全盖挖法地铁车站基坑及周边变形规律研究

研究目的:西安地铁3号线胡家庙地铁车站因周边情况复杂,故采用全盖挖顺作法施工。本文以西安地铁3号线胡家庙地铁全盖挖车站深基坑工程为背景,对地铁车站的围护结构、周边地表以及邻近构筑物的变形影响进行研究。本工程的设计及其监测结果可为全盖挖地铁深基坑工程的信息化施工提供一定的依据。研究结论:(1)设计的"围护桩+钢支撑+军便梁"支护结构体系在抑制基坑变形方面起到了很好的效果,方案选取合理可行;(2)对临近基坑边缘的长乐桥而言,对桥桩的注浆加固措施合理可行,保证了交通正常运行;(3)通过对全盖挖地铁车站运用FLAC3D进行模拟,模拟结果与监测结果基本一致,验证了计算结果的正确性;(4)本研究成果可为黄土地区其他全盖挖地铁车站深基坑的施工提供借鉴。

棉花全盖育苗的壮苗早发和后续效应研究

四川棉区受丘陵粮（油）棉两熟制雨养栽培条件的限制，棉苗移栽后入夏前由于自然有效热量不足，两苗期阶段日数偏长，不利壮苗早发、早熟优质高产。总结应用棉田地膜覆盖增温保水补偿原理和生物学效应演变规律，从开发利用春季热量、实施安全快速培育适龄棉苗出发，通过苗床延长盖膜日数，增地温促发根发苗，以壮促早、缩短苗期、调节和提高棉株最佳开花结铃数和比率。据试验示范验证，全盖育苗的壮苗早发效应突出，移栽的后续效应明显，对于实施节本促早调节栽培，具有较大的实用意义。

棉花“全盖育苗”效果与操作技术

棉花“全盖育苗”效果与操作技术王兆信，闫建平，李琼英，王远高（四川省农科院棉花所简阳６４１４００）一、作用与效果棉花育苗是缓解我省棉田粮棉两熟栽培季节重叠矛盾的有效途径，也是实施棉花“迟中争早”调节栽培的关键措施。但因６月前自然有效热量不足而导致苗期...

全盖挖逆作法地铁车站永久钢管柱施工关键技术

随着我国经济社会的快速发展,加大了现代化城市的建设力度,积极开展全盖挖逆作法施工工艺,结合各地区城市的建设要求与发展需求综合分析,确保整体施工结构的稳定性与安全性,选择竖向支撑受力体系。而钢管柱位置的选择,对相关工作人员提出了更高的要求,应具备专业水平的同时,有较强的工作经验,严格按照相关标准制度规范性地开展具体工作,确保工作项目的施工质量与效率。但是在实际施工的过程中,还是会受到不同因素的影响而引发事故,最常见的问题就是立柱中心偏离,对此,需要提高重视度,明确立柱的重要作用,在实施的过程中避免其发生偏移,也是全盖挖逆作法施工工艺中的难点工作。本文结合武汉地铁7号线徐家棚站实例,重点介绍全盖挖逆作法施工的地铁车站永久钢管柱桩基施工、定位器的安装、钢管柱的吊装和固定、钢管柱内混凝土灌注、管外填砂等施工关键技术,希望能够为相关施工人员提供可参考意见,进而确保施工质量,为我国地铁车站的更好运行提供全面保障,不断推动社会经济稳定有序发展。

盖挖法车站中柱上浮处理技术方案的研究

结合深圳地铁某车站全盖挖逆作法车站中柱施工案例,研究介绍盖挖逆作法施工过程中中柱出现上浮质量缺陷时的处理技术方案。主要包括对地层条件的判断、中柱施工工艺、中柱桩基成桩质量以及可选择的处理方案等方面。实践表明,中柱上浮处理方案取得了良好效果,承载能力及施工质量均满足各方设计要求,为后续地铁施工提供参考。

Design and Realization of Simple Intelligent Robotic Lawn Mower Based on Arduino Mega2560

Robotic lawn mowers available in markets are much more complicated with high cost, hence, a new robot is designed in the research. In detail, the control system is made up of Arduino Mega2560 and 11 sensors and the robot works with four wheels （two front and back wheels） driven by an electric motor. Furthermore, the platform of lawn-mowing is designed semicircle, equipped with three small high- speed and low-power electric motors; the cutting distance is determined by width of motherboard. In addition, the hardware of the system is made up of circuit control and working machines, of which the former includes a single chip unit, a wireless remote control, a sensor unit, an infrared array module, a driving module of electric motor, a display unit and a power source; the latter includes a mowing platform and a sensor window. In addition, the related software is programmed using C language and modular programming involving PWM program, Hall sensor program, liquid-crys- tal display, tilt program, supersonic sounding program, infrared obstacle-avoidance program, parking program, and remote control program. After hardware was adjust- ed, the robotic lawn mower was tested for multiple times in a standard lawn, and a satisfied effect was achieved.

