Time-resolved characteristics of a nanosecond pulsed multi-hollow needle plate packed bed dielectric barrier discharge

In this paper,self-designed multi-hollow needle electrodes are used as a high-voltage electrode in a packed bed dielectric barrier discharge reactor to facilitate fast gas flow through the active discharge area and achieve large-volume stable discharge.The dynamic characteristics of the plasma,the generated active species,and the energy transfer mechanisms in both positive discharge(PD)and negative discharge(ND)are investigated by using fast-exposure intensified charge coupled device(ICCD)images and time-resolved optical emission spectra.The experimental results show that the discharge intensity,number of discharge channels,and discharge volume are obviously enhanced when the multi-needle electrode is replaced by a multihollow needle electrode.During a single voltage pulse period,PD mainly develops in a streamer mode,which results in a stronger discharge current,luminous intensity,and E/N compared with the diffuse mode observed in ND.In PD,as the gap between dielectric beads changes from 0 to250μm,the discharge between the dielectric bead gap changes from a partial discharge to a standing filamentary micro-discharge,which allows the plasma to leave the local area and is conducive to the propagation of surface streamers.In ND,the discharge only appears as a diffusionlike mode between the gap of dielectric beads,regardless of whether there is a discharge gap.Moreover,the generation of excited states N_(2)^(+)(B^(2)∑_(u)^(+))and N2(C^(3)Π_(u))is mainly observed in PD,which is attributed to the higher E/N in PD than that in ND.However,the generation of the OH(A^(2)∑^(+))radical in ND is higher than in PD.It is not directly dominated by E/N,but mainly by the resonant energy transfer process between metastable N_(2)(A^(3)∑_(u)^(+))and OH(X^(2)Π).Furthermore,both PD and ND demonstrate obvious energy relaxation processes of electron-to-vibration and vibration-to-vibration,and no vibration-to-rotation energy relaxation process is observed.

Superior Anodic Lithium Storage in Core–Shell Heterostructures Composed of Carbon Nanotubes and Schiff-Base Covalent Organic Frameworks

Covalent organic frameworks(COFs)after undergoing the superlithiation process promise high-capacity anodes while suffering from sluggish reaction kinetics and low electrochemical utilization of redox-active sites.Herein,integrating carbon nanotubes(CNTs)with imine-linked covalent organic frameworks(COFs)was rationally executed by in-situ Schiff-base condensation between 1,1′-biphenyl]-3,3′,5,5′-tetracarbaldehyde and 1,4-diaminobenzene in the presence of CNTs to produce core–shell heterostructured composites(CNT@COF).Accordingly,the redox-active shell of COF nanoparticles around one-dimensional conductive CNTs synergistically creates robust three-dimensional hybrid architectures with high specific surface area,thus promoting electron transport and affording abundant active functional groups accessible for electrochemical utilization throughout the whole electrode.Remarkably,upon the full activation with a superlithiation process,the as-fabricated CNT@COF anode achieves a specific capacity of 2324 mAh g^(−1),which is the highest specific capacity among organic electrode materials reported so far.Meanwhile,the superior rate capability and excellent cycling stability are also obtained.The redox reaction mechanisms for the COF moiety were further revealed by Fourier-transform infrared spectroscopy in conjunction with X-ray photoelectron spectroscopy,involving the reversible redox reactions between lithium ions and C=N groups and gradual electrochemical activation of the unsaturated C=C bonds within COFs.

