Risk Stratification and Prognosis of Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Background:Current guidelines for managing pulmonary arterial hypertension(PAH)recommend a risk strati-fication approach.However,the applicability and accuracy of these strategies for PAH associated with congenital heart disease(PAH-CHD)require further validation.This study aims to validate the reliability and predictive accuracy of a simplified stratification strategy for PAH-CHD patients over a three-year follow-up.Additionally,new prognostic variables are identified and novel risk stratification methods are developed for assessing and managing PAH-CHD patients.Methods:This retrospective study included 126 PAH-CHD patients.Clinical and biochemical variables across risk groups were assessed using Kruskal-Wallis and Fisher’s exact tests.Indepen-dent risk factors were identified using ordered logistic regression,while Kaplan-Meier and Cox proportional hazards regression analyses evaluated their impact on all-cause mortality.A new stratification model for the PAH-CHD population was constructed based on these analyses.Results:Significant survival differences across stratified risk groups were observed(p<0.001),validating the effectiveness of the simplified risk stratification method in PAH-CHD patients.Prothrombin activity was a strong independent predictor of adverse outcomes of PAH-CHD patients(Hazard ratio 0.95,p<0.001,C-index 0.70).A model combining N-terminal pro-brain natriuretic peptide,prothrombin activity,albumin,and right atrial area achieved an area under the curve of 0.89 and a C-index of 0.85.Conclusions:The simplified risk stratification method is applicable to PAH-CHD patients.Prothrombin activity is a strong independent predictor of adverse outcomes.A comprehensive risk stratification approach,incorporating both established and novel biomarkers,enhances accessibility and offers predictive efficacy during follow-up for PAH-CHD patients,comparable to established models.

Interactive Media Visual Interpretation of Traditional Chinese Graphics in Urban Public Spaces

This paper focuses on the application of interactive media technology in the visual interpretation of traditional graphic urban public spaces in China.Case studies and practical exploration show that interactive media technologies such as projection mapping,interactive devices,virtual reality technology,etc.,have realized the diversity of traditional graphics display forms in urban public space.The rich interactive experience design enhances the sense of participation and experience of urban citizens and tourists and promotes the visual culture transmission of traditional Chinese graphics.The future urban public space exhibition is destined to continue to deepen the integration of technology and graphics,promote the visual communication of traditional Chinese graphics visual interpretation in urban public space,and promote sustainable innovation in cultural output in urban public space exhibitions around the world.

Thermal Compensation and Fuzzy Control for Developing a High-Precision Optical Lens Mold

Precision plastic lenses often exhibit dimensional deviations due to the thermal expansion of the mold during injection molding.Although this deviation is smaller in micron-sized(1–5μm)lenses,it exceeds the tolerance requirement of such lenses.It is difficult to resolve this dimensional issue by using injection molding parameters(e.g.,melt temperature,injection speed,and hold pressure).In this study,the thermal analysis of a mold was conducted,and it was confirmed that the deviation of lens dimension was caused by the thermal instability and thermal expansion of the mold.Due to the inconsistent heat distribution of the fixed and the movable side of the mold,the position of the location system was displaced approximately 1 to 5μm.In this study,thermal compensation technology for this the mold was investigated.The temperature on both sides of the mold was measured,and mold temperature could be adjusted automatically using a control strategy based on fuzzy theory.During the mold preheating or mass production stage,the temperature on both sides of the mold could be easily adjusted to quickly obtain the required temperature range.The dilatation on both sides of the mold was revised to improve the alignment accuracy of the cavity,and the decenter error of these injection lenses was reduced to 1μm.This technology can markedly improve the production yield and efficiency of plastic products requiring an extremely high dimensional accuracy.

Combination therapy to overcome ferroptosis resistance by biomimetic self-assembly nano-prodrug

Ferroptosis has emerged as a potent form of no-apoptotic cell death that offers a promising alternative to avoid the chemoresistance of apoptotic pathways and serves as a vulnerability of cancer.Herein,we have constructed a biomimetic self-assembly nano-prodrug system that enables the co-delivery of gefitinib(Gefi),ferrocene(Fc)and dihydroartemisinin(DHA)for the combined therapy of both ferroptosis and apoptosis.In the tumor microenvironment,this nano-prodrug is able to disassemble and trigger drug release under high levels of GSH.Interestingly,the released DHA can downregulate GPX4 level for the enhancement of intracellular ferroptosis from Fc,further executing tumor cell death with concomitant chemotherapy by Gefi.More importantly,this nano-prodrug provides highly homologous targeting ability by coating related cell membranes and exhibits outstanding inhibition of tumor growth and metastasis,as well as no noticeable side-effects during treatments.This simple small molecular self-assembled nano-prodrug provides a new reasonably designed modality for ferroptosis-combined chemotherapy.

