南水北调中线干线工程河南段的水环境 影响及对策研究

本文分析研究了南水北调中线工程实施对河南沿线地表水和地下水环境的影响,包括对河道、农业灌溉、渠道左岸洪水的影响以及降水施工对地下水位的影响等;预测了工程运行期渠道对地下水的阻隔和渠道渗漏对水环境的影响;分别提出了施工期和运行期消除不良影响的工程和管理方面的应对措施,旨在为缓解工程其他区段的水环境影响提供理论和实践参考。     

等离子束表面冶金技术在刮板机溜槽上的应用研究

槽是刮板输送机机身的主体，是工作时输送货载的承载构件和刮板链及货载的运输渠道。由于物料(煤及矸石)、刮板和链条在溜槽中板上滑行，中板受到严重的磨损，故刮板输送机中部槽是煤矿中用量最大、磨损最严重的设备部件之一。目前矿用刮板输送机中部槽和机头侧板挡板的首选材料为16Mn钢，其中中部槽两链道磨损最为严重。针对这种失效形式，研究人员采用了多种工艺来尝试解决这一制约采煤工作面产量的问题，如大面积花样焊条堆焊工艺等，     

明渠调水工程事故段上游闸门群应急调控研究

为了保障明渠调水工程突发事故下的安全、高效运行,以流量中断事故为例,开展了事故段上游闸门群的应急调控策略及方法研究。应急调控策略包括:及早消减过剩的流量和蓄量、维持分水口的正常分水、充分利用渠道自身调蓄能力、避免渠池蓄量的反复调整等。具体提出了混合式闸前常水位+等体积运行方式,给出了切换范围的计算方法,基于流量平衡和调蓄时间估算方程,设计了两步式闸门群应急控制方法,并在南水北调中线总干渠上游30个渠池591 km渠道使用一维明渠非恒定流仿真模型进行了测试。结果表明,运用所提出的应急调控策略和两步式闸门群应急调控技术,无论渠道采用传统的单一式闸前常水位运行方式,还是采用新提出的混合式"闸前常水位+等体积"运行方式,均能取得安全高效的应急调控效果。相较而言,采用新型混合式运行方式可有效降低应急调控过程中的蓄量变化,加快过渡过程,案例中在闸门操作次数相当的条件下,过渡时间缩短约50%。     

适合中高速滤棒成形的烟用聚丙烯丝束的研制

为提高烟用聚丙烯丝束的可用性,通过聚丙烯共混改性、合理选择原材料、改造喷丝板、卷曲机及打包机,使丝束的单丝强度降低,稳定性能及开松性能明显提高,打包密度提高.改造后生产的丙纤丝束完全能够满足中高速滤棒成形的需要,成棒性能接近醋纤.     

5×5全长非均匀加热棒束临界热流密度试验研究

主要描述了5×5全长非均匀加热棒束临界热流密度试验的试验系统、试验内容、试验参数范围、试验过程、试验数据处理及数据分析结果。通过本项试验研究,掌握了全长非均匀加热棒束临界热流密度试验的试验技术;通过不具有跨间搅混格架的A型与具有跨间搅混格架的B型燃料组件临界热流密度的对比试验,发现跨间搅混格架对提高燃料组件临界热流密度具有重要作用,在一定参数范围内,B型比A型燃料组件临界热流密度提高7.49%。     

Speciation of dissolved copper within an active hydrothermal edifice on the Lucky Strike vent field (MAR, 37°N)

