Experimental Study on the Influence of Curing Conditions on Capillary Absorption of Concrete

Both the hardening process and formation of microstructure of concrete are significantly influenced by the curing condition. The capillary absorption of concrete is closely related to the structure and distribution of the pores within the material. This paper presents an experimental study on the influence of four curing conditions, i.e., standard curing, natural curing, water curing, and sealed curing, on the capillary absorption of normal concrete. Compressive strength tests on the cylinder specimens that are core drilled from concrete slabs are carried out. The “pie” samples cut from three different locations along the height direction of cylinder specimens are then conducted to measure the ultrasonic pulse velocity (UPV) and porosity, which quantitatively characterize the internal state of concrete after 28 days initial curing. In order to realize the continuous observation of water absorption testing, an improved gravimetrical test setup for measuring the sorptivity (the rate of water absorption) of concrete is designed to investigate capillary absorption of the “pie” samples. The experimental results indicate that the curing condition has an important influence on compressive strength, ultrasonic pulse velocity, and porosity of concrete. The temperature and relative humidity are the key factors to ensure strength development during the curing procedure and to determine the internal pore structure and the compactness of concrete. For the same curing conditions, the cumulative water content, sorptivity, and porosity of concrete gradually decrease with the increase of distance from the surface, but the ultrasonic pulse velocity reverses

Caulis Lonicerae Japonicae extract shows protective effect on osteoporosis in rats

Purpose: To investigate the effect of Caulis lonicerae Japonicae extract (CLJE) on ovariectomyinduced osteoporosis in rats.Methods: Female Sprague-Dawley rats were randomly assigned to a control group (normal rats) and five ovariectomy (OVX) subgroups: OVX with vehicle (OVX), OVX with 17ß-estradiol (E2, 25μg/kg/day), and OVX with CLJE doses (150, 300, and 600 mg/kg/day). Daily oral administration of E2 or CLJE started 4 weeks after OVX and lasted for 16 weeks. The bone mineral density (BMD) of L4 vertebrae and right femurs was determined. The length of each femur was measured with a micrometer, and the center of the diaphysis was determined. Three representative L4 vertebrae were selected to evaluate trabecular microarchitecture. Serum alkaline phosphatase (ALP), urinary calcium (U-Ca), urinary phosphorus (U-P), urinary creatinine (Cr) and osteocalcin (OC) levels were measured using a diagnostic reagent kit.Result: The results show that a high-dose of CLJE (600 mg/kg) significantly inhibited bone mineral density (BMD) reduction of L4 vertebrae (0.24 ± 0.02, p < 0.05) and femur (0.24 ± 0.03, p < 0.05) caused by OVX, and prevented the deterioration of trabecular microarchitecture (p < 0.05). High-dose CLJE also improved morphometric parameters, viz, trabecular number (Tb-N) (4.6 ± 0.3, p < 0.05), trabecular thickness (Tb-Th, 0.084 ± 0.012, p < 0.05) and trabecular separation (Tb-Sp, 0.14 ± 0.02, p < 0.05) in L4 vertebrae significantly.Conclusion: The results indicate that CLJE prevents OVX-induced osteoporosis in rats. Thus, CLJE is a potential natural alternative for the treatment of postmenopausal osteoporosis in future.Keywords: Caulis Lonicerae Japonicae, Post-menopausal osteoporosis, Ovariectomy, Bone mineral density, Trabecular microarchitecture, Diaphysi

Exploring a Hybrid Algorithm for Price Volatility Prediction of Bitcoin

In recent years, the Bitcoin investment market has become increasingly popular. We collected existing literature on Bitcoin and found that predictions about the role of Bitcoin in investment portfolios and the volatility of Bitcoin price as well as return have become advanced research topics. This study shows our current work on the prediction of Bitcoin price volatility and proposes an idea for predicting the price volatility. We have designed an experiment that compares different combinations of machine learning algorithms with GARCH-type models, intending to compare the effects of these models in the prediction of Bitcoin time series and finally implement an optimized algorithm

New plants from the Lower Devonian Pingyipu Group, Jiangyou County, Sichuan Province, China

Descriptions of Lower Devonian plants from Yunnan, South China, have revolutionized concepts of diversity and disparity in tracheophytes soon after they became established on land. Sichuan assemblages have received little attention since their discovery almost 25 years ago and require revision. With this objective, fieldwork involving detailed logging and collection of fossils was undertaken in the Longmenshan Mountain Region, Jiangyou County and yielded the two new taxa described here. They are preserved as coalified compressions and impressions that allowed morphological but not anatomical analyses. Yanmenia (Zosterophyllum) longa comb nov is based on numerous rarely branching shoots with enations resembling lycophyte microphylls, without evidence for vasculature. The presence of sporangia is equivocal making assignation to the Lycopsida conjectural. The plant was recently described as a zosterophyll, but lacks strobili. These are present in the second plant and comprise bivalved sporangia. The strobili terminate aerial stems which arise from a basal axial complex displaying diversity in branching including H- and K- forms. These features characterise the Zosterophyllopsida, although the plant differs from Zosterophyllum in valve shape. Comparisons indicate greatest similarities to the Lower Devonian Guangnania cuneata, from Yunnan, but differences, particularly in the nature of the sporangium border, require the erection of a new species, G. minor. Superficial examination of specimens already published indicate a high degree of endemism at both species and generic level, while this study shows that Yanmenia is confined to Sichuan and Guangnania is one of the very few genera shared with Yunnan, where assemblages also show a high proportion of further endemic genera. Such provincialism noted in the Chinese Lower Devonian is explained by the palaeogeographic isolation of the South China plate, but this cannot account for differences/endemism between the Sichuan and Yunnan floras. Such an enigma demands further integrated geological, palaeobotanical and palynological studies

LogisticLDA: Regularizing Latent Dirichlet Allocation by Logistic Regression

PACLIC 23 / City University of Hong Kong / 3-5 December 200

Experimental Free-Space Distribution of Entangled Photon Pairs over a Noisy Ground Atmosphere of 13km

We report free-space distribution of entangled photon pairs over a noisy ground atmosphere of 13km. It is shown that the desired entanglement can still survive after the two entangled photons have passed through the noisy ground atmosphere. This is confirmed by observing a space-like separated violation of Bell inequality of $2.45 \pm 0.09$. On this basis, we exploit the distributed entangled photon source to demonstrate the BB84 quantum cryptography scheme. The distribution distance of entangled photon pairs achieved in the experiment is for the first time well beyond the effective thickness of the aerosphere, hence presenting a significant step towards satellite-based global quantum communication.Comment: 4 pages, 3 figure