新疆东天山灵北地区康南岩体岩石学#br# 特征及其构造意义

研究区位于新疆东天山觉罗塔格造山带吐哈盆地以南百灵山以北，多年来对于研究区古生代构造背景的认识受前人热议，存在争议。通过对研究区新发现基性岩体的岩石、地球化学特征与构造背景进行探讨，以期为大区域构造背景的研究提供一定的数据支持。主量元素研究表明，康南岩体具有高Mg、Fe，低Al的特征，说明研究区基性侵入岩为碱性岩石系列。微量元素测试结果表明具有同源演化的特征，Rb、Hf元素亏损较为严重。K、Ba、P、Sm富集明显，Tb、Nb、Ti表现为弱异常，在稀土元素球粒陨石标准化配分模式图中Eu的负异常不明显，表现为弱的正异常， Yb+Nb-Rb构造环境判别图解中样品落在“后碰撞”环境内，以上特征说明具有岛弧花岗岩的基本特征。岩性为深灰绿色弱蚀变细粒橄榄辉绿岩。     

Atmospheric deposition of nitrogen at five subtropical forested sites in South China

Elevated concentrations of reactive nitrogen (N) in precipitation have been reported for many cities in China. Due to increased use of fossil fuels and expansion in agriculture, further increases in deposition of ammonia (NHx) and reactive N oxides (NOy) are predicted. Increased deposition of reactive N is likely to affect N dynamics and N runoff in forest ecosystems. Yet, in China little work has been done to quantify the levels of atmospheric N deposition in such systems. Here, we assess the deposition of inorganic N (ammonium, NH4+ and nitrate, NO3-) for five subtropical forest ecosystems in remote and urban areas of South China. Annual volume-weighted concentrations in bulk precipitation range from 0.18 to 1.55 mg NH4+ -N L(-1) and from 0.12 to 0.74 mg NO3- -N L(-1). These values are large and several times greater than those reported for remote sites of the world. The fluxes of total inorganic N (TIN) in wet-only deposition range from 0.8 to 2.3 g N m(-2) yr(-1), with NH4+ -N contributing 54% to 77%. Both the tree canopy and the ground vegetation layer are important in determining the net N flux reaching the forest floor, but the net effect varies from site to site. At TieShanPing (TSP), close to Chongqing city, and at CaiJiaTang (CJT), near Shaoshan (Hunan province), the canopy represents a net source of N, probably due to dry deposition. At the other three sites (LiuChongGuan (LCG), LeiGongShan (LGS), both in Guizhou province, and LiuXiHe (LXH) in Guangdong), a net loss of reactive N from precipitation water occurs in the canopy, probably due to uptake processes. The total annual atmospheric TIN load is estimated to range from at least 0.8 g N m(-2) yr(-1) to 4.0 g N m(-2) yr(-1), with a considerable contribution from dry deposition. Concentrations and fluxes of inorganic N in tree canopy throughfall are greater than those in North America. Also the contribution of NH4+ -N to TIN fluxes in throughfall (40% to 70%) is greater than in North America. Our sites have N deposition levels and NH4+ -N contributions similar to those found in Northwest and central Europe. The TIN loads at TSP and CJT far exceed 2.5 g N m(-2) yr(-1), which is the N deposition load above which NO3- leaching is expected in temperate and boreal forests.     

An aeration energy model for an immersed membrane bioreactor

A simple model for evaluating energy demand arising from aeration of an MBR is presented based on a combination of empirical data for the membrane aeration and biokinetic modelling for the biological aeration. The model assumes that aeration of the membrane provides a proportion of the dissolved oxygen demanded for the biotreatment. The model also assumes, based on literature information sources, a linear relationship between membrane permeability and membrane aeration up to a threshold value, beyond which permeability is unchanged with membrane aeration. The model was benchmarked against two full-scale plant to obtain the most appropriate and conservative value of the slope of the flux:aeration curve and the blower efficiency. Benchmarking in this way produced a match to within 20% of all key process plant operational parameters.The model demonstrated that significant reductions in aeration energy could be obtained through operation at lower flux and reducing the membrane aeration requirement accordingly, so-called “proportional aeration” at lower flows. Similarly, increasing oxygen transfer from membrane aeration would also be expected to decrease energy demand. A sensitivity analysis of some of the key parameters revealed that, of the key operating parameters, loading, SOTE and MLSS concentration remain the most critical in determining energy demand. It is suggested that a key parameter representing membrane aeration in MBRs is the mean in-module air upflow velocity U, since this gives a reasonable representation of the shear applied through membrane aeration. U was found to vary between 0.04 and 0.1 m/s across a number of modern large pilot and full-scale plant.An analysis reveals that significant reductions in energy demand are attained through operating at lower MLSS levels and membrane fluxes. Evidence provided from recent controlled pilot trials implies that halving the flux can reduce the aeration is suggested whereby the number of membrane tanks on line and/or the membrane aeration intensity is adjusted according to the flow, and thus flux, so as to reduce the overall aeration energy demand.     

