新型砌块重力式挡土墙墙体裂隙渗流规律研究

为了研究新型砌块重力式挡土墙全断面排水规律及墙体裂隙堵塞对排水效率的影响,采用缩尺模型进行试验。试验研究结果表明,水位高度和墙体裂隙率是影响挡土墙排水效率的两个关键性因素。挡土墙等效渗透系数随着水位高度增加而增大;挡土墙等效渗透系数的变化与裂隙堵塞程度呈正比;垂直裂隙排水效果优于水平裂隙,水平裂隙会造成地下水一部分回流,降低挡土墙整体排水效率;设置土工布虽然会对挡土墙的等效渗透系数减小约20%,但可有效防止墙后土颗粒流失堵塞墙体裂隙;挡土墙在堆叠排块时应错缝堆叠,避免出现直缝或堆叠间隙相隔较大。

大肠杆菌噬菌体的分离鉴定及生物学特性分析

利用野生型大肠杆菌MG1655为宿主菌,从下水道污水中分离得到一株噬菌体,编号为Phage 1.其噬菌斑大小为3～4mm,透射电镜观察发现该噬菌体有正多面体头部和弯曲尾部,属于长尾科噬菌体.对该噬菌体的生物学特性包括最佳感染复数、一步生长曲线、温度、氯仿、pH进行检测,结果显示该噬菌体的潜伏期为10min,繁殖周期为20min,对温度、氯仿以及pH耐受性良好.经基因组测序鉴定,该噬菌体为E.coli T1噬菌体.

微生物絮凝剂对小球藻细胞氧化应激研究

小球藻作为能源藻,可以提供产生物柴油,但是小球藻生物质的获取成为能源藻发展的瓶颈.目前研究藻细胞生物质收集的方法很多,但不同收集方法对能源藻细胞的氧化应激研究却很少.分别研究絮凝功能细菌xn-1所产生物絮凝物质和离心法对能源藻——小球藻生物质在收集过程中对藻细胞的氧化应激,以期确定絮凝微生物对小球藻细胞的生物安全性.采用涂布划线法从藻际分离纯化絮凝功能微生物;通过梯度醇沉法获得絮凝物质;分别用絮凝微生物所分泌絮凝物质和离心法收集藻细胞生物质,并对藻细胞内蛋白含量、总糖含量、丙二醛含量(MDA)、过氧化氢酶(CAT)活性、谷胱甘肽(GSH)含量和抗坏血酸(AsA)含量进行测定;以分光光度计测定其吸光度值.经过测定并经过统计学显著性分析,发现离心作用下收集的藻细胞内的MDA,GSH和AsA含量显著高于利用絮凝物质絮凝得到的藻细胞.离心作用相对于絮凝作用造成藻细胞膜发生更高的脂质过氧化,产生大量的活性氧自由基,诱导非酶抗氧化系统响应.因此,离心法收集藻生物质相对于微生物絮凝对藻细胞的伤害更大,絮凝微生物比离心法更适合于收集能源藻生物质.

塑性铰区纵筋加密的少筋混凝土桥墩振动台试验研究

为探究少筋混凝土重力式桥墩塑性铰区纵筋加密设计思路的合理性,以配筋为0.3%的少筋混凝土重力式矩形桥墩为原型设计制作缩尺比例模型,并在此基础上,设计提出墩底塑性铰区局部纵筋加密的对比模型,采用El-Centro 波模拟地震进行振动台试验,测试2 种模型的破坏模式及桥墩墩顶位移与加速度时程反应。对比研究塑性铰区纵向钢筋加密后桥墩的抗震性能,试验研究结果表明塑性铰区纵筋加密设计的桥墩具有良好的抗震性能,说明了此方案的合理性。