磁性修饰的镧系上转换纳米晶体应用于指纹信息识别

新型磁性荧光材料的开发对鉴定和刑事侦查具有重要意义。由于传统相机中使用的光敏元件在500~700nm范围内表现出最高的量子效率,因此以507~533 nm、533~568 nm和637~683 nm为主发射峰的镧系上转换纳米粒子(UCNPs)适合用于构建磁性荧光材料。本文通过配体连接的方法证实了一种磁性上转换纳米颗粒—NaGdF_(4):Yb,Er-Fe_(3)O_(4)。在优化反应参数后,复合颗粒获得了优异的磁性能和上转换荧光强度,并且可在各种基底上实现高对比度的潜在指纹识别。得益于上转换发光与磁性的结合,指纹识别具有了高灵敏度与通用性。

Quantum State Transfer between a Mechanical Oscillator and a Distant Moving Atom

We propose a scheme for high fidelity quantum state transfer from a mechanical oscillator to a distant moving atom. In the scheme, two optical cavities connected by an optical fiber are interacted effectively through adiabatically eliminating fiber mode under large detuning limit. The quantum state transfer fidelity can be raised asymptotically to 100% by optimizing the Gaussian pulse G(t), the maximum atom-cavity coupling strength Ωmax, and the atomic velocity v. We also show that the affect of dissipation can be obviously depressed by synchronously increasing Ωmax and v.

层叠碳布加工设备技术改造研究

针对层叠碳布加工生产的现状及应用需求,结合碳纤维性质和加工形式造成的碳纤维断线问题,进行层叠碳布加工设备的改造设计。通过改变缝纫机缝针结构和运动方式,采用双针系统并配以松线辅助机构,明确各执行构件之间的相互配合关系,绘制相对应的运动循环图,并对改进机构进行三维建模、装配,对执行构件进行运动学分析。结果表明:改进后的层叠碳布加工设备解决了缝制过程中的断线问题,且双针机构在内外针不断交替的过程中缝纫变得更加平滑,缝纫效率提高了10%左右。认为:改进的双针机构与松线辅助机构能够实现降低断线率和提升层叠碳布生产效率的目的。

内嵌硫化镉与上转换纳米颗粒的二氧化钛复合纳米管用于近红外光驱动光催化（英文）

由于近红外光在太阳光谱中占44%,因此,近红外光驱动的光催化剂的研制具有十分重要的意义.上转换发光材料可将低能量的近红外光子转换为高能光子,这种高能光子可以通过构建荧光共振转移系统将能量转移并活化量子效率较高的半导体材料,对于太阳能的转化利用具有潜在的应用前景.在本文中,通过胶体化学的过程在电纺丝制备的内嵌CdS纳米颗粒以及上转换荧光纳米颗粒(UCNPs)的二氧化硅复合纳米纤维表面外延生长一层二氧化钛层,通过高温煅烧得到二氧化钛复合纳米管.我们通过二氧化硅结构将CdS纳米颗粒与上转换荧光纳米颗粒紧紧束缚在一起,实现较高的荧光共振能量转移.而且,选择β-NaYF_4:Yb(30%),Tm(0.5%)@NaYF_4:Yb(20%),Er(2%)作为纳米能量转换器,替代以前研究工作中使用的β-NaYF_4:Yb(30%),Tm(0.5%)或者β-NaYF_4:Yb(30%),Tm(0.5%)@NaYF_4纳米颗粒,来进一步提高近红外光的转换效率.通过透射电子显微镜照片很清楚的观察到制备的Ti O2复合纳米管内部内嵌有大量的CdS与上转换纳米颗粒.通过X-射线衍射以及X-射线光电子能谱能仪器对产物的物相以及表面的化学组成进行了细致的表征.结果显示,通过本实验方法已经成功获得了Ti O2复合纳米管.用稳态与瞬态荧光仪研究了最终样品的荧光性质.研究结果揭示,与上转换纳米颗粒以及二氧化硅复合纳米纤维相比,复合二氧化钛纳米管可以将上转换荧光纳米颗粒的(UV-Vis)部分荧光完全淬灭了.特别是,铒离子的荧光(650 nm)也被有效淬灭转移,说明本研究采用β-NaYF_4:Yb(30%),Tm(0.5%)@NaYF_4:Yb(20%),Er(2%)纳米能量转换器,可以提高近红外光的转换效率,紫外-可见吸收光谱证实,这种二氧化钛纳米管在紫外-可见光区中的吸收光谱与β-NaYF_4:Yb(30%),Tm(0.5%)@NaYF_4:Yb(20%),Er(2%)纳米颗粒的荧光光谱具有较大的重叠,使得上转换荧光纳米颗粒与CdS以及二氧化钛组分之间的荧光共振转移的效率大大提高,进而会显著提高光催化的效果.以罗丹明染料作为污染物为模型,我们研究了罗丹明染料在氙灯下或者近红外光光照下的光催化分解实验.研究结果表明,90%的罗丹明染料分子在20 min内就被降解掉,效率高于其它的近红外光催化剂.上转换荧光纳米颗粒的能量转换效率可以得到大幅度提高,本研究工作中制备的光催化剂利用太阳能的效率将会得到极大提高,在未来为能源危机以及环境保护提供一种可供选择的方法与技术.