市政隧道半明挖半盖挖支护体系设计研究

城市地下空间的开发利用,使得市政工程建设中隧道盖挖施工工程越来越普遍。其中半明挖半盖挖施工相比全盖挖法和明挖法而言,具有其显著的优势。通过对半明挖半盖挖支护体系设计的介绍,指出半明挖半盖挖施工既可确保车辆通行又可通过明挖部分进行材料倒运及混凝土浇筑,该工法既缓解施工空间和作业空间狭小问题,又提高工作效率,缩短施工周期,还节省投资,是值得推广的施工方法。

Study on Pesticide Residues of Phorate and Emamectin Benzoate in Cauliflower with Ball Well Protected

In order to study the difference between cauliflower varieties with ball well protected and unprotected in terms of pesticide residue and its causes, Jinpin 70, a new male sterile cauliflower variety with ball well protected, and Xuebao with ball unprotected were sprayed with high-toxic pesticide phorate and efficient bio-pesticide emamectin benzoate at a regular dose to investigate the impact of different cauliflower varieties on the pesticide residue. The results showed that from the 3rd to the 5th day after spraying, phorate and emamectin benzoate residues in Jinpin 70 with ball well protected reduced by 76.47%-87.65% and 67.86%-80.82% re- spectively compared with Xubao, and decreased by 9.23%-81.82% and 57.14%- 79.84% respectively compared with Jinpin 70 with ball unprotected. The results above demonstrates that inner leaves of cauliflower with ball well protected can prevent the ball from being polluted by phorate and emamectin benzoate, thereby improving its edible safety.

地铁换乘节点站基坑开挖施工技术

昆明机场轨道交通6号线塘子巷站是一个换乘站,由于设立在人口流动性大且建筑物密集的市中心地段,不免会加大整体施工难度。为了尽可能减小基坑开挖对周边环境的影响,保证开挖的稳定性及减小节点站两侧基坑开挖对建成节点站的影响,经实地勘察与全面研究后,初步制订了基坑开挖施工方案,其中车站基坑采用半盖挖法和全盖挖法两种基坑开挖技术,对于换乘节点两侧采用对称开挖方法,采取了相应的围护措施,以从源头上增强基坑稳定性,成功且迅速地完成该复杂换乘节点地铁站的施工。

阀控电池结构设计与节能环保包装

采用斜槽式电池盖,取消提手,使螺栓置于斜槽内。采用全盖式纸箱包装,取消泡沫垫,实现环保、节能、降低成本的目标。

Endoscopic ultrasound-guided biliary drainage with placement of a fully covered metal stent for malignant biliary obstruction

AIM:To determine the utility of endoscopic ultrasoundguided biliary drainage(EUS-BD)with a fully covered self-expandable metal stent for managing malignant biliary stricture. METHODS:We collected data from 13 patients who presented with malignant biliary obstruction and underwent EUS-BD with a nitinol fully covered selfexpandable metal stent when endoscopic retrograde cholangiopancreatography(ERCP)fails.EUS-guided choledochoduodenostomy(EUS-CD)and EUS-guided hepaticogastrostomy(EUS-HG)was performed in 9 patients and 4 patients,respectively. RESULTS:The technical and functional success rate was 92.3%(12/13)and 91.7%(11/12),respectively. Using an intrahepatic approach(EUS-HG,n=4),there was mild peritonitis(n=1)and migration of the metal stent to the stomach(n=1).With an extrahepatic approach(EUS-CD,n=10),there was pneumoperitoneum(n=2),migration(n=2),and mild peritonitis (n=1).All patients were managed conservatively with antibiotics.During follow-up(range,1-12 mo),there was re-intervention(4/13 cases,30.7%)necessitated by stent migration(n=2)and stent occlusion(n=2). CONCLUSION:EUS-BD with a nitinol fully covered self-expandable metal stent may be a feasible and effective treatment option in patients with malignant biliary obstruction when ERCP fails.

