杨木粉无胶温压成形复合材料环境友好性评价

在运用热脱附-气相色谱/质谱(TD-GC/MS)联机技术分析杨木粉末无胶温压成形复合材料在4,60,90和160℃等4个环境温度点的挥发物总离子流图的基础上,采用色谱峰面积归一化法鉴定出杨木粉末基复合材料在各温度下的保留时间及峰面积,进而评价杨木粉末基复合材料的环境友好性。结果表明:在不同温度下,杨木粉末基复合材料挥发物中的有益成分含量明显多于有害成分,在40,60和160℃时,有益成分含量为有害成分含量的6倍以上,90℃时有益成分为有害成分的29倍,环境友好性良好;杨木粉末基复合材料总挥发物种类及有益成分种类、有害成分种类与杨木原粉相应种类大致相当,但有益成分明显增多,有害成分减少,增减幅度较大。说明这类杨木粉末基复合材料不仅无胶温压成形工艺具有环境友好性,且其制品的制备和使用过程都具有环境友好性。     

钢桥面薄层环氧树脂混凝土铺装材料路用性能试验研究

针对桥梁工程实践中对于钢桥面铺装习惯采用较厚结构,而铺装仍然出现大量早期损坏的问题,对钢桥面铺装设计控制指标进行了分析,提出采用特制环氧树脂混凝土的钢桥面薄层铺装结构。对特制环氧树脂混凝土进行了圆柱体单轴压缩试验、冻融劈裂试验、车辙试验和小梁弯曲试验、小梁弯曲疲劳试验,分析了采用特制环氧树脂混凝土铺筑钢桥面薄层铺装的可行性。采用直道足尺疲劳试验,分析了钢桥面特制环氧树脂混凝土薄层铺装的施工性能,并对其综合路用性能进行了评价。试验结果表明,钢桥面采用特制环氧树脂混凝土薄层铺装能够满足力学上的要求,路用性能能够达到工程要求。     

同步薄层罩面技术简介

文章介绍了一种新型的养护技术"同步薄层罩面",描述了其发展过程和技术原理,分析其性能和特点,重点突出了同步薄层罩面抗磨耗、防水、降噪等优良的表面功能,介绍了同步薄层罩面施工的特点,指出同步薄层罩面在我国高等级公路的应用价值和前景。     

层状饱和土中单桩纵向振动分

基于饱和多孔介质理论,将土体视为液固饱和两相介质,利用Novak薄层法得到了饱和土的竖向动力阻抗,利用传递矩阵法研究了饱和土中桩的纵向振动并进行了参数分析。研究结果表明：桩周土的性质、土层厚度和土层分布对桩顶复刚度有很大的影响,土层剪切模量比越小,复刚度随频率变化曲线的峰值越小,峰值的间隔也越小;对于上软下硬土层,下层硬土层越厚,桩的复刚度随频率变化曲线的峰值越小;土层液固耦合系数的差异对桩的纵向振动特性也存在一定的影响,但相对较小。     

快速修补技术在水泥混凝土路面的应用研究

通过调整薄层快速修补混凝土的原材料配合比,试验研究了水胶比、胶凝材料掺量对薄层快速修补混凝土不同龄期抗折、抗压强度以及工作性能的影响规律。研究结果表明:当水胶比小于0.28,水泥与复合功能掺合料的比例小于3∶1时,配制的薄层快速修补混凝土路面满足4 h开放交通的要求,且工作性能良好。     

Study on chromatographic fingerprint of sarcandra glabra （Thunb.） by microwave-assisted extraction coupled to HPLC/DAD

Microwave-assisted extraction (MAE) was used for extraction of effective components of sarcandra glabra (Thunb.), and then chromatographic fingerprint of sarcandra glabra (Thunb.) was studied by high performance liquid chromatography/diode array detector (HPLC/DAD). The conditions of MAE were optimized by an orthogonal experiment, and then the authentication and validation of the chromatographic fingerprint were conducted. Nine peaks were identified as common peaks in the fingerprint chromatograms, and isofraxidin was considered as a reference compound and quantified. Relative standard deviations of retention time and peak area of each component were less than 3% and 8%, respectively. Similarity and difference analysis were conducted by use of PCA and relation coefficient. Twenty batches of sarcandra glabra (Thunb.) samples from two different producing areas could be classified into two different groups in the PCA model. The results showed that MAE-HPLC/DAD method was simple, efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra (Thunb.), which could provide more reliable and precise information for quality evaluation.     