Removal of a large foreign body in the rectosigmoid colon by colonoscopy using gastrolith forceps

Rectal foreign bodies are man-made injury that occurs occasionally.The management depends on its depth and the consequence it caused.We here report a case of rectal foreign body(a glass bottle measuring about 38 mm×75 mm)which was located 13-15 cm from the anus.The patient had no sign of perforation,and we managed to remove it using endoscopy with gastrolith forceps.

Application of blunt dissection in ESD of a gastric submucosal tumor

We performed endoscopic submucosal dissection of a gastric fundus tumor.It was difficult to strip the tumor completely due to space limitation,and we used blunt dissection to remove the tumor quickly and safely.Firstly,the basal area of the 2.5 cm submucosal tumor located in the gastric fundus was cut open,and the mucosa was dissected.The tumor was difficult to peel,therefore,a snare was used and the tumor was pulled and tightened slightly.Short electronic coagulation was used during the procedure.The tumor was then bluntly dissected.This method ensured rapid and complete removal of the tumor.

One-pot synthesis and optical properties of In- and Sn-doped ZnO nanoparticles

Colloidal indium-doped zinc oxide(IZO) and tin-doped zinc oxide(ZTO) nanoparticles were successfully prepared in organic solution,with metal acetylacetonate as the precursor and oleylamine as the solvent. The crystal and optical properties were characterized by X-ray diffraction,UV?visible spectrophotometry,and fluorescence spectroscopy,respectively; the surface and structure morphologies were observed by scanning electron microscopy and transmission electron microscopy. The XRD patterns of the IZO and ZTO nanoparticles all exhibited similar diffraction peaks consistent with the standard XRD pattern of Zn O,although the diffraction peaks of the IZO and ZTO nanoparticles were slightly shifted with increasing dopant concentration. With increasing dopant concentration,the fluorescent emission peaks of the IZO nanoparticles exhibited an obvious red shift because of the difference in atomic radii of indium and zinc,whereas those of the ZTO nanoparticles exhibited almost no shift because of the similarity in atomic radii of tin and zinc. Furthermore,the sizes of the IZO and ZTO nanoparticles distributed in the ranges 20–40 and 20–25 nm,respectively,which is attributed to the difference in ionic radii of indium and tin.

Small molecule interfacial cross-linker for highly efficient two-dimensional perovskite solar cells

The nonradiative recombination of charge carriers at the hole transport layer(HTL)/perovskite interface generally induces remarkable performance loss of the inverted two-dimensional perovskite solar cells(2D PSCs). Herein, a cross-linkable small molecule of 2-mercaptoimidazole(2-MI) was introduced into the nickel oxide(NiO_(x))/2D perovskite interface. Experiments have confirmed the formation of Ni-N covalent bond by N atom in the 2-MI and Ni in the NiO_(x) and the coordinating between S atom of 2-MI and under-coordinated Pb^(2+) near to the NiO_(x)/perovskite interface, which contributes to creating a crosslinking between NiO_(x)/perovskite interface to restrain charge carrier recombination and enhance the extraction of hole carriers at the interface. Besides, the 2-MI modification layer is also beneficial for promoting the crystallinity of 2D perovskite. Consequently, the inverted 2D PSCs with 2-MI modification achieved the best power conversion efficiency of 15%. This paves a route to acquire highly efficient 2D PSCs by constructing a cross-linking at the NiO_(x)HTL/2D perovskite interface.

