Complete laparoscopic resection of the rectum using natural orifice specimen extraction

AIM: To investigate how complete laparoscopic anterior resection with natural orifice specimen extraction (NOSE), as a novel minimally invasive surgery, compares to conventional laparoscopic surgery.

Design and feasibility analysis of a new completion monitoring technical scheme for natural gas hydrate production tests

As a prerequisite and a guarantee for safe and efficient natural gas hydrates(NGHs)exploitation,it is imperative to effectively determine the mechanical properties of NGHs reservoirs and clarify the law of the change in the mechanical properties with the dissociation of NGHs during NGHs production tests by depressurization.Based on the development of Japan’s two offshore NGHs production tests in vertical wells,this study innovatively proposed a new subsea communication technology-accurate directional connection using a wet-mate connector.This helps to overcome the technical barrier to the communication between the upper and lower completion of offshore wells.Using this new communication technology,this study explored and designed a mechanical monitoring scheme for lower completion(sand screens).This scheme can be used to monitor the tensile stress and radial compressive stress of sand screens caused by NGHs reservoirs in real time,thus promoting the technical development for the rapid assessment and real-time feedback of the in-situ mechanical response of NGHs reservoirs during offshore NGHs production tests by depressurization.

Passability test and simulation of sand control string with natural gas hydrates completion in large curvature hole

To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation.

An Analysis of the Origin of the Interaction Force between Electric Charges, including Justification of the ln<i>r</i>Term in the Completed Coulomb’s Law, in HM16 Ether

In this study, we demonstrate the correctness of our 2010 hypothesis regarding the need to complete Coulomb’s FC law with the term lnr, resulting in the completed FCC force. For this purpose, we consider the electrical interactions between charged microparticles (MPs), which develop as fundamental vibrations (FVs) in ether, producing the vibrational strains &epsilon;and &gamma;and the resulting stresses &sigma;and &tau;, as percussions of ether cells (ECs) upon the MP surface. The stresses &sigma;?and?&tau;produce a resultant force FP, due to the percussions which constitute the real electric force FCC. The spatial effect of ether on FP is demonstrated by an analytical method, considering the electrical interaction between MPs through various equidistant spatial paths li of FVs, modelled on the basis of the Huygens principle for waves. For this issue, we utilized a numerical calculation, which could be generalized. But this spatial effect of the ether leads at a very slow decreasing of the FP forces ratio rF when doubling the distance l, in contrast to Coulomb’s FC forces whose ratio rF?decreases accentuate with doubling l. Accordingly, the necessity of including the term ln r in the FCC force, which is limited to 1.0 for doubling l, at long distances, was justified.

New Properties of HM16 Ether, with Submicroparticles as Self-Functional Cells Interacting through Percussion Forces, Establishing Nature of Electrical Charges, including Gravitation

Article continues and complements our previous articles on the HM16 ether (ETH) model. Here, we describe the mechanism of occurrence of the submicroparticle (SMP). A general hypothesis, HFVI, is introduced for the modalities of interaction between two SMPs, based on periodic mechanical percussion forces, produced by fundamental vibrations FVs. A mechanism for describing the interaction between a SMPs and the ETH is presented. Positive and negative particles are defined by their membrane types of movement, such as +, −u/+, −v vibrations, and rotations at speeds +Ω/−Ω. The process of creating a pair of SMPs is discussed. Applying HFVI to the interaction between pairs of SMPs immobile in ETH, and considering longitudinal FVL, was obtained the forces of attraction/repulsion +FL21/–FL21, which correspond to the completed Coulomb force FCC including gravitation. The resultant FRL21 will form an oriented field of forces, which is a quasielectric field QE, equivalent to actual E electric field. Considering transversal FVT, was obtained the vibratory forces +, −FT21, whose resultant forms an vibrating field of forces, QHs, a quasimagnetic special field, which may explain some of the quantum properties of SMPs. Considering a mobile SMP, two new γ strains in ETH appear. Strains γL are created by the displacement of SMP with velocity V, whose force +, −FT12 is the support of a component of the magnetic field H (quasimagnetic field QH), giving the QHL component. Strains γR are created by the rotation of SMP with speed Ω, whose force +, −FR12 constitutes physical support of the component QHR of magnetic field H (i.e. QH). The creation of a photon PH is modelled as a special ESMP containing two zones of opposed rotations, and a mechanism is presented for its movement in the ETH with speed c based on the HS hypothesis of screwing in ETH, with frequency ν.

