Tanshinone ⅡA improves Alzheimer’s disease via RNA nuclearenriched abundant transcript 1/microRNA-291a-3p/member RAS oncogene family Rab22a axis

BACKGROUND Alzheimer’s disease(AD)is a neurodegenerative condition characterized by oxidative stress and neuroinflammation.Tanshinone ⅡA(Tan-ⅡA),a bioactive compound isolated from Salvia miltiorrhiza plants,has shown potential neuroprotective effects;however,the mechanisms underlying such a function remain unclear.AIM To investigate potential Tan-ⅡA neuroprotective effects in AD and to elucidate their underlying mechanisms.METHODS Hematoxylin and eosin staining was utilized to analyze structural brain tissue morphology.To assess changes in oxidative stress and neuroinflammation,we performed enzyme-linked immunosorbent assay and western blotting.Additionally,the effect of Tan-ⅡA on AD cell models was evaluated in vitro using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Genetic changes related to the long non-coding RNA(lncRNA)nuclear-enriched abundant transcript 1(NEAT1)/microRNA(miRNA,miR)-291a-3p/member RAS oncogene family Rab22a axis were assessed through reverse transcription quantitative polymerase chain reaction.RESULTS In vivo,Tan-ⅡA treatment improved neuronal morphology and attenuated oxidative stress and neuroinflammation in the brain tissue of AD mice.In vitro experiments showed that Tan-ⅡA dose-dependently ameliorated the amyloid-beta 1-42-induced reduction of neural stem cell viability,apoptosis,oxidative stress,and neuroinflammation.In this process,the lncRNA NEAT1-a potential therapeutic target-is highly expressed in AD mice and downregulated via Tan-ⅡA treatment.Mechanistically,NEAT1 promotes the transcription and translation of Rab22a via miR-291a-3p,which activates nuclear factor kappa-B(NF-κB)signaling,leading to activation of the pro-apoptotic B-cell lymphoma 2-associated X protein and inhibition of the anti-apoptotic B-cell lymphoma 2 protein,which exacerbates AD.Tan-ⅡA intervention effectively blocked this process by inhibiting the NEAT1/miR-291a-3p/Rab22a axis and NF-κB signaling.CONCLUSION This study demonstrates that Tan-ⅡA exerts neuroprotective effects in AD by modulating the NEAT1/miR-291a-3p/Rab22a/NF-κB signaling pathway,serving as a foundation for the development of innovative approaches for AD therapy.

Characterization of a Novel Esterase Belonging to Family V from Marinobacter flavimaris

Lipolytic enzymes have attracted enormous attentions because of their ability in ester hydrolysis,ester synthesis,transesterification and other biochemical reactions.Bacteria are important sources of lipolytic enzymes applied in industry.Here,a novel lipolytic enzyme encoded by esterase gene est1347 was identified in Marinobacter flavimaris WLL162,and was purified and characterized.The lipolytic enzyme Est1347 consisted of 312 amino acid residues and a 21-amino-acids N-terminal signal peptide with a predicted molecular weight of 34.2 kDa.It belongs to family V of bacterial lipolytic enzymes based on the amino acid sequence homology analysis.Est1347 is a mesophilic and alkali-resistant enzyme with the highest activity at 45℃and pH 8.5;it is stable at temperatures below 50℃and pH 7.5–11.0.Est1347 showed a preference for middle-length chain substrate p-NPC10 and a wide range of other substrates.The Km,Vmax,Kcat and Kcat/Km values of Est1347 for p-NPC10 in pH 8.5 at 45℃were 0.9411 mmol L^(−1),1285μmol min^(−1)mg^(−1),698.91 s^(−1)and 743.65 s^(−1)(mmol L^(−1))^(−1),respectively.It is also tolerant to the metal ions,organic solvents and detergents.In conclusion,the esterase Est1347 laid a foundation for further study of bacterial lipolytic enzyme family V.

