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1.
柴祥君 《地矿测绘》2002,18(4):27-27,34
根据勘测定界图不同用途的需要,在制作成图及用色方面存在着不同的要求,为使勘测定界图在经济建设中发挥更大的作用,结合实际工作情况,对勘测定界图的成图及用色进行了初步探讨。  相似文献   
2.
The efficiency of Co(II)-, Mn(II)-, and Ti(IV)-doped carbon aerogels for the transformation of ozone into (*)OH radicals was investigated. The carbon aerogels had a markedly acid surface character (pH(PZC approximately equal) congruent with 3-4) with very high surface oxygen concentrations (O approximately equal with 20%). X-ray photoelectron spectroscopy (XPS) analyses of the samples showed the oxidation state of the metals was +2 for Co and Mn and +4 for Ti. The presence of Mn(II)-doped carbon aerogel enhanced ozone transformation into (*)OH radicals, whereas the presence of Co(II) and Ti(IV) carbon aerogels presented no activity in this process. Moreover, it was observed that an increase in the concentration of Mn in the surface of the aerogel increases its efficiency to transform ozone into (*)OH radicals, with an Rct value ([OH]/[O(3)]) of 5.36 x 10(-8) for the aerogel doped with 16% of surface Mn(II) compared to an R(ct) of 2.68 x 10(-9) for conventional ozonation. Regardless of the aerogel used, XPS analysis of the ozonated aerogel samples showed an increase in the concentration of surface oxygen when the exposure to ozone was longer. However, presence of oxidized metal species after ozone treatment was only detected in the case of the Mn-doped aerogel, (Mn(III) and Mn(IV)). CO(2) activation of carbon aerogel produced a marked increase in its efficiency to transform ozone into (*)OH radicals compared with non-activated sample. The efficiency of Mn activated carbon aerogel to transform ozone into (*)OH radicals was greater than that of Witco commercial activated carbon or H(2)O(2) in the ozonation of water from Lake Zurich (Zurich, Switzerland).  相似文献   
3.
赵先锋 《山西建筑》2007,33(15):366-367
对岩爆问题进行了探讨,详细分析了工程区各种因素对岩爆的影响,对岩爆区的临界埋深进行了预测,并从改善预应力条件、预注水、加固围岩等方面提出了有关岩爆的防治措施,以减少岩爆的发生概率。  相似文献   
4.
郝攀  刘芳 《山西建筑》2007,33(26):129-130
根据一般拉拔试验的原理,采用反力架、钢筋焊接试验槽、应力环等设备对格栅与粉土间的拉拔试验做了全面的研究。试验过程中综合考虑了不同的含水量和不同的竖向压力对格栅与土体间摩擦系数的影响,从而得出了不同的摩擦系数。  相似文献   
5.
In our globalised, interconnected world the impact of borders on space and people is increasingly debated. This article aims to unpack the complex concept of “thick” and “thin” borders. It builds on the assumption that borders are boundary sets comprised of overlapping geopolitical, sociocultural, economic and biophysical layers and are the outcome of a bordering process. A two-step approach towards the decoding of borders is introduced. Using a planning perspective, the article seeks to explain the various functions of borders, to examine power practices within the bordering process and to ascertain the relational geographies demarcated by different types of boundaries. It illustrates why those cross-border activities which address only the geopolitical dimension of the border tend to fail.  相似文献   
6.
