公路工程临时用电设施永久化利用设计研究

文章在分析公路工程用电特点的基础上,总结了公路工程临时用电设施永久化利用基本设计原则和方法,介绍了其一般设计流程与用电负荷计算方法,并针对工程实际,提出了用电负荷简易估算方法和用电负荷参考值。

腹腔镜直肠癌经括约肌间切除术预防性造口永久化的术前预测因素及模型构建

目的预防性造口永久化会严重影响患者的生活质量。临床医师在进行临床决策时,需要权衡和考虑预防性造口永久化的风险。为方便临床评估,本研究分析腹腔镜直肠癌经括约肌间切除术(LISR)预防性造口永久化的术前预测因素并构建列线图预测模型。方法采取回顾性观察性研究方法,回顾性收集2012年1月至2020年12月期间收治的331例经内镜及病理确诊为原发性低位直肠腺癌、行LISR并行预防性造口患者的临床资料;排除结直肠多原发癌、因肠梗阻或出血或穿孔而行急诊手术者以及未完成18个月的随访者。其中男性258例,女性113例,年龄(58.8±11.2)岁,体质指数(23.7±3.1)kg/m^(2)。通过R软件采用随机抽样的方法,按约7∶3的比例选择234例患者作为建模组,剩余97例患者作为验证组。本组病例均在术前由造口师确定造口部位,选择距离回盲部30 cm的末端回肠行预防性造口。观察全组患者预防性造口永久化的情况,以及可能影响建模组患者预防性造口永久化的术前临床因素。预防性造口永久化的定义为术后18个月时患者预防性造口无法还纳。多因素logistic回归分析LISR预防性造口永久化的术前独立危险因素,采用R软件绘制列线图模型,通过受试者工作特征(ROC)曲线评估列线图模型的预测能力。结果331例LISR患者中,共37例(11.2%)最终预防性造口永久化,其中建模组26例,验证组11例。37例患者无法还纳造口的原因包括:吻合口漏不愈合或吻合口漏导致的狭窄(16例,43.2%)、远处转移(16例,43.2%)、无法耐受二次手术(3例,8.1%)、放射性直肠狭窄(1例,2.7%)和肛门功能恢复不良(1例,2.7%)。建模组单因素分析显示,接受新辅助放化疗、肿瘤低分化、cT3分期以及合并远处转移与预防性造口永久化有关(均P<0.05);多因素logistic分析显示,接受新辅助放化疗(OR=3.078,95%CI:1.326~7.147,P=0.009)、cT3分期(OR=2.257,95%CI:1.001~5.091,P=0.049)以及合并远处转移(OR=16.180,95%CI:2.753~95.102,P=0.002)是预防性造口永久化的独立危险因素。基于筛选出的危险因素成功构建预测低位直肠癌LISR术后预防性造口永久化的列线图模型,ROC曲线下面积为0.793,最佳截断值0.890,灵敏度0.577,特异度0.885;验证组的ROC曲线下面积为0.953。建模组和验证组的校正曲线均展现了较好的拟合度。结论新辅助放化疗、cT3分期以及远处转移是LISR患者预防性造口永久化的术前独立危险因素,本研究构建的列线图模型有助于预测其发生的概率。对于有高危因素行LISR的患者,外科医生术前应充分告知预防性造口不能还纳而致永久化的风险。

预防性造口永久化的危险因素和对策

预防性造口是减少直肠癌术后症状性吻合口漏的有效方法。约1/5的预防性造口存在无法还纳即预防性造口永久化问题,超出医生和患者的预期,值得引起足够的重视和关注。预防性造口永久化的原因比较复杂,主要包括吻合口相关并发症、原发肿瘤进展、围手术期死亡、肛门功能不良和患者意愿等。导致预防性造口永久化可能的因素包括有症状的吻合口漏、患者年龄、肿瘤位置、新辅助治疗、肛门功能、肿瘤TNM分期、美国麻醉医师协会(ASA)评分以及医院因素等;涉及新辅助治疗前、手术前、手术中、手术后及随访期。充分的医患沟通决策、完善的肿瘤评估及患者功能评估、合理的综合治疗策略、细致的手术操作及质量控制和全程细致的围手术期管理等,是避免预防性造口永久化的重要环节。在治疗决策和患者沟通时,须清楚患者的诉求,避免不必要的保肛预期;对预防性造口永久化要充分告知。安全的手术操作、尤其是吻合,是避免预防性造口永久化的关键环节;术后吻合口狭窄的早期发现及干预,值得重视。

