EPS混合土地基-沉箱抗震性能振动台模型试验

采用振动台试验研究了饱和砂土地基(CSS)和EPS混合土地基(CES)两种地基模型下沉箱结构的抗震性能。对比了两种不同地基模型下土体动力响应特征及沉箱结构动力稳定性,探讨了动力作用下沉箱的受力状态及失稳机制,分析了EPS混合土地基对上部沉箱结构地震稳定性的影响。试验结果表明:振动过程中CES工况的超孔压发展速率明显低于CSS,EPS混合土可显著提高模型抗液化性能。墙后填土作用于沉箱的动土压力沿深度方向呈三角形分布,沉箱中部位置动土压力最大。CES工况沉箱动力响应,包括加速度、位移及转动角等均小于CSS,表现出更好的抗震性能。CES沉箱所受动土推力与惯性力存在明显的相位差,有利于提高沉箱结构的稳定性。

碳纤维和EPS颗粒对RPC性能的影响

研究了不同掺量(0、0.2%、0.3%、0.4%、0.5%、1.0%)的碳纤维(CF)全取代钢纤维(SF)对活性粉末混凝土(RPC)工作性的影响,优选出了适宜CF掺量;在此基础上,研究了EPS颗粒掺量(10%、20%、30%、40%、50%)对掺CF的RPC(CF-RPC)工作性、力学性能、干表观密度和导热系数的影响,并与同EPS颗粒掺量条件下掺SF的RPC(SF-RPC)性能进行了对比。结果表明:CF的适宜掺量为0.3%;随着EPS颗粒掺量的增加,CF-RPC试件的扩展度先增大后减小,抗压强度、抗折强度、干表观密度和导热系数均降低,韧性提升;与掺EPS的SF-RPC试件相比,掺EPS的CF-RPC试件的抗压强度较低,但韧性较好,干表观密度和导热系数均较低。

EPS外墙外保温系统聚氨酯粘结胶加固后受力性能试验研究

通过EPS保温板抗拉试验、疲劳试验、加固疲劳试验,研究粘贴率、粘贴方式对EPS板及聚氨酯粘结胶加固试样的抗拉承载力和疲劳性能影响。结果表明:除满粘外,在相同条件下,EPS板抗拉承载力平均值由大到小为:条粘>点粘>十字粘>点框粘;EPS板疲劳次数与粘贴率呈正相关,条粘法疲劳性能最好;采用聚氨酯粘结胶加固后的试样抗拉承载力平均值均符合要求,且达到满粘抗拉承载力的90%;初始疲劳对加固效果的影响最大仅7%,加固后点粘、条粘、十字粘、点框粘的疲劳次数分别达到满粘的87%、89%、87%、75%;聚氨酯粘结胶加固后累计疲劳次数更多,EPS板整体使用寿命得到延长,加固方法较为可靠。

EPS混凝土的早龄期抗冲击性能

对早龄期(12 h、24 h、36 h)的EPS混凝土进行了动态力学试验,从动态抗压强度、峰值应变、极限应变和能耗密度等方面分析了冲击速度(4.5~6.5 m/s)和龄期(12 h、24 h、36 h)对EPS混凝土抗冲击性能的影响,并与28 d龄期时EPS混凝土的性能进行了对比。结果表明:EPS混凝土的动态抗压强度、峰值应变、极限应变和能耗密度均具有冲击速度强化效应。随着龄期的增大,EPS混凝土的动态力学性能指标及其对冲击速度的敏感性不断增大。28 d龄期时,EPS混凝土的动态抗压强度、峰值应变、极限应变和能耗密度最大,其对冲击速度的敏感性最强。EPS混凝土早龄期具有良好的变形和吸能特性。36 h龄期时,EPS混凝土的峰值应变、极限应变和能耗密度分别可达到28 d龄期时的66%~82%、91%~93%和72%~78%。