Indifference Pricing in the Single Period Binomial with Complete Market Model

Binomial no-arbitrage price have a method is the traditional approach for derivative pricing,which is,the complete model,which makes possible the perfect replication in the market.Risk neutral pricing is an appropriate method of asset pricing in a complete market.We have discussed an incomplete market,a non-transaction asset that produces incompleteness of the market.An effective method of asset pricing in incomplete markets is the undifferentiated pricing method.This technique was firstly introduced by Bernoulli in(1738)the sense of gambling,lottery and their expected return.It is used to command investors'preferences and better returns the results they expect.In addition,we also discuss the utility function,which is the core element of the undifferentiated pricing.We also studied some important behavior preferences of agents,and injected exponential effect of risk aversion in the model,so that the model was nonlinear in the process of claim settlement.

煤层气水平井扇形洞穴完井应力—渗透率演化机理

我国煤层渗透率低且地质条件复杂,采用常规油气储层改造的开发方式难度大、技术适应性差。近年来,基于应力释放的煤层气改造新方法“煤层气水平井水力喷射造穴”很好地解决了这一技术瓶颈问题,但是造穴卸压—增渗的作用机制及其主控地质因素尚不明晰。为此,考虑了煤岩层理和天然裂隙的影响,采用有限元—离散元耦合方法(Finite-Discrete Element Method,FDEM)建立了煤层气水平井扇形洞穴完井数值模型,探究了造穴后岩体的应力演化历程和储层的卸压—增渗机制,并对比分析了不同储层参数(孔隙压缩系数、储层强度、弱面强度和地应力场)对应力释放的影响规律。研究结果表明:(1)围岩演化过程为造穴后岩体收缩,储层发生应力重构,围岩强度逐渐降低,岩体内部发生新生裂隙萌生和原生裂隙扩展,形成开挖损伤区和应力释放区;(2)参数敏感性分析表明孔隙压缩系数是决定造穴完井储层适应性的关键,弱面强度、储层强度和地应力场分布决定了围岩的应力演化模式和裂缝扩展形态;(3)造穴卸压后储层增渗机制为穴周裂缝提升导流能力,储层应力释放提升基质渗透率。结论认为,模型首次综合考虑了地层特点、造穴过程和煤岩裂隙的影响,研究结果揭示了煤层造穴后的应力演化过程及其卸压、增渗作用机制,深化了对煤层气水平井洞穴完井增产机理的认识,对我国煤层储层改造具有重要的工程参考价值。

含天然裂缝的页岩油储层裂缝扩展规律研究

位于渤海湾盆地冀中坳陷南部的束鹿凹陷页岩油砾岩段是本区优质储层段,普遍裂缝发育,储层品质更好,如何实现水力裂缝与天然裂缝的充分沟通,实现缝控储量最大化,是实现页岩油高效开发的核心问题。基于地质工程一体化软件Frsmart,建立束鹿凹陷页岩油天然裂缝模型,模拟分析不同天然裂缝参数及簇间距、排量等完井工程参数对储层改造效果的影响,最终确定适合于束鹿凹陷页岩油砾岩段的压裂改造参数。模拟结果表明:①天然裂缝密度和方位角对于提高页岩油裂缝复杂程度具有重要影响,天然密度越大,裂缝复杂程度越高,累计产油量越高,而天然裂缝方位角能够控制裂缝扩展方向;②结合数值模拟结果,确定施工排量10 m^(3)/min和簇间距10 m时,裂缝形态更加复杂,簇间储量动用程度更高。研究结果可为束鹿凹陷页岩油密切割体积压裂技术提供理论参考。

竣工环境保护验收调查应注意的若干要点——以某输气管道类工程为例

天然气是人类生产生活不可缺少的资源,为满足社会发展需求,加快天然气管道工程建设意义重大。天然气管道工程建设期间,会对自然环境产生一定的影响,因此,竣工环节要高度重视环保验收调查工作,防范环境风险问题的发生。本文以粤北天然气主干管网韶关-广州干线项目为例,着重对竣工环节环境保护验收调查要点展开了深入探析。

