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.

The Durability of Alkali-Activated Materials in Comparison with Ordinary Portland Cements and Concretes:A Review

China is the largest producer and user of ordinary Portland cement(OPC),and the rapid growth of infrastructure development demands more sustainable building materials for concrete structures.Alkali-activated materials(AAMs)are a new type of energy-saving and environmentally friendly building material with a wide range of potential applications.This paper compares the durability of AAMs and 0 PC-based materials un der sulfate attack,acid corrosion,carb on ation,and chloride penetratio n.Different AAMs have shown distinct durability properties due to different compositions being formed when different raw materials are used.According to the calcium(Ca)concentration of the raw materials,this paper interprets the deterioration mechanisms of three categories of AAMs:calcium-free,low-calcium,and calcium-rich.Conflicts found in the most recent research are highlighted,as they raise concerns regarding the consistenee and long-term properties of AAMs.Nevertheless,AAMs show better durability performances than OPC-based materials in general.

Application of ultrasound-guided balloon occlusion in cesarean section in 130 cases of sinister placenta previa

Objective:To investigate the clinical utility of ultrasound-guided balloon occlusion in cesarean section in patients with sinister placenta previa.Methods:The Interventional and Ultrasound Departments of the authors’center assisted obstetrics to complete cesarean section in cases of sinister placenta previa.A total of 130 patients with implanted sinister placenta previa were diagnosed using obstetrical ultrasound and magnetic resonance imaging(MRI).Before cesarean section,the balloon was positioned in the bilateral radial or abdominal aorta.Immediately after delivery of the fetus,the balloon was temporarily filled to transiently seal the target vessel.According to the obstetrician’s assessment of hemostasis,the balloon was withdrawn at the appropriate time.Among the 130 patients,there was one case of abdominal aortic occlusion,with 129 cases blocked by the bilateral common iliac artery.Results:All 130 cases were successfully blocked,with an average blocking time of<15 min,while intraoperative blood loss was 800–1500 ml.Conclusion:Ultrasound-guided balloon blocking treatment before cesarean section can mitigate the dangers of placenta previa and significantly reduce blood loss with no exposure to X-ray radiation.Thus,the technique merits serious consideration.

Carbon quantum dots modified TiO_(2) composites for hydrogen production and selective glucose photoreforming

Lignocellulosic biomass photoreforming is a promising and alternative strategy for both sustainable H_(2) production and biomass valorization with infinite solar energy.However,harsh reaction conditions(high alkalinity or toxic organic solvents),with low biomass conversion and selectivity are often reported in literature.In this work,we report glucose photoreforming for coproduction of H_(2) and arabinose with improved selectivity under neutral condition using carbon quantum dots(CQDs)modified TiO_(2) composites.We show that the conventional CQDs fabricated by a facile one-step hydrothermal process could be endowed with novel color changing property,due to the particle aggregation under the regulation of incident light.The as-fabricated CQDs/TiO_(2) composites with certain colored CQDs could greatly improve glucose to arabinose conversion selectivity(-75%)together with efficient hydrogen evolution(up to 2.43 mmolh^(-1)g^(-1))in water.The arabinose is produced via the direct C1-C2 α-scissions mechanism with reactive oxygen species of·O_(2)^(-) and·OH,as evidenced by ^(13)C labeled glucose and the electron spin-resonance(ESR)studies,respectively.This work not only sheds new lights on CQDs assisted photobiorefinery for biomass valorization and H_(2) coproduction,but also opens the door for rationale design of different colored CQDs and their potential applications for solar energy utilization in the noble-metal-free system.

The regulatory network behind maize seed germination: Effects of temperature, water, phytohormones, and nutrients

Seed germination is the process by which an organism grows from a seed. It requires suitable conditions and environmental factors. Maize is one of the most important crops worldwide. Germination influences both final maize yield and quality. Seed germination is regulated by a complex gene network. It is also influenced by endogenous(phytohormones and nutrients) and exogenous(temperature and water)inputs, involving molecular networks only partly identified to date. This review describes current understanding of the influence of temperature, water, phytohormones, and nutrients in regulating maize seed germination, and indicates knowledge gaps that should be addressed.

Change of Phosphate Fraction during Composting of Fresh Waste Leaves of Tobacco

Environmental issue has concerned the public with the build-up of soil phosphorus(P) following application of organic manure.This demands a fully understanding of the change of phosphorus during composting of fresh waste leaves of tobacco and finding out the status of P fertilizer in leaf-made manure.This study had shown that water-soluble and HCl-soluble phosphon were the dominant fractions of P in the compost of fresh waste leaves,in the ranges of 19%-41% and 17%-43%,respectively.However,the former declined progressively upon composting time,but the latter increased,indicating transformation of the more vulnerable water soluble P to the more recalcitrant HCl-extractable P.