PCL公司向全数字化医院提供场外施工方案

新的亨伯河医院是加拿大最先进的全数字化急症护理中心,医院的设计建造者加拿大PCL承包股份有限公司运用虚拟施工技术,选取项目中可以采用场外施工的构件,放到PCL公司PMC生产基地进行预制。通过采用场外解决方案,节省时间并减少现场关键路径工作的物流和人力压力,同时工厂更可控的环境提高了项目的效率和质量。在模块化业务单元里,BIM的应用非常广泛,将工作按份额划分而不是按专业划分,增加了预制潜力。BIM也使车间的过程更加自动化,将模型连接到计算机数控和其他设备上,从而减少错误,提高效率。

高校音乐教育的课程改革——关于增设社区音乐教育人才培养方向的设想

高校音乐教育改革是新时期高等教育发展的要求,也是适应音乐教育自身发展的需要,当下的高校音乐教育改革应从音乐教育的本质及音乐教育的社会功能性入手,探索发展可持续性、广阔性的教育领域。社区是城市的细胞,音乐教育在社区可以拥有极其广阔的基础发展。开展社区音乐教育是发展继续教育、促进学习型社会,从而达到终身教育需求的教学手段,故而提及高校音乐教育改革增设社区音乐教育人才培养方向。通过为社区音乐教育培养人才这一目标,为高校音乐教育改革拓展思路,也为社区夯实音乐教育放大镜的基础,铺就了美育的桥梁。同时为实施全面提高民族文化自信及全民终身教育梳理了途径,也是音乐教育回归教育人性化的一种考量。

Symbiosis of Marshes and Permafrost in Da and Xiao Hinggan Mountains in Northeastern China

Recently, the degradation of permafrost and marsh environments in the Da and Xiao Hinggan Mountains has become a great concern as more human activities and pronounced climate warming were observed during the past 30 years and projected for the near future. The distr/bution patterns and development mechanisms of the permafrost and marshes have been examined both in theories and in field observations, in order to better understand the symbiosis of permafrost and marshes. The permafrost and marshes in the Da and Xiao Hinggan Mountains display discernible zonations in latitude and elevation. The marsh vegetation canopy, litter and peat soil have good thermal insulation properties for the underlying permafrost, resulting in a thermal offset of 3 ℃ to 4℃ and subsequently suppressing soil temperature. In addition, the much higher thermal conductivity of frozen and ice-rich peat in the active layer is conducive to the development or in favor of the protection of permafrost due to the semi-conductor properties of the soils overlying the permafrost. On the other hand, because permafrost is almost impervious, the osmosis of water in marsh soils can be effectively reduced, timely providing water supplies for helophytes growth or germination in spring. In the Da and Xiao Hinggan Mountains, the permafrost degradation has been accelerating due to the marked climate warming, ever increasing human activities, and the resultant eco-environmental changes. Since the permafrost and marsh environments are symbiotic and interdependent, they need to be managed or protected in a well-coordinated and integrated way.

