Formation,evolution,reconstruction of black shales and their influence on shale oil and gas resource

Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.

Medium-term outcomes of laparoscopic pubocervical fascia reconstruction and sacrospinous ligament fixation with posterior approach for a pelvic organ prolapse:A retrospective study of 124 cases

Objective:Pelvic organ prolapse(POP)is a common gynecological disease in middle-aged and older women that seriously affects patients'physical health and quality of life,increases the financial burden for patients,and becomes a major public health concern.The aim of this study was to investigate the medium-term outcomes of laparoscopic pubocervical fascia reconstruction and sacrospinous ligament fixation with a posterior approach for patients with severe POP.Methods:Patients with severe POP quantitation stage III-IV who underwent laparoscopic pubocervical fascia reconstruction and sacrospinous ligament fixation with a posterior approach at the Department of Obstetrics and Gynecology,Sir Run Run Shaw Hospital,Zhejiang University School of Medicine between September 2016 and December 2020 were enrolled in this study.The results and complications were recorded.Data were retrospectively reviewed.Results:In total,124 patients were analyzed.Patients were followed up for 32.2712.90 months.The objective cure rate for patients who underwent hysterectomy was 917%(100/109),with 7(6.4%)patients had anterior vaginal wall prolapse and 2(1.8%)patients had posterior vaginal wall prolapse.The objective cure rate for patients who retained uterus was 66.7%(10/15).All 5 patients with recurrence had uterine prolapse,and 3(20.0%)of them also had anterior vaginal wall prolapse.Conchusions:Laparoscopic pubocervical fascia reconstruction and sacrospinous ligament fixation with the posterior approach is a safe,minimally invasive,and effective method for patients with severe POP.Long-term follow-up is needed to confirm the clinical effects.

Survey of methods and principles in three-dimensional reconstruction from two-dimensional medical images

Three-dimensional(3D)reconstruction of human organs has gained attention in recent years due to advances in the Internet and graphics processing units.In the coming years,most patient care will shift toward this new paradigm.However,development of fast and accurate 3D models from medical images or a set of medical scans remains a daunting task due to the number of pre-processing steps involved,most of which are dependent on human expertise.In this review,a survey of pre-processing steps was conducted,and reconstruction techniques for several organs in medical diagnosis were studied.Various methods and principles related to 3D reconstruction were highlighted.The usefulness of 3D reconstruction of organs in medical diagnosis was also highlighted.

Reconstruction of liver organoid using a bioreactor

AIM： To develop the effective technology for reconstruction of a liver organ in vitro using a bio-artificial liver. METHODS： We previously reported that a radial-flow bioreactor （RFB） could provide a three-dimensional highdensity culture system. We presently reconstructed the liver organoid using a functional human hepatocellular carcinoma cell line （FLC-5） as hepatocytes together with mouse immortalized sinusoidal endothelial cell （SEC） line M1 and mouse immortalized hepatic stellate cell （HSC） line A7 as non parenchymal cells in the RFB. Two × 10^7 FLC-5 cells were incubated in the RFB. After 5 d, 2 × 10^7 A7 cells were added in a similar manner followed by another addition of 10^7 M1 cells 5 d later. After three days of perfusion, some cellulose beads with the adherent cells were harvested. The last incubation period included perfusion with 200 nmol/L swinholide A for 2 h and then the remaining cellulose beads along with adherent cells were harvested from the RFB. The cell morphology was observed by transmission electron microscopy （TEM） and scanning electron microscopy （SEM）. To assess hepatocyte function, we compared mRNA expression for urea cycle enzymes as well as albumin synthesis by FLC-5 in monolayer cultures compared to those of single-type cultures and cocultures in the RFB. RESULTS： By transmission electron microscopy, FLC-5, M1, and A7 were arranged in relation to the perfusion side in a liver-like organization. Structures resembling bile canaliculi were seen between FCL-5 cells. Scanning electron microscopy demonstrated fenestrae on SEC surfaces. The number of vesiculo-vacuolar organelles （WO） and fenestrae increased when we introduced the actin-binding agent swinholide-A in the RFB for 2h. With respect to liver function, urea was found in the medium, and expression of mRNAs encoding arginosuccinate synthetase and arginase increased when the three cell types were cocultured in the RFB. However, albumin synthesis decreased. CONCLUSION： Co-culture in the RFB system can dramatically change the structure and function of all cell types, including the functional characteristics of hepatocytes. Our system proves effective for reconstruction of a liver organoid using a bio-artificial liver.

