Change in Grain-Size Composition of Lignite under Cyclic Freezing-Thawing and Wetting-Drying

The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to repeated freezing-thawing and wetting-drying, which determines the possibility of changing their grain-size composition and structure. Experimental studies in laboratory conditions on the influence of cyclic freezing-thawing (FTC) and wetting-drying (WDC) on the quality indicators of lignites have been carried out, their granulometric (fractional) composition has been studied. Freezing-thawing cycle conditions are as follows (FTC): minimum exposure temperature: -20°C;maximum: +5°C;relative humidity: 30%;number of processing cycles: 3. Wetting-drying cycles are as follows (WDC): drying temperatures are +20, +40, +60, +80°C, drying time 90 minutes, the coals are further subjected to rain (soaking) for a period of water saturation to humidity of 30% - 40% and dry again. The number of wetting-drying cycles is 3 times. The tests have revealed the destructive effects of FTC and WDC on the samples of lower metamorphic grade coal, and the cycles of wet-dry lead to the much higher yield of fine sizes (-6+0;-13+0 mm) than the cycles of freeze-thaw. Furthermore, it is found that the increase in the yield of fines depends on the heating temperature: coal disintegration proceeds more intensively at a higher temperature of drying.

Numerical Simulation on Climate Effects of Freezing-Thawing Processes Using CCM3

A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.

Centrifugal and field studies on water infiltration characteristics below canals under wetting-drying-freezing-thawing cycles

Seepage is one of the main causes for the deformation and instability of canal slopes in Xinjiang,China.In this study,centrifugal model tests under wetting-drying(WD)and wetting-drying-freezing-thawing(WDFT)cycles were performed to investigate the water infiltration characteristics below a canal.The results show that the shallow soil of the canal models was fully saturated in the wetting process.Compared with the canal model under the WD cycles,the canal model under the WDFT cycles had larger saturated areas and a higher degree of saturation below the canal top after each cycle,indicating that the freezing-thawing(FT)process in the WDFT cycles promoted the water infiltration behavior below the canal slope.The cracks on the surface of the canal model under the cyclic action of WDFT developed further and had a higher connectivity,which provided the conditions for slope instability from a transverse tensile crack running through the canal top.On this basis,a field test was conducted to understand the water infiltration distribution below a typical canal in Xinjiang,China,which also verified the accuracy of the centrifugal results.This study provides a preliminary basis for the maintenance and seepage treatment of canals in Xinjiang,China.

Shear strength of frozen clay under freezing-thawing cycles using triaxial tests

Using a new low-temperature dynamic triaxial apparatus, the influence law of freezing-thawing cycles on clay shear strength is studied. In this research, the concept of correction coefficients of freezing-thawing cycles on clay static strength, cohesion and internal friction angles is proposed, and the change patterns, correction curves and regressive formulae of clay static strength, cohesion and internal friction angles under freezing-thawing cycles are given. The test results indicate that with increasing numbers of freezing-thawing cycles, the clay static strength and cohesion decrease exponentially but the internal friction angle increases exponentially. The performance of static strength, cohesion and internal friction angles are different with increasing numbers of freezing-thawing cycles, i.e., the static strength decreases constantly until about 30% of the initial static strength prior to the freezing-thawing cycling and then stays basically stable. After 5-7 freezing-thawing cycles, the cohesion decreases gradually to about 70% of the initial cohesion. The internal friction angle increases about 20% after the first freezing-thawing cycle, then increases gradually close to a stable value which is an increase of about 40% of the internal friction angle. The freezing-thawing process can increase the variation of the density of the soil samples; therefore, strict density discreteness standards of frozen soil sample preparation should be established to ensure the reliability of the test results.

