贵州某高速公路顺层岩质边坡稳定性分析与支护措施探讨

随着西部地区大规模工程建设的开展，在施工过程中不可避免的形成了大量的路堑顺层岩质边坡，文章将从地层岩性、岩体结构、工程环境等方面对贵州某高速公路顺层岩质边坡的稳定性进行分析，并结合工程实际提出支护措施，结论对顺层边坡的开挖防护有一定的参考价值。     

向家坝水电站右岸开关站边坡稳定分析与加固设计

向家坝水电站右岸开关站布置于110kV变电站与高程380混凝土生产系统Ⅱ区之间，上下边坡均为顺向到斜向倾外结构。根据地质揭露开关站下部地层中发育三个破碎夹泥层。为保证边坡不发生滑移变形，通过边坡稳定分析结果确定边坡支护参数，使边坡稳定达到工程设计要求。边坡支护设计经验可供类似工程参考。     

机场顺层填方边坡的稳定性在FLAC~(3D)中的分析

山区机场的填方边坡是山区机场建设的主要问题,尤其是顺层边坡的填筑影响最大。文章以贵州某机场13#顺层边坡为例,从斜坡的地质环境入手,分析斜坡的基本特征及变形规律,结合FLAC~(3D)数值模拟,揭示了填筑后的斜坡的破坏机制及其发展过程。     

浅埋粉细砂地层隧道塌方处理施工技术

对锡乌铁路芒罕图隧道出口浅埋粉细砂地层,存在地质偏压施工风险洞段,发生顺层滑塌的原因进行分析,确定了合理的坍塌施工处理技术方案,采用该方案顺利通过浅埋地质偏压、顺层塌方洞段。以期对今后浅埋粉细砂地层地质偏压条件下的隧道施工有所借鉴。     

不同地质条件下顺层岩质滑坡发生机制研究

地震不仅能诱发大型顺层岩质滑坡,也可形成潜在的顺层岩质滑坡灾害点。为探讨实际防治过程中不同发生机制条件下顺层岩质滑坡特点,通过对唐家山滑坡、新磨村滑坡进行影响因素和启动过程分析。结果显示:唐家山滑坡的地质-力学模型为滑动-拉裂-剪断,"锁固段"位于滑床上部。"6·24"新磨村滑坡滑源区的发生机制是滑移-剪断,"锁固段"位于滑床下部。边坡结构对顺层岩质滑坡的启动具有重要地位。滑坡机制的准确认识对于顺层滑坡防治具有十分突出的意义,并且不同类型的顺层岩质滑坡应采用不同的防治方案。     

洪泽县芒硝矿顺2井井下事故浅析

1顺2井地质简况1．1地质资源简介洪泽县芒硝矿顺2井位于江苏省洪泽县西顺河镇朱庄村西北，构造上届洪泽盆地顺河集次凹。钻井揭露的地层有：第四系车台组（酬）、上第三系盐城组（NY）、下第三系三垛组（Es）、戴南组（Ed）和阜宁组四段（Ef），岩性特征及地层厚度见地层简表（表1）。无水芒硝赋存于下第三系阜宁组四段含盐系地层的下盐亚段的第二岩性组合层内，矿床为层状结构，产状平缓，倾角6～10o，无水芒硝为棕黄色、质纯，顶部为灰、灰白色含无水芒硝泥质钙芒硝岩和含云泥岩，上覆为灰白色透明、半透明的岩盐层，底部为发、深灰色含…     

蜀南二里场构造嘉陵江组层序地层学研究

嘉陵江组是川南地区天然气的主要产层,二里场构造嘉陵江组富有勘探开发潜力。本文结合前人研究成果,依靠岩芯和测井曲线分析,划分认识了研究区嘉陵江组的层序和高频层序特征,建立了层序地层格架;通过岩性、物性、电性、含油气性综合解剖了嘉陵江组储层,编制了高频层序格架内的储层对比图,探讨了储层发育与层序地层的关系,指出区内嘉陵江组溶蚀孔隙型储层发育受三级层序及高频层序控制。     

某电站进厂交通洞边坡失稳滑移问题

某电站进厂交通洞边坡由三级边坡两级马道组成,一级边坡采取贴坡砼及锚索支护方式、二三级边坡采取框格梁支护方式,2011年3月份一级边坡开挖基本完成,但贴坡砼及锚索强支护手段未及时跟进,加之汛期降雨较多,边坡出现失稳滑移现象。经研究,最终采取顶部卸荷、底部压坡、加快贴坡砼及锚索张拉速度等措施,工程至今总体运行良好。     

