蛛网膜下腔出血患者外周血NLR、LMR、PLR和SII值变化的临床意义

目的 分析动脉瘤性蛛网膜下腔出血(aSAH)对血液学参数的影响及其与患者临床状态和短期预后的关系。方法 分析2019年3月至2022年5月于四川省科学城医院神经外科治疗的62例颅内动脉瘤(IA)破裂急性期患者和55例正常对照组。采用流式细胞术分析两组患者外周血中白细胞(WBC)与淋巴细胞(LC)计数的变化,计算中性粒细胞/淋巴细胞比(NLR)、淋巴细胞/单核细胞比(LMR)、血小板/淋巴细胞比(PLR)和全身免疫-炎症指数(SII),并分析血液学参数与患者临床状况和短期预后的关系。结果 与正常对照组相比,IA破裂组WBC、中性粒细胞(Ns)计数、NLR以及SII均明显升高,而LC计数和LMR降低。此外相比于临床状态恢复良好的患者,临床状态较差的患者LC计数明显降低,而NLR、PLR和SII值明显升高。格拉斯哥昏迷评分法(GCS)评分较低的患者CD3+、CD4-、CD8-细胞比例减少。此外,LC计数降低和PLR升高与较差的短期预后相关。结论 IA破裂后会导致全身免疫和炎症反应,LC计数、NLR、PLR和SII值可以作为临床状态及预后的标志物。

Microstructure and impact behavior of Mg-4Al-5RE-xGd cast magnesium alloys

This work investigated the microstructure and impact behavior of Mg-4Al-5RE-xGd(RE represents La-Ce mischmetal;x=0,0.2,0.7 wt.%)alloys cast by high-pressure die casting(HPDC),permanent mold casting(PMC),and sand casting(SC)techniques.The results indicated that with increasing Gd content,the grain sizes of the HPDC alloy had a slight change,but the grains of the PMC and SC alloys were significantly refined.Besides,the acicular Al_(11)RE_(3)phase was modified into the short-rod shape under the three casting conditions.The impact toughness of the studied alloy was mainly dominated by the absorbed energy during the crack initiation.With increasing Gd content,the impact toughness of the studied alloy monotonically increased due to the lower tendency of the modified second phase toward crack initiation.The impact stress was higher than the tensile stress,exhibiting a strain rate sensitivity for the mechanical response;however,the HPDC alloy had an inconsistent strain rate sensitivity during the impact event due to the transformation of the deformation mechanism from twinning to slip with increasing strain.Abundant dimples covered the fracture surface of the fine-grained HPDC alloys,indicating a typical ductile fracture.Nevertheless,due to the deficient{1012}twinning activity and the suppressed grain boundary sliding during the impact event,the HPDC alloys showed insufficient plastic deformation capacity.

Age-related secretion of grancalcin by macrophages induces skeletal stem/progenitor cell senescence during fracture healing

Skeletal stem/progenitor cell(SSPC)senescence is a major cause of decreased bone regenerative potential with aging,but the causes of SSPC senescence remain unclear.In this study,we revealed that macrophages in calluses secrete prosenescent factors,including grancalcin(GCA),during aging,which triggers SSPC senescence and impairs fracture healing.Local injection of human rGCA in young mice induced SSPC senescence and delayed fracture repair.Genetic deletion of Gca in monocytes/macrophages was sufficient to rejuvenate fracture repair in aged mice and alleviate SSPC senescence.Mechanistically,GCA binds to the plexin-B2 receptor and activates Arg2-mediated mitochondrial dysfunction,resulting in cellular senescence.Depletion of Plxnb2 in SSPCs impaired fracture healing.Administration of GCA-neutralizing antibody enhanced fracture healing in aged mice.Thus,our study revealed that senescent macrophages within calluses secrete GCA to trigger SSPC secondary senescence,and GCA neutralization represents a promising therapy for nonunion or delayed union in elderly individuals.