Interwoven Poly(Anthraquinonyl Sulfide)Nanosheets-Decorated Carbon Nanotubes as Core-Sheath Heteroarchitectured Cathodes for Polymer-Based Asymmetrical Full Batteries

Organic redox-active polymers provide promising alternatives to metal-containing inorganic compounds in Li-ion batteries(LIBs),whereas suffer from low actual capacities,poor rate/power capabilities,and inferior cycling stability.Herein,poly(anthraquinonyl sulfide)-coated carbon nanotubes(CNT@PAQS)are readily performed by in situ polymerization to form core-sheath nanostructures.Remarkably,flower-like PAQS nanosheets are interwoven around CNTs to synergistically create robust 3D hierarchical networks with abundant cavities,internal channels,and sufficiently-exposed surfaces/edges,thereby promoting electron transport and making more active sites accessible for electrolytes and guest ions.Apparently,the as-fabricated CNT@PAQS cathode delivers the large reversible capacity(200.5 mAh g^(-1)at 0.05 A g^(-1)),high-rate capability(161.5 mAh g^(-1)at 5.0 A g^(-1)),and impressive cycling stability(retaining 88.0%over 1000 cycles).In addition,an asymmetric full-battery using CNT@PAQS as a cathode and cyclized polyacrylonitrile-encapsulated CNTs as an anode is assembled that delivers a high energy density of 86.3 Wh kg^(-1),and retains 81.3%of initial capacity after 1000 cycles.This work opens up an efficient strategy to combine highly conductive and redox-active phases into core-sheath heterostructures to unlock the barrier of high-rate charge storage.The further integration of two polymer-based electrodes into asymmetric full cells would also consolidate the development of low-cost,sustainable,and powerful batteries.

集成电路领域的EDA发展现状及标准化

电子设计自动化(EDA)工具是在整个集成电路产业链中被广泛应用的软件系统。本文通过总结EDA产业的发展状况以及标准化情况,指出我国EDA标准体系建设面临的问题与挑战,从促进国产EDA高质量发展的角度提出国内EDA标准制定方向上的建议,旨在促进国产EDA工具的应用和标准化发展。

A landslide monitoring method using data from unmanned aerial vehicle and terrestrial laser scanning with insufficient and inaccurate ground control points

Non-contact remote sensing techniques,such as terrestrial laser scanning(TLS)and unmanned aerial vehicle(UAV)photogrammetry,have been globally applied for landslide monitoring in high and steep mountainous areas.These techniques acquire terrain data and enable ground deformation monitoring.However,practical application of these technologies still faces many difficulties due to complex terrain,limited access and dense vegetation.For instance,monitoring high and steep slopes can obstruct the TLS sightline,and the accuracy of the UAV model may be compromised by absence of ground control points(GCPs).This paper proposes a TLS-and UAV-based method for monitoring landslide deformation in high mountain valleys using traditional real-time kinematics(RTK)-based control points(RCPs),low-precision TLS-based control points(TCPs)and assumed control points(ACPs)to achieve high-precision surface deformation analysis under obstructed vision and impassable conditions.The effects of GCP accuracy,GCP quantity and automatic tie point(ATP)quantity on the accuracy of UAV modeling and surface deformation analysis were comprehensively analyzed.The results show that,the proposed method allows for the monitoring accuracy of landslides to exceed the accuracy of the GCPs themselves by adding additional low-accuracy GCPs.The proposed method was implemented for monitoring the Xinhua landslide in Baoxing County,China,and was validated against data from multiple sources.

营商环境何以优化?——企业行政负担的视角

优化营商环境的核心在于降低企业行政负担和提升企业获得感,然而企业行政负担如何生成、如何优化等问题仍然不甚明晰。以A市优化营商环境的实践为例,以通过深度访谈、公开政策文本与新闻报道等途径收集而来的质性资料作为支撑,论文重新审视并深入挖掘了企业行政负担的成因,结合优化营商环境治理实践,提出了降低企业行政负担的本土解释框架。研究发现,政企互动过程中,企业所背负的服从成本缘于申请材料冗杂、流程与环节复杂、材料内容不明晰等方面,学习成本缘于涉企政策来源多样且分散、涉企政策解读不明晰、涉企政策精准推送难等方面,心理成本缘于政企沟通不畅、政策稳定性差、政策普惠程度不高等方面。基于组织学视角,论文进一步从横向政府部门间的流程重塑、纵向政府部门间的考核问责以及外部场域环境中的需求回应三个方面,对降低行政负担的方式进行了学理建构。具体来说,降低企业的行政负担应当以营商环境优化全局观为基础,在坚持底线监管、审慎监管的基础上识别行政负担与管理的边界。在政企互动初期,应当侧重以技术治理推动涉企政策信息公开、集成与精准推送,以界面治理推动部门协同提升涉企事项的管理效率。随着政企互动程度的不断深入,应当提升审管协同与城市政务热线等治理水平,通过建立容错机制鼓励政府创新,从而支持政府部门为企业主动提供服务,有效回应企业需求。

