Modeling and Comprehensive Review of Signaling Storms in 3GPP-Based Mobile Broadband Networks:Causes,Solutions,and Countermeasures

Control signaling is mandatory for the operation and management of all types of communication networks,including the Third Generation Partnership Project(3GPP)mobile broadband networks.However,they consume important and scarce network resources such as bandwidth and processing power.There have been several reports of these control signaling turning into signaling storms halting network operations and causing the respective Telecom companies big financial losses.This paper draws its motivation from such real network disaster incidents attributed to signaling storms.In this paper,we present a thorough survey of the causes,of the signaling storm problems in 3GPP-based mobile broadband networks and discuss in detail their possible solutions and countermeasures.We provide relevant analytical models to help quantify the effect of the potential causes and benefits of their corresponding solutions.Another important contribution of this paper is the comparison of the possible causes and solutions/countermeasures,concerning their effect on several important network aspects such as architecture,additional signaling,fidelity,etc.,in the form of a table.This paper presents an update and an extension of our earlier conference publication.To our knowledge,no similar survey study exists on the subject.

Unraveling the therapeutic mechanisms of myristic acid and luteolin 7-rutinoside in oral cancer: insights from network pharmacology and molecular docking analysis

Background:The compound Luteolin-7-rutinoside(L7R)is a flavone derivative of luteolin,predominantly identified in plant species belonging to the families Asteraceae.Conversely,Myristic acid is characterized by its structure as a 14-carbon,unsaturated fatty acid.In this investigation,we endeavor to elucidate the putative mechanisms underlying the therapeutic effects of Myristic Acid and Luteolin 7-rutinoside in the context of oral cancer treatment,employing network pharmacology coupled with molecular docking methodologies.Methods:The protein targets of Myristic Acid and Luteolin 7-rutinoside were identified through a search on the Swiss Target Database.Subsequently,a compound-target network was constructed using Cytoscape 3.9.1.Targets associated with OC were retrieved from the OMIM and GeneCards databases.The overlap between compound targets and OC-related targets was determined,and the resulting shared targets were subjected to protein-protein interaction(PPI)network analysis using the STRING database.Additionally,gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were conducted on the identified targets.Molecular docking were performed to investigate the interactions between the core target and the active compound.Results:The component target network comprises 103 nodes and 102 edges.Among the proteins in the protein-protein interaction(PPI)network,those with higher degrees are TNF,PPARG,and TP53.Analysis through Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways indicates that the treatment of OC with Myristic Acid and Luteolin 7-rutinoside primarily involves the regulation of miRNA transcription and inflammatory response.The identified signaling pathways include Pathways in cancer,PPAR signaling pathway,EGFR signaling pathway,and TNF signaling pathway.Molecular docking studies reveal that Luteolin 7-rutinoside and Myristic acid exhibit higher affinity towards TNF,PPARG,TP53,and EGFR.Conclusion:This study reveals the potential molecular mechanism of Myristic Acid and Luteolin 7-rutinoside in the treatment of oral cancer,and provides a reference for subsequent basic research.

Attention-Based Residual Dense Shrinkage Network for ECG Denoising

Electrocardiogram(ECG)signal is one of the noninvasive physiological measurement techniques commonly usedin cardiac diagnosis.However,in real scenarios,the ECGsignal is susceptible to various noise erosion,which affectsthe subsequent pathological analysis.Therefore,the effective removal of the noise from ECG signals has becomea top priority in cardiac diagnostic research.Aiming at the problem of incomplete signal shape retention andlow signal-to-noise ratio(SNR)after denoising,a novel ECG denoising network,named attention-based residualdense shrinkage network(ARDSN),is proposed in this paper.Firstly,the shallow ECG characteristics are extractedby a shallow feature extraction network(SFEN).Then,the residual dense shrinkage attention block(RDSAB)isused for adaptive noise suppression.Finally,feature fusion representation(FFR)is performed on the hierarchicalfeatures extracted by a series of RDSABs to reconstruct the de-noised ECG signal.Experiments on the MIT-BIHarrhythmia database and MIT-BIH noise stress test database indicate that the proposed scheme can effectively resistthe interference of different sources of noise on the ECG signal.