Estimating the Texture of Purple Soils Using Vis-NIR Spectroscopy and Optimized Conversion Models

Soil texture is an indicator of soil physical structure which delivers many ecological functions of soils such as thermal regime, plant growth, and soil quality. However, traditional methods for soil texture measurement are time-consuming and labor-intensive. This study attempts to explore an indirect method for rapid estimating the texture of three subgroups of purple soils (i.e. calcareous, neutral, and acidic). 190 topsoil (0 - 10 cm) samples were collected from sloping croplands in Tongnan and Beibei Districts of Chongqing Municipality in China. Vis-NIR spectrum was measured and processed, and stepwise multiple linear regression (SMLR), partial least squares regression (PLSR), and back propagation neural network (BPNN) models were constructed to inform the soil texture. The clay fractions ranged from 4.40% to 27.12% while sand fractions ranged from 0.34% to 36.57%, hereby soil samples encompass three textural classes (i.e. silt, silt loam, and silty clay loam). For the original spectrum, the texture of calcareous and neutral purple soils was not significantly correlated with spectral reflectance and linear models (SMLR and PLSR) exhibited low prediction accuracy. The correlation coefficients and the goodness-of-fits between soil texture and the transformed spectra of all soil groups increased by continuum-removal (CR), first-order differential (R'), and second-order differential (R") transformations. Among them, the R" had the best performance in terms of improving the correlation coefficients and the goodness-of-fits. For the calcareous purple soil, the SMLR exceeds PLSR and BPNN with a higher coefficient of determination (R2) and the ratio of performance to inter-quartile distance (RPIQ) values and lower root mean square error of validation (RMSEV), but for the neutral and acidic purple soils, the PLSR model has a better prediction accuracy. In summary, the linear methods (SMLR and PLSR) are more reliable in estimating the texture of the three purple soil groups when using Vis-NIR spectroscopy inversion.

基于网络药理学和分子对接探讨巴戟天抗动脉粥样硬化的靶点及信号通路

[目的]应用中药系统药理学数据库与分析平台(TCMSP)及小分子药物靶点预测在线平台(Swiss Target Prediction)和疾病基因组数据库,结合分子对接技术,预测巴戟天抗动脉粥样硬化(As)的靶点及信号通路。[方法]通过中药网络药理学数据库及小分子药物靶点预测在线平台挖掘巴戟天的有效成分及其所对应的靶点,利用GeneCards、OMIM、Disgenet、UniProt收集并筛选As相关的疾病基因靶点,获取交集基因,将其导入String 11.5数据库中,构建疾病-药物蛋白互作分析(String-PPI)网络图,利用Cytoscape 3.9.1软件对关键靶点网络进行可视化;此外,运用Metascape网络在线平台进行GO、KEGG富集挖掘出其抗As的分子靶点,并通过KEGG数据库绘制通路图。最后,使用Autodock vina 1.1.2软件对核心化合物及核心靶点基因进行分子对接验证。[结果]通过以上数据库共收集得到包括β-谷甾醇和蒽醌在内的17个有效药物化合物、73个核心靶点和1 450个关键疾病基因;取交集后得到巴戟天治疗As的35个核心基因;经String-PPI得到基因间有相互作用的SRC、PGTS2、TGFβ1、REN、ESR1、CASP3等32个基因;KEGG富集到75条信号通路,涉及脂质-动脉粥样硬化、晚期糖基化终末产物及受体、PI3K-Akt信号通路等相关通路;其中脂质-动脉粥样硬化通路主要涉及SRC、BCL2、BAX、CASP3、GSK3B、RXRA等6个靶基因。分子对接结果显示,巴戟天的主要化学成分与核心基因之间有较强的结合活性。[结论]巴戟天可能通过β-谷甾醇、蒽醌等主要有效化学成分调控SRC、PGTS2、TGFβ1、REN、RXRA、ESR1、CASP3等32个主要靶基因表达,减轻血管内皮炎症反应,抑制细胞增殖、迁移和凋亡,发挥抗As的作用。

GO/HTPB composite liner for anti-migration of small molecules

Hydroxyl-terminated polybutadiene/toluene diisocyanate(HTPB/TDI)system is widely used in composite solid propellants.The migrations of plasticizers and water molecules from solid propellants and surrounding environment to the inhibitor have always been the important issues.This study focuses on the preparation,characterization and anti-migration behavior of graphene oxide(GO)/HTPB nanocomposite liner.The GO/HTPB(GH)composite liners affect the migration of small molecules through a tighter cross-linked structure and weakening function of small molecule adsorption.The anti-migration performance of the liner at different temperatures was analyzed,and the influence of the added amount of GO on the anti-migration performance and adhesion performance was also systematically studied.The overall performance of the liner is optimized when the amount of GO filler is 0.3 wt%.After adding 0.3 wt%GO,the concentration of dioctyl sebacate(DOS)migrated into the liner is decreased by 23.28%,and the concentration of water molecules is decreased by 51.89%,indicating that the introduction of GO can significantly improve the anti-migration performance of the liner.In addition,the bond strength is greatly increased from 0.25 MPa to 0.95 MPa,which meets the application requirements of the current propellant system.This research provides an important way for the preparation of structure-function synergistic anti-migration composite liners.