Experimental study of coal fracture dynamics under the influence of cyclic freezing-thawing using shear elastic waves

Cyclic freezing-thawing can lead to fracture development in coal,affecting its mechanical and consumer properties.To study crack formations in coal,an ultrasonic sounding method using shear polarized waves was proposed.Samples of three coal types(anthracite,lignite and hard coal)were tested.The research results show that,in contrast to the shear wave velocity,the shear wave amplitude is extremely sensitive to the formation of new cracks at the early stages of cyclic freezing-thawing.Tests also show an inverse correlation between coal compressive strength and its tendency to form cracks under temperature impacts;shear wave attenuation increases more sharply in high-rank coals after the first freezing cycle.Spectral analysis of the received signals also confirmed significant crack formation in anthracite after the first freeze-thaw cycle.The initial anisotropy was determined,and its decrease with an increase in the number of freeze-thaw cycles was shown.The data obtained forms an experimental basis for the development of new approaches to preserve coal consumer properties during storage and transportation under severe natural and climatic conditions.

Seasonal freezing-thawing process and hydrothermal characteristics of soil on the Loess Plateau, China

In seasonally frozen soil regions,freezing-thawing action and hydrothermal effect have strong influence on physical and mechanical behavior of shallow soil.A field experiment on the Loess Plateau in Northwest China was carried out to analyze the freezing-thawing process and hydrothermal characteristics of shallow soil considering the climate influence.The results show that the maximum seasonal freezing depth under bare ground surface in this area is from 20 cm to 50 cm.The ground temperature shows a similar changing trend with air temperature,but it has lagged behind the air temperature,and the ground temperature amplitude exponentially decreases with the increase of soil depth.The seasonally frozen soil has experienced four typical stages:unfrozen period,alternate freezing period,freezing period and alternate thawing period.The freezing-thawing process is characterized by unidirectional freezing and bidirectional thawing.The water content of shallow soil is significantly affected by air temperature,evaporation and precipitation,and the soil water content shows a"low-high-low"changing trend with the increase of depth.The soil temperature and water content interact with each other,and are often coupled.The variation trend of soil moisture with time is consistent with the change trend of the ground temperature with time in each soil layer,andthe degree of consistency is higher in the near surface soil than that in the lower layer.Also,the spatial-temporal characteristics of soil moisture and temperature is that the volumetric water content and ground temperatureof near surface soil have strong variability,and the range valueKa and coefficient of variation Cvof soil water content and ground temperaturein different seasons show a decreasing trend with the increase of depth.

Mechanical performances and microstructural characteristics of reactive MgO-carbonated silt subjected to freezing-thawing cycles

The characteristics of reactive magnesia(MgO)-carbonated silt in respect to long-term stability have not been well understood in severely cold climate despite the usage of reactive MgO in enhancing the engineering performances.Under the binder content of 15%and initial water content of 25%,MgO-admixed silt specimens were carbonized for 3 h and 6 h and then subjected to different numbers of freezingthawing(F-T)cycles.After different F-T cycles,the physico-mechanical properties of MgO-carbonated silt were analyzed in comparison with Portland cement(PC)-stabilized silt through physical and unconfined compression tests.Besides,a series of micro tests on MgO-carbonated specimens was performed including X-ray diffraction(XRD),scanning electron microscopy(SEM)and mercury intrusion porosimetry(MIP)tests.The results demonstrate that both mass change ratio and moisture content of carbonated/stabilized silt decrease,and these values of MgO-carbonated silt are significantly lower while the density is higher compared to PC-stabilized silt.The strengths and moduli of MgO-carbonated silt are still two times higher than those of PC-stabilized specimens and the strength change ratio of keeps above0.8 after F-T cycles.There is no visible transformation between nesquehonite and dypingite/hydromagnesite,although the XRD peaks of nesquehonite decrease and the bonding and filling effects weaken slightly.After 6 and 10 F-T cycles,the pore-size characteristics changed from a unimodal distribution to a three-peak and bimodal distribution,respectively.The total,macro and large pore volumes increase obviously while the medium and small pore volumes decrease except for intra-aggregate pore.The findings show better F-T durability of MgO-carbonated silt,which would be helpful for facilitating the application of MgO carbonation in the soil treatment.

