低温裂纹张开位移预测方法的讨论

把低温影响下的COD试验数据用灰色理论中的累加方法进行累加，可以使一组没有规律的数据成为一条光滑的曲线．然后利用人工神经网络和自适应模糊推理系统两种方法进行预测，算例的结果表明用一次累加后的数列预测精度较高。     

"牺牲"阳极法合成乙醇钽研究

研究了“牺牲“阳极法电化学合成乙醇钽过程中,添加剂种类与浓度、电解液温度、阴阳极极距和电流密度的影响.选取最佳合成条件为:四甲基氯化铵0.04 mol/L,温度为电解液的沸腾温度,极距约2 cm,电流密度220 A/m2.电合成的混合液经常压蒸馏和减压蒸馏,得到产品用红外光谱、拉曼光谱和元素分析进行表征,确定了产品为乙醇钽.电合成的电流效率大于95%,产品蒸馏时钽的直收率82.8%.     

EFFECT OF RARE EARTH ADDITIONS ON THE IMPACT FRACTURE OF Cr18Nil8Si2 STEEL

<正> Cr 18 Ni 18 Si 2钢经热处理后的低温冲击断口,其中加稀土的为穿晶断口,而未加稀土的为混合型断口。 试验用钢用高频感应炉冶炼,锭重20kg,锻成15×15mm方棒,再加工成冲击试样。其化学成分如下。稀土的加入是将一号混合稀土合金缚在钢棒上插入熔池。     

含钴锆基块状非晶合金的制备与力学性能

采用水淬法制备了Zr—Ti—Cu—Ni—Be—Co块状非晶合金(BMGs)。使用XRD进行相分析，采用热分析仪进行玻璃转变温度、晶化温度和热稳定性等的测定，用SEM观察试样压缩后的外表面和断口形貌。研究了Co对Zr—Ti—Cu—Ni—Be合金非晶形成能力(GFA)、热稳定性及力学性能的影响。结果表明：含Co的所有Zr—Ti—Cu—Ni—Be BMGs都有1个明显的玻璃转变点和宽的过冷液相区(△T）。Zr38Ti17Cu10.5Co12Be22.5合金具有和Zr41Ti14Cu12.5Ni10Be22.5合金相当的△T；Co的添加明显提高Zr—Ti—Cu—Ni—Be BMGs的力学性能，含Co量大于10at％的Zr—Ti—Cu—Ni—Be BMGs的压缩断裂强度（σf）超过2000MPa，Zr38Ti17Co22.5Be22.5合金的σf达到2230MPa，比Zr41Ti14Cu12.5Ni10Be22.5合金的σf提高23％。     

Ionization of Porous Hypercrosslinked Polymers for Catalyzing Room-Temperature CO2 Reduction via Formamides Synthesis

Catalysis Letters - Porous materials with heterogeneous nature occupy a pivotal position in the chemical industry. This work described a facile pre- and post-synthetic approach to modify porous...     

Adsorption characteristics of hexadecyl ammonium with different numbers of carbon chains in montmorillonite and the structure of the prepared composites

Journal of Porous Materials - The dynamics and thermodynamics of adsorption of hexadecyl ammonium with different numbers of carbon chains in montmorillonite (Mt) with different layer charge density...     

钢丝绳张紧装置在大行程拖链上的应用

介绍了给DY3000×20m数控机床大行程拖链增设的张紧装置,该装置解决了拖链无法自动复位的问题,使用方便、经济可行。     

Effect of sulfate on Cu(Ⅱ) sorption to polymer-supported nano-hydrated ferric oxides: Experimental and modeling studies

Incorporating of hydrous ferric oxide(HFO) inside porous supports with large sizes has become an effective way to decontaminate the water from heavy metals. Ubiquitous anions like sulfate are usually present in high concentrations in water, and might greatly affect adsorption behavior of hybrid HFO. Here, a polymer-based HFO-CPS was fabricated by encapsulating nano-HFO inside a chloromethylated polystyrene polymer(CPS) and the reactivity of HFO-CPS with Cu(Ⅱ) was evaluated in the presence of sulfate ions.Surface complexation theory was firstly employed to describe the effect of sulfate on Cu(Ⅱ) adsorption edges of hybrid HFO-CPS, where constant capacitance model(CCM) was adopted. The available weak adsorption site Fe_((2))OH of hybrid HFO-CPS was found to decrease from 20% Fe to 5% Fe, which might be caused by the pore plugging effect after HFO encapsulation. With the assumption that a ternary complex was formed, the effect of sulfate on Cu(Ⅱ) adsorption by HFO-CPS were successfully described by CCM using the optimized Fe_((2))OH site under different sulfate concentrations(1 or 10 mmol·L~(-1)) and Cu/Fe ratios(0.0042 or 0.0252). It is confirmed that the formation of Fe OHCu SO_4 ternary surface complexes played an important role in enhancing Cu(Ⅱ) adsorption on HFO-CPS in the presence of sulfate.     

ZrO2制备方法研究进展

以ZrO₂为活性组分或载体的催化剂,在酚类定向催化转化中具有较高的研究价值。总结了ZrO₂的各种制备方法,包括溶胶-凝胶法、共沉淀法、水热法、表面活性剂辅助法、静电纺丝法、热解法、多元醇还原法、反相微乳法和超临界合成法等。阐述了各种方法的反应原理,详细比较了不同制备方法的优劣,并具体分析了制备方法对催化剂结构及性能的影响。     

Preparation of High Strength and Toughness Aramid Fiber by Introducing Flexible Asymmetric Monomer to Construct Misplaced-Nunchaku Structure

High performance fibers with high strength and toughness have great potential in composites, but contradiction between tensile strength and elongation at break makes the preparation to become a current challenge. Herein, an asymmetric structure of more flexible diamine, 3,4′-diaminodiphenyl ether (3,4′-ODA), is introduced into heterocyclic aramid (PBIA) fibers to replace rigid symmetric p-phenylenediamine (PDA). By studying the properties of copolymer (mPEBA) fibers with different ratios of diamine, it is found that the mPEBA fiber reached the optimal mechanical properties with the 30% content of 3,4′-ODA. Compared with homopolymerized heterocyclic aramid fibers, the tensile strength and elongation at break of mPEBA fiber are improved by 26.2% and 38.7%, respectively. Results of X-ray diffraction show that the introduction of 3,4′-ODA structure can increase stretchability of mPEBA fibers, improving the orientation degree during hot-drawing. Molecular dynamics simulations confirm that 3,4′-ODA structure undergoes a conformation transformation to form a straightened chain during hot-drawing, while symmetrical 4,4′-diaminodiphenyl ether (4,4′-ODA) cannot form the same conformation. The misplaced-nunchaku structure is formed based on the special meta-para position of 3,4′-ODA, achieving the synergy of high strength and high toughness.