Failure mechanism of a large-scale composite deposits caused by the water level increases

The failure of slope caused by variations in water levels on both banks of reservoirs is common.Reservoir landslides greatly threaten the safety of reservoir area.Taking large-scale composite deposits located on the Lancang River in Southwest China as a study case,the origin of the deposits was analyzed based on the field investigation and a multi-material model was established in the physical model test.Combined with numerical simulation,the failure mechanism of the composite deposits during reservoir water level variations was studied.The results indicate that the deformation of the large-scale composite deposits is a staged sliding mode during the impoundment process.The first slip deformation is greatly affected by the buoyancy weight-reducing effect,and the permeability of soil and variation in the water level are the factors controlling slope deformation initiation.The high water sensitivity and low permeability of fine grained soil play an important role in the re-deformation of deposits slope.During the impoundment process,the deformation trend of the deposit slope is decreasing,and vertical consolidation of soil and increasing hydrostatic pressure on the slope surface are the main reasons for deformation attenuation.It is considered that the probability of large-scale sliding of the deposits during the impoundment period is low.But the damage caused by local bank collapse of the deposit slope still needs attention.The results of this paper will further improve our understanding of the failure mechanism of composite deposits caused by water level increases and provide guidance for the construction of hydropower stations.

Effects of Extracorporeal Shockwave Therapy and Hand Massage on Body Composition and Serum Lipids According to Serum Cholesterol Level in Korean Women

Obesity, particularly abdominal obesity, increases the risk of cardiovascular disease (CVD). This study investigates the effects of six-week (twice a week, 12 sessions total) extracorporeal shockwave therapy (SWT) and hand massage therapy (HT) on body composition and serum lipids in overweight and obese Korean women aged between 35 and 59, according to their serum cholesterol level (≥200 mg/dL versus <200 mg/dL). After the program, weights decreased significantly in both the HT Group and SWT Group (p < 0.05);weights of those with cholesterol < 200 mg/dL significantly decreased in the HT Group (p = 0.038), while weights of those with cholesterol ≥ 200 mg/dL significantly decreased in the SWT Group (p = 0.001). BMIs decreased significantly in both the HT Group and the SWT Group (p < 0.05);BMIs of those with cholesterol < 200 mg/dL significantly decreased in the HT Group (p = 0.018), while BMIs of those with cholesterol ≥ 200 mg/dL significantly decreased in the SWT Group (p = 0.001). The body fat percentage of subjects significantly decreased only in the SWT Group (p = 0.027);the waist-hip ratio significantly decreased only in HT Group (p = 0.034). Serum cholesterol levels significantly decreased in those with cholesterol < 200 mg/dL in the HT Group (p < 0.05) and those with cholesterol ≥ 200 mg/dL in SWT Group (p = 0.055). Triglyceride significantly decreased in both those with cholesterol < 200 mg/dL and those with cholesterol ≥ 200 mg/dL, but did not significantly decrease in either subgroup of the HT Group. The study results suggest that SWT is effective in improving body measurements and serum lipids in those with cholesterol ≥ 200 mg/dL, while HT therapy is effective in those with cholesterol < 200 mg/dL. In conclusion, SWT and HT improved abdominal obesity by reducing body weight and waist circumference and helped improving serum lip index, suggesting the benefit for managing body measurements and serum lipids of overweight and obese individuals.

