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61.
安静 《水利与建筑工程学报》2017,15(1)
针对泥岩隧道的特殊性,通过优化光面爆破的爆破参数,讨论泥岩隧道掘进的经济性、安全性。采用预埋振速传感器监测的方式,分析光面爆破对隧道周围岩体的扰动。现场光爆技术应用效果显著,隧道开挖轮廓线内基本未出现超欠挖现象,半孔率达86%以上,爆破进尺提升约15%,孔痕长度基本均匀分布一般都在孔长的66%以上;萨道夫斯基公式的系数K衰减明显、α基本稳定,光爆的振动速度和围岩扰动都得到了有效控制。 相似文献
62.
原盐洗涤工艺在精盐水制备中的应用 总被引:2,自引:0,他引:2
针对当前原盐中因Mg^2 、Ca^2 及泥沙含量较大而严重影响生产的实际情况,介绍了1种简单易行的原盐洗涤工艺。 相似文献
63.
介绍了锦化化工(集团)有限责任公司提高二次精制盐水质量的成功经验,讨论了过滤系统中碳素烧结管间距、一次盐水的质量及其游离氯含量、人为操作失误和助体给料量等五大因素对二次精制盐水质量的影响,并采取了相应的措施,如调整合适的碳素烧结管间距、改走砂滤器、更换过滤器碳素管等。介绍了二次精制盐水精制系统树脂塔精制盐水的操作要素,诸如控制盐水流量最高为68m3/h、温度在(60±5)℃、pH值在9左右,控制树脂塔的压差、树脂填充量、树脂性能、仪表阀的检查情况等,从而生产出高质量的二次精制盐水,保证了离子膜电解槽的平稳、高效运行。 相似文献
64.
节理化岩体力学参数是矿山工程地质和稳定性分析的重要基础数据,一般在实验室通过单轴、三轴试验只能得到岩石的力学参数,无法得到岩体的力学参数。目前,利用岩石力学参数确定岩体力学参数的方法较多,但都过于烦琐或准确度不高,急需一种新的简易确定方法。因此,通过利用基于广义Hoek-Brown准则的地质强度指标(GSI法),并结合相应的岩土分析软件,强度折剪岩石力学参数值,从而得到岩体的力学参数。通过将该方法应用于赤峰中色白音诺尔矿业有限公司岩体力学参数的计算中,证明采用该方法考虑岩体的结构面和完整性,可较为准确地反映节理化岩体的力学特性,且方便可行,具有工程实用价值。? 相似文献
65.
SSS Rajan 《Nutrient Cycling in Agroecosystems》1986,8(3):219-229
Four greenhouse experiments were conducted using three soils to determine the availability to plants of P from unground North Carolina phosphate rock (PR) treated with 20% to 50% of the H3PO4 required for complete acidulation. The influences of soil P retention, P status, the method of preparation of partially acidulated phosphate rocks (PAPRs) and the granule size of the products were investigated. Perennial ryegrass was grown as the test plant for up to 8 months. Triple superphosphate (TSP) was used as the standard fertilizer and unground North Carolina rock was included for comparison.The dry matter yield and P uptake response curves showed that in all experiments PAPRs were markedly superior to the PR. P status of soils appeared to influence the effectiveness of PAPRs to a greater extent than P retention. In soils of low P status the degree of acidulation required for PAPR to be nearly or as effective as TSP was 50% whereas in a soil of high P status even 30% PAPR applied as a maintenance fertilizer was effective. There was a significant positive correlation between water soluble P of fertilizers and P uptake by ryegrass. However, in general PAPRs were more effective per unit of water soluble P than TSP. Granule size (< 1 mm and 1–2 mm) and method of preparation of PAPRs did not alter the effectiveness of PAPRs. 相似文献
66.