5G语音EPS Fallback主叫流程优化思路

5G网络实现语音呼叫的方式有2种,一种是EPS Fallback回落方式,另一种是目标VoNR非回落方式。由于EPS Fallback方式需要先回落至4G网络,主叫接通时延相比VoNR方式要慢1 s左右。提出针对EPS Fallback主叫流程的优化思路,通过网络侧升级改造,最终达到EPS Fallback主叫时延与VoNR主叫时延一致的效果。

EPS及消毒剂对细菌表面附着和初期生物膜形成的影响

为探究胞外聚合物(extracellular polymeric substances, EPS)和消毒剂对细菌表面附着聚集行为的影响,文中以野生型铜绿假单胞菌和藻酸盐分泌过量的突变株为研究对象,分析不同氯浓度条件下细菌EPS生成及其对表面附着和初期生物膜形成的影响。结果表明,相较于野生型,突变型的生物膜形成优势显著,特别是当氯质量浓度≥1.0 mg/L时,强化了其形成优势;EPS也显著提高了生物膜的黏附强度以及降低其表面粗糙程度。低浓度氯促进细菌EPS的生成以及初期生物膜的形成,但高质量浓度氯(3.0 mg/L)则抑制了生物膜的形成,同时也降低了两种菌株生物膜的黏附力与表面粗糙度。对于两种菌株而言,聚氯乙烯(PVC)管材上生物膜的形成优势显著高于不锈钢(STS)管材。

EPS颗粒掺量对脱硫石膏基轻质复合材料性能的影响

为研究EPS颗粒对脱硫石膏基复合材料性能的影响,将EPS颗粒按50%~300%体积外掺加入脱硫石膏基复合材料中。从工作性能、物理性能、耐久性能、力学性能等方面分析了EPS颗粒掺量对复合材料性能的影响,并对其单轴应力-应变关系进行了拟合。研究结果表明:当EPS颗粒掺量逐渐增大时,除吸水率外,材料表观密度、导热系数,抗压、抗折强度等指标都呈现降低的趋势,而软化系数呈现上下波动的变化趋势,且除300%组外,都大于0.80;当EPS颗粒体积掺量为200%时,材料综合性能最佳,此时材料的密度为972.8 kg·m^(-3),导热系数为0.1751 W·(m·K)^(-1),软化系数为0.932,抗压强度、抗折强度分别为4.34、1.33 MPa。拟合的材料单轴应力-应变表达式与试验结果吻合良好。本文结果可为脱硫石膏基轻质复合材料的研究和应用提供一定的参考。

EPS颗粒混凝土改性现状及其发展趋势研究

EPS颗粒混凝土是当前热门的绿色环保轻质建材,EPS颗粒混凝土改性是提高EPS颗粒混凝土强度和研发高性能EPS颗粒混凝土的有效途径。首先,将EPS颗粒混凝土改性方法分为EPS颗粒改性、胶凝材料改性两大类,仔细梳理了已有EPS颗粒混凝土改性工艺和改性效果;其次,基于EPS颗粒改性和胶凝材料改性的综合讨论,提出了能够扬长避短的复合改性方法;最后,整理了当前EPS颗粒混凝土改性方法存在问题,对未来改性方法的发展进行了思考和展望。研究发现,EPS颗粒改性包括化学改性、裹砂改性、造壳改性;胶凝材料改性包括纤维改性、掺合料改性、外加剂改性;将EPS颗粒改性和胶凝材料改性有机结合的复合改性可以有效提高EPS颗粒混凝土性能,但技术复杂,需进一步研究;同时纳米材料改性、EPS陶粒改性、微胶囊改性、新养护工艺是EPS颗粒混凝土改性的未来发展方向,但新技术高昂的成本亟待降本增效研究。综上,可以为高性能EPS颗粒混凝土研发提供参考,具有较高的参考价值。

