土壤中侵蚀性离子对X70钢的侵蚀作用研究

采用极化曲线并结合E-pH图分析，研究了土壤中主要侵蚀性离子CO2-3、HCO-3、SO2-4、Cl-对管线钢X70钢的侵蚀作用。结果表明：在酸性介质中，SO2-4、Cl-2种离子对X70钢的侵蚀能力无明显差别；X70钢在含有SO2-4、Cl-离子的介质中发生活性溶解，由于含有多种钝性元素以及材料的组织结构较均匀，X70钢在此介质中的耐蚀性优于A3钢。但在含有CO2-3、HCO-3的碱性体系中，X70钢的耐蚀性随pH值变化。在含有HCO-3的弱碱体系（pH=8）中，X70钢具有一定的钝化能力，但A3钢的耐蚀性优于X70钢，在含有CO2-3的中等碱体系（pH=10）中，X70钢的耐蚀性优于A3钢，在含有CO2-3的强碱体系中,A3钢的耐蚀性优于X70钢。      

TC11钛合金中氧铝偏析与脆性断裂

借助ＳＥＭ及ＥＤＡＸ、ＡＥＳ对某些ＴＣ１１钛合金棒材机械性能差的原因进行了研究。。结果表明材料延伸率、断面收缩率及冲击值低，显微硬度值高的拉伸和冲击断口上都呈现脆性解理断裂的断裂源，源区显微组织为条状α及空洞，且氧铝偏高。氧铝偏高造成α＋β→β相变温度和再结晶温度升高，使加工变形中形成的条状α在随后的热处理中得不到改变，并导致拉伸、冲击时的脆性断裂     

Preparation and Characterization of K_n|Ga(H_2O)MW_(11)O_(39)|·xH_2O

In this paper the heteropoly complexes K_n[Ga(H_20)MW_(11)O_39)]·xH_20 [M=Cu(Ⅱ), Co(Ⅱ), Cr(Ⅲ),Fe(Ⅲ), Mn(Ⅳ)] have been prepared in this laboratory firstly. The products were characterized by chemicalanalysis, ionexchange, IR, UV and X-ray powder diffraction.     

铜钛合金调幅分解之特征

通过透射电子显微分析和Ｘ射线衍射分析对Ｃｕ－５２Ｔｉ（％，原子分数，下同）合金的调幅分解过程进行了研究。确认调幅分解是Ｃｕ－Ｔｉ合金相变初期的过程之一。盐水淬冷不能抑制调幅分解，淬火态调幅波长约为５７ｎｍ。研究表明，调幅分解与调幅组织的长大是两个完全不同的过程，分别属于连续相变和非连续相变。这两个过程的波长长大动力学均符合λ３－λ３０＝ｋｔ定律，长大激活能分别为１７６ｋＪ／ｍｏｌ和１３４ｋＪ／ｍｏｌ。电镜下看到的调幅组织不能作为调幅分解发生的判据。     

Ti－24Al－11Nb腐蚀疲劳断口形貌的研究

Ｔｉ－２４Ａｌ－１１Ｎｂ腐蚀疲劳断口形貌的研究张跃，褚武扬，王燕斌，肖纪美（北京科技大学北京１０００８３）１引言对Ｔｉ－２４ＡＩ－１１Ｎｂ合金的断裂特征和断口形貌已进行了较多的研究［“］．在３００ｏＣ的氢气中该合金能发生氢致开裂，其断口形貌与过载断口...     