为了合理判别软弱破碎围岩隧道的二衬施作时机,结合工程实践,通过洞室拱顶沉降和边墙变形收敛的现场监控量测,提出了利用围岩-初支系统变形实测数据判别软弱破碎围岩隧道二衬施作合理时机的考虑支护是否保守的五级速率比值法并研发了相应的软件,并通过工程实例进行了成功验证。研究表明:1研制的软件操作具有界面简洁、友好,以及操作简单易用的特点,具有测点围岩-初支系统位移和收敛的现场监测数据的录入、储存、修改和管理等功能,能方便地进行软弱破碎围岩隧道的二衬合理时机判别;2通过工程实例验证分析表明,提出的方法是可行的,与现行的二衬时机选择的方法本质上是相同的,但更加具有可操作性,研究成果可以为同类型隧道的二衬时机选择提供可资借鉴的方法。 相似文献
67.
十二烷基苯磺酸钠水溶液聚集性质的研究 总被引:8,自引:0,他引:8
用滴体积法测出十二烷基苯磺酸钠(SDBS)稀水溶液的表面张力;然后求出其临界胶束浓度(CMC)。同时通过溶液的电导率、吸收光谱以及荧光光谱测定求出其CMC。这样测出的CMC值为1.2~1.6×10-3mol/L,与文献值相符。也研究了部分水解的聚丙烯酰胺(PHPAM)对SDBS聚集性质的影响;发现SDBS的CMC值随PHPAM的加人而减少并且PHPAM水溶液的粘度随SDBS的存在而急剧降低(类似盐效应)。这些方法与性质对强化采油(EOR)是重要的。 相似文献
68.
The agronomic effectiveness of P fertilizers, as sources of phosphorus for crops, was evaluated using the quantities, Pf, of phosphorus taken up byLolium perenne grown on 14 soils during greenhouse experiments in pot cultures. The Pf quantities were determined using32P-labelled fertilizers. Data were analysed using a new concept: the Isotopic Relative Agronomic Effectiveness (IRAE). The IRAE value was defined as the ratio of the Pf quantity, taken up by a crop, of a tested fertilizer over the Pf quantity, taken up by a crop, of a fertilizer used as standard. In our experiments diammonium phosphate (DAP) was used as standard P fertilizer and two rock phosphates, the North Carolina rock phosphate (NCPR) and a calcium-iron-aluminium phosphate (Phospal), were tested. As a linear relationship between Pf(NCPR) quantities and Pf(DAP) quantities was obtained, with r2 = 0.95, when the application rates increased from 15 mgP (kg soil)–1 to 200 mgP (kg soil)–1, it is conciuded that IRAE values for a given fertilizer, other than the standard fertilizer, could be determined with a single rate of application. As regards soil pH in the range 4.7 to 8.2 the IRAENCPR is related to soil pH by a curvilinear relationship: log IRAENCPR = –(0.44) pH + 4.05 with r2 = 0.89. The average of IRAEphospal values was 0.15 with a standard error = 7% irrespective of soil pH. Then a logarithmic relationship was obtained between IRAE values of the two tested fertilizers and their water P-solubility determined at the soil pH where they were applied. 相似文献
69.
Jianfeng Wu Jian Li Xiaohong Xu Lanfang Yang Jufang Wu Fang Zhao Chuanguo Li 《武汉理工大学学报(材料科学英文版)》2009,24(4):651-653
A new type of high temperature energy storage material was obtained through the melt infiltration method, using compounding
SiC ceramic foam as matrix and Na2SO4 as phase change material. The resulting composite material was measured by XRD, SEM, TG-DSC methods. The experimental results
indicate that the composite is composed of silicon carbide, sodium sulfate and square quartz, and no chemical reactions occurs
between Na2SO4 and SiC matrix. Na2SO4 has a good bonding with the SiC ceramic foam matrix. As the composite material is characterized by high thermal energy storage
density and high thermal conductivity, it is suit for energy storage under high temperature.
Funded by the “863” Hi-Tech Research and Development Program of China (2008AA05Z418) 相似文献
70.
The zonal disintegration phenomenon (ZDP) is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plas-tic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass. 相似文献