淀粉水热稳定性的影响因素及其调控研究进展

淀粉是食品体系的主要碳水化合物来源,其在食品加工过程的水热稳定性与其糊性质及营养功能特性密切相关。通过提高淀粉的水热稳定性可明显延缓淀粉在机体内的消化速度与消化程度,对于机体血糖的调控具有十分重要的意义。本文从淀粉的多尺度结构与其功能性质的内在关联的角度出发,概述了淀粉水热稳定性的评价指标及评价方法,系统探讨了影响淀粉水热稳定性的食品加工条件及淀粉关键结构特征,指出调控淀粉水热稳定性的食品加工方法与手段,并针对淀粉水热稳定性的调控现状提出展望,以期为淀粉基功能营养食品的开发提供理论依据。

Progress and Prospects of Salt Lake Research in China

China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate （salt forming） have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits： the atlas （1：2500000） of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of ＂Continental Potash Deposition Theory＂; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCI production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production line, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, i.e. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond＂ the highest lithium production base at Zabuye Lake （4421 m）, Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture （Salt land agriculture） has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science ＂Salinology＂.

CCA Inferred Environmental Implications of Common Ostracods on the Qinghai-Tibetan Plateau

103 surface sediment samples in 71 water bodies, such as lakes with different salinity, swamps, shallow puddles and rivers on the Qinghai-Tibetan Plateau （QTP）, were collected to study the ecological distribution of living ostracods and their environmental implications. Total of 12 genus and 45 species living ostracods are identified. According to the frequencies and abundance of ostracods occurrence, Limnocythere dubiosa, Limnocytherellina kunlunensis, llyocypris bradyi, Candona candida, Eucypris rischtanica and Leucocythere dilatata are the common species on the QTP, with occurrence frequency of more than 8 and abundance of more than 570 in the 71 water bodies. Among them, L. dubiosa, occurring in 28 water bodies with 2177 shells, is the most widely distributed ostracod in this research. Canonical Correspondence Analysis （CCA） indicates high correlation between species and environmental variables, suggesting that the occurrence of species is strongly related to the changes in ecological conditions of habitats. Among eight environmental factors, salinity and pH value are the most affective variables that influence the species occurrence. L. kunlunensis is positively correlated with salinity while E. rischtanica is negatively correlated with salinity. C. candida has a positive correlation with salinity, as does I. bradyi although there is not such a strong correlation. L. dubiosa displays a positive correlation with pH value. Consequently, we discuss the environmental implications of the common living ostracods on the QTP based on the CCA as well as the distribution of ostracod species in different salinity and pH values water. L. dubiosa, L. kunlunensis and E. rischtanica are euryhaline species, among which, L. dubiosa is the most adaptable species on the QTP with large occurrence in sundry salinity water and the most widely adaptive range for pH values. L. kunlunensis prefers to saline water while E. rischtanica prefers to fresh water. Both L. kunlunensis and E. rischtanica can live in water from faintly acid to alkaline, in contrast, L. dubiosa only appears in neutral and alkaline water bodies. L bradyi only occurs in fresh water and oligohaline water with a large pH tolerance range tolerance range from weakly acidic water to alkaline water weakly acidic water to alkaline water. C. Candida lives in freshwater, with pH value above eight. The six common species reach maximum abundance in alkaline water （pH 8-10） except for llyocypris bradyi.

乌司他丁干预减体积肝移植模型大鼠的肝脏代谢

背景:乌司他丁在肝切除、肝移植后抗炎、脏器保护、改善微循环等方面的作用已经有大量的研究,然而其作用的microRNA调控机制尚未见报道。目的:观察模型大鼠减体积肝移植后乌司他丁干预microRNA及蛋白组学的变化,并在差异表达的microRNAs和蛋白中预测microRNA对其靶向蛋白的调控,为乌司他丁的临床应用提供更深入的理论依据。方法:以Kamada的双袖套法为基础建立40%减体积肝移植模型大鼠,实验分2组:实验组在肝移植后0,12,24,36,48 h经腹腔注入乌司他丁(100 U/g);对照组在同样时间点注入生理盐水2 mL。在移植后24,48 h取2组大鼠肝脏分别行microRNA芯片检查及蛋白质质谱分析。将二者的结果输入mirTarBase软件进行靶基因预测。结果与结论:①与对照组相比,实验组表达差异超过2倍的mi RNAs有19个,蛋白丰度表达差异超过1.5倍的蛋白有17个,靶基因预测发现一组具有强力证据推荐的microRNA目标蛋白的调控通道:rno-mi R-181a-5p和Gpx1;②结果表明,模型大鼠减体积肝移植后,乌司他丁的使用,改变了rno-mi R-181a-5p的表达,rno-mi R-181a-5p通过调控Gpx1表达来改善模型大鼠减体积肝移植术后肝脏的代谢,这可能是乌司他丁作用机制之一。