Combining single-cell RNA sequencing and population-based studies reveals hand osteoarthritis-associated chondrocyte subpopulations and pathways

Hand osteoarthritis is a common heterogeneous joint disorder with unclear molecular mechanisms and no disease-modifying drugs.In this study,we performed single-cell RNA sequencing analysis to compare the cellular composition and subpopulationspecific gene expression between cartilage with macroscopically confirmed osteoarthritis(n=5)and cartilage without osteoarthritis(n=5)from the interphalangeal joints of five donors.Of 105142 cells,we identified 13 subpopulations,including a novel subpopulation with inflammation-modulating potential annotated as inflammatory chondrocytes.Fibrocartilage chondrocytes exhibited extensive alteration of gene expression patterns in osteoarthritic cartilage compared with nonosteoarthritic cartilage.Both inflammatory chondrocytes and fibrocartilage chondrocytes showed a trend toward increased numbers in osteoarthritic cartilage.In these two subpopulations from osteoarthritic cartilage,the ferroptosis pathway was enriched,and expression of iron overload-related genes,e.g.,FTH1,was elevated.To verify these findings,we conducted a Mendelian randomization study using UK Biobank and a population-based cross-sectional study using data collected from Xiangya Osteoarthritis Study.Genetic predisposition toward higher expression of FTH1 mRNA significantly increased the risk of hand osteoarthritis(odds ratio=1.07,95%confidence interval:1.02–1.11)among participants(n=332668)in UK Biobank.High levels of serum ferritin(encoded by FTH1),a biomarker of body iron overload,were significantly associated with a high prevalence of hand osteoarthritis among participants(n=1241)of Xiangya Osteoarthritis Study(P-for-trend=0.037).In conclusion,our findings indicate that inflammatory and fibrocartilage chondrocytes are key subpopulations and that ferroptosis may be a key pathway in hand osteoarthritis,providing new insights into the pathophysiology and potential therapeutic targets of hand osteoarthritis.

Enhanced selective hydrogenation of glycolaldehyde to ethylene glycol over Cu^(0)-Cu^(+)sites

Selective hydrogenation of hydroxyaldehydes to polyalcohols is challenging due to the competitive hydrogenation of C=O and CAO.This study develops heterogeneous Cu catalysts for the selective synthesis of ethylene glycol via batch liquid-phase hydrogenation of glycolaldehyde.SiO_(2)supported Cu,fabricated by ammonia evaporation,enables to catalyze the C=O bond hydrogenation with retaining the CAO bond intact,yielding higher selective hydrogenation activity with ethylene glycol selectivity up to 99.8%relative to MgO,Al_(2)O_(3),CeO_(2),and TiO_(2)supports and Cu/SiO_(2)synthesized by deposition–precipitation and impregnation.Characterizations confirm that highly efficient 20Cu/SiO_(2)-AE-623 K catalyst fabricated by ammonia evaporation is featured with larger Cu^(0)and Cu^(+)surface areas,of which the Cu^(+)species created from reducing copper phyllosilicate exhibit higher reactivity.A synergistic effect between Cu^(+)and Cu^(0)facilitates the selective adsorption/activation of glycolaldehyde on Cu^(+)sites and the dissociation of H_(2)on Cu^(0)sites,bringing a remarkable improvement in the selective hydrogenation performance.