微米级银粉微观结构分析

通过使用XRD方法对热分解方法和碱体系还原得到的微米级银粉微观结构分析,结果表明微米级银粉都是纳米级的银晶体颗粒组成,且为面心立方结构;银粉晶粒表现为各向异性;制粉条件会影响银粉晶粒尺寸,升高热分解温度促使晶粒变小,机械整形和磨制促使晶粒变小;制备的银粉存在晶格畸变,均表现为晶格膨胀;制粉条件会影响晶面的布拉格衍射强度,且对不同晶面的影响程度存在差异。     

Between-herd variation in resilience and relations to herd performance

Resilient cows are minimally affected in their functioning by infections and other disturbances, and recover quickly. Herd management is expected to have an effect on disturbances and the resilience of cows, and this effect was investigated in this study. Two resilience indicators were first recorded on individual cows. The effect of herd-year on these resilience indicators was then estimated and corrected for genetic and year-season effects. The 2 resilience indicators were the variance and the lag-1 autocorrelation of daily milk yield deviations from an expected lactation curve. Low variance and autocorrelation indicate that a cow does not fluctuate much around her expected milk yield and is, thus, subject to few disturbances, or little affected by disturbances (resilient). The herd-year estimates of the resilience indicators were estimated for 9,917 herd-year classes based on records of 227,655 primiparous cows from 2,644 herds. The herd-year estimates of the resilience indicators were then related to herd performance variables. Large differences in the herd-year estimates of the 2 resilience indicators (variance and autocorrelation) were observed between herd-years, indicating an effect of management on these traits. Furthermore, herd-year classes with a high variance tended to have a high proportion of cows with a rumen acidosis indication (r = 0.31), high SCS (r = 0.19), low fat content (r = ?0.18), long calving interval (r = 0.14), low survival to second lactation (r = ?0.13), large herd size (r = 0.12), low lactose content (r = ?0.12), and high production (r = 0.10). These correlations support that herds with high variance are not resilient. The correlation between the variance and the proportion of cows with a rumen acidosis indication suggests that feed management may have an important effect on the variance. Herd-year classes with a high autocorrelation tended to have a high proportion of cows with a ketosis indication (r = 0.14) and a high production (r = 0.13), but a low somatic cell score (r = ?0.17) and a low proportion of cows with a rumen acidosis indication (r = ?0.12). These correlations suggest that high autocorrelation at herd level indicates either good or poor resilience, and is thus a poor resilience indicator. However, the combination of a high variance and a high autocorrelation is expected to indicate many fluctuations with slow recovery. In conclusion, herd management, in particular feed management, seems to affect herd resilience.     

Partnership patterns and homeownership: a cross-country comparison of Germany,the Netherlands and the United Kingdom

Using detailed micro-level survey data for three advanced European welfare-state economies (Germany, Netherlands and UK), our analyses suggest a fairly common hierarchy to homeownership, according to partnership status, exists. In all three countries, a variety of interrelated factors appear to encourage greater propensities for homeownership amongst co-residential households (married/cohabiting), as compared to single-person households. However, important macro-contextual differences do appear to play a significant role in mediating the magnitude of difference within this hierarchy. For instance, in Germany the importance of marriage as a predictor of homeownership is found to be particularly strong, with married couples having far higher propensities for homeownership, even when compared to non-married cohabiters. In the Netherlands and UK, where an emphasis on traditional family and marriage is less pronounced, and where homeownership is generally more popular and accessible, the differentiation between married/unmarried partners is greatly reduced. Furthermore, we find no evidence to suggest that living-apart-together partners are more/less likely to own their home than singles.     

Electrical double-layer capacitors: evaluation of ageing phenomena during cycle life testing

This paper represents an assessment of the main ageing phenomena in electrical double-layer capacitors (EDLCs). In this study the cycle life of the EDLC cells with a rated capacitance of 1,600 F has been investigated at different ambient temperatures and current rates. From the experimental results we can observe that the impact of the high ambient temperature is significant on the cycle life of the cells. Moreover, the results also show the negative impact of the current rate. The internal resistance tests showed that the increase of the resistance is much higher than the decrease of the capacitance. Thus, the ageing of the EDLC during cycling was clearly non-linear. Further the EIS measurements indicated the higher increase of the imaginary part of the impedance at low frequencies during cycling, which indicates the capacitance fade.     

Haptic shared control: smoothly shifting control authority?

Literature points to persistent issues in human-automation interaction, which are caused either when the human does not understand the automation or when the automation does not understand the human. Design guidelines for human-automation interaction aim to avoid such issues and commonly agree that the human should have continuous interaction and communication with the automation system and its authority level and should retain final authority. This paper argues that haptic shared control is a promising approach to meet the commonly voiced design guidelines for human-automation interaction, especially for automotive applications. The goal of the paper is to provide evidence for this statement, by discussing several realizations of haptic shared control found in literature. We show that literature provides ample experimental evidence that haptic shared control can lead to short-term performance benefits (e.g., faster and more accurate vehicle control; lower levels of control effort; reduced demand for visual attention). We conclude that although the continuous intuitive physical interaction inherent in haptic shared control is expected to reduce long-term issues with human-automation interaction, little experimental evidence for this is provided. Therefore, future research on haptic shared control should focus more on issues related to long-term use such as trust, overreliance, dependency on the system, and retention of skills.     

驾驶员座椅悬架系统主动控制研究与仿真分析

针对车辆座椅悬架系统,建立电控空气弹簧悬架座椅系统的车辆-座椅三自由度物理模型和数学模型,以路面信号为激励源,应用随机线性二次型最优控制理论(LQG),根据系统性能要求选取合适的频率加权系数,设计出控制系统的最优反馈规律,并在MATLAB中对该模型进行仿真.结果表明:这种控制策略对路面激励通过车辆系统传递到驾驶员座椅的振动控制具有更好的适应性,能有效降低驾驶员所承受的垂直振动加速度.