Pure transvaginal natural orifice transluminal endoscopic surgery right hemicolectomy for colon cancer:A case report

BACKGROUND Pure natural orifice transluminal endoscopic surgery(NOTES)for colorectal cancer is a complex procedure and rarely used in clinical practice because of the ethical concerns and technical challenges,including loss of triangulation,in-line orientation,and instrument collision.Transvaginal(v)NOTES,however,can overcome these technical challenges.We report a case of pure vNOTES right hemicolectomy for colon cancer,attached with surgical video.CASE SUMMARY A 65-year-old woman with a 2-year history of intermittent diarrhea was diagnosed with ascending colon adenocarcinoma by colonoscopy and biopsy.Pure vNOTES right hemicolectomy was performed with complete mesocolic excision by well-experienced surgeons.The operative time was 200 min and the estimated blood loss was 30 mL.No intraoperative or postoperative complications occurred within 30 d after the surgery.The visual analog scale pain score on postoperative day 1 was 1 and dropped to 0 on postoperative days 2 and 3.The patient was discharged at postoperative day 6.The pathologic specimen had sufficient clear resection margins and 14 negative harvested lymph nodes.CONCLUSION vNOTES right hemicolectomy,performed by well-experienced surgeons,overcomes the technical challenges of pure NOTES and may be feasible for colon cancer.

CHARACTERISTIC THEOREMS OF TH ENATURAL TCHEBYSHEFF SPLINE FUNCTION

In this paper,we give four characteristic theorems of the natural Tchebysheff splint functionassociated with multiple knots.These theorems possess specific form,that arc convenient forapplicaton;In the case of with simple knots or polynomial splint,the corollaries of this paper’s the-orems give corresponding results.

Natural selection in vertebrate evolution under genomic and biosphere biases based on amino acid content: Primitive vertebrate hagfish (<i>Eptatretus burgeri</i>)

Cluster analyses using the amino acid content predicted from the coding regions (13 genes) of complete vertebrate mitochondrial genomes as traits grouped selected vertebrates into two clusters, terrestrial and aquatic vertebrates. Exceptions were the hagfish (Eptatretus burgeri), thought to be an early ancestor of vertebrates, and the black spotted frog (Rana nigromaculata), which is terrestrial as an adult and aquatic as a larva. These two species fall into the terrestrial and aquatic clusters, respectively. Using the nucleotide (G, C, T and A) content in the coding and non-coding regions, and in the complete genome as traits, similar results were obtained but with some additional exceptions. In addition, phylogenetic analyses of 16S rRNA sequences produced a consistent result. The results of this study indicated that vertebrate evolution is controlled by natural selection under both an internal bias as a result of nucleotide replacement genomic rules, and an external bias caused by environmental biospheric conditions.

直接转调与变音转调——中国扬琴乐器改革的两种思路

20世纪50年代,中国的扬琴乐器改革围绕着半音与转调问题出现了两种改革方式,即“直接转调”与“变音转调”。在之后三十余年的改革历程中,两种改革思路从最初简单的二元对立关系,发展到彼此影响、互取精华,再到相互依赖、协同演化。二者共同实践了对扬琴音位排列的多种可能性,并将中国的扬琴乐器改革推上了一个全新的高度。

DIN 75220标准阳光模拟试验与海南户外暴露试验对比研究

为了对比DIN 75220标准阳光模拟试验与我国海南户外暴露试验,以某型汽车整车和PC、PS标准板为研究对象,对自然曝晒试验和基于DIN 75220标准的整车阳光模拟试验中汽车典型部位微环境、汽车典型部件失效行为以及温度校正太阳辐射量的结果进行了对比研究。分析了2种试验方法中各统计量间的相关关系,进一步结合2种方法下的油漆件色差、内外饰件间缝隙变化结果以及关键部件典型失效问题,提出了适合用于模拟我国海南典型湿热自然环境的定制化阳光模拟试验循环。研究结果表明,基于DIN 75220标准的1个周期整车阳光模拟试验可以反映约80%的湿热自然环境整车曝晒试验3~6个月出现的失效问题。DIN 75220标准中,潮湿气候循环试验可以较好地模拟我国海南湿热自然环境,35个潮湿气候循环可以模拟海南整车自然曝晒1 a。