The Impact of Nursing Staff’s Work Attitude on the Fear of Patients Recovering from Benign Tumors:Family Support as a Mediating Variable

The perception of nursing staff’s attitude influences patient fear.Understanding this dynamic is crucial for fostering a supportive environment conducive to patient well-being and effective healthcare practices.The purpose of this research is to investigate how the attitudes and behaviours of nursing staff influence the fear and anxiety levels of patients recovering from benign tumors,aiming to improve patient care and recovery outcomes.Data was collected from a sample of 100 participants,comprising 20 nursing staff and 80 patients recovering from benign tumors.Surveys were administered to gather quantitative data on attitudes and fear levels.Participants were selected randomly from hospital records and outpatient clinics.Our analysis encompassed nursing staff attitude,patient fear levels,the influence of family support,progression of tumor recovery,patient-reported satisfaction,and the quality of healthcare services provided.The quantitative aspect utilized PLS-SEM software to perform regression analysis,evaluating both direct and indirect effects.Statistical analysis assessed the relationships between nursing staff attitudes,patient fear during benign tumor recovery,and the mediating role of family support.The findings of the study demonstrate that better nurse attitudes(Hypothesis 1,β=0.45,p<0.001)and stronger family support(Hypothesis 2,β=0.32;p<0.001) are linked to lower levels of patient fear.Partially mediating the relationship between nurse attitudes and patient fear,according to Hypothesis 3(β=0.28,p<0.002),is family support.Patients’perceptions of family support are highly influenced by nursing behaviour,as demonstrated by Hypothesis 4(β=0.38;p<0.001).Our research showed a strong relationship between the attitudes of nursing personnel and patient fear levels.Family support demonstrated a strong mediating effect on patient fear.Patient-reported satisfaction is positively correlated with family support.However,no significant relationship was found between healthcare service quality and patient fear.

Impact of Different Rates of Nitrogen Supplementation on Soil PhysicochemicalProperties and Microbial Diversity in Goji Berry

Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.

Research on the Influence of Family Education on Children’s Behavioral Habits

Under the background of the all-round deepening of quality education,the cultivation of comprehensive quality has become the main theme of contemporary education reform.Good behavior and habits are of great significance to children’s future learning,growth,and development.Through literature review and other methods,this paper analyzes the current situation of children’s family education and the influence of family education on the cultivation of children’s behavioral habits and provides some strategies for cultivating children’s good behavioral habits in family education.

双金属MOFs碳化材料的结构对锂硫电池正极性能的影响

利用硝酸钴和铁氰化钾在水溶液中沉淀反应以及ZIF-8在水溶液中的部分分解,分别制备了2种组成相近但结构不同的双金属有机框架前驱体Co-Fe precursor和ZCF precursor。经过多巴胺包覆,对2种产品在氩气气氛下退火获得碳化产物。将碳化产物与纳米硫粉混合得到的碳/硫复合材料(E-CoFeCN@C/S、E-ZCF@C/S)分别作为正极,组装扣式锂硫电池并测试电化学性能。利用X射线衍射仪、扫描电子显微镜、透射电子显微镜、热重分析仪进行形貌和结构分析。在组成相似的情况下,核壳结构碳载体(E-CoFeCN@C)与发散式结构碳载体(E-ZCF@C)对锂硫电池性能的影响呈现出“此消彼长”的特点:E-ZCF@C/S在循环伏安测试中表现出更小的极化以及更强的电流响应,在电化学阻抗测试中表现出更低的电荷转移阻抗,表明该材料有利于促进正极电荷传递过程,即加快电极反应动力学。E-ZCF@C/S在0.2C倍率下放电初始比容量为1211.3mAh/g,在2C倍率下放电初始比容量为794mAh/g,均优于E-CoFeCN@C/S。而核壳结构的优势主要体现在容量衰减方面,E-CoFeCN@C/S在0.2C倍率下经过100次循环后平均衰减率为0.074%(E-ZCF@C/S为0.26%),在2C倍率下循环300次后平均衰减率为0.047%(E-ZCF@C/S为0.13%),说明核壳结构对活性物质的锚固作用明显而对电荷转移不利。

Structural, elastic, and electronic properties of topological semimetal WC-type MX family by first-principles calculation