The Planning, Organization and Management of Post-disaster Reconstruction of the Lushan Earthquake Based on the Local as the Main Body

A new organization and management mechanism with the local government as the main body was created during the post-disaster reconstruction of the "4. 20 " Lushan earthquake,in which the experiences and lessons were drawn from the "5. 12"Wenchuan earthquake. Correspondingly, the local government conducted an exploration of the organization and management mode in the field of planning and construction. The effective experiences have been accumulated, including working out a full coverage planning,taking the leading part in the urban-rural planning,and exercising whole space control over the disaster area. An innovation management mode named as "Five Generals Pattern"was implemented in the construction projects. In view that the rural housing reconstruction was a weak link, a new approach to improving the construction management was investigated,by means of strengthening on-site supervision,establishing a technical platform,and bolstering public participation.

Organization and Ultra-Structural Components of Endothelial Surface Glycocalyx Revealed by Stochastic Optical Reconstruction Microscopy(STORM)

Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system.In addition to forming a transport barrier between the blood and vessel wall,vascular ECs play important roles in regulating circulation functions.Besides biochemical stimuli,blood flow induced(hemodynamic)mechanical stimuli,such as shear stress,pressure and circumferential stretch,modulate EC morphology and functions by activating mechanosensors,signaling pathways,and gene and protein expressions.The EC responses to the hemodynamic forces(mechano-sensing and transduction)are critical to maintaining normal vascular functions.Failure in the mechano-sensing and transduction leads to serious vascular diseases including hypertension,atherosclerosis,aneurysms and thrombosis,to name a few[1].On the luminal surface of our blood vessels,there is a thin layer called endothelial surface glycocalyx(ESG)which consists of proteoglycans,glycosaminoglycans(GAGs)and glycoproteins.The GAGs in the ESG are heparan sulfate(HS),hyaluronic acid(HA),chondroitin sulfate(CS),and sialic acid(SA)[2].In order to play important roles in vascular functions,such as being a mechanosensor and transducer for the endothelial cells(ECs)to sense the blood flow,a molecular sieve to maintain normal microvessel permeability and a barrier between the circulating cells and endothelial cells forming the vessel wall,the ESG should have an organized structure at the molecular level.Due to the limitations of optical and electron microscopy,the ultra-structure and organization of ESG has not been revealed until recent development of a super high resolution fluorescence optical microscope,STORM(Stochastic Optical Reconstruction Microscopy).The diffraction of a single fluorescence molecule can be described as the point spread function(PSF).When the light of wavelengthλexcites the fluorophore(emitter),the intensity profile of the spot is defined as the PSF with the width^0.6λ/NA,NA is the numerical aperture of the objective.The diffraction-limited image resolution,for a high numerical aperture objective lens,is^200 nm in the lateral direction and^500 nm in the axial direction,for a conventional fluorescence microscope.The key idea of the single-molecule localization microscopy is to light the molecule,in turn,to achieve the nanometer-level accuracy of their position and reconstruction into a super-resolution image,such as STORM.STORM employs photo-switching mechanisms to stochastically activate individual molecules(photo-switchable or photoactivatable fluorophores)within the diffraction-limited region at different times.Then images with sub-diffraction limit resolution are reconstructed from the measured positions of individual fluorophores[3].To trade the super spatial resolution(accuracy),STORM sacrifices its temporal resolution(efficiency)by switching the state and sequentially exciting the emitters at a high density.Rust et al[3]employed organic dyes and fluorescent proteins as photo-switchable emitters to trade temporal resolution for a super spatial resolution(~20 nm lateral and^50 nm axial at present,can go down to a couple of nanometers if using smaller peptides or antibody fragments instead of currently used whole anti-bodies),which is an order of magnitude higher than conventional confocal microscopy.In the current study,we employed STORM to reveal the major ultra-structural components of the ESG,HS and HA,and their organization at the surface of the cultured EC monolayer[4].Materials and methods We used newly acquired Nikon-STORM system to observe the ESG on in vitro EC(bEnd3,mouse brain microvascular endothelial cells)monolayers.After confluency,the bEnd3 cells were immunolabeled with anti-HS,fol-lowed by an ATT0488 conjugated goat anti-mouse IgG,and with biotinylated HA binding protein,followed by an AF647 conjugated anti-biotin.The ESG was then imaged by the STORM with a 100x/1.49 oil immersed lens.Multiple Reporters of ATT0488 and AF647 with alternating illumination were used to acquire the 3D images of HS and HA.The field of 256×256(40×40μm2)of HS and HA at the surface of ECs was obtained based on totally 40,000 of EM-CCD captured images for each reporter at a capturing speed of 19 ms/frame.Results HA is a long molecule weaving into a network which covers the endothelial luminal surface.The diameter of the HA segments is 185.3±44.7 nm,155.5±57.2 nm,and 156.9±56.1 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.In contrast,HS is a shorter molecule,perpendicular to the cell surface.HA and HS are partially overlapped with each other at the endothelial luminal surface.We quantified the length,diameter,orientation,and density of HS at the top,middle and bottom regions of the endothelial surface.The diameter of the observed HS is 191.0±46.0 nm,284.3±71.1 nm,and 184.2±59.6 nm,and the length of the HS is 621.0±75.7 nm,651.0±118.0 nm,and 575.2±105.6 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.For the HS orientation,its angle with the cell surface is 92.9±1.9,88.7±8.2,and 96.2±10.9 degree,respectively,at the top,middle and bottom regions.The angle of 90 degree is perfectly perpendicular to the cell surface.For the HS distribution,the average density is0.398 elements/μm2,0.345 elements/μm2 and 0.665 elements/μm2,respectively,and the distance between the adjacent HS is 1 694.4±628.1 nm,1 844.8±758.5 nm,and 1 221.9±450.7 nm,respectively,at the top,middle and bottom regions.Conclusions Our results suggest that HS plays a major role in mechanosensing and HA plays a major role in the molecular sieve,due to their organization,ultra-structure and distribution.