北碚某路基顺层滑坡稳定性分析与治理措施

北碚工业园区的Z3路,其中K0+140～K0+280段处于岩质顺层边坡上部,由于坡脚挡墙基槽的开挖,导致顺向岩层中的软弱夹层处于临空状态,随后该段路基沿软弱夹层发生了下滑,严重影响了工程的建设工作,文章在该滑坡补充勘察工作的基础上,结合岩土体各项物理力学测试指标,对滑坡产生的原因及变形模式进行了分析,对滑坡的稳定性进行了分析计算和评价,提出了相应的工程治理措施及建议。     

接触面参数对挡土墙边坡稳定性的影响分析

为考虑接触面参数对挡土墙边坡稳定性的影响,采用有限元极限分析软件OPTUM G2建立了边坡数值模型,分析了接触面的黏聚力及内摩擦角对挡土墙边坡稳定性的影响规律。研究结果表明,随着接触面黏聚力及内摩擦角的增加,挡土墙边坡的下、上限安全系数都逐渐增加,但是接触面内摩擦角对挡土墙边坡稳定性的影响更大。研究结果可为挡土墙的设计提供一定参考依据。     

Assessment of human stratum corneum thickness and its barrier properties by in-vivo confocal Raman spectroscopy

IFSCC Magazine , 12 (2009) (1) 9–15
Measurement of water concentration profiles across living human skin by confocal Raman spectroscopy has developed into a powerful tool for a better understanding of distribution and function of water in the epidermis. From the water profile across the epidermis the border between stratum corneum and stratum granulosum can be estimated. This is due to the steep drop in water concentration from the inner to the outer side of the stratum corneum. Water content drops from approximately 70% at the inner stratum corneum to only 30% at the skin surface. This slope of the curve becomes clearly flatter in the stratum granulosum. A second parameter is usually taken from confocal Raman spectroscopy to define the stratum corneum border. This is the content of natural moisturization factor (NMF), which should be present only in the stratum corneum. Located at the depth at which the NMF content levels off and the slope of the water profile curve changes is the stratum corneum border. The goal of this work was to develop stratum corneum thickness detection into a robust and semi-automated measurement relying only on the water profile. Further, the aim was to base the empirical findings of water distribution in the epidermis on a well established theory, Fick's law of diffusion. A mathematical model was developed to fit the water profile curve for a robust and automated detection of the stratum corneum border. In addition, the new model automatically resulted in an accurately determined slope of the water concentration curve in the stratum corneum. This slope, or more exactly the gradient, is one of two parameters directly related to transepidermal water transport across the stratum corneum.
Keywords:  Barrier function, Fick's law, Raman spectroscopy, stratum corneum, transepidermal water loss     

三峡库区调味油脂产品中邻苯二甲酸酯类塑化剂的含量测定和分析

目的采用气相色谱-三重四极杆串联质谱法(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)测定三峡库区调味油脂产品中的邻苯二甲酸二正丁酯(dibutyl phthalate,DBP)、邻苯二甲酸二(2-乙基)己酯[bis(2-ethylhexyl)phthalate,DEHP]2种塑化剂的含量,并对污染情况进行分析。方法样品采用乙腈提取,固相萃取(solid-phase extraction,SPE)玻璃小柱净化,氮吹近干后正己烷复溶,经气相色谱-三重四极杆串联质谱法测定。结果DBP、DEHP在一定浓度范围内线性关系良好,相关系数均大于0.998,检出限分别为0.05、0.10 mg/kg,定量限分别为0.17、0.33 mg/kg,平均加标回收率为82.79%~96.70%,相对标准偏差为0.59%~1.76%。在采集的32组调味油脂样品中,DBP的检出率高达68.75%,含量范围在0.15~517.00 mg/kg;DEHP检出率为28.12%,含量范围在0.57~125.00 mg/kg,超标率分别为62.50%和-18.75%。结论三峡库区调味油脂产品中存在一定程度的邻苯二甲酸酯类物质污染,可能与生产、环境等方面的迁移污染相关,需引起重视并进行连续监测。     