天然气产业链国产装备科技创新与实践

在“双碳”目标下,天然气对于保障国家能源安全,改善国家能源结构,促进节能减排等具有重要意义。从分析天然气产业供应链上存在的卡点、难点、痛点入手,介绍了能源企业围绕天然气产业链开展国产装备科技创新的背景,概述了国产装备科技创新要担当“国家战略科技力量”的内涵,阐释了装备科技创新的做法,并验证了这些装备在自主可控、标准化采购和降本增效方面发挥的重要作用。

复社的红色文献和史料价值研究

上海“孤岛”时期的复社是党领导下创办的出版机构,出版了《西行漫记》《续西行漫记》《鲁迅全集》等一批红色文献和进步文献。近年来在对复社的出版物考证后发现:《中国革命性质及动力》是《续西行漫记》正式面世前推出的单行本,其文献价值在对复社所发行的图书和出版史研究中未曾提及,有可深入研究的空间;复社《鲁迅全集》纪念本的遗存较少,但收藏者既有之前未曾发现的公共机构也有私人藏书家,尚需进一步梳理及挖掘。

海域含天然气水合物地层钻完井面临的挑战及展望

全球天然气水合物资源丰富,被世界各国视为未来石油和天然气的战略性接替能源。天然气水合物主要分布于深水海底浅层和陆地冻土区中,其中海域天然气水合物资源较为丰富,然而,目前海域天然气水合物储层钻完井工程实践较少,存在着许多技术难题和挑战。为了研究和应用海域天然气水合物地层钻完井技术,介绍了美国、日本、印度、中国等国家海域天然气水合物地层的钻探与试采活动,分析了海域天然气水合物地层钻完井技术发展现状,指出在天然气水合物地层钻完井工程中存在的基础性技术难题主要包括钻井液密度窗口窄、天然气水合物相变、井壁失稳、井口不稳定性、出砂防砂等。此外,针对钻完井工程存在的技术难题,对海域天然气水合物地层控压钻井、套管钻井、水平井钻井、防砂和钻井液等关键技术的未来发展进行了展望分析,以期为我国海域天然气水合物地层安全高效钻完井设计提供参考。

套管磨损机理及其防磨措施研究

在大位移井、大斜度井、水平井和深井钻井中 ,或者在狗腿严重度较大的井段以及在技术套管下入后的长裸眼钻井过程中 ,常常出现套管磨损问题。由此而诱发的套管抗挤强度和抗内压强度降低问题影响了油气井的后续完井测试作业、降低了油气井寿命 ,严重时还会导致某段油气井报废或整口油气井报废。为此 ,文章提出分别以水基泥浆、油基泥浆、清水作为润滑介质 ,用实验手段分别研究了法向载荷、温度、转盘转速、摩擦副材料特性对套管磨损的影响。同时 ,在对国内外防磨措施进行研究后 ,指出敷焊耐磨带是一种经济可行的防磨措施 ,在深井钻井、大位移井钻井和大斜度钻井中应重点推广。

天然气欠平衡钻井完井技术

利用欠平衡钻井数值模拟软件对井内压力分布规律、环空速度分布、环空岩屑浓度分布及井口回压 影响规律进行了分析,讨论了地层出液对天然气钻井的影响,介绍了天然气排量与井底压力的关系、天然气欠平衡 钻井注入参数的确定、天然气钻井完井技术措施和天然气欠平衡钻井完井的条件。应用该套技术,在井浅2井、平 落19井和白浅111H井等进行了现场实践,取得了良好的技术经济效益。

川西致密砂岩气层保护技术——进展与挑战

为了解决妨碍致密砂岩天然气勘探开发中的地层损害问题 ,以川西致密砂岩气藏为研究对象开展了国家重点科技攻关。项目研究立足于钻井完井中有效地保护天然裂缝 ,以屏蔽式暂堵技术思想作指导 ,通过建立井筒周围原地裂缝参数预测技术、裂缝性致密储层的敏感性和损害评价技术 ,基本形成了适于裂缝性致密砂岩气层保护的钻井—完井—增产配套技术系统 ,关于裂缝性致密砂岩气层开发获得了“保护与改造并举 ,二者相得益彰”的新认识。文章分析了面临的技术—经济—环境方面的严重挑战 ,提出要不断完善适应各种复杂地质对象的能力 ,在保护致密气层新技术开发中应特别注重与环境保护需求的结合。