Characterization of ramie yarn treated with sodium hydroxide and crosslinked by 1,2,3,4‐butanetetracarboxylic acid

Ramie yarns were treated with various concentrations of NaOH at room temperature and subsequently crosslinked with 1,2,3,4‐butanetetracarboxylic acid (BTCA). The microstructure and tensile properties of the treated yarns were characterized. X‐ray diffraction (XRD) and FTIR were used to study the crystalline structure of the resultant ramie yarns. The results showed that the maximum change in the structure of the alkali‐modified ramie took place at 16% NaOH, which would completely transform cellulose I to cellulose II. At the same time, the crystallinity index and fiber orientation decreased to the minimum value while the absorption properties were enhanced. The average degree of polymerization (DP ) of the treated ramie yarns slightly decreased after NaOH treatment. Tensile properties including tenacity, breaking elongation, and modulus of the treated yarns were also investigated. Scanning electron microscopy (SEM) was used to investigate the breakage of the treated yarns. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1857–1864, 2004     

Event-driven,pattern-based methodology for cost-effective development of standardized personal health devices

Experiences applying standards in personal health devices (PHDs) show an inherent trade-off between interoperability and costs (in terms of processing load and development time). Therefore, reducing hardware and software costs as well as time-to-market is crucial for standards adoption. The ISO/IEEE11073 PHD family of standards (also referred to as X73PHD) provides interoperable communication between PHDs and aggregators. Nevertheless, the responsibility of achieving inexpensive implementations of X73PHD in limited resource microcontrollers falls directly on the developer. Hence, the authors previously presented a methodology based on patterns to implement X73-compliant PHDs into devices with low-voltage low-power constraints. That version was based on multitasking, which required additional features and resources. This paper therefore presents an event-driven evolution of the patterns-based methodology for cost-effective development of standardized PHDs. The results of comparing between the two versions showed that the mean values of decrease in memory consumption and cycles of latency are 11.59% and 45.95%, respectively. In addition, several enhancements in terms of cost-effectiveness and development time can be derived from the new version of the methodology. Therefore, the new approach could help in producing cost-effective X73-compliant PHDs, which in turn could foster the adoption of standards.     

Observation of 3‐D Structure of Bubbles in a Fluidized Catalyst Bed

The interface area between the bubble and emulsion phases in a fluidized catalyst bed is one of the important parameters used to analyze and design the fluidized bed reactor. We used a fast‐scanning X‐ray CT system to observe the bubble shape and structure. We then obtained the transient 2‐dimensional cross sectional gas‐phase distribution in a fluidized catalyst bed. Using image‐processing techniques, pseudo 3‐dimensional images of the bubbles were reconstructed. The bubble structure was studied based on the 3‐dimensional images and the previously obtained results in a 2‐dimensional fluidized bed. It was found that the bubble shape was not spherical but complicated, and that the bubbles ascending in a fluidized catalyst bed consisted of some smaller bubbles.     

Implicit Bayesian Inference Using Option Prices

Abstract. A Bayesian approach to option pricing is presented in which posterior inference about the underlying returns process is conducted implicitly via observed option prices. A range of models allowing for conditional leptokurtosis, skewness and time‐varying volatility in returns are considered, with posterior parameter distributions and model probabilities backed out from the option prices. Models are ranked according to several criteria, including out‐of‐sample predictive and hedging performance. The methodology accommodates heteroscedasticity and autocorrelation in the option pricing errors, as well as regime shifts across contract groups. The method is applied to intraday option price data on the S&P500 stock index for 1995. While the results provide support for models that accommodate leptokurtosis and skewness, no one model dominates when all criteria are considered.     

13X沸石吸附处理水中苯胺的性能及应用

用天然岩石矿物为原料，经过较简单的工艺过程合成13X沸石去除水中苯胺，模拟废水的实验结果表明：沸石对苯胺的吸附速率非常快，吸附时间为10min时，吸附基本达饱和；一般当沸石用量为10g/L时，水蝇苯胺的吸附率达95％，随着pH值的增加，苯胺在沸石上的吸附率较小；温度增加，吸附率有所增加。但常温下，苯胺的吸附率也能达到93％，13X沸石对苯胺的最大吸附量可达10mg/g，其吸附规律较好地符合Freundlich吸附等温式，饱和了苯胺的沸石，用质量分数为20％，温度为60℃的氯化钠溶液洗脱，解吸率近于100％，且解吸后的沸石在未经任何处理的情况下仍能吸附苯胺；对实际苯胺废水的处理结果，也表明13X沸石不仅可有效地去除苯胺，还可以有效地去除废水中的SS，CODCr，氨氮及油等。