Inflammatory response, stress response and urodynamic changes after total pelvic floor reconstruction in patients with pelvic organ prolapse

Objective: To investigate the changes of inflammatory response, stress response and urodynamic changes after total pelvic floor reconstruction in patients with pelvic organ prolapse. Methods: According to random data table method, 80 cases of pelvic organ prolapse were randomly divided into the control group (n=40) and observation group (n=40), patients in the control group were given conventional vaginal hysterectomy plus vaginal wall repair sugery and the observation group received total pelvic floor reconstruction. The levels of the serum inflammatory factor,oxidative stress before and after surgery, and postoperative urodynamic changes were compared. Results: The levels of serum hs-CRP, IL-1β,TNF-α, NE, E and Ins in the two groups before treatment were not statistically significant. Compared with the group before treatment, the levels of hs-CRP, IL-1β, TNF-α, NE, E were significantly increased in both groups after treatment, and the observation group levels were significantly lower than those in the control group after treatment;in terms of urodynamics, the postoperative maximal bladder volume and Qmax were significantly higher in the observation group than in the control group, the postoperative levels of PdetQMax, PdetMax and PVR in the observation group were significantly lower than those in the control group. Conclusion: Compared with vaginal hysterectomy plus vaginal wall repair sugery, total pelvic floor reconstruction can light the patient's inflammation, stress response and improve the patient's urinary function, and the overall effect is better which has important clinical value.

Degradation Process of Coated Tinplate by Phase Space Reconstruction Theory

The degradation process of organosol coated tinplate in beverage was investigated by electrochemical noise (EN) technique combined with morphology characterization.EN data were analyzed using phase space reconstruction theory.With the correlation dimensions obtained from the phase space reconstruction,the chaotic behavior of EN was quantitatively evaluated.The results show that both electrochemical potential noise (EPN) and electrochemical current noise (ECN) have chaotic properties.The correlation dimensions of EPN increase with corrosion extent,while those of ECN seem nearly unchanged.The increased correlation dimensions of EPN during the degradation process are associated with the increased susceptibility to local corrosion.