High performance SiC trench-type MOSFET with an integrated MOS-channel diode

A novel SiC double-trench metal-oxide-semiconductor field effect transistor(MOSFET) with integrated MOS-channel diode is proposed and investigated by Sentaurus TCAD simulation. The new SiC MOSFET has a trench gate and a stepped-trench source, and features an integrated MOS-channel diode on the top sidewall of the source trench(MT MOS). In the reverse conduction state, the MOS-channel diode turns on firstly to prevent the internal parasitic body diode being activated, and thus reduces the turn-on voltage VFand suppresses the bipolar degradation phenomena. The VFof1.70 V(@Ids=-100 A/cm^(2)) for the SiC MT MOS is 38.2% lower than that of SiC double-trench MOSFET(DT MOS).Meanwhile, the reverse recovery charge Qrrof the MT MOS is 58.7% lower than that of the DT MOS at Iload= 700 A/cm^(2),and thus the reverse recovery loss is reduced. Furthermore, owing to the modulation effect induced by the double trenches,the MT MOS preserves the same superior forward conduction and blocking performance as those of DT MOS, with 22.9% and 18.2% improvement on breakdown voltage and RON,spcompared to the trench gate MOSFET with planar integrated SBD(ST MOS).

Novel double channel reverse conducting GaN HEMT with an integrated MOS-channel diode

A novel normally-off double channel reverse conducting(DCRC)HEMT with an integrated MOS-channel diode(MCD)is proposed and investigated by TCAD simulation.The proposed structure has two features:one is double heterojunctions to form dual 2DEG channels named the 1^(st)path and the 2^(nd)path for reverse conduction,and the other is the MCD forming by the trench source metal,source dielectric,and Ga N.At the initial reverse conduction stage,the MCD acts as a switch to control the 1^(st)path which would be turned on prior to the 2^(nd)path.Because of the introduction of the 1^(st)path,the DCRC-HEMT has an additional reverse conducting channel to help enhance the reverse conduction performance.Compared with the conventional HEMT(Conv.HEMT),the DCRC-HEMT can obtain a low reverse turn-on voltage(VRT)and its VRTis independent of the gate-source bias(VGS)at the same time.The DCRC-HEMT achieves the VRTof 0.62 V,which is 59.7%and 75.9%lower than that of the Conv.HEMT at VGS=0 V and-1 V,respectively.In addition,the forward conduction capability and blocking characteristics almost remain unchanged.In the end,the key fabrication flows of DCRC-HEMT are presented.

城市轨道车辆“弓”系转向架结构研究

目前我国城市轨道交通行业发展迅速,轨道交通里程飞速增长,转向架作为车辆运行的重要部件,其结构的设计与材料的选择对车速度及安全性起到重要影响。“弓”系转向架作为新概念,将对其结构进行建模与研究,并将磁性齿轮技术应用于新结构,减小振动摩擦以及噪声。从各部件的材料、空间结构、实用性角度出发,提出更优方案,使转向架向更具轻量化、强度高、耐腐蚀的方向发展。

COF-derived Co nanoparticles@N-doped carbon electrocatalysts for high performance Zn-air batteries

Precise modulation of the structure and composition of electrocatalysts is critical for promoting the kinetically sluggish process of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Covalent organic frameworks(COF)offer a novel way to create highly efficient electrocatalysts due to their tunable composition,structure and surface area.Herein,we report a high-efficiency bifunctional electrocatalyst comprising Co nanoparticles embedded within N-doped carbons(Co@NCs)for Zn-air batteries(ZABs).The Co@NC is yielded via the coordination of a triazine COF with Co-containing precursors and subsequent calcination under inert atmosphere.The as-prepared Co@NC exhibits remarkable ORR/OER performance and great potential in rechargeable ZABs.The liquid ZAB constructed with Co@NC provides both high specific capacity and power density.Remarkably,the ZAB exhibits a voltage gap of 0.8 V during discharge and charge cycles and high stability for 220 h compared to the Pt/C-assembled battery.This strategy for regulating electrocatalytic activities of COF-derived carbon materials could be expanded for creating various carbon catalysts.

Experimental investigation on the instability for NiO/β-Ga_(2)O_(3) heterojunction-gate FETs under negative bias stress

A NiO/β-Ga_(2)O_(3) heterojunction-gate field effect transistor(HJ-FET)is fabricated and it_(s)instability mechanisms are exper-imentally investigated under different gate stress voltage(V_(G,s))and stress times(t_(s)).Two different degradation mechanisms of the devices under negative bias stress(NBS)are identified.At low V_(G,s)for a short t_(s),NiO bulk traps trapping/de-trapping elec-trons are responsible for decrease/recovery of the leakage current,respectively.At higher V_(G,s)or long t_(s),the device transfer char-acteristic curves and threshold voltage(V_(TH))are almost permanently negatively shifted.This is because the interface dipoles are almost permanently ionized and neutralize the ionized charges in the space charge region(SCR)across the heterojunction inter-face,resulting in a narrowing SCR.This provides an important theoretical guide to study the reliability of NiO/β-Ga_(2)O_(3) hetero-junction devices in power electronic applications.