For LEO Satellite Networks: Intelligent Interference Sensing and Signal Reconstruction Based on Blind Separation Technology

In LEO satellite communication networks,the number of satellites has increased sharply, the relative velocity of satellites is very fast, then electronic signal aliasing occurs from time to time. Those aliasing signals make the receiving ability of the signal receiver worse, the signal processing ability weaker,and the anti-interference ability of the communication system lower. Aiming at the above problems, to save communication resources and improve communication efficiency, and considering the irregularity of interference signals, the underdetermined blind separation technology can effectively deal with the problem of interference sensing and signal reconstruction in this scenario. In order to improve the stability of source signal separation and the security of information transmission, a greedy optimization algorithm can be executed. At the same time, to improve network information transmission efficiency and prevent algorithms from getting trapped in local optima, delete low-energy points during each iteration process. Ultimately, simulation experiments validate that the algorithm presented in this paper enhances both the transmission efficiency of the network transmission system and the security of the communication system, achieving the process of interference sensing and signal reconstruction in the LEO satellite communication system.

Damage Diagnosis of Bleacher Based on an Enhanced Convolutional Neural Network with Training Interference

Bleachers play a crucial role in practical engineering applications, and any damage incurred during their operationposes a significant threat to the safety of both life and property. Consequently, it becomes imperative to conductdamage diagnosis and health monitoring of bleachers. The intricate structure of bleachers, the varied types ofpotential damage, and the presence of similar vibration data in adjacent locations make it challenging to achievesatisfactory diagnosis accuracy through traditional time-frequency analysis methods. Furthermore, field environmentalnoise can adversely impact the accuracy of bleacher damage diagnosis. To enhance the accuracy and antinoisecapabilities of bleacher damage diagnosis, this paper proposes improvements to the existing ConvolutionalNeural Network with Training Interference (TICNN). The result is an advanced Convolutional Neural Networkmodel with superior accuracy and robust anti-noise capabilities, referred to as Enhanced TICNN (ETICNN).ETICNN autonomously extracts optimal damage-sensitive features from the original vibration data. To validatethe superiority of the proposed ETICNN, experiments are conducted using the bleacher model from Qatar Universityas the subject. Comparative studies under identical experimental conditions involve TICNN, Deep ConvolutionalNeural Networks with wide first-layer kernels (WDCNN), and One-Dimensional ConvolutionalNeural Network (1DCNN). The experimental findings demonstrate that the ETICNN model achieves the highestaccuracy, approximately 99%, and exhibits robust classification abilities in both Phases I and II of the damagediagnosis experiments. Simultaneously, the ETICNN model demonstrates strong anti-noise capabilities, outperformingTICNN by 3% to 4% and surpassing other models in performance.

PKHD1L1 blocks the malignant behavior of lung adenocarcinoma cells and restricts tumor growth by regulating CBX7

Objective:To explore the role of polycystic kidney and hepatic disease 1-like 1(PKHD1L1)in lung adenocarcinoma(LUAD).Methods:Bioinformatics tools were utilized to examine the clinical profile of PKHD1L1 and chromobox protein homolog 7(CBX7)in LUAD.The Cell Counting Kit-8,colony formation,terminal deoxynucleotidyl transferase dUTP nick end labeling,Transwell,and wound-healing assays were carried out to assess the proliferative,apoptotic,invasive,and migrative capacities of the cells.Furthermore,the interrelation between PKHD1L1 and CBX7 was validated using a co-immunoprecipitation assay.A LUAD mice model was constructed by subcutaneous injection of A549 cells.Finally,immunohistochemical staining was performed to evaluate CBX7 and Ki67 expression.Results:PKHD1L1 was downregulated in LUAD and predicted dismal outcomes in patients with LUAD.PKHD1L1 upregulation repressed the proliferative,invasive,and migrative capabilities of A549 cells and exacerbated the apoptotic rate.Additionally,PKHD1L1 may bind to CBX7 and positively modulate CBX7 expression.CBX7 deletion partly abrogated the effects of PKHD1L1 upregulation on the cellular biological activities in A549 cells.Furthermore,the PKHD1L1/CBX7 axis regulates the Hippo signaling pathway in A549 cells.PKHD1L1 restricted tumor growth in LUAD xenograft mice;this was partly abolished by CBX7 knockdown.Conclusion:PKHD1L1 can hinder LUAD progression by regulating CBX7-mediated Hippo signaling.