Endoscopic ultrasound-guided choledochoduodenostomies with fully covered self-expandable metallic stents

AIM:To investigate the long-term outcomes of endoscopic ultrasound-guided choledochoduodenostomy(EUS-CDS) with a fully covered self-expandable metallic stent(FCSEMS).METHODS:From April 2009 to August 2010,15 patients with distal malignant biliary obstructions who were candidates for alternative techniques for biliary decompression due to a failed endoscopic retrograde cholangiopancreatography(ERCP) were included.These 15 patients consisted of 8 men and 7 women and had a median age of 61 years(range:30-91 years).The underlying causes of the distal malignant biliary obstruction were pancreatic cancer(n = 9),ampulla of Vater cancer(n = 2),renal cell carcinoma(n = 1),advanced gastric cancer(n = 1),lymphoma(n = 1),and duodenal cancer(n = 1).RESULTS:The technical success rate of EUS-CDS with an FCSEMS was 86.7%(13/15),and functional success was achieved in 100%(13/13) of those cases.In two patients,the EUS-CDS failed because an FCSEMS with a delivery device could not be passed into the common bile duct.The mean duration of stent patency was 264 d.Early adverse events developed in three patients(3/13,23.1%),including self-limited pneumoperitoneum in two patients and cholangitis requiring stent reposition in one patient.During the follow-up period(median:186 d,range:52-388 d),distal stent migration occurred in four patients(4/13,30.8%).In 3 patients,the FCSEMS could be reinserted through the existing choledochoduodenal fistula tract.CONCLUSION:EUS-CDS with an FCSEMS is technically feasible and can lead to effective palliation of distal malignant biliary obstructions after failed ERCP.

Calculation of slope-cover height under price fluctuation in open-pit mines

Leaving ditches between adjacent mining areas can effectively reduce re-stripping in the latter mining area and simultaneously lead to an increment in internal dumping costs in the former mining area. This paper establishes calculation models for these two marginal costs. The optimizing model for slope cover height can be determined by including marginal cost models in the objective function. The paper has two main contributions:(a) it fully considers redistribution of dumping space in the model;(b) it introduces price fluctuations and cash discounts in the model. We use the typical open-pit mine as an example to test and prove the model. We conclude that a completely covered slope is reasonable in Haerwusu open pit mine; in addition to an increasing price index, the slope cover height can be reduced; and that price changes are one of the most important influencing factors of slope cover height optimization in an open-pit mine.

An Artificial Neural Network-Based Snow Cover Predictive Modeling in the Higher Himalayas

With trends indicating increase in temperature and decrease in winter precipitation, a significant negative trend in snow-covered areas has been identified in the last decade in the Himalayas. This requires a quantitative analysis of the snow cover in the higher Himalayas. In this study, a nonlinear autoregressive exogenous model, an artificial neural network （ANN）, was deployed to predict the snow cover in the Kaligandaki river basin for the next 30 years. Observed climatic data, and snow covered area was used to train and test the model that captures the gross features of snow under the current climate scenario. The range of the likely effects of climate change on seasonal snow was assessed in the Himalayas using downscaled temperature and precipitation change projection from - HadCM3, a global circulation model to project future climate scenario, under the AIB emission scenario, which describes a future world of very rapid economic growth with balance use between fossil and non-fossil energy sources. The results show that there is a reduction of 9% to 46% of snow cover in different elevation zones during the considered time period, i.e., 2Oll to 2040. The 4700 m to 52oo m elevation zone is the most affected area and the area higher than 5200 m is the least affected. Overall, however, it is clear from the analysis that seasonal snow in the Kaligandaki basin is likely to be subject to substantialchanges due to the impact of climate change.

Coverage Probability Analysis for Full-Duplex Relay Aided Device-to-Device Communications Networks

The coverage probability of both the cellular users and the Device-to-Device(D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station(BS) either by relying on the assistance of Full-Duplex(FD) mode relays or via direct user-to-BS links with high-enough Signal-to-Interference-plus-Noise-Ratio(SINR). Note that the FD-mode devices are capable of simultaneously operating in two modes,i.e. the D2D mode and the cooperative relay mode,with the sum power consumption at these devices kept constant. The closedform expressions for coverage probability of both tier users are derived. After that,numerical analyses are provided,showing that the coverage probability of the both the cellular and the D2D users can be substantially influenced by a variety of parameters,including the power allocation factor of the relays,the density of users,and the self-interference imposed on the FD mode relays,etc. Furthermore,in the D2D enabled networks,it is shown that the FD relay aided transmission is beneficial to enhancing the coverage probability of the cellular users if the target SINR is lower than 5 d B.