Aerodynamic Characteristics of Projectile with Exotic Wraparound Wings Configuration

A projectile with exotic wraparound wings( WAW) configuration is designed to improve the finstabilized projectile shooting quality. Two fin-stabilized projectiles with the same body with and without exotic WAW configuration are simulated numerically by applying the Roe scheme. The shear-stress transport turbulence models and the lower-upper symmetric Gauss-Seidel implicit method are used to solve 3D Reynoldsaveraged Navier—Stokes equations. The differences in aerodynamic coefficients and aerodynamic characteristics of the projectiles when the Mach number varies from 0. 35 to 0. 95 are obtained,and the cause of these differences is analyzed. The calculation results indicate that the lift-to-drag ratio of the projectile significantly increases,the rolling moment decreases,and the position of the pressure center of the projectile shows relatively small changes when the exotic WAW configuration is used. Therefore,this projectile can obviously reduce rolling effect,enlarge range and improve flying stability.

气肋式膜结构及其应用

气肋式膜结构是一种采用高压气肋作为支承体系的充气膜结构,通过将多根气肋连接成整体的方式创造出使用空间,具有轻质便携、可快速运输、低耗能、安全可靠等优点。为满足跨度大、承载性能强的要求,国内外学者对此进行了充分的研究,气肋式膜结构得到了广泛的应用和发展,成为国内外众多城市的象征性建筑。为此,首先对气肋式膜结构的结构形式进行了综述,概述了气肋内压的作用和设计要求,简述了工程应用中的设计内压,概括了使用性能监测手段和失效性能研究方法。随后对气肋式膜结构工程应用案例进行了归纳,此种结构形式已广泛应用于展览馆、运动场所、实验室、充气机库、存储仓库等实际工程项目中。在大跨度气肋式膜结构建筑中,索笼绑带型气肋式膜结构提供了一种有效的方法来连接多根气肋使其形成整体。绑带式连接可以通过增加绑带布置提高单根气肋的承载能力以及气肋之间的协同工作能力,着重介绍了索笼绑带型气肋式膜结构的结构特点和BUILDAIR公司采用索笼绑带型气肋式膜结构建设的大型飞机机库工程应用。最后对索笼绑带型气肋式膜结构工程应用中的气肋直径与结构跨度的关系进行了统计分析,结果表明,在大部分索笼绑带型气肋式膜结构工程案例中气肋直径与结构跨度的比值约为1/10,但具体气肋直径的选取,还需根据实际的工程条件通过设计分析后确定。

Parametric analysis of craniocerebral injury mechanism in pedestrian trafficaccidents based on finite element methods

Purpose:The toughest challenge in pedestrian traffic accident identification lies in ascertaining injurymanners.This study aimed to systematically simulate and parameterize 3 types of craniocerebral injuryincluding impact injury,fall injury,and run-over injury,to compare the injury response outcomes ofdifferent injury manners.Methods:Based on the total human model for safety(THUMS)and its enhanced human model THUMShollow structures,a total of 84 simulations with 3 injury manners,different loading directions,andloading velocities were conducted.Von Mises stress,intracranial pressure,maximum principal strain,cumulative strain damage measure,shear stress,and cranial strain were employed to analyze the injuryresponse of all areas of the brain.To examine the association between injury conditions and injuryconsequences,correlation analysis,principal component analysis,linear regression,and stepwise linearregression were utilized.Results:There is a significant correlation observed between each criterion of skull and brain injury(p<0.01 in all Pearson correlation analysis results).A 2-phase increase of cranio-cerebral stress andstrain as impact speed increases.In high-speed impact(>40 km/h),the Von Mises stress on the skull waswith a high possibility exceed the threshold for skull fracture(100 MPa).When falling and makingtemporal and occipital contact with the ground,the opposite side of the impacted area experienceshigher frequency stress concentration than contact at other conditions.Run-over injuries tend to have amore comprehensive craniocerebral injury,with greater overall deformation due to more adequate kinetic energy conduction.The mean value of maximum principal strain of brain and Von Mises stress ofcranium at run-over condition are 1.39 and 403.8 MPa,while they were 1.31,94.11 MPa and 0.64,120.5 MPa for the impact and fall conditions,respectively.The impact velocity also plays a significant rolein craniocerebral injury in impact and fall loading conditions(the p of all F-test<0.05).A regressionequation of the craniocerebral injury manners in pedestrian accidents was established.Conclusion:The study distinguished the craniocerebral injuries caused in different manners,elucidatedthe biomechanical mechanisms of craniocerebral injury,and provided a biomechanical foundation forthe identification of craniocerebral injury in legal contexts.

