Hydration Characteristics and Mechanical Properties of Cement-Based Materials Modified by Calcined Zeolite and Montmorillonite

Montmorillonite and clinoptilolite zeolite were used as representative materials to prepare calcined clay-cement binary cementitious materials in order to study the effect of calcination treatment on the activation of clay minerals and the activity difference between layered and framed clays in this research.The influence of different calcined clay content(2%,4%,6%,8%,10%)on the fluidity,compressive strength,microstructure,phase change,and hydration heat of cement-based materials were analyzed.The calcined clay improves the fluidity of cement-based materials as compared with the uncalcined group.The addition of calcined montmorillonite(CMT)improves the development of mechanical strength,and the optimal compressive strength reaches 85 MPa at 28 days with 8%CMT.However,the activity of calcined clinoptilolite zeolite(CZL)is weak with few reaction sites,which slightly reduced the mechanical strength as compared to the blank sample.The addition of CMT changes the microscopic morphology of hydration products such as C-S-H and C-A-H,leading to the formation and transformation of ettringite in the early stage.It promotes the gradual polymerization of Si-O bonds into Si-O-Si bonds simultaneously,which accelerates the early hydration process.However,CZL acts mainly as a filling function in the cementitious system.In brief,CMT as an admixture can improve the mechanical properties of cement,but CZL has little effect.This work provides a guideline for the applications of calcined clay in cement,considering the influence of clay type on workability and mechanical strength.

Elliptically polarized high-order harmonic generation in nitrogen molecules with cross-linearly polarized two-color laser fields

Circularly and elliptically polarized high-order harmonics have unique advantages when used in studying the chiral and magnetic features of matter.Here,we studied the polarization properties of high-order harmonics generated from alignment nitrogen molecules driven by cross-linearly polarized two-color laser fields.Through adjusting various laser parameters and targets,such as the relative phase,the crossing angle,the intensity ratio of the driving fields,and the molecular alignment angle,we obtained highly elliptically polarized high-order harmonics with the same helicity in a wide spectral range.This provides a possible effective way to generate elliptically polarized attosecond pulses.Finally,we showed the probability of controlling the spectral range of elliptically polarized harmonics.

疫情后高校教师对混合式教学的接受度研究

疫情后的混合式教学改革已经成为教育信息化改革的新方向。抛开高校政策性影响,以高校教师为调查对象,对疫情后其采用混合式教学的影响机理进行实证研究。结果显示,教师采用混合式教学的意愿受其对混合式教学的态度的影响,态度与学生对疫情期间在线教学的认可和教师对采用混合式教学的感知收益、损失有关,另外学生的认可会提升感知收益且削弱感知损失。据此,为高校引导教师采用混合式教学提出了开辟交流渠道、宣传教改价值和引导形成态度三条对策。

Manipulating Nonsequential Double Ionization of Argon Atoms via Orthogonal Two-Color Field

Using a three-dimensional classical ensemble model,we investigate the dependence of relative frequency and relative initial phase for nonsequential double ionization(NSDI)of atoms driven by orthogonal two-color(OTC)fields.Our findings reveal that the NSDI probability is clearly dependent on the relative initial phase of OTC fields at different relative frequencies.The inversion analysis results indicate that adjusting the relative frequency of OTC fields helps control returning probability and flight time of the first electron.Furthermore,manipulating the relative frequency at the same relative initial phases can vary the revisit time of the recolliding electron,leading that the emission direction of Ar^(2+)ions is explicitly dependent on the relative frequency.

Atramacronoids A-C,three eudesmanolide sesquiterpene-phenol hybrids with an unprecedented C-C linkage from the rhizomes of Atractylodes macrocephala

Three eudesmanolide sesquiterpene-phenol hybrids,atramacronoids A-C(1-3),featuring an unusual6/6/5/5/6 skeleton furnished by forming an unexpected C-8-C-16 linkage,were obtained from the rhizomes of Atractylodes macrocephala.Their structures and absolute configurations were elucidated by spectroscopic data analysis,chemical calculations,combined with X-ray diffractions.The plausible biosynthetic pathways for compounds 1-3 are proposed.Surprisingly,compound 1 exhibited cytotoxicity against SGC-7901 cells by inducing cells apoptosis,which might relate to the promotion of synthesis of neutrophil elastase.

Antihyperglycemic and antihyperlipidemic action of cinnamaldehyde in C57blks/j Db/db mice

OBJECTIVE:To investigate the effects of cinnamaldehyde(CA),an active and major compound in cinnamon,on glucose metabolism and insulin resistance in C57BLKS/J db/db mice.METHODS:Sixteen male C57BLKS db/db mice were randomly divided into control and CA treatment groups.CA was given(20 mg.kg-1.day-1,p.o.) for 4 weeks.Pure water was given to control and db/+ mice.Subsequently,the levels of fasting blood glucose(FBG),fasting serum insulin,triglyeride,cholesterol,low-density lipoprotein-cholesterol(LDL-C),high-density lipoprotein-cholesterol(HDL-C),and free fatty acids(FFA),as well as the mRNA content of adiponectin and tumor necrosis factor(TNF)-α in adipose tissue,glucose transporter type 4(GLUT-4) in skeletal muscle,and protein expressions of Akt,phospho-Akt(Thr308),AMPKα,phospho-AMPKα(Thr172) in skeletal muscle were measured.RESULTS:1) CA decreased serum levels of FBG and insulin as well as body weight in db/db mice;2) CA increased serum HDL-C levels;3) CA significantly decreased the mRNA expression of TNF-α in adipose tissue and upregulated mRNA expression of GLUT-4 in skeletal muscle;4) protein expression of p-Akt was increased in CA-treated mice,but Akt,AMPKα and p-AMPKα showed no change.CONCLUSION:CA has antihyperglycemic and antihyperlipidemic actions in db/db mice and could be useful in the treatment of type-2 diabetes.