A self-healing and conductive ionic hydrogel based on polysaccharides for flexible sensors

In this study,we proposed a self-healing conductive hydrogel based on polysaccharides and Li+to serve as flexible sensors.At first,the oxidized sodium alginate(OSA)was obtained through the oxidation reaction of sodium alginate(SA).Then OSA,carboxymethyl chitosan(CMC),and agarose(AGO)were dissolved in LiCl solution,respectively.Finally,the hydrogel was obtained through heating,mixing,and cooling processes.Because of the Schiff base structure and hydrogen bonding,the hydrogel demonstrates good mechanical and self-healing properties.The presence of Li+provides good conductivity for the hydrogel.In addition,we demonstrated the application of the hydrogel as the flexible sensors.It can perceive the process of pressing Morse code with the index finger as a pressure sensor and monitor sliding movement of the thumb as the strain sensor to browse the web with the mobile phone.Thus,the selfhealing conductive hydrogel may have potential applications in flexible wearable sensors.

High-performance vertical GaN field-effect transistor with an integrated self-adapted channel diode for reverse conduction

A vertical GaN field-effect transistor with an integrated self-adapted channel diode(CD-FET)is proposed to improve the reverse conduction performance.It features a channel diode(CD)formed between a trench source on the insulator and a P-type barrier layer(PBL),together with a P-shield layer under the trench gate.At forward conduction,the CD is pinched off due to depletion effects caused by both the PBL and the metal-insulator-semiconductor structure from the trench source,without influencing the on-state characteristic of the CD-FET.At reverse conduction,the depletion region narrows and thus the CD turns on to achieve a very low turn-on voltage(V_(F)),preventing the inherent body diode from turning on.Meanwhile,the PBL and P-shield layer can modulate the electric field distribution to improve the off-state breakdown voltage(BV).Moreover,the P-shield not only shields the gate from a high electric field but also transforms part of C_(GD)to CGS so as to significantly reduce the gate charge(Q_(GD)),leading to a low switching loss(E_(switch)).Consequently,the proposed CD-FET achieves a low V_(F)of 1.65 V and a high BV of 1446 V,and V_(F),Q_(GD)and E_(switch)of the CD-FET are decreased by 49%,55%and 80%,respectively,compared with those of a conventional metal-oxide-semiconductor field-effect transistor(MOSFET).

Global burden of cirrhosis and other chronic liver diseases due to nonalcoholic fatty liver disease,1990-2019

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)has become the leading cause of cirrhosis and other chronic liver diseases(COCLDs).AIM To conduct a comprehensive and comparable updated analysis of the global,regional,and national burden of COCLDs due to NAFLD in 204 countries and territories from 1990 and 2019 by age,sex,and sociodemographic index.METHODS Data on COCLDs due to NAFLD were collected from the Global Burden of Diseases,Injuries,and Risk Factors Study 2019.Numbers and age-standardized prevalence,death,and disability-adjusted life years(DALYs)were estimated through a systematic analysis of modelled data from the Global Burden of Diseases,Injuries,and Risk Factors Study 2019.The estimated annual percentage change was used to determine the burden trend.RESULTS In 2019,the global age-standardized prevalence rate of COCLDs due to NAFLD was 15022.90 per 100000 population[95%uncertainty interval(UI):13493.19-16764.24],which increased by 24.51%(22.63%to 26.08%)from 1990,with an estimated annual percentage change of 0.78(95%confidence interval:0.74-0.82).In the same year,however,the age-standardized death rate and age-standardized DALYs per 100000 population were 1.66(95%UI:1.20-2.17)and 43.69(95%UI:31.28-58.38),respectively.North Africa and the Middle East had the highest prevalence rates of COCLDs due to NAFLD.The death rate increased with age up to the 95+age group for both sexes.Males had higher numbers of prevalence,death rate,and DALYs than females across all age groups before the 65-69 age group.The sociodemographic index was negatively correlated with the age-standardized DALYs.CONCLUSION Globally,the age-standardized prevalence rate has increased during the past three decades.However,the agestandardized death rate and age-standardized DALYs decreased.There is geographical variation in the burden of COCLDs due to NAFLD.It is strongly recommended to improve the data quality of COCLDs due to NAFLD across all countries and regions to facilitate better monitoring of the burden of COCLDs due to NAFLD.