Efficient carrier transport via dual-function interfacial engineering using cesium iodide for high-performance perovskite solar cells based on NiOx hole transporting materials

As a famous hole transporting material, nickle oxide (NiOx) has drawn enormous attention due to its low cost and superior stability. However, the relatively low conductivity and high-density surface trap states of NiOx severely limit device performance in solar cell applications. Interfacial engineering is an efficient approach to achieve remarkable hole-transporting performance by surface passivation. Herein, the efficient NiOx hole transport layer was prepared by surface passivation engineering strategy via facile solution processes with cesium iodide (CsI). It is demonstrated that CsI plays a super-effective dual-function role in inverted solar cell device: On one hand, the presence of CsI hugely passivates the surface trap states at the NiOx/perovskite interface along with obviously improved conductivity by the incorporated Cs^(+);on the other hand, the ions immigration is significantly suppressed by the presence of I ion for high-quality perovskite films, resulting in a stable contact interface. The ameliorative interface leads to largely reduced carrier non-radiative recombination, attributing to boosted carrier extraction efficiency. As a result, decent power conversion efficiency (PCE) of 18.48% with a noticeable fill factor (FF) beyond 80% was achieved. This facile and efficient surface engineering approach with dual-function shows excellent potential for the design of high-performance functional interfacial modification layer to achieve high-performance solar cells.

Multi-class detection of cherry tomatoes using improved YOLOv4-Tiny

The rapid and accurate detection of cherry tomatoes is of great significance to realizing automatic picking by robots.However,so far,cherry tomatoes are detected as only one class for picking.Fruits occluded by branches or leaves are detected as pickable objects,which may cause damage to the plant or robot end-effector during picking.This study proposed the Feature Enhancement Network Block(FENB)based on YOLOv4-Tiny to solve the above problem.Firstly,according to the distribution characteristics and picking strategies of cherry tomatoes,cherry tomatoes were divided into four classes in the nighttime,and daytime included not occluded,occluded by branches,occluded by fruits,and occluded by leaves.Secondly,the CSPNet structure with the hybrid attention mechanism was used to design the FENB,which pays more attention to the effective features of different classes of cherry tomatoes while retaining the original features.Finally,the Feature Enhancement Network(FEN)was constructed based on the FENB to enhance the feature extraction ability and improve the detection accuracy of YOLOv4-Tiny.The experimental results show that under the confidence of 0.5,average precision(AP)of non-occluded,branch-occluded,fruit-occluded,and leaf-occluded fruit over the day test images were 95.86%,92.59%,89.66%,and 84.99%,respectively,which were 98.43%,95.62%,95.50%,and 89.33% on the night test images,respectively.The mean Average Precision(mAP)of four classes over the night test set was higher(94.72%)than that of the day(90.78%),which were both better than YOLOv4 and YOLOv4-Tiny.It cost 32.22 ms to process a 416×416 image on the GPU.The model size was 39.34 MB.Therefore,the proposed model can provide a practical and feasible method for the multi-class detection of cherry tomatoes.