Effects of Dietary Energy Level and Source on Blood Metabolites,Hormone Secretion and Follicular Fluid Composition in Gilts

The objective of the study was to investigate the effects of dietary energy levels and sources on the blood metabolites,hormone secretion and the composition of follicular fluid in gilts.Fifty-four gilts with initial body weight of(59±4.2) kg were randomly allotted to six treatments.Treatments were low, normal,and high energy feeding levels,which were 87.5%,100%and 112.5%of recommendatory energy requirements by NRC(1998),respectively,and dietary energy sources(starch or fat).Blood samples and follicular fluids were collected on D18 and D19 of the second estrous cycle.The results showed that plasma concentrations of triglycerides and total cholesterol were higher in the fat group than that in the starch group(P【0.05),but those of glucose were similar between the two energy sources(P】0.05);dietary energy level exerted no effect on blood metabolites concentration(P】0.05).Gilts fed the high energy diet had a higher area under curve of plasma insulin(Insulin AUC),insulin-like growth factor-Ⅰ(IGF-Ⅰ) and leptin than did gilts fed the lower energy diet(P【0.05),but there was no significant difference between fat versus starch(P】0.05).Luteinizing hormone(LH) pulses were higher in gilts fed high energy rather than that in low energy diets(P】0.05),plasma concentration of estradiol(E2) was higher in the fat group than that in the starch group(P【0.05).The number of large follicles(diameter≥4 mm) and concentrations of IGF-Ⅰand E2 in follicular fluid were increasing significant as the level of energy increased(P【0.05),but the numbers of large follicles and follicular fluid composition were not affected by the source of dietary energy(P】0.05).The results indicate that gilts fed high energy diets had elevated plasma concentrations of metabolic hormones,IGF-Ⅰand LH secretion,and increased follicular fluid concentrations of IGF-Ⅰ,E2 and numbers of large follicles;gilts fed the dietary fat had a higher plasma concentration of cholesterol and E2.

Effect of stress level on fatigue behavior of 2D C/C composites

Laminated carbon fiber clothes were infiltrated to prepare carbon fiber reinforced pyrolytic carbon （C/C） using isothermal chemical vapor infiltration （CVI）. The bending fatigue behavior of the infiltrated C/C composites was tested under two different stress levels. The residual strength and modulus of all fatigued samples were tested to investigate the effect of maximum stress level on fatigue behavior of C/C composites. The microstructure and damage mechanism were also investigated. The results showed that the residual strength and modulus of fatigued samples were improved. High stress level is more effective to increase the modulus. And for the increase of flexural strength, high stress level is more effective only in low cycles. The fatigue loading weakens the bonding between the matrix and fiber, and then affects the damage propagation pathway, and increases the energy consumption. So the properties of C/C composites are improved.

基于声发射b值分析的风力机叶片材料损伤特性研究

风力发电机叶片主要材料玻璃纤维环氧树脂增强复合材料(GFRP)的损伤,会造成叶片寿命减少甚至断裂,必须进行损伤检测。采用声发射方法可分析GFRP复合材料损伤特性,实现在线监测叶片性能。该文采用声发射b值特征来表征GFRP损伤程度,并通过主成分分析和k-均值++算法进行声发射参数聚类来分析GFRP损坏模式。结果表明:1)对整个声发射事件进行b值分析,观察到GFRP试样在断裂前b值呈明显下降趋势,表明b值的变化率可作为材料断裂的预警信号。2)根据主成分分析9种声发射参数所占主成分比重,选择声发射信号的幅度、峰值频率两个特征参数。通过k-均值++算法对特征参数进行聚类分析,发现拉伸过程的声发射信号分为了4个簇,并找到每个簇的特征频率。3)通过使用扫描电子显微镜(SEM)对GFRP试样拉伸断口进行观察,得到4个簇分别对应于基体开裂、纤维/基体脱粘、分层和纤维断裂4种损伤模式。基于声发射b值分析方法适用于GFRP损伤特性研究,可在风力发电机叶片损伤检测领域推广。

氮含量对Ti-B-C-N薄膜微观结构和性能的影响

采用反应磁控溅射法在高速钢基体上制备氮原子分数分别为10.8%,15.6%,28.1%,36.4%的Ti-B-C-N薄膜,研究了氮含量对薄膜微观结构、硬度和摩擦磨损性能的影响。结果表明:Ti-B-C-N薄膜均由α-Fe和Ti(C,N)纳米晶组成,具有Ti(C,N)纳米晶镶嵌在非晶基体相中的纳米复合结构;随着氮含量增加,非晶相含量增加,Ti(C,N)纳米晶的含量和晶粒尺寸减小;随着氮含量增加,Ti-B-C-N薄膜的显微硬度增大,摩擦因数和磨损率均减小,表面磨痕变浅,磨损机制由剥落和微观犁削转变为微观抛光。