Preliminary study on Salvia miltiorrhiza bung endophytic fungus

Objective To select the strains which can produce tanshinone ⅡA like its host plant Salvia miltiorrhiza bung. Methods A total of 50 strains of endophytic fungi were isolated from healthy, living and symptomless tissues of Salvia miltiorrhiza bung, among which 29 strains were obtained from the root, 14 from the stem, 3 from the leaf, 3 from the flower and 1 from the seed. Their antimicrobial activities against nine different bacteria, including both Gram-negative and Gram-positive bacteria, were measured by Oxford plate agar diffusion bioassay. Results Our data showed that all but four strains had significant antibacterial activities on at least one indicator bacterium to some extent, and five strains (DR1, DR4, DR16, DR18 and DF2) manifested quite prominent antibacterial activities against certain pathogenic bacteria. In some degree, it might indicate that this endophytic fungus isolated from the tissues of Salvia miltiorrhiza bung has a potential value as a natural antibacterial medicine as well. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) were carried out to test selected strains, both inside and outside of the cell to see if any strain can produce tanshinone ⅡA. The result showed that extracts from three strains, labeled as DR12 (outside cell), DR21 (inside cell) and DF3 (inside cell), had a component with the same Rf value in TLC assay as that of authentic tanshinone ⅡA. The extract from DR12 (outside cell) and DR21 (inside cell) had a peak at retention time identical to that of authentic tanshinone ⅡA in HPLC. Conclusion The fungi appear to produce the bioactive compound tanshinone ⅡA, and they could be used to produce tanshinone ⅡA by fermentation. It provides a new way to synthesize this natural medicine.     

热拌薄层罩面力学响应分析

本文利用ABAQUS有限元软件对原路面加铺罩面层后的应力响应进行了分析,考察了不同罩面厚度以及超载作用下的剪应力响应,认为水平力的作用将对罩面层表面材料提出更高的抗剪要求,罩面层厚在1.5~2.5 cm范围内其剪应力变化不大,经综合考虑,热拌罩面层厚2 cm是经济而且合适的。     

大跨度地下厂房岩锚梁结构施工过程受力与变形计算和监测分析

重庆乌江彭水水电站地下厂房纵轴线与薄层、陡倾角灰岩、夹软弱页岩层走向呈0°交角布置,岩性自稳时间短、卸荷变形快,对布置在高边墙上的锚梁结构的安全极为不利。针对岩体加载和卸荷过程中的力学性质的本质区别,为分析岩体卸荷规律对布置在洞室高边墙上梁体结构安全的影响,掌控岩锚梁结构的安全度,施工中选取厂房区域的典型地段作为计算剖面,采用有限差分法模拟地下厂房的开挖、加固和岩锚吊车梁的建造及运行状态,重点分析主厂房围岩与支护及岩锚吊车梁的变形及受力状态。通过受力计算分析以指导施工,借助安全监测数据分析,表明梁体结构安全可靠。     

农村公路薄层水泥混凝土路面板尺寸确定

根据农村公路实际情况和试验路段条件,利用有限元法,计算分析了路面板平面尺寸对荷载应力的影响,确定了农村公路薄层水泥混凝土路面板的合理平面尺寸.研究表明,农村公路薄层水泥混凝土路面板的平面尺寸对板底最大拉应力有明显影响.利用荷载疲劳应力确定路面板的平面尺寸,与试验路观测分析的结果一致.