Expression of genes involved in progesterone receptor paracrine signaling and their effect on litter size in pigs

Background： Embryonic mortality during the period of implantation strongly affects litter size in pigs. Progesterone receptor（PGR） paracrine signaling has been recognized to play a significant role in embryonic implantation. IHH,NR2F2, BMP2, FKBP4 and HAND2 were proved to involve in PGR paracrine signaling. The objective of this study was to evaluate the expression of IHH, NR2F2, BMP2, FKBP4 and HAND2 in endometrium of pregnant sows and to further investigate these genes＇ effect on litter size in pigs. Real-time PCR, western blot and immunostaining were used to study target genes/proteins expression in endometrium in pigs. RFLP-PCR was used to detect single nucleotide polymorphisms（SNPs） of target genes.Results： The results showed that the m RNA and protein expression levels of IHH, NR2F2 and BMP2 were up-regulated during implantation period（P 〈 0.05 or P 〈 0.01）. All target proteins were mainly observed in luminal epithelium and glandular epithelium. Interestingly, the staining of NR2F2 and HAND2 was also strong in stroma. SNPs detection revealed that there was a-204 C 〉 A mutation in promoter region of NR2F2 gene. Three genotypes were found in Large White, Landrace and Duroc sows. A total of 1847 litter records from 625 sows genotyped at NR2F2 gene were used to analyze the total number born（TNB） and number born alive（NBA）. The study of the effect on litter size suggested that sows with genotype CC tend to have higher litter size.Conclusions： These results showed the expression patterns of genes/proteins involved in PGR paracrine signaling over implantation time. And the candidate gene for litter size was identified from genes involved in this signaling. This study could be a resource for further studies to identify the roles of these genes for embryonic implantation in pigs.

Research on Supercritical Methanol Treatment of Lignite

China has rich lignite reserves which are the proper resources to be liquefied. As its low coalification degree, much hydrogen is wasted. Solvent extraction can save hydrogen and improve its liquefaction performance. The paper studies supercritical methanol treatment of lignite with a device at high temperature and pressure. Experiments mainly focus on the effects of temperature, pressure, catalysts and pretreatment ways on the extraction rate. Results indicate that the extraction rate increases with raising of temperature and pressure below 330 ℃,10 MPa. When temperature exceeds 330 ℃, extraction rate decreases slightly.? After swelling pretreatment in methanol for 8 h, the lignite is treated for 60 min at 330 ℃,8.2 MPa with NaOH as catalyst(1%wt).? The weight ratio of methanol/ Xilinhaote lignite is 5/1.? Under these conditions, the extraction rate can reach 22.88%.

Ultrasound-driven self-decomposition porphyrins as metal-free CO precursors for gas and sonodynamic synergistic therapy

Carbon monoxide(CO) is an endogenous therapeutic gas with an anti-tumor effect. The precise delivery and controlled release of CO in tumor tissues play crucial roles in anti-cancer treatment. However, efficient in situ generation of CO from metal-free COreleasing molecules(CORMs) remains a formidable challenge. Herein, we develop ultrasound(US)-driven self-decomposition porphyrin as organic and metal-free US-CORMs, which can spatiotemporally control the CO release(347 mmol CO/mol porphyrin) efficiently under physiologically harmless US conditions(1.0 MHz, 1.5 W/cm^(2), 50% duty cycle, 50 min). Moreover,porphyrin as a sonosensitizer can also generate reactive oxygen species(ROS) under US treatment to achieve sonodynamic therapy(SDT). Advanced functions of such porphyrin-based CORMs in CO gas-sonodynamic synergistic treatment have been demonstrated by evaluating the in vitro and in vivo anti-tumor effects.

The effect of different gravity fields on mass transfer in the rat bone lacunar-canalicular system

The bone lacunar-canalicular system(LCS)is an important microscopic infrastructure for signaling and solute transport in bone tissue,which guarantees normal physiological processes of the tissue,but the mass transfer laws in the LCS under different gravity fields have not yet been clarified.SD rats were injected intraperitoneally with different concentrations of sodium fluorescein tracer and subjected to mass transfer experiments in the LCS under normal gravity and hypergravity.The fluorescence distribution in the osteon was observed using laser scanning confocal microscopy.The hypergravity environment was provided by a self-designed high-G loading centrifuge.The fluorescence intensity of the Haversian canal in the osteon was the highest.The fluorescence intensity of lacunae farther away from the Haversian canal was lower,and the fitted curve was parabolic.With the increasing distance from the Haversian canal,the curve first rapidly decreased,and then the decreasing trend gradually became slower.Hypergravity promoted mass transfer in the LCS,and the 10 G hypergravity showed varying degrees of fluorescence intensity in each layer of the osteon relative to normal gravity,with intensity enhancements in the range of 132.7–249.0%.The fluorescence intensity was also significantly increased when the tracer concentration was halved and the gravity field magnitude was increased to 10G.In conclusion,hypergravity promoted the transport of solute molecules,nutrients,and signaling molecules within the LCS.The effect of hypergravity on mass transfer in the LCS was greater than that of tracer concentration.This may help to understand bone diseases from a mass transfer perspective.