GZMB在乳腺癌和乳腺良性肿物患者中的表达及与T淋巴细胞水平的关系研究

目的:探讨颗粒酶B(granzyme B,GZMB)在乳腺癌和乳腺良性肿物患者中的表达及与T淋巴细胞水平的关系。方法:选取2022年1月至2023年8月南阳市第一人民医院收治的乳腺癌患者63例为观察组,根据肿瘤分期分为T_(1)N_(0)M_(0)组、T_(2)N_(0)M_(0)组、T_(2)N_(1)M_(0)组、T_(3)N_(0)M_(0)组及T_(3)N_(1)M_(0)组;选择同期治疗的乳腺良性肿物患者9例为对照组;采用流式细胞仪测定各组GZMB及T淋巴细胞水平;对乳腺癌患者GZMB与T淋巴细胞参数完成相关性分析。结果:观察组乳腺癌患者GZMB水平高于对照组(P<0.05);CD_(3)^(+)、CD_(4)^(+)及CD_(4)^(+)/CD_(8)^(+)水平低于对照组(P<0.05);乳腺癌不同分期下CD_(8)^(+)水平无统计差异(P>0.05);乳腺癌患者中T_(3)N_(1)M_(0)组GZMB水平高于其余4组(P<0.05),CD_(3)^(+)、CD_(4)^(+)及CD_(4)^(+)/CD_(8)^(+)水平低于其余4组(P<0.05);乳腺癌患者分期越高,GZMB水平越高,CD_(3)^(+)、CD_(4)^(+)及CD_(4)^(+)/CD_(8)^(+)水平越低;Pearson相关性结果表明,乳腺癌患者GZMB水平与CD_(3)^(+)、CD_(4)^(+)及CD_(4)^(+)/CD_(8)^(+)水平呈负相关(P<0.05)。结论:GZMB在乳腺癌患者中呈高表达,其表达水平在不同分期中存在差异,且与T淋巴细胞水平存在相关性,可指导临床诊疗。

Caries-related factors and bacterial composition of supragingival plaques in caries free and caries active Algerian adults

Objective: To compare oral hygiene practices, education and social background, food intake and oral malodor of Algerian adults suffering from dental caries with normal controls, and to determine and compare the bacterial composition of the supragingival plaques from the above-mentioned groups.Methods: Participants completed a questionnaire and were clinically examined for dental caries using decayed, missing and filled teeth index according to the criteria laid down by the World Health Organization. Supragingival plaque samples were collected from 50 caries-free adults(CF) and 50 caries-active adults(CA). Standard procedures of culture and identification of aerobic and anaerobic bacteria were used. Data were analyzed using Chi-square test.Results: A total of 117 bacterial strains were isolated from supragingival plaques in CF group subjects, 76(64.96%) of them belonged to 9 aerobic genera, and 41(35.04%) to 9anaerobic genera(P < 0.05). While in the second group, 199 strains were isolated, 119(59.80%) of the strains belonged to 10 aerobic genera and 80(40.20%) to 10 anaerobic bacteria(P < 0.05). Streptococcus mutans, Enterococcus faecium, Aerococcus viridans,Actinomyces meyeri, Lactobacillus acidophilus and Eubacterium limosum showed a significantly higher prevalence in the CA group(P < 0.05). The findings revealed that CA group had a high sugar intake(80%). A significantly higher frequency of tooth brushing(P < 0.000) and a significantly less self-reported oral malodor(P < 0.000) and tooth pain(P < 0.000) were found in CF group, while there was no association of socioeconomic levels and intake of meal snacks with dental caries.Conclusions: This study confirms the association of some aciduric bacteria with caries formation, and a direct association of sugar intake and cultural level with dental caries.Furthermore, oral hygiene practices minimize the prevalence of tooth decay.