Based on previous findings (Jans, U., Hoigné, J., 1998. Ozone Sci. Eng. 20, 67-87), the activity of activated carbon for the transformation of ozone into *OH radicals including the influence of operational parameters (carbon dose, ozone dose, carbon-type and carbon treatment time) was quantified. The ozone decomposition constant (k(D)) was increased by the presence of activated carbon in the system and depending on the type of activated carbon added, the ratio of the concentrations of *OH radicals and ozone, the R(ct) value ([*OH]/[O3]), was increased by a factor 3-5. The results obtained show that the surface chemical and textural characteristics of the activated carbon determines its activity for the transformation of ozone into *OH radicals. The most efficient carbons in this process are those with high basicity and large surface area. The obtained results show that the interaction between ozone and pyrrol groups present on the surface of activated carbon increase the concentration of O2*- radicals in the system, enhancing ozone transformation into *OH radicals. The activity of activated carbon decreases for extended ozone exposures. This may indicate that activated carbon does not really act as a catalyst but rather as a conventional initiator or promoter for the ozone transformation into *OH radicals. Ozonation of Lake Zurich water ([O3] = 1 mg/L) in presence of activated carbon (0.5 g/L) lead to an increase in the k(D) and R(ct) value by a factor of 10 and 39, respectively, thereby favouring the removal of ozone-resistant contaminants. Moreover, the presence of activated carbon during ozonation of Lake Zurich water led to a 40% reduction in the content of dissolved organic carbon during the first 60 min of treatment. The adsorption of low concentrations of dissolved organic matter (DOM) on activated carbon surfaces did not modify its capacity to initiate/promote ozone transformation into *OH radicals.  相似文献   
7.
为研究我国不同地域边销茯砖茶的香气品质特点,试验选取具有代表性的陕西、湖南和浙江三主产区的边销茯砖茶为研究对象,采用同时蒸馏萃取法结合气质联用(GC-MS:Gas Chromatography-Mass Spectrometer)对其香气成分进行了分析,并结合感官审评初步探明了不同主产区边销茯砖茶的香气特征。三产区边销茯砖茶香气以纯正为主要特点,但陕西茯砖茶带高火香,湖南茯砖茶"菌花香"较明显,浙江茯砖茶略带青气。GC-MS分析结果表明:从陕、湘和浙三产区的边销茯砖茶样品中分别检测出46、56和53种香气成分,共有香气成分45种,主要以醇类、醛类和酮类物质为主,分别占陕、湘和浙边销茯砖茶检出香气总量的65.22%、69.01%和73.22%;含量较高的共有组分有:棕榈酸、植醇、橙花叔醇、6,10,14-三甲基-2-十五烷酮、(E,E)-2,4-庚二烯醛、香叶基丙酮、β-紫罗酮等,其中具高火香的杂环类化合物在陕西茯砖茶中含量较高,与"菌花香"紧密相关的烯醛类物质在湖南茯砖茶中含量最高,具青气味的低级脂肪醛在浙江茯砖茶中含量较高,与感官审评结果一致。  相似文献   
8.
Creating a continental transportation system that supports the efficient movement of goods between Canada and the United States is essential to the economies of both countries. However, 25 years after the passage of the Canada–US Free Trade Act and many agreements and accords later, poor connectivity, congestion and delays still plague many transborder corridors. Recent attempts to improve this situation involving several proposed new bridge projects have either been halted or significantly delayed over the last decade. This paper will review and critically examine the bi-national planning process that has been followed in an attempt to build a new bridge across the Detroit River, known as the Detroit River International Crossing (DRIC) project.  相似文献   
9.
针对图像信息处理机信号进行图像处理,相比于传统的图像预处理技术,提出了一种新的通过阈值去噪及基于八连通域和链码跟踪的边缘检测的图像处理方法,该算法可以进一步改善图像处理效果,提高了边缘检测的质量,有利于后续处理如性能评估等。  相似文献   
10.
TD-LTE网络基于AoA+TA功能的接入控制应用   总被引:1,自引:1,他引:0  
本文论述了在TD-LTE网络中遇见的新问题,即边境优化问题。中国移动TD-LTE网络建设与朝鲜隔江而建,参考丹东边境GSM网络的方法,结合TD-LTE网络自身特点,TD-LTE网络采用宏站小区覆盖朝鲜新义州沿江区域,令宏站小区采用基于位置的接纳控制算法(如Ao A+TA方法等),通过UE距离站点的远近限制朝鲜用户接入TD-LTE网络进行业务。  相似文献   
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