Uterus-reserved or hysterectomized total pelvic floor reconstruction for female pelvic dysfunction:a clinical analysis of 74 cases

Objective To evaluate the effectiveness and safety of the entire pelvic floor reconstruction(Prolift) with uterus reserved in the treatment of pelvic floor dysfunction diseases.Methods From March 2008 to January 2009,74 female cases from our hospital who had different defects in pelvic organ prolapse were treated with the entire reconstructive pelvic surgery,in which 38 had uterus retained(observation group) and 36 cases had hysterectomy(control group).The two groups were compared.The patients with combined stress urinary incontinence had transobturator tension-free vaginal tape(TVT-O technique) at the same time.The results of operations were objectively evaluatedaccording to Pelvic Organ Prolapse Quantification sub-degree method(POP-Q) developed by the International Continence Society.Results For observation group,the average operative time was 50 min,and the average amount of bleeding was 100 mL.For control group,the average operative time was 110 min,and the average amount of bleeding was 200 mL.During the postoperative follow-up(8 ~18 months),in the observation group the structures of patients' pelvic floor were normal;stress urinary incontinence was all cured;related symptoms disappeared or were markedly improved;and no postoperative infection appeared.In control group,two cases had postoperative infection;the patients ' pelvic structures were normal during the postoperative follow-up;the related symptoms disappeared or were significantly improved.After 3 months,POP-Q score was significantly elevated in the two groups.Conclusion Full reconstructive pelvic surgery with uterus retained can complete the whole pelvic floor structure and function of all or part of the reconstruction with fast recovery and clear short-term effect.However,the long-term efficacy remains to be revealed.

SYMPOSIUM ON PHYSICAL GEOGRAPHY AND RECONSTRUCTION

The Symposium on Physical Geography and Reconstruction Geography, Sponsoredand organized by Geographical Society of China (GSC), Planning Commission of WeinanDistrict, Integrated Physical Geography Teaching Society of China, and Editorial Board ofJournals of "Territorial Development and Management" and "Sciences, Technology anddialectics" was held in Weinan, Shaanxi Province, China 18—23 November 1991. About

Aliphatic biomarker signatures of early Oligocene-early Miocene source rocks in the central Qiongdongnan Basin:Source analyses of organic matter

The geochemical signatures of fifty-four rock samples and three supplementary drill stem test(DST)oils from the Yacheng-Sanya formations in the central Qiongdongnan Basin(CQB)were analysed.Reconstruction of the early Oligocene-early Miocene(36–16 Ma)palaeovegetation and source analyses of organic matter(OM)were conducted using aliphatic biomarkers in ancient sediments and DST oils.Both the interpreted aquatic and terrigenous OM contributed to the CQB source rocks(SRs)but had varying relative proportions.The four distribution patterns derived from n-alkanes,terpanes,and steranes are representative of four OM composition models of the Yacheng-Sanya SRs,including model A,model B,model C,and model D,which were classified based on the increasing contribution from terrigenous OM relative to aquatic OM.Some terrigenous higher plantderived biomarkers,including oleanane,des-A-oleanane,C_(29)ααα20R sterane,bicadinanes,the C_(19)/(C_(19)+C_(23))tricyclic terpane ratio,and other n-alkane-derived ratios suggest that angiosperms had increased proportions in the palaeoflora from early Oligocene to early Miocene,and the bloom of terrigenous higher plants was observed during deposition of upper Lingshui Formation to lower Sanya Formation.These findings are consistent with the incremental total organic carbon and free hydrocarbons+potential hydrocarbons(S_1+S_2)in the lower Lingshuilower Sanya strata with a significant enrichment of OM in the E_3l_1-N_1s_2 shales.The maturity-and environmentsensitive aliphatic parameters of the CQB SRs and DST oils suggest that all the samples have predominantly reached their early oil-generation windows but have not exceeded the peak oil windows,except for some immature Sanya Formation shales.In addition,most of the OM in the analysed samples was characterised by mixed OM contributions under anoxic to sub-anoxic conditions.Furthermore,terrestrial-dominant SRs were interpreted to have developed mainly in the Lingshui-Sanya formations and were deposited in sub-oxic to oxic environments,compared to the anoxic to sub-anoxic conditions of the Yacheng Formation.