Huatan Qushi formula alleviates non-alcoholic fatty liver disease via PI3K/Akt signaling and gut microbiota modulation

Objective:To provide the mechanism-based pharmacotherapy of the Huatan Qushi formula(HTQS for-mula),for the health management and treatment of non-alcoholic fatty liver disease(NAFLD).Methods:A rat model of NAFLD was employed to examine the efficacy and safety of the HTQS formula.In vivo active components and potential mechanisms of the HTQS formula were identified using UPLC‒MS/MS combined with network pharmacology.The influence of the HTQS formula on the dominating proteins in PI3K/Akt pathway was validated in vivo using western blot.Finally,16S rRNA sequencing of the gut microbiome was conducted followed by targeted metabolomics detecting fecal short-chain fatty acids(SCFAs)and bile acids to determine the impact of the HTQS formula on gut microbiota.Results:The HTQS formula reduced weight gain and hepatic steatosis in NAFLD rats and decreased serum total cholesterol(TC),triglycerides,blood glucose,and insulin resistance(IR)without causing liver or kidney injury.We detected 28 components using UPLC‒MS/MS and identified 439 shared targets be-tween NAFLD and the HTQS formula.Primarily,we focused on the PI3K/Akt signaling pathway based on protein‒protein interaction network analysis.We validated that the HTQS formula inhibited liver stea-tosis and inflammation by increasing the phosphorylation levels of PI3K,AKT,P27,GSK3b in the PI3K/Akt signaling pathway.16S rRNA sequencing revealed that the HTQS formula reduced the abundance of the genus Family_XIII_AD3011_group,which was positively correlated with IR and taurodeoxycholic acid.In addition,Lachnospiraceae_UCG_010 inversely correlated with TC and five bile acids,which could be essential to the therapeutic effect of the HTQS formula against NAFLD.Conclusions:The HTQS formula proved to be an effective pharmacotherapy for NAFLD without causing liver or kidney injury.Multiple potent components of the HTQS formula could alleviate liver steatosis and lipid metabolism disorder by modulating the PI3K/Akt signaling pathway and restoring gut microbiota composition.

Action Mechanism of Components from Gardenia jasminoides on Eye Skin Based on Network Pharmacology

[Objectives]To explore the pharmacological effects of Gardenia jasminoides and its potential benefits on eye skin.[Methods]TCMSP and SymMap databases were used to screen the active components and corresponding targets of G.jasminoides.Human eye skin-related targets were screened,and the active component-target network and protein-protein interaction(PPI)network were established.Gene ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis were performed.[Results]Twenty-six active compounds were screened out from G.jasminoides,and 277 targets were obtained.From the Gencards database,26652 disease targets were retrieved and 205 related gene targets were screened.The active component-action target network of G.jasminoides constructed by Cytoscape software revealed the potential of G.jasminoides to play a role in multiple biological pathways.In addition,PPI-network analysis,GO function analysis and KEGG pathway enrichment analysis revealed that the active components of G.jasminoides mainly regulate the biological processes such as inflammatory response,oxidative stress and apoptosis,involving MAPK,NF-κB and other important signaling pathways.[Conclusions]This study provides a theoretical basis for the eye skin protection of G.jasminoides and an important clue for future drug development.

Network pharmacology and molecular docking analysis reveal insights into the molecular mechanism of Gualou Qumai Wan in clear cell renal cell carcinoma

