且易于压裂的特点。综合认为加拿大西加盆地泥盆系页岩气储层具有很好的勘探开发潜力。     

非国有经济投资心理和行为的研究

本文首先对非国有经济的内涵进行了新的界定，其次从社会因素，心理因素等方面详细分析了非国有投资主体的研究心理和行为，最后本文提出了一些具体的建议。     

The Syntheses of 1-Dimensional(1-D)Chain, 2-D Layered, and 3-D Microporous Alumino-phosphates with Occluded Amine or Ammonium Templates from Alcoholic Systems

ＴｈｅＳｙｎｔｈｅｓｅｓｏｆ１┐Ｄｉｍｅｎｓｉｏｎａｌ（１┐Ｄ）Ｃｈａｉｎ，２┐ＤＬａｙｅｒｅｄ，ａｎｄ３┐ＤＭｉｃｒｏｐｏｒｏｕｓＡｌｕｍｉｎｏ┐ｐｈｏｓｐｈａｔｅｓｗｉｔｈＯｃｃｌｕｄｅｄＡｍｉｎｅｏｒＡｍｍｏｎｉｕｍＴｅｍｐｌａｔｅｓｆｒｏｍＡ...     

动态触觉传感中基于垂直采样的速度求解方法

提出了在触觉传感器动态触摸物体表面时，只利用传感器信号本身求触摸速度的方法，该方法利用了不同学深度的触觉传感信号，并对该信号的时间频率和空间频率进行分析，根据它们的时空尺度变换特征求解速度，仿真结果表明，该方法可以对一定范围内的速度进行较精度地测量。