Efficient activation of the Co/SBA-15catalyst by high-frequency AC-DBD plasma thermal effects for toluene removal

Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.

Experimental investigation of closed-loop active control to modulate coherent structures by mu-level method

The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocity signals in the turbulent boundary layer were measured by HWA. The drag reduction rate of 16.7% is obtained comparable to that of the open-loop control and saves 75% of the input energy at the asynchronous 100 V/160 Hz control case, which reflects the advantages of the closed-loop control. The experimental findings indicate that the intensity increases in the near-wall region.The perturbation of the PZT vibrators on the skewness factor is concentrated in the region y+< 60. The generation of highspeed fluids is depressed and the downward effect of high-speed fluids weakens. The alteration of energy distribution and the discernible impact of modulation between structures of varying scales are observed. The correlation coefficient exhibits a strong positive correlation, which indicates that the large-scale structures produce modulation effect on small-scale ones.The occurrence of burst events is effectively suppressed. The disturbance has the characteristics of stable periodicity,positive and negative symmetry, low intermittency, and high pulsation strength. The conditional phase waveform shows that the fluctuation amplitude increases, indicating amplitude modulation effects on coherent structures.

Dynamic Hypergraph Modeling and Robustness Analysis for SIoT

The Social Internet of Things(SIoT)integrates the Internet of Things(IoT)and social networks,taking into account the social attributes of objects and diversifying the relationship between humans and objects,which overcomes the limitations of the IoT’s focus on associations between objects.Artificial Intelligence(AI)technology is rapidly evolving.It is critical to build trustworthy and transparent systems,especially with system security issues coming to the surface.This paper emphasizes the social attributes of objects and uses hypergraphs to model the diverse entities and relationships in SIoT,aiming to build an SIoT hypergraph generation model to explore the complex interactions between entities in the context of intelligent SIoT.Current hypergraph generation models impose too many constraints and fail to capture more details of real hypernetworks.In contrast,this paper proposes a hypergraph generation model that evolves dynamically over time,where only the number of nodes is fixed.It combines node wandering with a forest fire model and uses two different methods to control the size of the hyperedges.As new nodes are added,the model can promptly reflect changes in entities and relationships within SIoT.Experimental results exhibit that our model can effectively replicate the topological structure of real-world hypernetworks.We also evaluate the vulnerability of the hypergraph under different attack strategies,which provides theoretical support for building a more robust intelligent SIoT hypergraph model and lays the foundation for building safer and more reliable systems in the future.

Left ventricular thrombosis caused cerebral embolism during venoarterial extracorporeal membrane oxygenation support: A case report

BACKGROUND Venoarterial(VA)extracorporeal membrane oxygenation(ECMO),an effective short-term circulatory support method for refractory cardiogenic shock,is widely applied.However,retrospective analyses have shown that VA-ECMO-assisted cases were associated with a relatively high mortality rate of approximately 60%.Embolization in important organs caused by complications of left ventricular thrombosis(LVT)during VA-ECMO is also an important reason.Although the incidence of LVT during VA-ECMO is not high,the consequences of embolization are disastrous.CASE SUMMARY A 37-year-old female patient was admitted to hospital because of fever for 4 d and palpitations for 3 d.After excluding the diagnosis of coronary heart disease,we established a diagnosis of“clinically explosive myocarditis”.The patient still had unstable hemodynamics after drug treatment supported by VA-ECMO,with heparin for anticoagulation.On day 4 of ECMO support,a left ventricular thro-mbus attached to the papillary muscle root of the mitral valve was found by transthoracic echocardiography.Left ventricular decompression was performed and ECMO was successfully removed,but the patient eventually died of multiple cerebral embolism.CONCLUSION LVT with high mobility during VA-ECMO may cause embolism in important organs.Therefore,a"wait and see"strategy should be avoided.