作物农艺性状与形态结构表型智能识别技术综述

[目的/意义]作物农艺性状与形态结构表型智能识别是作物智慧育种的主要内容,是研究“基因型—环境型—表型”相互作用关系的基础,对现代作物育种具有重要意义。[进展]大规模、高通量作物表型获取设备是作物表型获取、分析、测量、识别等的基础和重要手段。本文介绍了高通量作物表型主流平台和感知成像设备的功能、性能以及应用场景。分析了作物株高获取、作物器官检测与技术等农艺性状智能识别和作物株型识别、作物形态信息测量以及作物三维重建等形态结构智能识别技术的研究进展及挑战。[结论/展望]从研制新型低成本田间智能作物表型获取与分析装备、提升作物表型获取田间环境的标准化与一致性水平、强化田间作物表型智能识别模型的通用性,研究多视角、多模态、多点连续分析与时空特征融合的作物表型识别方法,以及提高模型解释性等方面,展望了作物表型技术主要发展方向。

农民组织化再造的内生机制及路径优化——基于鄂南P村的调研经验

乡村振兴的前提是将农民组织起来,而农民组织化程度影响着基层治理的水平。目前农民组织化建设多依赖外部资源和制度规则的输入,但收效甚微。经过实地调研发现,农民内生型的组织化建设机制展现了更为强大的动力,在返乡能人带头下,通过仪式性活动激发了农民的共同体意识,甚至形成了内生性的规则体系。但目前内生型组织化再造仍然面临组织建设的后备人才不足、资源供给的可持续性存疑以及内生规则的有效性有待确认等问题。为优化农民组织化建设机制,进一步提高农民参与自治的积极性,在充分激活内生性动力的同时,可强化外源性资源的赋能作用,以保障农民组织化再造的长效机制。

发挥学术资源优势,利用人工智能技术提升大学图书馆支撑个性化学习的能力

大学的使命和任务在发展中不断地变化和丰富,但人才培养作为大学的中心任务并没有发生变化。大学图书馆为大学人才培养提供了强有力的学术资源支持,促进了知识传承与创新,推动了学生自主学习与研究能力的提升。人工智能,特别是大语言模型技术可以基于个性化需求对学术资源进行再加工,突破学术资源的传统使用模式,丰富学习资源,改变呈现方式和组织模式,提升图书馆学术资源的使用成效和学生的学习效率。结合图书馆的学术资源优势和人工智能等新一代信息技术发展和应用趋势,立足高校图书馆支撑人才培养的使命,以学生学习为中心,学习和发展成效为驱动,提出了改变图书馆服务模式、学术资源组织模式和使用方式,支撑学生开展个性化学习的设想和思路。

关系再造:基层党组织引领社区治理共同体的运行逻辑

构建社区治理共同体是国家推进基层治理现代化的重要路径,需要基层党组织发挥坚强的引领作用。基层开展的“共同缔造”或“熟人创建”等治理实践的深层逻辑在于,基层党组织是以“关系”为切入点,探索“关系激活—关系联结—关系治理”的关系再造路径,形成关系联结型治理模式。关系再造需要激活社区的价值要素、组织要素、情感要素、利益要素和制度要素,通过关系联结为社区治理共同体的形成提供治理理念、治理结构、治理信任、治理动能和治理规则。社区治理共同体的运行逻辑在于发挥基层党组织的引领作用推进关系要素的激活生成,组织驱动和制度嵌入推进关系联结的高效运行,情感动员和利益整合推进关系网络的治理修复。

巨厚高原山地式页岩高频沉积旋回特征与有机质富集机理

高频沉积旋回是地球轨道驱动力周期性变化引起海平面升降和气候波动的高频周期性响应(吴怀春等,2011)。同时,高频沉积旋回对有机质富集和储集空间的分布具有重要的控制作用(钟寿康等,2022)。因此,高频沉积旋回分析不仅有利于揭示古气候演化、古环境重建和古地貌恢复等重要的基础科学问题,而且能为油气实践勘探提供重要理论指导。柴达木盆地位于青藏高原东北部.