Recently, the non-centrosymmetric WC-type materials(i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological properties.By means of the first-principles calculations, here we have investigated the structural, thermodynamic, elastic, and electronic properties of the WC-type MX compounds(TiS, TiSe, TiTe, ZrS, ZrSe,ZrTe, HfS, HfSe, and HfTe).Among these nine compounds, five of them(TiS, ZrS, ZrSe0.9, ZrTe, and Hf0.92 Se) have been experimentally synthesized to crystallize in the WC-type structure and other four members have never been reported.Our calculations demonstrated that they are all structurally, thermodynamically, and dynamically stable, indicating that all of them should be possibly synthesized.We have also derived their elastic constants of single crystalline and their bulk and shear moduli in terms of the R.Hill approximations.Furthermore, in similarity to ZrTe, all these compounds have been theoretically derived to be topological semimetals.Whereas TiS is unique because of the coexistence of the Dirac nodal lines(DNLs) and sixfold degenerate nodal points(sixfold DNPs), the other eight members are revealed to exhibit coexisted Weyl nodes(WPs) and triply degenerate nodal points(TDNPs).Their electronic and topological properties have been further discussed.

The protective effect of cyclodextrin on the color quality and stability of Cabernet Sauvignon red wine

The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.

A gated recurrent unit model to predict Poisson’s ratio using deep learning

Static Poisson’s ratio(vs)is crucial for determining geomechanical properties in petroleum applications,namely sand production.Some models have been used to predict vs;however,the published models were limited to specific data ranges with an average absolute percentage relative error(AAPRE)of more than 10%.The published gated recurrent unit(GRU)models do not consider trend analysis to show physical behaviors.In this study,we aim to develop a GRU model using trend analysis and three inputs for predicting n s based on a broad range of data,n s(value of 0.1627-0.4492),bulk formation density(RHOB)(0.315-2.994 g/mL),compressional time(DTc)(44.43-186.9 μs/ft),and shear time(DTs)(72.9-341.2μ s/ft).The GRU model was evaluated using different approaches,including statistical error an-alyses.The GRU model showed the proper trends,and the model data ranges were wider than previous ones.The GRU model has the largest correlation coefficient(R)of 0.967 and the lowest AAPRE,average percent relative error(APRE),root mean square error(RMSE),and standard deviation(SD)of 3.228%,1.054%,4.389,and 0.013,respectively,compared to other models.The GRU model has a high accuracy for the different datasets:training,validation,testing,and the whole datasets with R and AAPRE values were 0.981 and 2.601%,0.966 and 3.274%,0.967 and 3.228%,and 0.977 and 2.861%,respectively.The group error analyses of all inputs show that the GRU model has less than 5% AAPRE for all input ranges,which is superior to other models that have different AAPRE values of more than 10% at various ranges of inputs.

进口再生塑料颗粒中双酚A、双酚S的溶出特性研究

为了加强我国进口塑料颗粒的监管,降低我国进口再生塑料颗粒使用风险,建立更加完善、更加严格的限值标准。本文以聚对苯二甲酸乙二醇酯(PET)、聚丙烯(PP)、聚乙烯(PE)、聚苯乙烯(PS)以及丙烯腈-丁二烯-苯乙烯共聚物(ABS)为原料的进口再生塑料颗粒为研究对象,采用高效液相色谱-紫外检测法对5种进口再生塑料颗粒中双酚A和双酚S的含量进行分析,并进一步探究接触时间、温度及模拟溶液对再生塑料颗粒中双酚A和双酚S溶出的影响。结果表明:(1)5种进口再生塑料颗粒中,ABS颗粒中双酚A、双酚S含量均为最高,含量平均值分别为(69.44±5.32)mg/kg与(125.59±5.62)mg/kg。(2)探究接触时间影响因素过程中,双酚A和双酚S在模拟溶液的溶出量总体在96~168 h内增长较快,直到240 h溶出量达到平衡。(3)探究温度影响因素过程中,在70℃条件下双酚A和双酚S总溶出量均明显大于40℃与25℃。(4)探究模拟溶液影响因素过程中,双酚S在乙酸模拟液中均未溶出,双酚A在乙醇中的溶出量明显高于乙酸,存在相似相溶解效应。