Effects of Nitrogen Application on N_2O Flux from Fluvo-Aquic Soil Subject to Freezing-Thawing Process

A lab-incubation experiment was conducted to investigate the effects of different forms of nitrogen application （ammonium, NH4＋-N; nitrate, NO3--N; and amide-N, NH2-N） and different concentrations （40, 200 and 800 mg L-1） on N2O emission from the fluvo-aquic soil subjected to a freezing-thawing cycling. N2O emission sharply decreased at the start of soil freezing, and then showed a smooth line with soil freezing. In subject to soil thawing, N2O emission increased and reached a peak at the initial thawing stage. The average N2O emissions with addition of NH4＋-N, NO3 -N and NH2-N are 119.01, 611.61 and 148. 22 ug m-2 h-1, respectively, at the concentration of 40 mg L-1; 205.28, 1 084.40 and 106.13 ug m2 h-1 at the concentration of 200 mg L-1; and 693.95, 1 820.02 and 49.74 ug m-2 h4 at the concentration of 800 mg L-1. The control is only 100.35 ug m-2 h-1. N2O emissions with addition of NH4＋-N and NO3--N increased with increasing concentration, by ranging from 17.49 to 425.67% for NH4＋-N, and from 563.38 to 1458.6% for NO3--N compared with control. There was a timelag for N2O emission to reach a steady state with an increase of concentration. In contrast, by adding NH2-N to soil, N2O emission decreased with increasing concentration. In sum, NH4＋-N or NO3--N fertilizer incorporated in soil enhanced the cumulative N2O emission from the fluvo-aquic soil relative to amide-N. This study suggested that ammonium and nitrate concentration in overwintering water should be less than 200 and 40 mg L-1 in order to reduce N2O emissions from soil, regardless of amide-N.

Experimental research on the development of residual strain in seasonal frozen soil under freezing-thawing and impact type traffic loads

Vehicle load is among the main factors affecting the deformation of subgrade soil.In this research study,the concept of impact type traffic load is introduced to investigate the effects of vehicle load based on the dynamic stress and displacement time histories acquired from seasonal frozen subgrade soils.Using freezing-thawing and dynamic triaxial tests and considering the amplitude and loading sequence of impact type traffic load,the residual deformation characteristics of subgrade soil under impact type traffic loads and freezing-thawing cycles is studied.It was found that under impact type traffic load,the residual deformation of soils increased sharply as the amplitude of impact type traffic load increased.It was also found that the increase in the amplitude of impact type traffic load led to the increase of residual deformation in a scale of power and exponential function.The amplitudes of impact type traffic load affect the development stress-strain path of the residual strain.After the soil experienced the proper amount of pre-vibration of the light load,residual deformation decreased by 15%.After freezing-thawing,the residual strain of soil increased as the amplitude of the impact type traffic loads increased.Also,when the amplification effect of freezing-thawing on the residual strain was basically stable,the residual deformation increased by about 10%.The peak impact type traffic load had a large effect on soil deformation after the freezing-thawing process,leading to the observation that of the earlier the peaks,the stronger the effect of freezing-thawing.After the soil was subjected to preloading with a small load,the influence of the freezing-thawing cycles gradually stabilized.The results may be useful in preventing and controlling the risk of subgrade soil failure when construction takes place spring thaw periods.

Response Relationship between the Seasonal Freezing-Thawing Process of Soil and Spatial Factor Changes in the Dayekou Basin of the Qilian Mountains

