Stress corrosion cracking behavior of 310S in supercritical water with different oxygen concentrations

The effect of dissolved oxygen(DO) on the stress corrosion cracking(SCC) of 310 S in supercritical water was investigated using slow-strain-rate tensile tests.The tensile properties, fracture morphology, and distribution of the chemical composition of the oxide were analyzed to evaluate the SCC susceptibility of 310 S. The results showed that the rupture elongation decreased significantly as the degree of DO increased. A brittle fracture mode was observed on the fracture surface, and only intergranular cracking was observed on the surface of the gauge section, regardless of the DO. Cracks were widely distributed on the gauge surface near the fracture surface.Oxides were observed in the cracks with two-layered structures, i.e., a Cr-rich inner oxide layer and an Fe-rich outer oxide layer.     

分汊型河道潜洲阻力特性的试验研究

利用含潜洲结构的分汊河道模型,对潜洲阻力特性进行了试验研究.结果表明:①对于断面形状固定的河道,其糙率系数并不为常数,而是随均匀流水深、流量、断面平均流速以及雷诺数等水力要素的变化而变化;②对于不同床面布置的河道,其糙率系数也不为常数,而是随床面布置的变化而改变.     

影响黄土丘陵区次降水泥沙输移比的水文要素

以桥沟小流域为研究对象,利用该流域不同地貌部位的野外径流场及沟道水文站网观测资料,计算了不同场次降水的泥沙输移比,较为系统地研究了影响桥沟流域次降水泥沙输移比的水文要素。结果表明:土壤前期含水量、流域的降水过程特征、洪峰流量、径流量、水流含沙量是影响次降水泥沙输移比的主要水文要素;提出了表示降水、径流、泥沙对泥沙输移比影响的表征参数,即降水峰现系数、径流侵蚀力和泥沙相对容重。     

国内外钻探用金刚石复合片性能的研究

主要介绍国内外金刚石复合片性能及采用四高复合片钻探硬岩的初试,为快速钻探提供一个新的途径.     

An efficient soft demapper for APSK signals using extreme learning machine

Neural Computing and Applications - In this paper we introduce an efficient soft demapping method for amplitude phase shift keying (APSK) constellations using extreme learning machine (ELM). The...     

辛酰丙氨酸镁（Ⅱ）、钙（Ⅱ）及锌（Ⅱ）配合物的溶解性及其聚集行为

采用镁、钙和锌的氢氧化合物分别与辛酰丙氨酸配体[CH3(CH2)6CONHCH(CH3)COOH]反应,合成了辛酰丙氨酸镁、钙和锌表面活性剂配合物。通过配合物的纯溶媒及水/有机溶媒系的溶解性测试发现,镁和钙的配合物均在大部分有机纯溶媒和水/有机溶媒系里有极高的溶解性,而锌的配合物在大部分有机纯溶媒系里有很低的溶解性。此外,通过核磁共振(NMR)光谱、电导、蒸汽压降下(VPO)和FTIR方法研究了溶液中镁、钙和锌表面活性剂配合物的聚集行为。Mg(oct-ala)2、Ca(oct-ala)2和Zn(oct-ala)2配合物在有机溶媒系里吸附水易发生聚集行为,并有形成逆胶束体的倾向。     

Mechanically activated disproportionation of NdFeB alloy by ball milling in hydrogen

1　INTRODUCTIONSincethediscoveryoftheuniaxialNd2 Fe14 Bcompoundin 1983[1,2 ] ,theNdFeBalloyshavebeenwidelyusedforpermanentmagnetapplicationsowingtotheirexcellentmagneticproperties ,suchashighcoercivity ,high energy products[3,4 ] .Intheserareearthpermanentmagnets ,afurtherexcitingrecentdevelopmentisthesuggestionofnano compositeex changemagnetscombiningthelargecoercivitiesinhardmagnetswithlargeinductionsfoundinsoftertransitionmetalmagnets[5,6 ] .Indeed ,thenano com positemagnetshavebeent…     

Selective Covalent Protein Modification by 4‐Halopyridines through Catalysis

We have investigated 4‐halopyridines as selective, tunable, and switchable covalent protein modifiers for use in the development of chemical probes. Nonenzymatic reactivity of 4‐chloropyridine with amino acids and thiols was ranked with respect to common covalent protein‐modifying reagents and found to have reactivity similar to that of acrylamide, but could be switched to a reactivity similar to that of iodoacetamide upon stabilization of the positively charged pyridinium. Diverse, fragment‐sized 4‐halopyridines inactivated human dimethylarginine dimethylaminohydrolase‐1 (DDAH1) through covalent modification of the active site cysteine, acting as quiescent affinity labels that required off‐pathway catalysis through stabilization of the protonated pyridinium by a neighboring aspartate residue. A series of 2‐fluoromethyl‐substituted 4‐chloropyridines demonstrated that the pK_a and k_inact/K_I values could be predictably varied over several orders of magnitude. Covalent labeling of proteins in an Escherichia coli lysate was shown to require folded proteins, indicating that alternative proteins can be targeted, and modification is likely to be catalysisdependent. 4‐Halopyridines, and quiescent affinity labels in general, represent an attractive strategy to develop reagents with switchable electrophilicity as selective covalent protein modifiers.     

能源动力类专业基础课参与式教学设计与实践

以教学实践为基础,结合能源动力类专业基础课课程的教学特点,深入探讨创新型人才培养背景下参与式教学在《热工理论基础》系列课程中应用的设计理念、实施策略、实践过程及其结果,结果表明参与式教学对于提高学生学习兴趣、自主能力和创新能力起着积极地作用,探索出了行之有效的工科专业基础课参与式教学模式。