Petrophysical properties and their influencing factors of carbonates in the fourth member of Sinian Dengying Formation, Sichuan Basin, SW China

Based on the measurements of petrological, petrophysical and elastic properties of the samples of different sedimentary facies in the fourth member of Sinian Dengying Formation (Deng 4 Member) in the Sichuan Basin, the diagenetic processes of reservoirs of different sedimentary facies and their controls on the petrophysical properties were discussed. The results show that cracks and mineral composition jointly control the petrophysical properties, and both are significantly influenced by sedimentary environment and diagenesis. The microbial dolomite of mound-shoal facies mainly experienced multi-stage dolomitization, penecontemporaneous dissolution, tectonic rupture and hydrothermal/organic acid dissolution processes, giving rise to cracks and dissolved pores. The grannular dolomite of inter-mound-shoal bottomland or dolomitic lagoon facies mainly underwent mechanical compaction, burial dolomitization and tectonic-hydrothermal action, creating cracks and intercrystalline pores. The diagenesis related to crack development increases the pressure- and saturation-dependent effects of samples, leading to significant decrease in the compressional wave impedance and Poisson's ratio. Dolomitization changes the properties of mineral particles, resulting in a Poisson's ratio close to dolomite. The muddy, siliceous and calcareous sediments in the low-energy environment lead to the decrease of impedance and the differential change of Poisson's ratio (significantly increased or decreased). The samples with both cracks and dissolved pores show high P-wave velocity dispersion characteristics, and the P-wave velocity dispersion of samples with only fractures or pores is the lowest.

[WS_(3)Cu_(2)]簇基超分子框的组装、结构及其三阶非线性光学响应

将二(4-吡啶)硫烷(L_(1))、4,4'-二(4-吡啶)二苯甲酮(L_(2))分别与(Et_(4)N)(Tp*WS_(3))(A)(Tp*=三(3,5-二甲基吡唑)氢合硼酸根)和[Cu(Me CN)_(4)]PF_(6)进行反应,得到2个W/Cu/S簇基超分子化合物[Tp*WS_(3)Cu_(2)(L_(1))]_(2)(PF_(6))_(2)·2Me CN·2CHCl_(3)(1·2Me CN·2CHCl_(3))和[Tp*WS_(3)Cu_(2)(L_(2))(Me CN)]_(2)(PF_(6))_(2)·4Me CN (2·4Me CN)。对配合物1·2Me CN·2CHCl_(3)和2·4Me CN分别进行了单晶X射线衍射、核磁、质谱、红外、紫外可见和元素分析表征。单晶X射线衍射分析表明,它们是由2个L_(1)/L_(2)配体连接2个[Tp*WS_(3)Cu_(2)]~+簇核形成的阳离子型簇基超分子框。核磁氢谱和高分辨电喷雾离子化质谱(HRESI-MS)证明它们在溶液中具有一定的稳定性。并利用Z扫描技术测试了超分子化合物1·2Me CN·2CHCl_(3)和2·4MeCN溶液的三阶非线性光学特性,测试结果表明它们的三阶非线性光学响应强于前驱体A。

TC4表面WC/Ni-MoS_(2)钛基复合涂层组织与摩擦学性能

拟在TC4表面合成Ti-S系自润滑耐磨熔覆层,并探究WC添加对涂层组织与摩擦学性能的影响,设计了TC4+Ni-MoS_(2)+xWC(x=5%、10%和15%)钛基材料体系,通过同轴送粉激光熔覆技术完成了涂层制备。研究表明,增加WC含量不利于改善涂层成形质量,但WC添加量变化并未影响涂层析出相种类,三种涂层均包括TiC、Ti_(2)Ni、Ti_(2)S和β-Ti基体;随着WC含量增大,TiC分布数量增多,粒径增大,生长形态由类球状逐渐演变为花瓣状;润滑相MoS_(2)未能在涂层中得到保留,其完全溶解后在钛基熔池体系下合成了与润滑相TiS等形态相似的条状相Ti_(2)S。三种WC含量的涂层显微硬度和耐磨性能均高于TC4基材,磨损机理均为磨粒磨损,但减摩性能均不低于TC4基材,说明原位Ti_(2)S相不具备自润滑功能;WC含量增加虽然有利于增大涂层的显微硬度和耐磨性能,但引起了涂层磨损面质量下降,摩擦系数波幅增大。