Objective: In this study, the influence and response relationship between the seasonal freezing-thawing process of soil and the spatial factor changes in the management and utilization of water resource processes were explored. Methods: The monitoring equipment in this study was arranged at different altitudes, gradients, and slope directions, such as the typical forest sample area in the Dayekou Basin of the Qilian Mountains. The spatial variation characteristics of the seasonal freezing-thawing process of the soil were analyzed, and a regression model was established. Results: 1) The results of this study determined that the rate of the soil’s freezing increased with the altitude in a trend of volatility. However, the rate of the thawing of the frozen soil was found to have an opposite trend. The variation degree of the freezing-thawing process increased with the altitude in a trend of volatility. The end time of the approximate soil freezing with altitude increased in a volatility trend ahead of schedule. However, the opposite was observed in the thawing rate of the frozen soil;2) The rate of the soil’s freezing under the mosses of the spruce forest at an altitude of 3028 m was found to be the lowest. However, in the sub-alpine scrub forest at an altitude of 3300 m, a maximum in the spatial ordering was observed, with an average of 1.9 cm·d-1. The thawing rate of the frozen soil in scrub-spruce forest at an altitude of 3300 m was found to be minimal. However, in the sunny slope grassland at an altitude of 2946 m, a maximum in the spatial ordering was observed, with an average of 1.5 cm·d-1. In the spatial ordering of the variation degree of the process of freezing-thawing with an average of 1.2, the scrub-grassland at an altitude of 2518 m was found to be the lowest, and the scrub-spruce forest at an altitude of 3195 m was also low;3) The soil freezing began on approximately October 20th, and the rate of soil freezing gradually became reduced. The arrival time of the frozen soil of up to 150 cm in depth in sub-alpine scrub forest was first observed at an altitude of 3028 m. However, the scrub-spruce forest at an altitude of 3100 m did not become frozen until approximately January 12th on average. Then, the thawing rate of the frozen soil increased gradually. The end time of the thawing was earliest observed in the sunny slope grassland at an altitude of 2946 m. However, the scrub-spruce forest at an altitude of 3100 m was found to be the last to thaw, and averaged approximately July 27th. The average durations of the freezing and thawing of the soil were 77 and 121 days, respectively, and the average duration of the entire process of freezing-thawing was 199 days;4) This study’s established regression models of the duration time of frozen soil’s thaw, and the rate of frozen soil’s thaw, all passed the R test of goodness of fit, F test of variance, and t test. Conclusions: The characteristics of the seasonal freezing-thawing process of the soil with the spatial changes were seasonal. However, the characteristics under the different spatial factor influences were not the same.

Effects of freezing-thawing on the engineering performance of core wall soil materials of a dam in the process of construction

The construction of water conservancy projects in cold regions experiences freezing-thawing cycles,which can greatly change the engineering properties of soil and have a significant impact on the construction of projects.Lianghekou Hydropower Station(LHS),is a controlling station with the largest installed capacity among the 7 middle reach projects in the Yalong River,the secondary tributary of the Yangtze River.LHS is located in a seasonally frozen soil area.Based on the measured data of air and ground temperature in winter in the dam core wall,the freezing-thawing variation of gravelly soil and contact clay during the filling process of the core wall are compared and analyzed,then the main impact factors of the freezing-thawing variation of soils are discussed.The results show that under the influence of air temperature,soil freezes unidirectionally from ground surface downward and deepens gradually,and the thawing processes are different at the aspects of thawing direction and rate.Air temperature and physical properties of soil including soil type,moisture content and dry density affect the freezingthawing processes of soils.And the impact of engineering construction is more remarkable than natural factors.The engineering construction affects soil temperature and freezing-thawing process by controlling the initial temperature of soil,the speed and duration of the technological conversion of paving,compaction,and the length of placed duration at night.Due to the long placed duration of soil with the slow construction method,the initial temperature of soil gradually reduces,the heat transfer process inside soil is fast.Then the internal heat of soil releases,the decreasing rate of ground temperature of soil at different depths is fast and the frozen depth deepens.While due to the short placed duration of soil with the rapid construction process,the initial temperature of soil is high,high internal heat of soil is supplied every day,and the heat transfer process inside soil is slow.Then the decreasing rate of temperature of soil at different depths is slow,and the variation amplitude of frozen depth is small.This study provides useful guidance for the freezingthawing prevention during the construction process of core wall dams located at high altitude region in winter.

Advances in studies on concrete durability and countermeasures against freezing-thawing effects

This paper is a meta-analysis of recent domestic and foreign research on freezing-thawing effects on concrete durability. The main theories on the mechanisms of freeze-thaw damage to concrete are introduced： the hydrostatic pressure theory, the osmotic pressure theory, the critical water saturation degree theory, the dual mechanism theory, and the micro-ice-crystal lens model theory. The influence laws of freezing-thawing on the mechanical properties of concrete are summarized, and countermeasures to improve concrete durability in freezing-thawing circumstances are presented. This work provides valuable references for future engineering constructions in cold regions.