Health promotion and education proposal among Chinese female college students:eliminating cervical cancer is no longer a dream

Cervical cancer is a serious threat to women’s health.Persistent high-risk human papillomavirus(HPV)infection is a necessary factor for cervical cancer development and has become a serious public health threat to women.At present,young women have become a high-risk group for potential HPV infection.HPV vaccination is an effective method to prevent HPV infection and related diseases and is a primary preventive measure for HPV infection-related diseases.This study explores the influencing factors of female college students’willingness to receive HPV vaccination,their ability to understand college students’HPV awareness,their motivation for HPV vaccination,their behavioral skills related to HPV vaccination,their willingness to receive HPV vaccination and their vaccination rate.The aim of this study was to increase the HPV vaccination rate of Chinese female college students through health education programs and thus reduce the incidence of cervical cancer.

The effect of HPV infection on mental health status in women

Human papillomavirus(HPV)infection is one of the most common sexually transmitted infections globally,and its close association with the development of cervical cancer has become a major public health concern.HPV infection not only leads to physical health problems,but also has an impact on a woman’s mental health,such as:severe anxiety,fear,depression,negativity,and other psychological distress.The purpose of this review is to systematically summarize the current knowledge on this topic and to explore its current development in accordance with the PRISMA guidelines.We can provide interventions that may alleviate or even eliminate psychological problems in women,depending on their psychological characteristics.A total of 82 records were included in the study,including 37 papers on the effect of HPV infection on the mental health status of women and 45 studies on the effect of implementing interventions on the mental health of patients with HPV infection.The results show that HPV infection can make women produce anxiety,depression,shame,low self-esteem and other negative psychological.However,active and proper medical treatment,psychological counseling and support,and strengthening health education have positive effects on HPV-infected women,and can promote the mental health of HPV-infected women.

心脏磁共振评估肥厚型心肌病微循环障碍的研究进展

冠状动脉微血管功能障碍(CMD)是肥厚型心肌病患者心肌缺血的主要原因。CMD是发生左心室不良重构、收缩功能障碍和恶性心律失常的预测因子,因此准确评估CMD对肥厚型心肌病的危险分层、治疗决策制订及预后评估具有重要意义。心脏磁共振在CMD诊断中具有重要作用。本文拟对心脏磁共振评估肥厚型心肌病微循环障碍的研究进展进行综述。

Clinical observation of endometrial prescription combined with TAM on FET of thin endometrial patients with kidney deficiency and blood stasis

Objective:To explore the best endometrial preparation scheme of freeze-thawed embryo transfer(FET)for patients with thin endometrium with kidney deficiency and blood stasis by comparing the clinical outcomes of three endometrial preparation schemes of estradiol valerate tablets Hormone Replacement(HRT),Tamoxifen(TAM)and Endometrial Prescription combined with TAM(EP-TAM group).Method:Retrospective analysis of 318 patients with thin endometrium with kidney deficiency and blood stasis who underwent FET in Changle People's Hospital of Shandong Province,Shandong Maternal and Child Health Hospital,and Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine from September 2018 to March 2023,including 101 patients in HRT group(estradiol valerate tablets);108 patients in TAM group;109 patients in EP-TAM group.The cycle cancellation rate,intimal thickness,clinical pregnancy rate,embryo implantation rate,early abortion rate and ectopic pregnancy rate were compared among the three groups.Result:Cycle cancellation rates of TAM group and EP-TAM group were significantly lower than HRT group(8.3%,9.2%vs 17.8%,P<0.05).The intimal thickness of TAM group[(8.11±0.36)mm]and EP-TAM group[(8.21±0.40)mm]was significantly thicker than HRT group[(7.11±0.43)mm](P<0.05).The clinical pregnancy rate and implantation rate of TAM group and EP-TAM group were higher than HRT group,the early abortion rate and ectopic pregnancy rate were lower than HRT group,and EP-TAM group was more significant(P<0.05).Conclusion:Patients with thin endometrium underwent FET can try Endometrium Prescription combined with TAM(EP-TAM)to prepare the endometrium.