A Family of Global Attractors for the Generalized Kirchhoff-Beam Equations

In this paper, we discuss the existence and uniqueness of global solutions, the existence of the family of global attractors and its dimension estimation for generalized Beam-Kirchhoff equation under initial conditions and boundary conditions, using the previous research results for reference. Firstly, the existence of bounded absorption set is proved by using a prior estimation, then the existence and uniqueness of the global solution of the problem is proved by using the classical Galerkin’s method. Finally, Housdorff dimension and fractal dimension of the family of global attractors are estimated by linear variational method and generalized Sobolev-Lieb-Thirring inequality.

Dominance property based tabu search for single machine scheduling problems with family setups

The problem of minimizing the maximum lateness on a single machine with family setups is considered.To solve the problem, dominance property is studied and then introduced into the tabu search（TS） algorithm.With the dominance property, most unpromising neighbors can be excluded from the neighborhood, which makes the search process always focus on the most promising areas of the solution space.The proposed algorithms are tested both on the randomly generated problems and on the real-life problems.Computational results show that the proposed TS algorithm outperforms the best existing algorithm and can solve the real-life problems in about 1.3 on average.

Fine quantitative characterization of high-H2S gas reservoirs under the influence of liquid sulfur deposition and adsorption

In order to clarify the influence of liquid sulfur deposition and adsorption to high-H2S gas reservoirs,three types of natural cores with typical carbonate pore structures were selected for high-temperature and high-pressure core displacement experiments.Fine quantitative characterization of the cores in three steady states(original,after sulfur injection,and after gas flooding)was carried out using the nuclear magnetic resonance(NMR)transverse relaxation time spectrum and imaging,X-ray computer tomography(CT)of full-diameter cores,basic physical property testing,and field emission scanning electron microscopy imaging.The loss of pore volume caused by sulfur deposition and adsorption mainly comes from the medium and large pores with sizes bigger than 1000μm.Liquid sulfur has a stronger adsorption and deposition ability in smaller pore spaces,and causes greater damage to reservoirs with poor original pore structures.The pore structure of the three types of carbonate reservoirs shows multiple fractal characteristics.The worse the pore structure,the greater the change of internal pore distribution caused by liquid sulfur deposition and adsorption,and the stronger the heterogeneity.Liquid sulfur deposition and adsorption change the pore size distribution,pore connectivity,and heterogeneity of the rock,which further changes the physical properties of the reservoir.After sulfur injection and gas flooding,the permeability of TypeⅠreservoirs with good physical properties decreased by 16%,and that of TypesⅡandⅢreservoirs with poor physical properties decreased by 90%or more,suggesting an extremely high damage.This indicates that the worse the initial physical properties,the greater the damage of liquid sulfur deposition and adsorption.Liquid sulfur is adsorbed and deposited in different types of pore space in the forms of flocculence,cobweb,or retinitis,causing different changes in the pore structure and physical property of the reservoir.

Nano-multilayered ZrN‒Ag/Mo‒S‒N film design for stable anti-frictional performance at a wide range of temperatures