Comparison on the Chemical Compositions in the K326 Tobacco from Different Tobacco-planting Areas of Yunnan Province

[Objective] To compare the regional differences of the conventional chemi- cal compositions in the K326 B2F tobacco from different tobacco-planting areas of Yunnan Province. [Methed] Continuous flow analyzer was used to detect the con- ventional chemical compositions, and SPSS 17.0 statistical package was used to conduct data statistical analysis and variance analysis. [Result] Significant differences were existed among most of the indicators for conventional chemical compositions of K326 tobacco in different areas： the differences of total sugar, reducing sugar and nicotine reached a high Significant level; potassium ion and total nitrogen differences reached a significant level, while there was no significant difference in chlorine ion. Most of the conventional chemical compositions in K326 B2F tabacco planted in Yuxi region and those planted in Qujing, Dali and Chuxiong were significantly different. The total sugar, reducing sugar and nicotine contents of tobacco planted in eastern Yunnan, central Yunnan and western Yunnan were significantly different; while the conventional chemical compositions contents in the tobacco planted in Chuxiong and Dali, which all belong to western Yunnan, showed no obvious significant difference, indicating different ecological environments in large area had a great impact on the tobacco of Yunnan Province. [Conclusion] It revealed the regional characteristics of the conventional chemical compositions in K326 flue-cured tobacco leaves from Yunnan Province, providing references for the cigarette blending and production of high-quality tobacco with characteristics.

Factors Associated with Antibody Levels among Children Aged 15 to 59 Months Vaccinated against Hepatitis B during the Expanded Program on Immunization in Cameroon

Background: the hepatitis B virus infection remains a major public health problem worldwide. It can lead to a liver cirrhosis and/or hepatocellular carcinoma. The World Health Organisation (WHO) has recommended the implementation of generalised vaccination programs against hepatitis B. In Cameroon, this vaccine was introduced in the expanded program on immunization (EPI) in 2005, but few studies have assessed the immune response. Objective: the general objective of this study was to identify factors associated with antibody levels among children aged from 15 to 59 months vaccinated against hepatitis B during the EPI in Cameroon. Method: this was a cross-sectional study carried out from December 2021 to June 2022 in a paediatric centre of Yaoundé (Cameroon). We analysed the antibody level in children vaccinated against hepatitis B within the framework of the EPI. We enrolled children who had received a series of 3 intramuscular doses of hepatitis B vaccine at 6, 10 and 14 weeks after birth. Some children could receive a 4th booster dose between 12 months. The antibody level was assessed by measuring the anti-HBs in such children, aged 15 - 59 months. A good immunization was defined as a serum level of anti-HBs antibody level above 100 IU/mL;a poor immunization, for an anti-HBs antibody level between 10 and 100 IU/mL;and a non-immunization, for an anti-HBs antibody level < 10 IU/mL. Association between explored factors and poor or non-immunization was evaluated through the Chi square test. The significance threshold was defined at p < 0.05. Results: sixty subjects were included in the study with a slight female majority: 31 cases (52%). The average age was 38.5 ± 15.7 months (range 15 - 59 months). We found 32 (53%) cases of good immunization;21 (35%) of poor immunization;and 7 children (12%) with a non-immunization. The only factor associated with poor or non-immunization was the age between 37 - 59 months (p = 0.016). Conclusion: Anti HBs Antibody levels in children vaccinated against hepatitis B virus were globally satisfactory in our series. Results show an association between low antibody levels with older age (over 36 months), suggesting a circulating antibodies levels decrease over time, yet deemed protecting until 59 months.