Application of an electrophysiological technique combined with auricular acupuncture in gynecological perioperative gastrointestinal dysfunction

Objective:This study aimed to evaluate the effectiveness and safety of combining low-frequency pulsed electrophysiological techniques with auricular acupuncture(a fusion of traditional Chinese and Western medicine)for patients experiencing perioperative gastrointestinal dysfunction(POGD)following gynecological surgery.Methods:Eighty patients undergoing gynecological surgery were randomly assigned to an experimental group and a control group.Both groups received enhanced recovery after surgery(ERAS)care,with the experimental group receiving additional treatment combining electrophysiology and auricular acupuncture.Postoperative recovery indicators,including bowel sound recovery time,time to first exhaust and defecation,duration and incidence of abdominal pain and distension,nausea and vomiting,and specific gastrointestinal markers(HSP70,I-FABP,DAO,D-lactate),were monitored and compared between the two groups.Results:After treatment,the postoperative bowel sound recovery time,first postoperative exhaust time,duration of abdominal pain,and duration of abdominal distension were shorter in the experimental group than in the control group(P<0.05).The 6-hour and 48-hour integral values of the experimental group were significantly lower than those of the control group.In the experimental group,60%of the patients were completely cured of gastrointestinal function after surgery,whereas only 32.5%of the patients in the control group were cured.The main symptom scores(abdominal pain,abdominal distension,nausea and vomiting)on the third postoperative day and the total symptom scores on the third postoperative day were significantly lower in the experimental group than in the control group(P<0.05).The values of HSP70,I-FABP,DAO,and D-lactate in the experimental group on postoperative day one were significantly lower than those in the control group(P<0.05).Conclusion:The combination of the Chinese and Western medicine ERAS programs of low-frequency pulse electrophysiology technology plus auricular acupuncture can accelerate local gastrointestinal blood circulation during the perioperative period of gynecology,promote the recovery of gastrointestinal function,promote anal exhaustion,and prevent the occurrence of postoperative abdominal pain and bloating.The combination of Chinese and Western medicine ERAS can increase gastrointestinal fluid secretion,increase gastrointestinal hormone and blood flow values,increase gastrointestinal electrophysiological detection values,and change the indicators of gastrointestinal dysfunction.

A retrospective observational study on maintenance and complications of totally implantable venous access ports in 563 patients:Prolonged versus short flushing intervals

Objectives:To assess whether the extension of the flushing interval will increase risks of complications associated with totally implantable venous access port(TIVAP)in the off-treatment period.Methods:A retrospective single-center observational study was performed.Patients with a TIVAP in the off-treatment period that underwent regular flushing in our clinic were included.Data concerning patients and their TIVAPs were recorded.Patient baseline characteristics and TIVAP-related complications were analyzed.Continuous variables were analyzed by ANOVA or the Kruskal-Wallis H test.To compare the occurrence of TIVAP-related complications,the chi-square test was used;if needed,Fisher’s exact test was used.Results:Totally 607 patients were reviewed,and 563 patients were finally included.Thirteen complications were recorded,including 11 cases of catheter occlusion(1.95%),one case of port cannula rotation(0.18%),and one case of catheter tip malposition(0.18%).No device-related infection or venous thrombosis was recorded.Among these patients,the average flushing interval was 35.27±13.09 days.Patients were divided into three groups according to the flushing interval:every 28 days or less(Group 1,n=133);every 29-44 days(Group 2,n=350);and every 45 days or more(Group 3,n=80).No significant difference in catheter-related complications was found among the three groups(P>0.05).Conclusions:In the TIVAP off-treatment period,patients without any history of TIVAP-related complications during approximately one year can attempt to prolong the flushing interval to more than 4 weeks;we further suggest that 5-6 weeks may be an appropriate option for these patients.