A multilayer film,composed by ZrN‒Ag(20 nm)and Mo‒S‒N(10 nm)layers,combining the intrinsic lubricant characteristics of each layer was deposited using DC magnetron sputtering system,to promote lubrication in a wide-range of temperatures.The results showed that the ZrN‒Ag/Mo‒S‒N multilayer film exhibited a sharp interface between the different layers.A face-centered cubic(fcc)dual-phases of ZrN and Ag co-existed in the ZrN‒Ag layers,whilst the Mo‒S‒N layers displayed a mixture of hexagonal close-packed MoS_(2)(hcp-MoS_(2))nano-particles and an amorphous phase.The multilayer film exhibited excellent room temperature(RT)triblogical behavior,as compared to the individual monolayer film,due to the combination of a relative high hardness with the low friction properties of both layers.The reorientation of MoS_(2)parallel to the sliding direction also contributed to the enhanced anti-frictional performance at RT.At 400℃,the reorientation of MoS_(2)as well as the formation of MoO_(3)phase were responsible for the lubrication,whilst the hard t-ZrO_(2)phase promoted abrasion and,consequently,led to increasing wear rate.At 600℃,the Ag_(2)MoO_(4)double-metal oxide was the responsible for the low friction and wear-resistance;furthermore,the observed transformation from t-ZrO_(2)to m-ZrO_(2),could also have contributed to the better tribological performance.

SnAgCu-Al_(2)O_(3)在不同织构角度下对TiNi润滑行为的影响

目的研究高镍钛基合金(TiNi)的摩擦学性能以提高其使用精度和服役寿命。方法以TiNi为研究对象,结合仿生学方法在TiNi表面设计并制备了鱼鳞状表面织构。随后将复合固体润滑剂Sn AgCu-Al_(2)O_(3)(S-A)均匀填充至织构,使用摩擦磨损测试仪对制备的样品进行摩擦实验。最后利用场发射扫描电子显微镜和三维表面形貌仪对磨痕表面进行表征,重点分析表面织构的角度参数对复合材料Sn Ag Cu-Al_(2)O_(3)/TiNi(S-A/TiNi)摩擦学性能的影响。结果与TiNi相比,当表面织构的角度为70°时,S-A/TiNi-70°的平均摩擦因数和磨损率分别降低约81.8%和85.5%,其值分别约为0.1和1.2×10^(-13)m^(3)/(N·m)。结论研究过程中发现,S-A/TiNi-70°试样表现的优异摩擦学性能依赖于S-A固体润滑膜的完整性,摩擦表面形成的固体润滑膜越连续其表面磨损越小。S-A/TiNi-70°试样优异的摩擦学性能主要归因于在表面织构角度为70°时,织构凹槽中的S-A固体润滑剂相较于其他角度更容易流动。这导致织构凹槽中的润滑剂能够大量迁移到摩擦表面形成S-A固体润滑膜,从而减少了摩擦副和基体直接接触。

碲改质C70S6非调质钢的旋转弯曲疲劳性能

采用升降法和成组法对碲改质C70S6非调质钢进行旋转弯曲疲劳试验,研究了试样的旋转弯曲疲劳性能,分析了碲改质作用机理。结果表明:当置信度为95%,失效概率分别为10%,50%时采用升降法得到的疲劳强度分别为385.0,458.8 MPa,采用成组法时分别为379.9,432.0 MPa,两种方法所测疲劳强度均高于企业要求和未经碲改质C70S6非调质钢;试验钢中硫化物为MnS和Mn(S,Te),大多呈曲率半径小的椭球状,评级结果为细系1.5级,粗系2.0级,其尺寸小于国内未经碲改质C70S6非调质钢,与国外未经碲改质C70S6非调质钢相当;碲改质主要通过调控硫化物形态、减小硫化物尺寸来改善C70S6非调质钢的旋转弯曲疲劳性能。

纳米C-S-H晶核对水泥浆体流变性能的影响

纳米C-S-H晶核由于对水泥早期水化的显著加速效果逐渐被广泛用作早强剂,通过流变仪测试掺纳米C-S-H晶核水泥浆体的塑性黏度、动态屈服应力、静态屈服应力和触变性,以研究纳米C-S-H晶核对水泥浆体流变性能的影响。结果表明:纳米C-S-H晶核掺入水泥浆体后,水泥浆体塑性黏度、动态屈服应力、静态屈服应力和触变性均随之增加,掺量越大,增加越多。水灰比对水泥浆体的流变性能也具有显著影响,水灰比越小,浆体的塑性黏度、动态屈服应力、静态屈服应力和触变性越大。