黄山-镜儿泉铜镍成矿带地层时代的厘定及其地质意义探讨

本文对东天山黄山-镜儿泉岩浆铜镍硫化物成矿带原来古生物地层学方法厘定的早石炭统干墩组和晚石炭统梧桐窝子组的碎屑锆石进行了激光等离子质谱(LA-ICP-MS)U-Pb年代学研究。干墩组碳质板岩、变质砂岩和变质长石石英砂岩中的碎屑锆石U-Pb年龄分别为301~491 Ma、307~426 Ma和313~461 Ma,最年轻锆石的加权平均值分别为307.1±3.7 Ma、310.4±2.2 Ma、315.0±10 Ma,表明干墩组最大沉积年龄为晚石炭世。而梧桐窝子组变质砂岩和变质凝灰岩的碎屑锆石年龄为384~448 Ma和393~448 Ma,最年轻锆石的加权平均值分别为386.5±5.8 Ma、394.6±4.5 Ma,确定其最大的沉积年龄为早—中泥盆世。这与近年来对侵位于这些地层的火成岩体的锆石U-Pb年龄一致,说明康古尔-雅满苏岛弧带至少从中泥盆世就开始发育。中—下泥盆统梧桐窝子组与上石炭统干墩组地层之间上泥盆统—下石炭统地层厚度约为10 km,说明侵位于这两套地层中的含铜镍硫化物镁铁-超镁铁岩体分别代表了岩浆通道系统的深部岩浆通道相和浅部岩浆房,整个岩浆通道系统的纵向规模大约为10 km。

一桩一柱先插法结合高精度倾角传感器的质量控制要点

随着城市化的不断发展,密集城区的建造项目越来越多,对老旧城区进行改造也成为城市发展的必然趋势,建造项目的开展受周边环境的制约也越来越大,可用于施工的面积也越来越小,逆作法的出现使这些问题得到了极大的改善。本文以勤诚达云邸项目为依托,总结出了一套用于全逆作法施工过程中一桩一柱先插法的质量控制要点,结合高精度倾角传感器,将钢管柱的偏差情况数据化,进而通过技术措施进行有效调垂,保证一桩一柱的施工质量,减少后期的结构安全风险。

基于网络药理学的党参抗胰腺癌机制研究

目的:利用网络药理学技术与平台挖掘党参治疗胰腺癌的作用机制。方法:使用TCMSP数据库收集党参的有效化合物和潜在作用靶点,通过GeneCards数据库获取与胰腺癌相关的基因,Venny获得党参有效化合物靶点与胰腺癌靶点的交互基因,将交互基因绘制成PPI网络,并筛选出关键靶点。将交互基因导入DAVID数据库进行GO注释和KEGG信号富集。结果:通过TCMSP数据库共筛选到21种党参有效化合物及潜在98个下游靶基因。通过GeneCards数据库获得1 278个胰腺癌靶基因,最后获得两者交互基因共54个,其中10个关键节点基因为CASP3、TP53、MDM2、AKT1、ESR1、BCL2L1、MCL1、HSP90AA1、CASP9和CCND,这些交互基因共涉及30个典型的GO条目和20条KEGG信号。结论:党参可能通过多组分、多靶点和多信号通路的方式在胰腺癌的治疗上发挥作用。

基于区域增长方法的点云分割

点云分割作为现在机器视觉中的热点问题是点云分类、识别以及三维重建的基础,分割结果对后续的场景分析有着重要作用。本文通过对点云分割展开研究,对三维点云数据进行体素化处理得到体素云,然后在体素空间内进行网格化处理来筛选种子体素,再利用聚类算法形成超体素,完成过分割的处理过程。根据区域增长算法原理,对过分割得到的超体素数据进行平面拟合,实现点云数据的分割。实验结果表明本文的分割算法可以提高处理效率,使计算量大大减少,并且使最后的分割结果更加精确。