Nanoengineered Shear-Thinning Hydrogel Barrier for Preventing Postoperative Abdominal Adhesions

More than 90%of surgical patients develop postoper-ative adhesions,and the incidence of hospital re-admissions can be as high as 20%.Current adhesion barriers present limited efficacy due to difficulties in application and incompatibility with minimally invasive interventions.To solve thisclinical limitation,we developed an injectable and sprayable shear-thinning hydrogel barrier(STHB)composed of silicate nanoplatelets and poly(ethylene oxide).We optimized this technology to recover mechanical integrity after stress,enabling its delivery though inject-able and sprayable methods.We also demonstrated limited cell adhesion and cytotoxicity to STHB compositions in vitro.The STHB was then tested in a rodent model of peritoneal injury to determine its e cacy preventing the formation of postoperative adhesions.After two weeks,the peritoneal adhesion index was used as a scoring method to determine the formation of postoperative adhesions,and STHB formulations presented superior e cacy compared to a commercially available adhesion barrier.Histological and immunohistochemical examination showed reduced adhesion formation and minimal immune infiltration in STHB formulations.Our technology demonstrated increased e cacy,ease of use in complex anatomies,and compatibility with di erent delivery methods,providing a robust universal platform to prevent postoperative adhesions in a wide range of surgical interventions.

Decorating ketjen black with ultra-small Mo_(2)C nanoparticles to enhance polysulfides chemisorption and redox kinetics for lithium-sulfur batteries

The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile "in-situ growth" method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.

Improved Adaptive Differential Evolution Algorithm for the Un-Capacitated Facility Location Problem

The differential evolution algorithm is an evolutionary algorithm for global optimization and the un-capacitated facility location problem (UFL) is one of the classic NP-Hard problems. In this paper, combined with the specific characteristics of the UFL problem, we introduce the activation function to the algorithm for solving UFL problem and name it improved adaptive differential evolution algorithm (IADEA). Next, to improve the efficiency of the algorithm and to alleviate the problem of being stuck in a local optimum, an adaptive operator was added. To test the improvement of our algorithm, we compare the IADEA with the basic differential evolution algorithm by solving typical instances of UFL problem respectively. Moreover, to compare with other heuristic algorithm, we use the hybrid ant colony algorithm to solve the same instances. The computational results show that IADEA improves the performance of the basic DE and it outperforms the hybrid ant colony algorithm.

横缝深止水布设对蜗壳应力的影响规律研究

横缝深止水方案的布设对轴流式机组蜗壳部位的应力影响较大,而深止水方案的布设通常根据工程经验确定,没有统一的规范。止水方案的布设在满足防渗和安全的同时,应选择最优布设使其对蜗壳应力的影响较小。依托某轴流式水电站实际工程,建立厂房的ANSYS三维有限元模型,模拟在机组正常运行和检修工况下,横缝深止水在上游处闭合和上游处联通两种方案的不同止水布设对蜗壳应力的影响。对比两种深止水方案下蜗壳进口断面、内部典型断面和外包混凝土的应力变化,结果表明:随着止水位置的上移,两种深止水方案下的蜗壳应力变化规律相同,但相同的止水位置下,上游联通方案对蜗壳各种应力的减小幅度是上游闭合方案的2倍以上,横缝深止水布设时可优先采用上游联通方案进行止水。