吡啶偶氮邻氨基类有机试剂5-Br-PADMA的合成及其性质的研究

本文报道了一个吡啶偶氮邻氨基类有机试剂5-Br-PADMA的合成与提纯方法,初步研究了该试剂与C_o^(2+)、P_b^(2+)、C_u^(2+)、Ni^(2+)和F_e(3+)等离子的显色反应。

孟加拉Padma大桥施工场地垮塌区整治防护施工技术

2014年8—10月期间,孟加拉Padma大桥Mawa侧主桥施工营地,经三次严重河水冲刷形成垮塌区。根据垮塌区水下地形测量成果,决定采用抛投土工沙袋+填沙的防护施工方案,最大限度地利用了项目既有资源,相对节约了整治防护施工成本,确保了Mawa Construction Yard在Padma大桥施工期间的安全,本文对此加以介绍。

Tibetan herbal formula Padma Digestin modulates gastrointestinal motility in vitro

AIM:To examine the effects of Padma Digestin on the smooth muscle motility of different gastrointestinal segments in vitro . METHODS:The effects of the ethanolic extract of Padma Digestin (at 8.16 mg/mL or 81.6mg/mL) on the contractility and susceptibility to acetylcholine (ACh) of muscle strips from the cardia, antrum, pylorus, duodenum, jejunum, ileum and colon of male Wistar rats were analyzed.RESULTS:Compared with the control treatment, the Padma Digestin extract had a procontractile effect on the antral smooth muscle strips. Padma Digestin decreased ACh sensitivity in cardia muscle strips and increased it in those from the antrum and pylorus. In the intestinal segments, spontaneous contractility was inhibited in both the duodenal and jejunal strips, whereas reactivity to ACh was inhibited in the jejunal strips only. In the colonic samples, Padma Digestin inhibited spontaneous and ACh-stimulated contractility at a low dose but seems to have increasing effects at a high dose. CONCLUSION:Padma Digestin extract has regionspecific effects on the contractility and excitability of gastrointestinal smooth muscle. Our results support the traditional use of Padma Digestin for maldigestion and functional gastrointestinal disorders.

Climate Change and Anthropogenic Interferences for the Morphological Changes of the Padma River in Bangladesh

This research aims to identify the morphological changes of the Padma River due to the effects of anthropogenic climate change. The morphological changes were measured by aerial satellite images and their historical comparison, terrestrial survey, sedimentation in the riverbed, water flow, water discharge, siltation, and erosion along the river, etc. The Padma River has been analyzed over the period from 1971 to 2020 using multi-temporal Landsat images and long-term water flow data. The climatic parameters data related to temperature and rainfall were collected from 21 metrological stations distributed throughout Bangladesh over a 50-year period (1965-2015) to evaluate the magnitude of these changes statistically and spatially. The Padma, traditionally considered as a dominantly meandering river, is switching over into a braided river due to its highly susceptible nature of erosion and deposition. Results reveal that the tidal range is high during the dry season and increases from upstream to downstream of the river. Climate change may bring changes upstream by changing rainfall intensity, flood severity, and extreme temperature. More inundation can occur due to sedimentation, and more bank erosion can occur at the same time. An exponential increase of morphological activity with increased river flow, water discharge, bank erosion might substantially increase in the future. The changes in the flow introduced by climate change would impact the morphology of the Padma River of Bangladesh during the monsoon. A major change has been observed in the location of the bank and channel, as well as bars, along with their geometry and morphology over time. It is also observed that the bank line is not stable and migrated continuously. The overall width of the Padma River is varied significantly during the last 50 years. Maps and Landsat images represented that the river channel is shifting abnormally. Both climatic parameters and anthropogenic activity play an important role in fish biology and production. From this study, it is hypothesized that this assessment’s findings might help understand the overall hydrodynamic and morphological nature of the Padma River. It will suggest possible future developmental works that might be implemented on this river.

孟加拉国Padma水厂地基处理技术应用

在地震设防烈度较高的孟加拉国河口三角洲地区的软土地基处理工程中,采用无骨料振冲技术和振动沉管桩技术相结合,成功消除新吹填粉砂土和砂土层的液化作用。检测结果表明:振动沉管桩和振冲桩技术,施工工艺成熟,质量可靠,能有效提高地基承载力和减小地基沉降。振动沉管桩和振冲桩技术,施工机具简单,造价低,非常适合经济欠发达的孟加拉河口三角洲地区地基处理工程。

THE HAPPY LIFE OF PADMA DROLKAR

Padma Drolkar is from a small village located in the Dranang County of Lhoka within the Tibet Autonomous Region. Although the village is about 20 kilometers away from the downtown area of the county, the nearby mountain range makes it nearly impossible for the village to have access to the outside world, and the dirt road does not make anything at all easier. With all these factors, the village is basically as remote as remote can get.