基于四节点体温调节模型的睡眠系统舒适性预测

为了优化设计人体睡眠系统,考虑了不同睡眠时期生理参数的差异性,建立并验证了睡眠状态下四节点体温调节模型,预测了核心温度和皮肤温度的变化,探讨了环境温度、被褥热阻及人体与被褥的接触面积3个因素对睡眠人体热舒适性的影响。研究结果表明:核心温度和皮肤温度均随环境温度的升高而上升,但在较低环境温度下处于非快速眼动时期的核心温度几乎不受环境温度的影响;被褥热阻对核心温度的影响不大,皮肤温度随被褥热阻的增大而上升;核心温度和皮肤温度均随人体与被褥接触面积的增大而上升,但核心温度受接触面积的影响较小。此研究结果将为高性能家用纺织品的开发提供科学的参考。     

婴儿被服热舒适性研究进展

为促进婴儿热生理舒适,推动婴儿被服热舒适性测评方法及理论体系的建立,回顾了婴儿被服热舒适性的相关研究,在分析婴儿与环境热传递机制的基础上,讨论了婴儿被服热舒适性的影响因素及测评方法,并根据当前研究现状提出了发展方向。研究表明：婴儿主要依靠传导、对流、辐射显热热交换维持人体热平衡,其体表热传递系数明显大于成人;被服的过高隔热、头部覆盖与俯卧姿势可能造成睡眠时婴儿的热应激反应;目前,婴儿暖体假人被认为是研究被服热舒适性最理想的装置,未来的发展应聚焦于婴儿被服热湿传递过程、使用数值模拟方法研究婴儿体表热传递及建立婴儿体温调节模型等方面。     

浅谈盐卤生产老区定向对接井的施工

在盐矿山生产老区,井下盐层溶腔已经大面积连通,部分顶板出现垮塌,区域内孔隙发育地层已经与盐腔产生通道,因此在这种区域内钻井施工时,极易在盐层顶板附近发生井漏、井涌等突发性事故。罗60井则为一次成功的施工经验。     

Bedding and bedding management practices are associated with mesophilic and thermophilic spore levels in bulk tank raw milk

Mesophilic and thermophilic spore-forming bacteria represent a challenge to the dairy industry, as these bacteria are capable of surviving adverse conditions associated with processing and sanitation and eventually spoil dairy products. The dairy farm environment, including soil, manure, silage, and bedding, has been implicated as a source for spores in raw milk. High levels of spores have previously been isolated from bedding, and different bedding materials have been associated with spore levels in bulk tank (BT) raw milk; however, the effect of different bedding types, bedding management practices, and bedding spore levels on the variance of spore levels in BT raw milk has not been investigated. To this end, farm and bedding management surveys were administered and unused bedding, used bedding, and BT raw milk samples were collected from dairy farms (1 or 2 times per farm) across the United States over 1 yr; the final data set included 182 dairy farms in 18 states. Bedding suspensions and BT raw milk were spore pasteurized (80°C for 12 min), and mesophilic and thermophilic spores were enumerated. Piecewise structural equation modeling analysis was used to determine direct and indirect pathways of association among farm and bedding practices, levels of spores in unused and used bedding, and levels of spores in BT raw milk. Separate models were constructed for mesophilic and thermophilic spore levels. The analyses showed that bedding material had a direct influence on levels of spores in unused and used bedding as well as an indirect association with spore levels in BT raw milk through used bedding spore levels. Specific bedding and farm management practices as well as cow hygiene in the housing area were associated with mesophilic and thermophilic spore levels in unused bedding, used bedding, and BT raw milk. Notably, levels of spores in used bedding were positively related to those in unused bedding, and used bedding spore levels were positively related to those in BT raw milk. The results of this study increase the understanding of the levels and ecology of mesophilic and thermophilic spores in raw milk, emphasize the possible role of bedding as a source of spores on-farm, and present opportunities for dairy producers to reduce spore levels in BT raw milk.     

被服系统热舒适性研究进展

被服系统作为调节人体睡眠舒适性必不可少的产品,比室内环境对睡眠热舒适性的影响更大。为合理评价被服系统的热舒适性能,通过回顾国内外相关研究,从实验研究和舒适性模型研究的角度总结睡眠热舒适性研究中常用的评价方法;基于“人体—被服—环境”系统热湿交换理论,从被服系统热阻、湿阻、被内微气候等被服因素,人体热生理、性别和工作状态差异性等人体因素,环境温度、湿度、风速等环境因素3个角度分析了各类因素对睡眠热舒适性的具体影响;剖析当前研究中的不足和缺陷,展望被服系统睡眠热舒适性的研究趋势。提出建立普遍适用的“人体—被服—环境”系统舒适性模型,以提高对睡眠热舒适性评价的准确性。     

Bacterial counts in organic materials used as free-stall bedding following treatment with a commercial conditioner