Background:To initially clarify the potential therapeutic targets and pharmacological mechanism regarding Gualou Qumai Wan(GQW),a kind of traditional Chinese medicine(TCM),in clear cell renal cell carcinoma(ccRCC)by virtue of the network pharmacology analysis and molecular docking analysis.Methods:The screening of bioactive components and targets of GQW was based on the Traditional Chinese Medicine System Pharmacology(TCMSP)and the UniProt platform served for standardizing their targets.Online Mendelian Inheritance in Man(OMIM),PharmGkb,TTD,DrugBank and GeneCards databases were searched to collect the disease targets of ccRCC.Cytoscape assisted in constructing herb-compound-target(H-C-T)networks.The STRING database was searched for constructing the target protein-protein interaction(PPI)networks,while the R programming language served for analyzing GO functional terms and the KEGG pathways related to potential targets.Analyses of core genes related to survival and tumor microenvironment(TME)were conducted respectively based on the GEPIA2 database and TIMER 2.0 database.Human Protein Atlas(HPA)and The Cancer Genome Atlas(TCGA)helped to obtain core genes’protein expression as well as transcriptome expression level.Autodock Vina software validated the molecular docking regarding GQW components and pivotal targets.Results:The constructed H-C-T networks mainly had 33 compounds and 65 targets.A topological analysis of the PPI network identified that ESR1,AKT1,HIF1A,PTGS2,TP53 and VEGFA serve as core targets in the way GQW affects ccRCC.According to the GO and KEGG pathway enrichment analyses,the effects of GQW are mediated by genes related to hypoxia and oxidative stress as well as the Chemical carcinogenesis-receptor activation and PI3K-Akt signaling pathways.AKT1 shows a close relation to the recruitment of various immune cells and can remarkably affect disease prognosis according to reports.Molecular docking and molecular dynamics simulations showed that diosgenin has higher affinity with core targets.Conclusion:The study makes a comprehensive explanation of the biological activity,potential targets,as well as molecular mechanism regarding GQW against ccRCC,which promisingly assists in revealing the action mechanism of TCM formulae in disease treatment and the respective and scientific basis.

CCR7/p-ERK1/2/VEGF signaling promotes retinal neovascularization in a mouse model of oxygen-induced retinopathy

AIM： To investigate the role of CCR7/p-ERKI/2/VEGF signaling in the mouse model of oxygen-induced retinopathy （OIR）. METHODS： Neonatal C57BL/6J mice were evenly randomized into four groups： normoxia, OIR, OIR control （treated with scramble siRNA）, and OIR treated （treated with CCR7 siRNA）. Normoxia group was not specially handled. Postnatal day 7 （P7） mice in the OIR group were exposed to 75%±5% oxygen for 5d （P7-P12） and then maintained under normoxic conditions for 5d （P12-P17）. Mice in the OIR control and OIR treated groups were given injections of scramble or CCR7 siRNA plasmid on P12 before returning to normoxic conditions for 5d （P12-P17）. Retina samples were collected from all mice on P17, stained with adenosine diphosphatase （ADPase）, and retinal neovascularization （RNV） was assessed. Retinas were also stained with hematoxylin and eosin （H＆E） for RNV quantitation. The distribution and expression of CCR7, p-ERKI/2 and vas- cular endothelial growth factor （VEGF） were assessed via immunohistochemistry, Western blot, and quantitative real-time polymerase chain reaction （qRT-PCR）. RESULTS： High oxygen promoted retinal neovascularization （P〈0.05） and increased the number of endothelial nuclei in new vessels extending from the retina to the vitreous body; CCR7 promoted this process （P〈0.05）. CCR7 and VEGF mRNA were expressed at higher levels in the OIR and OIR control groups than in the normoxia and OIR treated groups. CCR7, p-ERK1/2, and VEGF protein were expressed in the retinas of mice in the OIR and OIR control groups. Intravitreal injection of CCR7 siRNA significantly reduced CCR7, p-ERKI/2, and VEGF expression in the OIR mouse model （all P〈0.05）. CCR7 significantly enhancedthe neovascularization and non-perfusion areas in the OIR group （P〈0,05）, CCR7 siRNA significantly reduced levels of p-ERK1/2 and VEGF as compared to OIR controls （P〈0.05）. CONCLUSION： These results suggest that CCR7/p-ERK I/2NEGF signaling plays an important role in OIR, CCR7 may be a potential target for the prevention and treatment of retinopathy of prematurity.