Protective mechanism of Coprinus comatus polysaccharide on acute alcoholic liver injury in mice,the metabolomics and gut microbiota investigation

Coprinus comatus polysaccharide(CCP)has significant hepatoprotective effect.To explore hepatoprotective mechanism of CCP,the study analyzed preventive effect of CCP on acute alcoholic liver injury in mice by histopathological examination and biochemical analysis.Simultaneously,hepatoprotective mechanism was also analyzed in conjunction with metabolomics and proliferation of gut microbiota.The results showed that CCP significantly decreased alanine aminotransferase(ALT),aspartate aminotransferase(AST)and triglyceride(TG)levels in serum of alcoholic liver disease(ALD)mice.Histopathological examination showed that CCP can significantly improve liver damage.Metabolomics results showed that there were significant differences in the level of metabolites in liver tissue of control group,ALD group and CCP group,including taurine,xanthosine,fumaric acid and arachidonic acid,among others.Metabolites pathways analysis showed that hepatoprotective effect of CCP was related to energy metabolism,biosynthesis of unsaturated fatty acids,amino acids metabolism and lipid metabolism.Additionally,CCP inhibited an increase in the number of Clostridium perfringens,Enterobacteriaceae and Enterococcus,and a decrease in the number of Lactobacillus and Bifidobacterium in the gut of ALD mice.All these findings suggested that CCP treatment reversed the phenotype of ethanol-induced liver injury and the associated metabolites pathways.

Adsorption,in vitro digestion and human gut microbiota regulation characteristics of three Poria cocos polysaccharides

Poria cocos(PC)is a famous traditional Chinese medicine(TCM)and a widely used healthcare ingredient,which has antiobesity,enhancing immunity and improving sleep effects.Traditionally,only water-soluble poria polysaccharide(WSP)is extracted and applied for clinical application,while insoluble polysaccharide(alkali-soluble poria polysaccharide,ASP)is discarded as herb residue.However,the whole PC has also been historically utilized as functional herbal food.Considering the beneficial role of dietary fiber and the traditional use of PC,ASP may also contribute substantially to the therapy function of PC.Compared to WSP,little attention has been paid to ASP and ASP modified product carboxymethyl poria polysaccharide(CMP)which has been used as an antitumor adjuvant drug.In this study,the oil,cholesterol,metal ions and polyphenols adsorption ability,in vitro simulated digestive and the gut microbiota fermentation characteristics of WSP,ASP and CMP were studied to evaluate the functional values of three P.cocos polysaccharides(PCPs).The results showed that all three PCPs had good adsorption capacity on cholesterol,polyphenols and metal ions(Cd^(2+)/Zn^(2+)/Mg^(2+)),among which ASP showed the highest capacity than WSP and CMP.The adsorption capacity of all three PCPs on heavy metal ions(Cd^(2+)/Zn^(2+))was stronger than that of non-heavy metal ions(Mg^(2+));The in vitro digestibility of all three PCPs was very low,but WSP was slightly higher than ASP and CMP;Moreover,the indigestible residue of all three PCPs could improve the richness and diversity of gut microbiota,among which ASP had the greatest influence.In general,ASP and CMP could significantly promote the proliferation of some probiotics and inhibit the growth of some harmful bacteria.The gut microbiota diversity of CMP was reduced,but the richness of probiotics,especially Parabacteroides distasonis was significantly enhanced compared with the ASP group,and the growth of harmful bacteria Klebsiella pneumoniae was inhibited after CMP treatment.The short-chain fatty acids(SCFAs)analysis results showed that all three PCPs could significantly promote the production of acetic acid,propionic acid and the total acid content compared with blank control group,and SCFAs producing activity was positively correlated with the proliferative capacity of probiotics.Taken together,the good adsorption characteristics and gut microbiota regulatory activity of ASP may lay foundation for its lipid-lowering and immune-improving function.Additionally,the probiotic effect of CMP and ASP indicated that except for only use the water extract of PC in clinic,CMP and ASP also can be used in healthcare to take full advantage of this valuable medicine.