An acidic conditioner was tested in recycled manure and sawdust used as free-stall bedding to determine the effect on bacterial counts of common environmental mastitis pathogens. Free stalls were bedded with 10 kg of either kiln-dried sawdust or recycled manure per stall. All bedding was removed and fresh bedding was applied every 7 d. Approximately 1 kg of commercial bedding conditioner containing 93% sodium hydrosulfate (wt/wt) was spread evenly over bedding in the back one-third of each treated stall. Control bedding received no treatment. Cows were bedded on the same material for 3 consecutive weeks. After 3 wk on a bedding treatment, cows remained in the same pens and bedding treatments were changed between rows within pens in a switch back design. The addition of bedding conditioner to sawdust reduced gram-negative bacterial, coliform, Klebsiella spp., and streptococcal counts immediately after application and 1 d after application. Bacterial counts did not differ between treated and untreated sawdust on d 2 and 6 after the conditioner treatment. Each bacterial count measured was reduced in recycled manure immediately after application. Gram-negative bacterial and streptococcal counts were reduced in treated recycled manure compared with untreated recycled manure on d 1 after conditioner was applied. Bacterial counts did not differ between treated and untreated recycled manure bedding on d 2 and 6 after application in free stalls. The antibacterial activity of the conditioner was related to the pH of the bedding and was diminished by d 2 after application in both bedding types.     

Influence of bedding material on ammonia emissions from cattle excreta

Dairy cattle barns are a major source of NH₃ emissions to the atmosphere. Previous studies have shown that the bedding material used in the barn can influence the magnitude of NH₃ emissions, but little is known about which bedding characteristics are important in this respect. The aims of this study were to assess, at a laboratory scale, the relative importance of the chemical [pH, cation exchange capacity (CEC), C:N] and physical (urine absorbance capacity, bulk density) characteristics of 5 bedding materials (chopped wheat straw, sand, pine shavings, chopped newspaper, chopped corn stalks, and recycled manure solids) on NH₃ emissions from dairy cattle urine. Recycled manure solids were the most absorbent of the bedding types (4.2 g of urine/g of bedding), and sand was the least (0.3 g of urine/g of bedding). When beddings were soaked in urine to their absorbance capacities, NH₃ emissions over 48 h (expressed as a proportion of the urine N absorbed) were not significantly different among bedding types, despite differences in initial bedding pH, CEC, and C:N. When equal volumes of urine were applied to equal depths of dry bedding, NH₃ emissions over 48 h were significantly less from sand and pine shavings (23 and 42% of applied urine N, respectively) than from chopped newspaper, chopped corn stalks, and recycled manure solids (62, 68, and 65% of applied urine N, respectively), whereas emissions from chopped wheat straw (55% applied urine N) only differed significantly from that from sand. Differences in the chemical characteristics of the beddings did not explain differences in emission; NH₃ emissions increased linearly with CEC contrary to expectations, and there was no significant relationship with initial bedding pH. The physical characteristics of bedding materials were of more importance, as NH₃ emissions increased linearly with absorbance capacity and decreased as the bulk density of the packed beddings increased.     

Short communication: Bacterial counts in recycled manure solids bedding replaced daily or deep packed in freestalls

An experiment was conducted to compare bacterial counts of mastitis pathogens in deep-packed manure solids bedding with those in manure solids bedding replaced daily from mattresses. Eighteen Holstein cows were housed in 1 pen with 18 stalls. One row of 9 stalls was equipped with mattresses topped with bedding. The back one-third of these stalls toward the alleyway was covered in 25 mm of recycled manure solids, which was removed daily for the next 6 d and replaced with bedding from the brisket board and lunge space areas of stalls. The second row of 9 stalls was bedded for 3 wk with 100 to 150 mm of deep-pack recycled manure bedding from which only fecal matter was removed daily. After 3 wk, bedding treatments were changed between rows in a switchback design. Mean total gram-negative bacterial counts did not differ between treatments throughout the experiment. Coliform and Klebsiella spp. bacterial counts were lower in daily replaced bedding compared with deep pack across the experiment and on each of d 0, 1, 2, and 6. Streptococcal counts were reduced in daily replacement stalls compared with deep-pack stalls on d 0 and greater in daily replacement stalls compared with deep-pack stalls on d 1, 2, and 6. Daily replacement of recycled manure bedding from the back one-third of the stalls appeared to be an effective approach to reducing exposure to coliforms, specifically Klebsiella, but not streptococci. However, bacterial counts in bedding from both treatments were elevated throughout the trial and resulted in considerable risk for exposure to teats and development of intramammary infections.