The objective of this study was to determine the concentrations of different fractions of dissolved copper (after filtration at 0.45 μm) along the cold part of the hydrothermal fluid-seawater mixing zone on the Tour Eiffel edifice (MAR). Dissolved copper was analyzed by stripping chronopotentiometry (SCP) after chromatographic C₁₈ extraction. Levels of total dissolved copper (0.03 to 5.15 μM) are much higher than those reported for deep-sea oceanic waters but in accordance with data previously obtained in this area. Speciation measurements show that the hydrophobic organic fraction (C₁₈Cu) is very low (2 ± 1%). Dissolved copper is present mainly as inorganic and hydrophilic organic complexes (nonC₁₈Cu). The distribution of copper along the pH gradient shows the same pattern for each fraction. Copper concentrations increase from pH 5.6 to 6.5 and then remain relatively constant at pH > 6.5. Concentrations of oxygen and total sulphides demonstrate that the copper anomaly corresponds to the transition between suboxic and oxic waters. The increase of dissolved copper should correspond to the oxidative redissolution of copper sulphide particles formed in the vicinity of the fluid exit. The presence of such a secondary dissolved copper source, associated with the accumulation of metal sulphide particles, could play a significant role in the distribution of fauna in the different habitats available at vents.     

A gradient composite coating to protect SiC-coated C/C composites against oxidation at mid and high temperature for long-life service

To improve the oxidation resistance of carbon/carbon (C/C) composites at mid and high temperature, a gradient composite coating was designed and prepared on SiC-coated C/C composites by in situ formed-SiO₂ densifying the porous SiC-ZrSi₂ pre-coating. SiO₂ gradient distribution was conducive to inhibiting the cracking of the coating. A dual-layer structure with the outer dense layer and the inner microporous layer was formed in the coating during densifying. The dense layer had excellent oxygen diffusion resistance and the microporous layer alleviated CTE mismatch between SiC inner coating and dense layer. Moreover, ZrSiO₄ particles inhibited crack propagation and stabilized SiO₂ glass. Therefore, the coating can protect the C/C composites from oxidation at 1473 K, 1573 K and 1773 K for 810 h, 815 h and 901 h, respectively. The coated samples underwent 30 thermal cycles between room temperature and 1773 K without mass loss, exhibiting good thermal shock resistance.     

A comparison and joint use of NIR and MIR spectroscopic methods for the determination of some parameters in European Emmental cheese

The determination of winter cheese chemical properties, namely, fat, sodium chloride (NaCl), pH, non protein nitrogen (NPN), total nitrogen (TN) and water soluble nitrogen (WSN) was done using spectroscopic technologies with different wavelength zones. The Emmental cheeses provided from different European countries were studied. A total of 91 cheeses produced during the winter time in Austria (n=4), Finland (n=6), Germany (n=13), France (n=30) and Switzerland (n=38) were analysed by near infrared (NIR) and mid infrared (MIR) spectroscopies. The combination of these two spectral regions (sum of their spectra) was also studied. The partial least square (PLS) regression with the leave one-out cross validation technique was used to build up calibration models using data set designated as calibration set. These models were validated with another data set designated as validation set. The obtained results suggest the use of the NIR for the determination of fat and TN contents, and the MIR for NaCl and NPN contents as well as for the pH. Similar results were obtained for WSN using the two techniques together. The combined spectra of both NIR and MIR did improve the results, while providing comparable results to those obtained from either the NIR or MIR spectroscopy.     

中频反应磁控溅射TiO2薄膜对敌敌畏的光催化降解性能

作者利用中频反应磁控溅射技术制备了厚度低于 4 0 0nm的TiO2 薄膜 ,并对其在紫外线作用下对敌敌畏 (DDVP)的光催化降解性能进行了系统的研究。实验结果显示 :敌敌畏的降解速率与光照时间和紫外辐照强度成正比 ,在TiO2 薄膜催化下 ,12 5W紫外灯辐照 4h后降解率可达 97%。 30 0℃下退火处理有利于提高薄膜的催化能力。薄膜厚度的增加亦可提高其催化能力     

中基性火山岩对查干凹陷油气成藏条件的影响

查干凹陷为一白垩纪断陷湖盆，发育白垩纪含油气系统。经多年勘探与研究，一致认为查干凹陷具有良好的勘探前景，但至今尚未找到工业油流，认真分析了前人研究成果及勘探成果，认为中基性岩浆的活动对查干凹陷油气成藏起着重要的控制作用。在早白垩世早期板内拉张凹陷发育阶段。深部物质上涌，造成大陆溢流型中基性岩浆喷发，导致生烃凹陷与构造高部位隔断，油气的生成，运移，富集都受到火山岩的影响。