Effect of Freezing-Thawing Process on Wetland Soil Iron

The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ), Calamagrostis angustifolia wet meadow(Ⅱ),dry land (Ⅲ)and paddy field(Ⅳ),of Sanjiang Plain Wetland, Northeast China.Each sample was collected from three sites of one microhabitat,mixed together, filtrated with 0.45μm membrane,and tested using atomic absorption spectrometry(AAS)for iron measurement.The iron concentrations of soil solutions were investigated as well.Each soil solution was in-situ extracted by negative pressure,filtrated with 0.45μm membrane,and tested using AAS,too. The results showed that the wet precipitation of iron from snow were little to detect.The loss of iron was attributed to the interaction of water and soil surface. The iron concentrations of snowmelts were 7.4,15,

Comprehensive analysis of clinical and biological value of ING family genes in liver cancer

BACKGROUND Liver cancer(LIHC)is a malignant tumor that occurs in the liver and has a high mortality in cancer.The ING family genes were identified as tumor suppressor genes.Dysregulated expression of these genes can lead to cell cycle arrest,senescence and/or apoptosis.ING family genes are promising targets for anticancer therapy.However,their role in LIHC is still not well understood.AIM To have a better understanding of the important roles of ING family members in LIHC.METHODS A series of bioinformatics approaches(including gene expression analysis,genetic alteration analysis,survival analysis,immune infiltration analysis,prediction of upstream microRNAs(miRNAs)and long noncoding RNAs(lncRNAs)of ING1,and ING1-related gene functional enrichment analysis)was applied to study the expression profile,clinical relationship,prognostic significance and immune infiltration of ING in LIHC.The relationship between ING family genes expression and tumor associated immune checkpoints was investigated in LIHC.The molecular mechanism of ING1 mediated hepatocarcinogenesis was preliminarily discussed.RESULTS mRNA/protein expression of different ING family genes in LIHC was analyzed in different databases,showing that ING family genes were highly expressed in LIHC.In 47 samples from 366 LIHC patients,the ING family genes were altered at a rate of 13%.By comprehensively analyzing the expression,clinical pathological parameters and prognostic value of ING family genes,ING1/5 was identified.ING1/5 was related to poor prognosis of LIHC,suggesting that they may play key roles in LIHC tumorigenesis and progression.One of the target miRNAs of ING1 was identified as hsa-miR-214-3p.Two upstream lncRNAs of hsa-miR-214-3p,U91328.1,and HCG17,were identified.At the same time,we found that the expression of ING family genes was correlated with immune cell infiltration and immune checkpoint genes.CONCLUSION This study lays a foundation for further research on the potential mechanism and clinical value of ING family genes in the treatment and prognosis of LIHC.

RE而意用ECO-WORKING“环乐同创”

2024年5月1日至6月2日,RE而意与小布(BROMPTON)、FREITAG、抱朴再生BOTTLOOP合作,在上海张园呈现了一场精彩纷呈的展览。本次展览的主题为“ECO-WORKING!环乐同创”。展览以“倡导时尚、环保、可持续的生活方式”为主导,展现一系列具有长效设计、实用、可循环利用且令人愉悦的时尚单品。

the Roll’ING进京 网红品牌如何才能长红

动排队数小时的网红瑞士卷进京,是真需求还是饥饿营销的话题也再次引发热议。近日,上海网红瑞土卷烘培品牌the Roll'ING手作瑞士卷专门店在朝阳大悦城开出北京首店,并迅速在社交平台上走红,不乏出现排队时间长、出餐效率低、黄牛加价乱象等吐槽,不少消费者直呼是“饥饿营销”。值得注意的是,这家品牌同样出自于网红烘培品牌KUMOKUMO创始人姜浩文之手,此前上海首店开业时也受到“口碑危机”。