Thermal state of soils in the active layer and underlain permafrost at the kilometer post 304 site along the China-Russia Crude Oil Pipeline

On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafrost regions.Significant thaw subsidence of ground surfaces along the ChinaRussia Crude Oil Pipeline(CRCOP) from Mo'he to Daqing,Heilongjiang Province,Northeast China have been observed at some segments underlain by ice-rich warm(>1.0°C) permafrost since the official operation in January 2011.Recent monitoring results of the thermal states of foundation soils at the kilometer post(KP) 304 site along the CRCOP are presented in this paper.The results indicate that during the period from 2012 to 2014,shallow soils(at the depths from0.8 to 4.0 m from ground surface) has warmed by approximately 1.0°C in the lateral range of 1.2 to 2.1 maway from the pipeline axis,and deeper permafrost(such as at the depth of 15 m,or the depth of zero annual amplitude of ground temperatures) by 0.08°C per year 4 m away from the pipe axis,and 0.07°C per year 5 m away from the pipeline axis.The results indicate an all-season talik has developed around and along the CRCOP.The thaw bulb,with a faster lateral expansion(compared with the vertical growth),enlarges in summer and shrinks in winter.This research will provide important references and bases for evaluating thermal influences of warm pipeline on permafrost and for design,construction,operation and maintenance of pipelines in permafrost regions.

Adaptability of Permanent Grassland to Drought

Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.

An Assessment of the Groundwater Potential of Bayero University Kano Permanent Site Using Induced Polarization and Self-potential Methods

This paper centers on the investigation of the subsurface condition of Bayero University Kano Permanent Site with the aim of understanding the lithology and also mapping out the groundwater patterns within the area. To achieve this, time domain IP （induced polarization） and SP （self-potential） methods were adopted using VES （vertical electrical sounding） technique with 49 stations sounded. The result of the interpreted and analyzed measured data shows that the area is underlain by two to five subsurface layers. These layers are top soil, laterite, weathered basement complex rocks, fractured basement complex rocks and fresh basement complex rocks. The aquiferous zone of the study area occurs in the weathered and fractured basements and its thickness ranges from 1.44 m to 70.157 m while the overburden thickness lies between 1.6 m and 72.104 m. SP values were plotted against depths of investigation in order to identify areas with greater depth of flow in the study area. From the analysis of the overburden thickness, aquifer thickness and SP values, the most favorable regions for groundwater exploitation were found around VES 6, 11, 13, 19, 26, 38, 44 and 48. The investigation also provides information about the subsurface condition with regards to engineering construction and safe place for refuse dumping in order to avoid groundwater contamination.

Microbiota of Fossil Animals Preserved in Yakut Permafrost

Microbiological investigation of the fossil animals preserved in permafrost represents obvious interest for science. Lack of data in this sphere gives even greater importance to any findings giving us opportunity to learn more about remote past of microorganisms. In this respect, preserved remains of fossil are considered as unique biological materials for scientific investigations. Bacillus bacteria strains isolated from the paleomicrobiota of mammoth fauna are not only have high durability （20-30 thousand of years） in permafrost, but are still able to produce biologically active substances. Strains of bacteria of the genus Bacillus, isolated from the tissues of the representatives of the mammoth fauna have strong antagonistic properties to hemolytic streptococci--Streptococcus equi, pathogenic for animals--Salmonella abortus equi, also toxigenic micromycetes genera Aspergillus, Alternuria, Penicillum and fungal pathogens of plant diseases--Botrytis cimeria and Fuzarium oxysporium. The strains of bacteria of the genus Bacillus are not pathogenic to plants and animals, but initially resistant to wide range of antibiotics. Dominance strains of Bacillus bacteria, producing strong bacteriocins in the soft tissues of fossil animals, contributing to their long cryo bio conservation. In addition, bacterial strains of Bacillus subtilis, isolated from paleo microbiota have strong oxidizing properties. Microbiota of fossils preserved in permafrost of Yakutia is of particular interest for microbiology and modem biotechnology.