高秆野生稻内生固氮细菌多样性

高秆野生稻(Oryza alta)是一种重要的种质资源,其组织内也蕴藏着非常宝贵的功能微生物资源。本实验采用无氮培养基,从高秆野生稻中分离到43株内生固氮菌,结合乙炔还原法测定其固氮酶活性。经固氮酶基因(nifH)的PCR扩增检测,43株内生固氮菌代表菌株均能扩增出固氮酶基因片段。利用IS-PCR DNA指纹图谱和SDS-PAGE全细胞蛋白电泳图谱将获得的菌株聚类为6个类群(I、II、III、IV、V、VI)。对各个类群的代表菌株(ZF3,ZF8,ZF13,ZF15,ZF24,ZF43)进行16S r RNA基因序列测定,结果表明,类群I属于土生拉乌尔菌(Raoultella terrigena),类群II属于类肺炎克雷伯氏菌类肺炎亚种(Klebsiella quasipnmoniae subsp.quasipneumoniae),类群III属于越南伯克氏菌(Burkholderia vietnamiensis),类群IV的菌株代表肠秆菌属的一个类群(Enterobacter sp.),类群V的菌株属于门多萨假单胞菌(Pseudomonas mendocina),类群VI归属于固氮植物菌(Phytobacter diazotrophicus)。Biolog聚类结果与IS-PCR指纹图谱类型及SDS-PAGE全细胞蛋白聚类结果一致。Biolog板测定结果显示,来自不同类群的代表菌株对碳源的利用差异显著,说明野生稻内多样的内生固氮菌从环境中获取碳源和氮素的适应能力较强。

Analysis of chronic kidney disease staging with different estimated glomerular filtration rate equations in Chinese centenarians

Background: Accurate estimation of the glomerular filtration rate (GFR) and staging of chronic kidney disease (CKD) are important. Currently, there is no research on the differences in several estimated GFR equations for staging CKD in a large sample of centenarians. Thus, this study aimed to investigate the differences in CKD staging with the most commonly used equations and to analyze sources of discrepancy. Methods: A total of 966 centenarians were enrolled in this study from June 2014 to December 2016 in Hainan province, China. The GFR with the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Berlin Initiative Study 1 (BIS1) equations were estimated. Agreement between these equations was investigated with the k statistic and Bland-Altman plots. Sources of discrepancy were investigated by partial correlation analysis. Results: The k values of the MDRD and CKD-EPI equations, MDRD and BIS1 equations, and CKD-EPI and BIS1 equations were 0.610, 0.253, and 0.381, respectively. Serum creatinine (Scr) explained 10.96%, 41.60% and 17.06% of the variability in these three comparisons, respectively. Serum uric acid (SUA) explained 3.65% and 5.43% of the variability in the first 2 comparisons, respectively. Gender was associated with significant differences in these 3 comparisons (P<0.001). Conclusions: The strengths of agreement between the MDRD and CKD-EPI equations were substantial, but those between the MDRD and BIS 1 equations and the CKD-EPI and BIS 1 equations were fair. The difference in CKD staging of the first 2 comparisons strongly depended on Scr, SUA and gender, and that of CKD-EPI and BIS1 equations strongly depended on Scr and gender. The incidence at various stages of CKD staging was quite different. Thus, a new equation that is more suitable for the elderly needs to be built in the future.

Numerical study on Rayleigh-Taylor effect on cylindrically converging Richtmyer-Meshkov instability

Evolution of a two-dimensional air/SF6 single-mode interface is numerically investigated by an upwind CE/SE method under a cylindrically converging circumstance. The Rayleigh-Taylor effect caused by the flow deceleration on the phase inversion(RTPI)is highlighted. The RTPI was firstly observed in our previous experiment, but the related mechanism remains unclear. By isolating the three-dimensional effect, it is found here that the initial amplitude(a0), the azimuthal mode number(k0) and the re-shocking moment are the three major parameters which determine the RTPI occurrence. In the variable space of(k0, a0), a critical a0 for the RTPI occurrence is solved for each k0, and there exists a threshold value of k0 below which the RTPI will not occur no matter what a0 is. There exists a special k0 corresponding to the largest critical a0, and the reduction rule of critical a0 with k0 can be well described by an exponential decay function. The results show that the occurrence of the RTPI requires a small a0 which should be less than a critical value, a large k0 which should exceed a threshold, and a right impinging moment of the re-shock which should be later than the RTPI occurrence. Finally, the effects of the incident shock strength, the density ratio and the initial position of the interface on the threshold value of k0 and on the maximum critical a0 are examined. These new findings would facilitate the understanding of the converging Richtmyer-Meshkov instability and would be helpful for designing an optimal structure of the inertia confinement fusion capsule.