Structure and immunomodulatory activity of Lentinus edodes polysaccharides modified by probiotic fermentation

Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.

The interventional effect of Polygonatum cyrtonema Hua polysaccharide on atherosclerosis in mice of different sexes

In the present study,we investigated the intervention effects of a purified Polygonatum cyrtonema polysaccharide(PCP)on high-fat diet(HFD)-induced atherosclerosis in male and female LDLr-/-mice.Results showed that HFD caused severe dyslipidemia,atherosclerotic lesions,oxidative damages and inflammation in male and female mice,and these effects seemed to be more pronounced in males than in females.However,the above variations could be dose-dependently reversed by PCP treatment,and the intervention effects on males were greater than those on females.Nuclear factor kappa-B(NF-κB),mitogen-activated protein kinase(MAPKs)and protein kinase B(Akt)are 3 pivotal signaling pathways mediating the development of atherosclerosis.Consistently,PCP was also found to significantly decrease the phosphorylation of p65,p38,extracellular-regulated kinase 1/2(ERK1/2)and Akt,and increase the protein expression of inhibitor of NF-κB(IκB)in the aortas of male and female mice induced by HFD.Taken together,these findings indicated that PCP could be effective for the prevention of atherosclerosis,and the intervention effect of PCP on male mice was more obvious than that of female mice.

某越野车型EPS台架抗冲击分析

电动助力转向(EPS)系统在越野车型上更容易受到来自凹凸不平的地面磕碰冲击,因此,整车要求EPS的电子控制单元(ECU)在设计过程中要考虑可承受较大冲击而不损坏,如何快速验证ECU的抗冲击设计有效性成为行业内的难题。文章结合车辆在越野耐久验证工况下,从逆向设计视角制定了一套有效的越野工况验证方案,通过采集路谱数据经处理后输入到振动台架,快速验证EPS抗冲击性能,可用于快速识别潜在的ECU被冲击失效风险点。研究结果表明,该方法理论意义清晰,具有提高验证有效性、节约试验时间的工程应用价值,缩短产品开发周期,为后续模拟试验奠定基础。

基于多指标下POM纤维对EPS轻型混凝土性能的影响

为探究聚甲醛(POM)纤维对聚苯乙烯(EPS)轻型混凝土性能的综合影响,避免以往单纯依赖力学性能指标评价的不足,比选后基于长度为12 mm的POM纤维研究了不同性能评价指标下POM纤维的最优掺量。结果表明:基于基本的力学性能及相对动弹性模量变化绝对值,掺量为0.9%时,POM纤维对EPS轻型混凝土的增强效果最优,冻融损伤最低;基于吸水性及流变性能指标,掺量同样为0.9%时浆体稠度及抗吸水能力最佳;基于干缩性能,则掺量为1.2%时,浆体抗干缩效果最优;基于冻融后相对弹性模量变化率,则掺量为0.6%时相对弹性模量衰减率最低;研究揭示了POM纤维增强EPS轻型混凝土的复杂性和多样性,进一步通过微观分析,辅证了POM纤维增强增韧EPS轻型混凝土的机理。

楼地面用EPS复合保温材料研究

EPS复合保温材料因具有轻质、保温、耐久的特点,在楼地面保温系统中应用较为广泛。通过探讨原材料对低干密度范围内EPS复合保温材料抗压强度、干密度、导热系数等基本性能的影响特征,提出EPS复合保温材料性能优化措施,旨在为提升楼地面保温系统的性能提供技术借鉴。