Challenges faced by community health nurses to achieve universal health coverage in Myanmar:A mixed methods study

Objective:This study aimed to identify the challenges of community health nurses(CHNs)in delivering effective community health care to achieve universal health coverage(UHC)in Myanmar.Methods:A total of 30 CHNs from township health centers in the northeastern,southern,and western parts of Myanmar were purposefully recruited for quantitative and qualitative interviews.Quantitative data were processed using Microsoft Excel software,and qualitative data were analyzed using thematic analysis.This study is registered with researchregistry6201.Results:Around the country,30 CHNs uncovered their hardships in implementing primary health care to achieve UHC.Over 90%of the participants agreed to the problem of inadequate health infrastructure,while half of them felt unmotivated when they encountered role conflicts among various cadres of healthcare providers and poor opportunities for career promotion.Major problems arose from the lack of standard professional education at the entry point to community settings because most CHNs did not achieve specialized training in providing public health services.Complications are incapable of evaluating health services for policy-making and the inability to conduct health research to develop evidencebased practices.Insecure work and living conditions,unsupportive community relationships,and undereducation in professional practices were supportive major themes explored by CHNs to achieve a deeper understanding of the barriers to UHC.Not only the health system itself but also the population and other geographical factors have contributed to many challenges to CHNs.Conclusion:Myanmar’s CHNs face many challenges in achieving UHC.These challenges are not confined to the health sector.Some situations,such as geographical barriers and transportation problems,remain persistent challenges for healthcare providers.This study highlights the fact that current health systems should be strengthened by qualified healthcare providers and sufficient infrastructure.Meanwhile,public empowerment plays a critical role in promoting health development.

Set (k, n)-Exactly covering problem

With the （ k, n ）-threshold scheme of secret sharing in the field of information security technology as an application background, the concept of set （ k, n ）-exact cover is presented in this paper. It is a modification of the original concept of set covering problem. It is also different from the concept of exact cover defined by J.E. Hopcmft. Some properties of （k, n ） -exact cover are investigated; a sufficient condition for a set to be （ k, n ） -exactly coverable is given. It follows that a feasible assignment scheme of a set for the （ k, n） -exact eover is obtained if this set satisfies the sufficient condition.

Land Use Changes in Northeast China Driven by Human Activities and Climatic Variation

Human-induced land use/cover change (LUCC) forms an important component of global environmental change. Therefore, it is important to study land use/cover and its change at local, regional and global scales. In this paper we conducted the study of land use change in Northeast China, one of the most important agricultural zones of the nation. From 1986 to 2000, according to the study results obtained from Landsat images, widespread changes in land use/cover took place in the study area. Grassland, marsh, water body and woodland decreased by 9864, 3973, 1367 and 10,052km2, respectively. By comparison, paddy field, dry farmland, and built-up land expanded by 7339, 17193 and 700km2, respectively. Those changes bore an interactive relationship with the environment, especially climate change. On the one hand, climate warming created a potential environment for grassland and marsh to be changed to farmland as more crops could thrive in the warmer climate, and for dry farmland to paddy field. On the other hand, the changed surface cover modified the local climate. Those changes, in turn, have adversely influenced the local environment by accelerating land degradation. In terms of socio-economic driving forces, population augment, regional economic development, and national and provincial policies were confirmed as main driving factors for land use change.

飘雪的日子很美

漫天飞舞的雪花天使般曼舞着扑向大地,世界变得银装素裹。在我的记忆中,儿时的冬天特别冷,雪也格外大,有时一下就是一夜。第二天睁开眼睛,窗子上一片洁白,用手捂开一看,家家户户的茅草房全盖在雪里了。

Minimum Coverings of Complete Directed Graphs with Odd Size Circuits

Let DKv denote the symmetric complete directed graph with v vertices, the covering number C(v,m) is a minimum number of covering DKv by m-circuits. In this paper, C(v,m) is determined for any fixed odd positive integer m and positive integer v, m ≤ v ≤ m + 6.