西沙群岛中新世藻礁白云岩植物格架、储层特征和成礁模式

传统生物礁成因理论质疑钙藻形成坚固生物礁抗浪结构的能力,将钙藻归类于附礁生物群落。文章利用微焦X射线扫描成像技术(X-CT),研究“西科1井”、“西永2井”中新世红藻珊瑚藻科南海奇石藻(新种)格架岩和绿藻仙掌藻节片岩岩芯。通过三维层析成像直观透视图像,发现钙藻生物营造的藻礁抗浪结构,包括典型红藻柱状格架结构、障积结构和绿藻仙掌藻节片结构,证实钙藻植物是主要的造礁造岩生物。通过三维孔隙重构,获得总孔隙体积、面孔率、孔隙度的物性参数,验证了藻礁是南海沉积盆地中新世重要的油气储集层。提出了藻礁成因模式:造礁钙藻适应海面升降逐步演替–取代,经过钙化–埋藏化石化–白云石化,沉积生成藻礁云岩,造成中新世西沙礁纵向序列的增长。

中美高速公路改扩建作业区布设标准比对分析

高速公路改扩建作业区是改扩建安全管理工作的重点区域。为了更好地借鉴美国道路交通管理工作经验、支撑我国相关标准修订,本文梳理了美国《统一交通设施控制手册》修订情况,并与我国相关国家标准和行业标准进行比对,提出了中美标准在作业区设置、典型作业区布设方案方面的主要技术差异,从临时护栏使用、渠化设施安装拆除时的安全防护和临时交通安全设施组合设置等方面提出了标准修订建议。

盆底重建术后泌尿道网片/吊带暴露的手术处理——单中心经验

目的对盆底重建术后网片/吊带泌尿道暴露的手术干预方法及长期治疗结局进行分析探讨。方法对2011年11月—2020年9月四川大学华西医院泌尿外科收治的因经阴道盆底重建术后网片或吊带发生泌尿道暴露再次接受手术治疗的9例患者的临床资料进行回顾性分析,探讨其一般临床特点,再次手术方式及治疗结局。结果9例患者的中位年龄为53(39~73)岁,身体质量指数中位数为23.0(19.5~27.3)。6例患者既往因盆腔脏器脱垂接受经阴道网片植入术而于术后发生网片暴露,其中3例患者接受经阴道部分网片切除术、3例接受膀胱镜下钬激光消融手术。另外3例患者既往因尿失禁接受无张力尿道中段悬吊术而于术后发生吊带暴露,其中2例接受膀胱镜下部分网片切除术治疗,1例接受膀胱镜下钬激光消融手术治疗。9例患者的中位随访时间为69(16~121)个月。截至末次随访时所有患者均未再次发生网片暴露。结论经阴道途径及经尿道途径的网片/吊带切除术均是治疗盆底重建术后泌尿道网片/吊带暴露的有效手术方法。

低轨互联网星座发展研究

近年来,随着互联网用户激增,SpaceX、OneWeb等创新型企业纷纷计划打造低轨互联网星座,引发全球低轨卫星互联网星座的发展热潮。因此,研究国内外低轨互联网星座的发展情况及当前面临的技术难题有着很重要的意义。基于此,介绍了国外具有代表性的3个低轨互联网星座计划(Starlink、OneWeb、Lightspeed)及国内星座的最新发展情况;根据低轨互联网星座的特点,着重分析了低轨互联网星座面临的五大技术挑战:星座相对运动演化预报、星座自主导航与定轨、星座构型重构的路径规划、星座自组织协同构型控制、星座通信与网络服务;根据当前低轨互联网星座的发展趋势,对中国在低轨互联网星座的发展给出了建议。