Comparative study of anti-inflammatory effects of different processed products through the COX-2/PGE2 signaling pathway: based on network pharmacology and molecular docking

Background:Radix Aconiti Lateralis Preparata(Fu-zi)is a traditional Chinese medicinal herb,which has been widely used in the clinic and has potent anti-inflammatory activities.we aimed to explore the mechanisms of extract containing alkaloids from different Fu-zi Processed Products(FPP)in treating inflammation,especially rheumatoid arthritis(RA).Methods:Firstly,using network pharmacology technology,the ingredients,and targets of Fu-zi were obtained by searching and screening,the targets involving RA were acquired,the intersection targets were constructed a"component-target-pathway"network.A comprehensive investigation was conducted on the anti-rheumatoid arthritis mechanisms of 5 FPPs in lipopolysaccharide(LPS)induced RAW264.7 cells,which serve as a model for RA.The production of NO and inflammatory cytokines were measured by ELISA kit.Quantitative Real-time PCR(qRT-PCR)was utilized to measure the mRNA levels.COX-2/PGE2 signaling pathway-associated proteins were determined by western blot.Results:According to a network pharmacological study,16 chemical components and 43 common targets were found in Fu-zi and 6 key targets including PTGS2 were closely related to the mechanism of Fu-zi in treating RA.The in vitro study revealed that the levels of NO,TNF-α,and IL-1βwere substantially decreased by the 5 FPPs.The 5 FPPs significantly suppressed the expression of proteins COX-2,iNOS,and NF-κB,with particularly notable effects observed for PFZ and XFZ.Conclusion:Altogether,these results demonstrated that the 5 PPS containing alkaloids have a good anti-RA-related inflammatory effect,and the mechanism may be related to COX-2/PGE2 signaling pathway,particularly,Fu-zi prepared utilizing a traditional Chinese technique.

FOXC2调控DLL4/Notch1信号通路对乳腺癌MCF-7细胞血管生成的影响

目的:探讨转录因子FOXC2对乳腺癌MCF-7细胞血管生成的影响,阐明FOXC2促进肿瘤血管生成的作用机制。方法:应用FOXC2慢病毒基因转染技术将FOXC2基因和空载体基因分别转染至乳腺癌MCF-7细胞株中,获得稳定转染细胞株;实验分为未转染组、空载体组和过表达组。采用Matrigel基质胶血管形成实验和Transwell小室实验检测各组细胞上清作用下人脐静脉内皮细胞(HUVECs)成管能力和迁移能力,RT-PCR和Western blotting法检测各组细胞中FOXC2、DLL4和Notch1mRNA和蛋白表达。结果:与未转染组和空载体组比较,过表达组MCF-7细胞上清诱导HUVECs闭合小管数和迁移细胞数增加(P<0.05);FOXC2、DLL4和Notch1mRNA和蛋白相对表达水平明显增加(P<0.05)。结论:MCF-7细胞中过表达FOXC2能显著增加HUVECs的成管能力和迁移能力,其机制可能是通过Notch信号通路来实现的。

骨形态发生蛋白-7对胚胎小鼠髓核细胞成骨分化和Notch信号表达的影响

目的:探索骨形态发生蛋白-7(bone morphogenetic protein-7,BMP-7)诱导胚胎小鼠椎间盘髓核细胞(nucleus pulposus,NP)的成骨分化及对经典Notch信号通路的调控作用。方法:重组腺病毒BMP-7(recombinant adenovirus-mediated bone morphogenetic protein-7,Ad-BMP-7)、绿色荧光蛋白(green fluorescent protein,Ad-GFP)在HEK293细胞中扩增,感染NP细胞。实验分为BMP-7组(n=3)、GFP组(n=3)、空白组(n=3)。RT-PCR检测BMP-7的m RNA水平表达;Real-time PCR检测成骨指标骨桥蛋白(osteopontin,OPN)、骨保护素(osteoprotegerin,OPG)以及经典Notch信号通路分子的m RNA表达水平;Western blot检测成骨转录因子Runx2和OPN的蛋白表达水平;采用碱性磷酸酶(alkaline phosphatase,ALP)读数和ALP染色检测ALP活性。结果:Ad-BMP-7和Ad-GFP在HEK293细胞中高滴度的扩增。NP细胞中BMP-7的基础表达很低,Ad-BMP-7感染NP细胞可高表达BMP-7,并明显提高OPN、OPG的m RNA水平表达(OPN:BMP-7组21.16±0.45,GFP组1.00±0.07,空白组2.84±1.27,F=613.815,P=0.000,BMP-7组与GFP组、空白组比较均P=0.000;OPG:BMP-7组2.05±0.37,GFP组1.00±0.06,空白组1.22±0.36,F=10.046,P=0.012,BMP-7组与GFP组比较P=0.016,与空白组比较P=0.047),成骨转录因子Runx2及OPN的蛋白表达水平也均高于对照组,特异性成骨指标ALP的活性明显增强,ALP染色呈紫蓝色,明显高于对照组(BMP-7组222 676.8±7 643.2,GFP组31 455.5±4 930.6,空白组42 407.3±10 926.8,F=513.417,P=0.000,BMP-7组与GFP组、空白组比较均P=0.000)。AdBMP-7感染3 d可促进Notch信号通路Notch-1、Notch-2、Jag-1、Hey-1的m RNA水平表达增高(Notch-1:BMP-7组5.90±0.66,GFP组2.83±0.32,空白组1.00±0.05,F=94.574,P=0.002,BMP-7组与GFP组比较P=0.003,与空白组比较P=0.004;Notch-2:BMP-7组150.35±11.78,GFP组1.94±0.46,空白组1.01±0.19,F=318.962,P=0.001,BMP-7组与GFP组、空白组比较均P=0.000;Jag-1:BMP-7组7.97±0.00,GFP组2.22±0.71,空白组1.00±0.00,F=166.476,P=0.001,BMP-7组与GFP、空白组比较均P=0.000;Hey-1:BMP-7组11.23±0.4,GFP组0.42±0.04,空白组1.00±0.10,F=1 082.054,P=0.000,BMP-7组与GFP组、空白组比较均P=0.000),但第7天回复到基础表达水平,其余信号分子表达无明显差异。结论:腺病毒介导的BMP-7可诱导NP细胞成骨分化,可能与Notch信号通路部分分子的一过性上调相关。