Perpetual Professor： Changing Patterns of Faculty-Student Interaction in the Twenty-First Century

Current communication technologies have provided new modalities for students to contact professors outside of the normal office settings and regulated office hours traditionally found in higher education. This study concentrates on the faculty perceptions of how the usage of e-mail and cell phones has changed interactions with students over the past decade. General levels of usage are analyzed as well as correlation to curricular disciplines, An online survey of faculty members at Indiana University of Pennsylvania found maior changes in the type and frequency of contact between professors and students as well as a shift from personal contact to e-mail and telephone usage. The expanded level of communication opportunities has placed faculty in the position of having to extend direct student-oriented time outside of the classroom, while continuing to maintain academic scholarship and other professional responsibilities.

The Degradation and Pollution of Soils on the Territory of the Kovykta Gas Condensate Field

In this paper, research results from the time interval 2002-2012 are used to give an account of the chemical composition of soils on the territory of the Kovykta gas condensate field. The findings presented provide a better understanding of the ecological state of soil cover, its resilience to anthropogenic impacts, and its possible disturbance caused by the drilling pad construction activity, and by the laying of geophysical profiles. An analysis of soil pollution for the study territory generally showed that the soils are polluted with chemical elements which refer to toxicity classes： Pb, Cu, Ni, Cr, Ba and Mn. High levels ofoil products were detected near boreholes. Strong mineralization was recorded in the soil near borehole. It has a chloride-sodium chemical composition. As a result of the construction of foundation pits, recesses, ditches and earth embankments, the soil is totally destroyed, and rock outcrops show up. Disturbances of the sod cover due to road construction or even by all-terrain vehicles in these extreme conditions entail an accelerated development of linear erosion to form scours and gullies. Elimination of the canopy layer leads to an increase in surface heating, and to an acceleration of permafrost thawing. Swamping is accelerated on negative relief forms due to the increased entry of melt waters.

Optimal Design of Electromagnetic Acoustic Transducer

This paper considers the design of EMAT （Electro-Magnetic Acoustic Transducer） based on numerical simulation. The EMAT consists of an exiting coil and two permanent magnets, which transmits the ultrasonic wave by the Lorentz force between the eddy current and the static magnetic field by the magnets. From the experimental result on self-prepared EMATs, the intensity and the directivity of the transmitted wave depend on the widths of the coil and the magnets. By means of EEM analysis the authors attempt to determine the optimal values of the above widths such that both the intensity and the directivity achieve the maximum or allowable performance.

Geochemistry and genesis of authigenic pyrite from gas hydrate accumulation system in the Qilian Mountain permafrost, Qinghai, northwest China

A type of authigenic pyrites that fully fill or semi-fill the rock fractures of drillholes with gas hydrate anomalies are found in the Qilian Mountain permafrost; this type of pyrite is known as ＂fracture-filling＂ pyrite. The occurrence of ＂fracture-filling＂ pyrite has a certain similarity with that of the hydrate found in this region, and the pyrite is generally concentrated in the lower part of the hydrate layer or the hydrate anomaly layer. The morphology, trace elements, rare earth elements, and sulfur isotope analyses of samples from drillhole DK-6 indicate that the ＂fracture-filling＂ pyrites are dominated by cubic ones mainly aligned in a step-like fashion along the surfaces of rock fractures and are associated with a circular structure, lower Co/Ni and Sr/Ba, lower ZREE, higher LREE, significant Eu negative anomalies, and 634ScDT positive bias. In terms of the pyrites＇ unique crys- tal morphology and geochemical characteristics and their relationship with the hydrate layers or abnormal layers, they are closely related with the accumulation system of the gas hydrate in the Qilian Mountain permafrost. As climate change is an important factor in affecting the stability of the gas hydrate, formation of fracture-filling pyrites is most likely closely related to the secondary change of the metastable gas hydrate under the regional climate warming. The distribution intensity of these py- rites indicates that when the gas hydrate stability zone （GHSZ） is narrowing, the hydrate decomposition at the bottom of the GHSZ is stronger than that at the top of the GHSZ, whereas the hydrate decomposition within the GHSZ is relatively weak. Thus, the zone between the shallowest and the deepest distribution of the fracture-filling pyrite recorded the largest possible original GHSZ.