A Machine Learning-Based Web Application for Heart Disease Prediction

This work leveraged predictive modeling techniques in machine learning (ML) to predict heart disease using a dataset sourced from the Center for Disease Control and Prevention in the US. The dataset was preprocessed and used to train five machine learning models: random forest, support vector machine, logistic regression, extreme gradient boosting and light gradient boosting. The goal was to use the best performing model to develop a web application capable of reliably predicting heart disease based on user-provided data. The extreme gradient boosting classifier provided the most reliable results with precision, recall and F1-score of 97%, 72%, and 83% respectively for Class 0 (no heart disease) and 21% (precision), 81% (recall) and 34% (F1-score) for Class 1 (heart disease). The model was further deployed as a web application.

p33ING1b和p53在银屑病和基底细胞癌中的表达及临床意义

目的:探讨肿瘤抑制因子p53和生长抑制因子p33ING1b在人类银屑病和基底细胞癌(basal cell carcinoma,BCC)中的表达情况及临床意义。方法 :采用免疫组织化学Envision方法检测p53和p33ING1b在36例寻常型银屑病皮损(银屑病组)、28例BCC皮损(BCC组)和14例正常表皮(正常对照组)中的蛋白表达。结果:p53在正常对照组、银屑病组和BCC组中表达递增,p33ING1b在3组中表达递减,组间比较差异均有显著性(均P<0.05)。银屑病组和BCC组中,p53与p33ING1b之间均存在显著正相关(均P<0.05)。结论:p53和p33ING1b协同作用于增生性皮肤病的局部皮损,是细胞异常增殖的重要机制之一。

舒神汤联合穴位拔罐治疗慢性顽固性失眠50例

目的观察舒神汤联合神门、三阴交穴位拔罐治疗慢性顽固性失眠的临床效果。方法选择100例病程6个月以上的慢性顽固性失眠患者。双盲随机分成治疗组与对照组。对照组行常规治疗,采用安眠类西药;治疗组应用舒神汤,联合神门、三阴交穴位拔罐。两组治疗4周,观察治疗效果。结果治疗组治愈率64.0%(32/50)高于对照组的8.0%(4/50),总有效率100.0%(50/50)高于对照组的66.0%(33/50),差异均有统计学意义(P<0.05)。治疗后,治疗组汉密尔顿焦虑量表(HAMA)和汉密尔顿抑郁量表(HAMD)评分较治疗前明显降低,且治疗组低于对照组,差异有统计学意义(P<0.05);治疗组匹兹堡睡眠质量指数(PSQI)评分较治疗前明显降低,且治疗组低于对照组,差异有统计学意义(P<0.05);治疗组健康状况调查问卷(SF-36)评分较治疗前明显升高,差异有统计学意义(P<0.05),且治疗组高于对照组,差异有统计学意义(P<0.05)。对照组不良反应总发生率为46.0%(23/50),高于治疗组的2.0%(1/50),差异有统计学意义(P<0.05)。结论舒神汤联合神门、三阴交穴位拔罐治疗慢性顽固性失眠安全性高、有显著效果。

ING5基因表达对胃癌细胞生长抑制作用的研究

目的探讨ING5基因表达对胃癌生长抑制作用。方法构建p EGFP-N1-ING5重组质粒,获得ING5高表达SGC-7901细胞株,分别通过CCK-8、流式细胞术、划痕、transwell、real-time PCR、Western blot、裸鼠成瘤实验、免疫组化检测并比较SGC-7901细胞与克隆细胞增殖率、周期与凋亡、迁移与侵袭、m RNA、裸鼠成瘤大小以及相关蛋白表达。结果与SGC-7901组及Mock组比较,转染p EGFP-N1-ING5后,胃癌SGC-7901细胞增殖显著抑制(P<0.05),凋亡减少(P<0.05),G1期比例增加,G2期比例下降(P<0.05),迁移与侵袭能力减弱(P<0.05),NF-κB、PI3K、p-Akt1/2/3、Bcl-2、XIAP、β-catenin、c-myc m RNA及蛋白表达水平均升高(P<0.05);Akt1/2/3、MMP9 m RNA及蛋白表达降低(P<0.05)。结论 ING5基因表达降低胃癌SGC-7901细胞株增殖、减少凋亡、发生G1期阻滞、抑制其迁移与侵袭、有效调控增殖、周期、黏附相关基因与蛋白的表达,从而抑制胃癌的演进与发展。