黄皮新肉桂酰胺B的小鼠降脂活性及毒副作用

目的:探究鸡心黄皮果核中黄皮新肉桂酰胺B(lansiumamide B,LB)作用于高脂饮食(high fat diet,HFD)模型C57BL/6J小鼠的降脂活性及在实验过程中的毒副作用,为其应用于更多活性领域研究提供安全性依据。方法:以C57BL/6J小鼠为动物模型,经口灌胃LB以探究对小鼠的无可见有害作用水平(no observed adverse effect level,NOAEL),作为降脂实验浓度设置依据;建立HFD模型后,以LB 1/100、1/50、1/25 NOAEL剂量对小鼠给药灌胃4周,通过体质量、血脂生化指标、胰岛素抵抗、氧化应激等指标评价LB降脂活性。结果:经口急性毒性实验结果得出LB对C57BL/6小鼠的NOAEL为2 g/kg mb;HFD模型实验结果显示LB能够显著降低小鼠体质量,LB高剂量组与HFD组相比,体质量下降15.51%、Lee’s指数下降3.25%、血清高密度脂蛋白胆固醇浓度上升38.04%,超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活力分别提高41.86%、41.95%和105.50%。结论:LB的NOAEL为2 g/kg mb,LB在NOAEL剂量范围内对小鼠具有显著降脂活性且无明显可见毒副作用。

连续碳纤增强B柱加强板结构设计与铺覆仿真

针对连续纤维复合材料成型过程中在大曲率位置易导致纤维断裂、褶皱、撕裂等缺陷问题,本文基于连续纤维复合材料随模铺覆仿真方法,理论分析了铺覆起点、初始取向对铺覆效果的影响规律。以减少纤维成型缺陷为目标,开展了连续碳纤维增强复合材料B柱加强板的结构优化和铺覆优化设计,确定了面向热压成型工艺的B柱加强板几何结构和预浸料铺覆方式。通过分块铺覆优化,使0°、90°、45°、-45°的铺层不合格占比分别由45.18%、52.83%、72.21%、71.78%降至2.47%、3.45%、5.31%、4.77%,有效提高了连续碳纤维的随模铺覆性。基于优化的铺覆设计,成功试制出满足性能要求的B柱加强板。

B-g-C_(3)N_(4)/BiOBr复合材料光催化降解盐酸四环素的研究

文章通过研磨和煅烧合成掺杂硼的g-C_(3)N_(4)(BCN-n),再通过溶剂热法制备硼掺杂g-C_(3)N_(4)/溴氧铋(BCN-n/BiOBr)材料,用于光催化降解盐酸四环素(TCH)污染物。文章探究了不同复合比、pH值、催化剂投加量及不同污染物浓度下BCN-n/BiOBr材料的光催化性能,并通过TEM、XRD等对材料进行表征分析。实验结果证明,BCN-2(简称BCN)∶BiOBr最佳复合质量比为2∶1。在盐酸四环素溶液浓度为20 mg/L,原液pH=5.5,催化剂投加量0.2 g/L的条件下,BCN/BiOBr(2∶1)材料对盐酸四环素的降解率达到95.1%,与相同条件下BCN和BiOBr材料相比,降解率分别提高了10.7%和14.0%。BCN/BiOBr光催化剂是一种有前景的降解TCH的光催化材料。

累积损伤对B炸药冲击起爆影响的仿真研究

采用LS-DYNA软件进行数值仿真,通过改变炸药撞击速度以改变损伤程度,探究损伤和垫层材料对B炸药起爆行为的影响。计算结果表明,当第2次撞击速度一定时,起爆时间t与第1次撞击速度v_(1)的关系为:t=-0.02 v_(1)+C_(1),冲击起爆的距离也随之减小。主要因为第1次撞击速度增大,导致B炸药发生轻微变形,内部的损伤程度随之增大,第2次撞击时更容易被起爆。3种不同垫层中,波阻抗较大的材料抗撞击能力强,B炸药内部不易产生损伤,冲击起爆的时间和距离较长;而B炸药的临界起爆压力差别不大,临界起爆压力的范围在31.4832.98 GPa之间。表明不同垫层材料会影响损伤后B炸药冲击起爆的时间和距离,而不会影响临界起爆压力。