Microbial Mats in Tibetan Hot Springs and their Contributions to the Cesium-bearing Geyserite Ore Formation

Microbial mats, mainly dominated by filamentous algae Calothrix and Oscillatoria, are well developed in Tibetan hot springs. A great number of fossil microorganisms, which existed as algae lamination in thermal depositional cesium-bearing geyserite in this area, are identified as Calothrix and Oscillatoria through microexamination and culture experiments. These microbial mats show the ability to accumulate cesium from spring water to the extent of cesium concentration of 0.46-1.03% cell dry weight, 900 times higher than that in water, and capture large numbers of cesium-bearing opal grain. Silicon dioxide colloid in spring water replaces and fills with the organism and deposits on it to form algae laminated geyserite after dehydration and congelation. Cesium in the microbial mats and opal grain is then reserved in the geyserite. Eventually, cesium-bearing algae laminated geyserite is formed. Study on cesium distribution in geyserite also shows that cesium content in algae lamination, especially in heavily compacted algae lamination, is higher than in the opal layer. For geyserite with no algae lamination or other organism structure, which is generally formed in spring water with low silicon content, cesium accumulation and cesium-bearing opal grain assembled by the microbial mats are also indispensable. After the microbial mats accumulating cesium from spring water, silicon dioxide colloid poorly replaces and fills with the organism to form opal grain-bearing tremellose microbial mats. The shape and structure of the organisms are then destroyed, resulting in cesium-bearing geyserite with no algae lamination structure after dehydration and congelation. It is then concluded that microbial mats in the spring area contribute to the enrichment of cesium in the formation of cesium-bearing geyserite, and a biological genesis of the geyserite, besides of the physical and chemical genesis, is likely.

刺络放血联合龙氏手法治疗气滞血瘀型慢性非特异性下腰痛35例

目的:观察刺络放血联合龙氏手法治疗气滞血瘀型慢性非特异性下腰痛(CNLBP)的临床疗效。方法:选取气滞血瘀型CNLBP患者70例,按信封法将患者随机分为对照组及观察组,每组各35例。对照组采用电针联合龙氏手法治疗;观察组采用刺络放血联合龙氏手法治疗。两组均连续治疗1周为1个疗程,2个疗程后观察临床疗效。分别比较两组治疗前、治疗1疗程及治疗2疗程的视觉模拟评分法(VAS)评分、日本骨科协会(JOA)评分及匹兹堡睡眠质量指数(PSQI)评分。结果:两组治疗1个疗程、2个疗程VAS评分、PSQI评分均较治疗前显著降低(P<0.01),JOA评分较治疗前显著增高(P<0.01);治疗2个疗程后,观察组VAS评分、PSQI评分均显著低于对照组(P<0.01),JOA评分显著高于对照组(P<0.01)。结论:刺络放血联合龙氏手法更能有效减轻气滞血瘀型CNLBP患者的腰痛不适,改善患者腰椎功能状况及睡眠质量。

Ostracodes from Recent Surface Deposits in Tibet,Response to Environmental Changes

1 Introduction Ostracodes are good materials for studying palaeoenvironmental evolution because of their sensitive response to environment changes.At present,the environmental implications of ostracodes are mainly based

基于GSO改进TOPSIS的灾区救援道路选择研究--以地震为例

灾区道路选择是灾后应急救援必须解决的问题之一,现有的灾区救援道路选择模型中较少考虑评价指标之间的相关性。该文构建了基于格兰姆--施密特正交化法(Gram-Schmidt Orthogonalization,GSO)的客观赋权评价方法(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)灾区救援道路选择综合评价模型。在构建的模型中,利用GSO去除指标间相关性所造成的信息重叠,通过对地震灾区的道路损毁率、二次灾害危险度、地震烈度这三项指标进行深入分析。以汶川地震数据为例,验证了所构建模型的有效性,研究结果对灾区救援道路选择研究提供了新的思路。