Geological characteristics and key exploration technologies of continental shale oil sweet spots: A case study of Member 2 of Kongdian Formation in the Cangdong sag in the Huanghua depression, Bohai Bay Basin

Under the general trend of stepping-up oil and gas exploration and development in China,the unconventional oil and gas resources such as shale oil and gas have become an important alternative.Abundant continental shale oil resources are developed in Member 2 of Kongdian Formation(Ek2)of the Cangdong sag in the Huanghua depression of the Bohai Bay Basin which has complex structure,strong heterogeneity,and large buried depth,thus,the geological characteristic of shale oil accumulation and key exploration technologies are investigated on base of the system coring of 635.8 m,centimeter-level fine description and analysis of over ten thousand samples,therefore,the“four accurate”technologies have been developed,including the accurate selection of sweet spot areas,accurate drilling of sweet spot layers,accurate fracturing of sweet spot layers and accurate measure of fracture-rich sections.The results show that the continental shale strata in Member 2 of Kongdian Formation can be divided into three types:felsic shale,limy dolomitic shale and mixed shale.The Member 2 of Kongdian Formation is characterized by diverse mineral components,abundant laminae,good source rocks and medium thermal evolution degree,tight reservoir with rich micropore and microfractures,high oil saturation and brittle mineral content,indicating good prospect of shale oil exploration.Through sedimentological study,TOC and Ro evaluation,brittle mineral calculation,and seismic fusion inversion,a total of 126 km^(2) of Class I sweet spots in Member 2 of Kongdian Formation was delineated comprehensively,which guides horizontal well deployment(Well GD1701H and Well GD1702H).The drilling rate of sweet spot of these two horizontal wells is up to 96%by tracing thin layer through fine calibration,locating compartment through fine inversion,ensuring window entry through precise positioning,and tracking sweet spot through adjustment.The “one-excellent and five-highs”criterion is used to select perforation points to realize differential designs of fracturing intervals and clusters.Micro-seismic and potentiometry monitoring show that the artificial fractures formed by volumetric fracturing are 300e400 m long and 120 m high,and control a volume of about 0.07 km^(3).The maximum daily oil production of two horizontal wells is 48 t and 66 t respectively to realize the economic exploitation of shale oil reserves controlled by fractures.The shale oil exploration in Member 2 of Kongdian Formation shows that the continental shale oil has great potential of exploration and development,and the above technologies are critical and effective for shale oil efficient recovery.

Three new decarbonyl prenylphloroglucinols bearing unusual spirost subunits from Hypericum scabrum and their neuronal activities

Three novel polycyclic polyprenyled acylphloroglucinols,Hyperscabins A-C,were obtained from the aerial parts of Hypericum scabrum.They featured an unprecedented 5,5-spiro ketal subunit with the loss of C-2’carbonyl in the phloroglucinol ring.Their structures were characterized by extensive spectroscopic analyses,NMR calculations with DP4+analysis,calculated electronic circular dichroism(ECD)spectra and the application of modified Mosher’s methods.In the assay of[^(3)H]-5-HT and[^(3)H]-NE reuptake inhibition,compounds 1 and 2 showed good inhibito ry activity(81.8%and 83.2%)in 10μmol/L.In addition,compound 1 significantly increased cell viability in the experiment of oxygen and glucose deprivation/deoxygenation.

Hydrolyzable tannins from Balanophora polyandra

This study reports an investigation of the chemical constituents of Balanophora polyandra Griff.Fifteen compounds were isolated by column chromatography on silica gel,Toyo-pearl HW-40C,Sephadex LH-20 and by HPLC.Their structures were elucidated as 1,4-di-O galloy-2-O-[(E)-p-coumaroyl]-β-D-glucopyranose(1),1-O-galloyl-β-D-pyranglucose(2),1-p-coumaryl-β-D-pyranglu-cose(3),1-O-(E)-caffeoyl-β-D-pyranglucose(4),1,3-di-O-galloyl-β-D-pyranglucose(5),1,6-di-O-galloyl-β-D-pyranglucose(6),1-O-(E)-caffeoyl-4-O-galloyl-β-D-pyranglucose(7),1-O-(E)-caffeoy1-6-O galloyl-β-D-pyranglucose(8),1-0-(E)-caffeoy1-4,6-di-O-galloyl-β-D-pyranglucose(9),1-O-(E)-caffeoyl-4,6-(S)-HHDP-B-D-pyranglucose(10),1,23,6-tetra-O-galloyl-β-D-pyranglucose(11),4,6-(S)-hexahydroxydi-phenoyl-(α/β)-D-glucose(12),1-O-(E)-caffeoyl-4,6-[1′,1″-3′,3″,4′,4″-tetrahydroxydibenzofurandicar-boxyl)]-β-D glucopyranose(13),flavogallonic acid(14),and phloretin-4′-O-β-D-glucoside(15)on the basis of spectral analysis.Compound 1 was a new hydrolyzable tannin,9 was obtained from this genus for the first time,and compounds 5,6 and 11-14 were isolated from this plant for the first time.

Causality fields in nonlinear causal effect analysis

Compared with linear causality,nonlinear causality has more complex characteristics and content.In this paper,we discuss certain issues related to nonlinear causality with an emphasis on the concept of causality field.Based on widely used computation models and methods,we present some viewpoints and opinions on the analysis and computation of nonlinear causality and the identification problem of causality fields.We also reveal the importance and practical significance of nonlinear causality in handling complex causal inference problems via several specific examples.