Experimental Investigation of Two-Dimensional Shock Initiation Process of Cast Composition B

A two-streak high-speed photography measuring system is designed, which can successfully record the reactive shock front and the reaction profile within the run distance of shock initiation under two-dimensional shock initiation. The strong reaction delay time and the shape of reaction shock front are determined in the cast composition B (RDX/TNT/60/40). A low level reaction zone has been found and analyzed..

弱B对称流形

本文研究了一类特殊的对称流形(弱B对称流形,简记(WBS)n)的几何性质问题.利用B张量的对称性,获得了(WBS)n是一个2阶爱因斯坦流形的充分条件并证明这个流形是拟爱因斯坦流形.根据指标的轮换,分别获得了1-形式K和ω是闭形式的充要条件,继而考虑满足爱因斯坦度量条件的(WBS)_(n)(n>2).最后给出一个(WBS)_(4)的例子.

Predictive Value of Serum pgRNA on HBeAg Clearance in Patients with Chronic Hepatitis B with Low HBeAg Levels Treated with Pegylated Interferon

Objective:To study the predictive value of serum pregenomic RNA(pgRNA)on HBeAg clearance in patients with chronic hepatitis B with low HBeAg levels during pegylated interferon therapy.Methods:Twenty chronic hepatitis B patients with HBeAg positive and quantitative<50S/CO were selected for this study.The subjects underwent pegylated interferon therapy for 48-96 weeks and were followed up in the outpatient clinic after treatment.The patients were then divided into groups based on whether their HbeAg turned negative.The predictive ability of each indicator for HBeAg negative conversion was evaluated in the HBeAg negative group and the HBeAg positive group.Results:The results of logistic regression analysis suggested that pgRNA and HBcrAg were better indicators for predicting the clearance of HBeAg after treatment.Conclusion:For patients with chronic hepatitis B with low HBeAg levels,pgRNA is a good indicator in predicting HBeAg clearance during pegylated interferon therapy.

Review on article of effects of tenofovir alafenamide and entecavir in chronic hepatitis B virus patients

This letter comments on the article which reported that tenofovir alafenamide may increase blood lipid levels compared with entecavir in patients with chronic hepatitis B published on World J Hepatol 2023 August 27.We review the related research content,topic selection,methodology,conclusions,strengths and weaknesses of this article.And evaluate it in relation to other published relevant articles.

锂离子电池TiO_(2)-B/Li复合负极的制备及电化学性能研究

本文探讨了TiO_(2)-B/Li复合负极的合成与电化学性质。锂金属和TiO_(2)-B通过机械搅拌和熔融共混两种方法被制备成不同比例的复合负极。通过对半电池的倍率性能和循环稳定性测试,发现熔融共混法制备的质量比为5∶5的Li/TiO_(2)-B复合负极展现出最优异的电化学性能。该复合负极在电池循环过程中未观察到明显的锂枝晶和“死锂”的形成。在3 mA·cm^(-2)和1.5 mAh·cm^(-2)条件下,由m(TiO_(2)-B)∶m(Li)=5∶5复合负极构成的半电池能够稳定地循环1000圈,且极化电压维持在大约68 mV。此外,还将TiO_(2)-B/Li复合负极与锂离子电池正极材料NCM811和锂硫电池正极材料S@NC配对,构建了全电池,并在1 C和0.5 C的电流密度下进行了循环稳定性测试。TiO_(2)-B/Li-S@NC全电池在0.5 C下循环500圈后,容量保持率为85.37%,容量为640.3 mAh·g^(-1)。同时,TiO_(2)-B/Li-NCM811全电池在1 C下循环500圈后,容量保持率为83.32%。

液滴微流控技术制备B/CuO延期药微球及性能研究

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