No.7信令系统及其在程控交换机中的应用

介绍了程控交换机中的No .7信令系统软硬件配置及维护 ,并结合科研实践分析了不同交换机之间开通No .7信令时遇到的问题及处理方法。

NO.7信令网络系统及其面临的困扰

NO.7信令网络系统是现代通信网的重要组成部分,它支持目前整个通信网的所有业务。宽带通信(BISDN)是通信网发展的必然趋势,NO.7信令网络系统不支持BISDN的业务。分析了NO.7信令网络系统面临的困扰,指出在研制和开发宽带通信的宽带信令网络系统时,可把NO.7信令网络系统逐步改造为宽带信令网络系统中一个子系统的新观点。

No.7信令监测系统的设计——兼谈我国与国外各种制式交换机No.7信令的转换技术

Ｎｏ．７信令网是现代通信网的重要组成部分，Ｎｏ．７信令系统的测试成为通信安全的必要措施。作者论述了Ｎｏ．７信令监测系统的总体设计，讨论了实现Ｎｏ．７信令监测系统的软硬件划分方法，介绍了Ｎｏ．７信令监测系统的软硬件设计。讨论了不同制式交换机Ｎｏ．７信令的互通故障，强调了在Ｎｏ．

固定智能网中No.7信令的负荷分担

基于智能网和No.7信令技术原理,分析了S12 No.7信令系统的MTP和SCCP的负荷分担机制,针对固定智能网中信令负荷不均匀的现实情况,提出了固定智能网中No.7信令负荷分担的解决方案,包括MTP负荷分担方案和SCCP负荷分担方案,有利于固定智能网中信令链路组之间和信令链路之间的负荷尽可能均衡,进一步提高固定智能网中No.7信令系统工作的可靠性,保证了智能网业务服务的连续性.

探索C5级程控端局No.1与No.7信令的接口

作者在本文研究了我国本地网中端局至端局的Ｎｏ．７信令系统基础上，探索了一种Ｃ５级程控端局Ｎｏ．１与Ｎｏ．

No.7 信令系统中 GT 翻译的设计与实现

从Ｎｏ．７信令系统ＳＣＣＰ的应用模式入手，探讨了ＧＴ翻译功能在ＳＣＣＰ中的重要性，描述了一种ＧＴ翻译性能与ＧＴ数据容量无关的ＧＴ数据库结构以及相应的ＧＴ翻译算法。

C3本地网的No.7信令网的组建

作者在该文中就Ｎｏ．７信令网的规范要点，阐述了我国Ｎｏ．７信令网的等级结构，并针对国家ＨＳＴＰ网组建的情况下，提出了Ｃ３本地网实现ＬＳＴＰ的方案及步骤。