Cd^(2+)浓度对好氧颗粒污泥EPS各组分形成的影响

为探究重金属Cd^(2+)对好氧颗粒污泥系统运行的影响,采用紫外分析法和三维荧光光谱分析法研究了SBR反应器中不同浓度的重金属Cd^(2+)对好氧颗粒污泥EPS总量以及各组分(LB-EPS、SB-EPS、TB-EPS)的产生与组成成分的影响。试验结果表明:低浓度Cd^(2+)(小于0.1mg/L)促进EPS的产生,高浓度Cd^(2+)(大于3mg/L)抑制EPS的产生;SB-EPS随着Cd^(2+)浓度的增加逐渐减少,其中蛋白质含量增加,多糖、腐殖酸明显减少;当Cd^(2+)浓度小于0.1mg/L时TB-EPS显著增加,其中主要增加的成分是蛋白质;当Cd^(2+)浓度大于3mg/L时,TB-EPS的分泌受到抑制,但蛋白质含量仍高于空白对照组,多糖、腐殖酸含量显著降低;LB-EPS受到的影响因素较多,其含量变化不规律。采用扩展DLVO理论剖析了EPS各组分含量的变化对好氧颗粒污泥沉降性能的影响,以期为好氧颗粒化技术在工业废水处理中的应用提供有力的支持。

Hypoglycemic mechanism of Tegillarca granosa polysaccharides on type 2 diabetic mice by altering gut microbiota and regulating the PI3K-akt signaling pathwaye

Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin.TGP(5.1×10^(3) Da)was composed of mannose,glucosamine,rhamnose,glucuronic acid,galactosamine,glucose,galactose,xylose,and fucose.It could significantly alleviate weight loss,reduce fasting blood glucose levels,reverse dyslipidemia,reduce liver damage from oxidative stress,and improve insulin sensitivity.RT-PCR and Western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance.TGP increased the abundance of Allobaculum,Akkermansia,and Bifidobacterium,restored the microbiota abundance in the intestinal tracts of mice with T2DM,and promoted short-chain fatty acid production.This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.

某轻型商用汽车 EPS 偶发助力失效分析

文章介绍了某轻型商用车在耐久试验过程中的EPS偶发助力失效故障,通过参照对比及数据分析确认是转向完全无助力,对该故障进行多个角度分析,锁定故障为软件系统异常导致,车辆偶发一次从启动—熄火—启动的时间为2.06 s,系统助力状态从全助力—助力缓降—无助力—Post run的准备时间为2.04~2.06 s,此时不满足进入Post run条件,系统状态持续无助力。后续通过更改EPS软件逻辑,允许Post run准备运行中断后根据车速和发动机状态判断是否需要提供助力,有效解决了EPS偶发助力失效问题。该优化方案和分析思路,对解决其他车型的偶发助力失效问题具有较好的指导意义。

大扭矩商用车EPS系统回正补偿策略研究

车辆回正控制是决定转向系统好坏的一个重要因素。针对新能源大扭矩商用车存在回正不足或回正超调问题,文章提出了基于多种群遗传算法(MPGA)优化的模糊比例-积分-微分(PID)控制算法,建立了电动助力转向(EPS)系统动力学模型、方向盘转角估计模型与回正补偿控制策略,根据估计的方向盘转角确定电机的期望输出扭矩,以此确定电机电枢电压,从而实现回正补偿。利用MPGA优秀的全局寻优性能,对模糊PID控制器参数进行优化。经Simulink仿真试验证明,提出的基于MPGA优化的模糊PID控制算法,相较于PID控制与模糊PID控制,回正性能得到改善。

EPS路基在下埋管道高路基道路施工中的应用

城市地下管道设施是城市功能正常运转的“生命线”,下埋管道高路基施工过程中,为保证城市管道设施的正常使用,需控制附加荷载与地面沉降。文章以东靖路新建工程上跨污水处理管道的道路施工为例,分析了常规施工和EPS(发泡聚苯乙烯)施工的附加荷载与沉降差异,并介绍了EPS路基在管道上方施工的具体方法。该案例作为EPS路基在下埋管道高路基施工中的成功实践,对类似工程施工具有借鉴意义。