酸性磷酸酶在5′-肌苷酸生产中的研究进展

5′-肌苷酸具有独特鲜味,在食品、药品和饲料等多个领域发挥重要作用。目前,肌苷酸主要通过发酵与化学磷酸化相结合工艺进行生产,而生物磷酸化应用中最具前景的是酸性磷酸酶转化法。与传统化学磷酸化法相比,酶转化法具有专一性强、反应条件温和和绿色环保等优点。笔者综述了酸性磷酸酶、重组菌株构建及对转化生产肌苷酸工艺的研究现状,为5′-肌苷酸的进一步推广应用奠定基础。

Ecological Distribution and Significance of Metadiaptomus asiaticus Uljanirs,a Copepod Recently Found on the Qinghai-Tibetan Plateau

1 Introduction In 2006,plankton investigation was carried out in the lakes in Ali district,Tibet.7 planktonic crustaceans were identified and reported.Metadiaptomus asiaticus Uljanirs was reported for the first time on the QTP(Yuan et al.,2007).However,detailed data on this species,especially its ecological significance,were not mentioned.In this

曲线槽型梁刚构桥转体T构稳定性分析及计算模型研究

为研究曲线槽型梁刚构桥转体T构的稳定性,并探讨该类桥梁简单实用的结构计算方法,以半径为580 m的铁路曲线槽型梁刚构桥为研究对象,采用Midas/FEA有限元分析软件建立不同支座偏心距的曲线槽型梁转体T构模型,对主梁根部截面的弯矩、应力和梁端位移进行计算,并对单梁、梁格和实体模型在结构计算中的适用性进行对比分析。结果表明:设置合理的支座偏心距可有效减小主梁根部截面的弯矩、应力和梁端位移,显著提高转体T构的稳定性;梁格模型能够较好地反映曲线槽型梁刚构桥的变形和应力状态,可作为曲线槽型梁刚构桥结构的实用计算方法。

病毒性脑炎患儿外周血T淋巴细胞亚群、IL-17、IL-12、P物质水平变化及临床意义

目的探究病毒性脑炎(VE)患儿外周血T淋巴细胞亚群、白细胞介素-17(IL-17)、白细胞介素-12(IL-12)、P物质(SP)水平变化及临床意义。方法抽取2019年4月至2022年4月开封市儿童医院收治的VE患儿72例(VE组,包括重症组33例、非重症组39例)及同期非中枢神经系统感染患儿40例(对照组)为研究对象。比较VE组和对照组、VE重症组和非重症组、VE急性期和恢复期患儿T淋巴细胞亚群,并比较IL-17、IL-12、SP水平。结果VE组外周血CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)水平低于对照组(t=2.97、4.83、5.81,P均<0.05),CD8^(+)及血清IL-17、IL-12、SP水平高于对照组(t=4.44、33.07、20.25、42.08,P均<0.05)。重症组外周血CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)水平低于非重症组(t=2.83、4.71、3.65,P均<0.05),CD8^(+)及血清IL-17、IL-12、SP水平高于非重症组(t=3.75、33.07、9.24、5.45,P均<0.05)。VE患儿恢复期外周血CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)水平高于急性期(t=4.34、5.78、5.58,P均<0.05),CD8^(+)及血清IL-17、IL-12、SP水平低于急性期(t=6.54、49.65、25.03、46.98,P均<0.05)。Pearson相关分析结果显示,急性期VE患儿血清IL-17、IL-12、SP水平与外周血CD4^(+)和CD4^(+)/CD8^(+)水平呈负相关(P<0.05),与CD8^(+)呈正相关(P<0.05),且血清IL-17、IL-12、SP表达互呈正相关(P<0.05)。结论T淋巴细胞亚群功能紊乱及炎症因子表达异常可能与VE发生、疾病进展及预后有关。