Padma Chogya and the Tibetan Black Ceramic Handicraft

Walking into the Exhibition Hall located in Zone A of the Academy of Arts and Design of Tsinghua University,I began to search for Padma Chogya in the crowd.The university was undergoing its first exhibition of intangible cultural heritages,and as I was matching things up with what I had on my phone,my eyes finally fell upon a long-haired Khampa man who was busy working on a

PADMA WANGLANG A FALLEN CORNER OF HEAVEN

Padma Wanglang, a state-level nature reserve, is situated within the Pingwu County, Mianyang City, Sichuan Province. The place is well-known as the first county to be inhabited with pan das. This reserve is composed of 12 independent sub-reserves and connects with two other famous tourist attractions, Huang Long and Jiuzhai Valley, to form a threelegged tripod of a grand attraction, characterized by primitive, natural, tranquil, and mysterious landscapes.

THE LIFE OF PADMA CHOJOR,A LAYMAN CHAMS ARTIST

Editor’s note:In March 2013,A Comprehensive Survey of the Economic and Social Development of Early 21st Century Minority Areas in China started in Beijing as a special project of the National Social Sciences Fund as well as an important innovation program with the Chinese Academy of Social Sciences.The minority population exceeds 100 million in China,and the development of

藏药Padma Circosan胶囊对复方中药产品欧盟简化注册的启示

欧盟2004/24/EC法令对传统草药药品实行简化注册,为中药以药品身份进入欧盟提供了可能,欧盟注册也成为实现中药国际化的重要途径。复方配伍应用是中医辨证思想指导下中药的主要临床应用形式,如何使复方中药产品在欧盟成功注册上市则成为中药国际化的重要现实问题之一。截至2016年底,欧盟各成员国已累计批准630个复方传统草药药品的注册申请,藏药Padma Circosan胶囊是唯一的源于中国传统医药领域的获批复方产品。以该产品为注册实例,系统剖析其审评过程与要点,得出对复方中药产品欧盟注册的3点启示:复方中药产品注册的“非临床”与“临床”申报资料要点为产品安全性资料和传统应用“证据”;“相关产品”的传统应用和安全性证据以及欧盟草药专论的有关资料和数据是复方中药产品在欧盟成员国注册审批的重要参考;申请人应重视产品的“致突变性”研究(Ames实验)和上市后药物警戒数据。

3,5-diCl-PADMA 作指示剂配位滴定硅酸盐样品中的铝

研究了以２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺（３，５－ｄｉＣｌ－ＰＡＤＭＡ）为指示剂，配位滴定硅酸盐样品中的铝的方法。实验结果表明，在ｐＨ３．８～４．８范围内，终点变色灵敏、准确度高。用于硅酸盐样品中铝的测定，结果准确可靠。

2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯胺与铑显色反应的研究及应用

本文报道了以新试剂2-(5-硝基-2吡啶偶氮)-5-二甲氨基苯胺(5-NO_2-PADMA)作分光光度法测定铑的新体系.结果表明,在 PH=5.25～6.75范围内,铑与 5-NO_2-PADMA形成 1:1的紫红色络合物,其 λ_(max)在 525 nm处,该络合物在 1.8mol/L的盐酸溶液中转变为绿兰色,其最大吸收峰位于620nm处,表观摩尔吸光系数为1.39×10～5L·mol～1·cm～1.反应具有良好的选择性,常见金属离子在一定范围内无干扰.铑含量为0～0.56μg/mL范围内遵守比耳定律.所拟方法操作简便,灵敏度高,用于催化剂中微量铑的测定,结果满意.

分光光度法测定微量铂(Ⅳ)的高灵敏显色反应及其应用研究

研究了２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺（３，５－ｄｉＣｌ－ＰＡＤＭＡ）光度法测定铂（Ⅳ）的最佳条件．结果表明，在ｐＨ３．２５～５．２５的ＨＡｃ－ＮａＡｃ缓冲介质中，铂与试剂在沸水浴中加热２５ｍｉｎ后能形成稳定的蓝色配合物，加入无机酸及乙醇后转变为绿蓝色，其最大吸收波长位于６３４ｎｍ，表观摩尔吸光系数高达１．０４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１．以ＥＤＴＡ为掩蔽剂，较大量的常见金属离子不干扰测定．铂含量在０～１２μｇ／１０ｍＬ范围内符合比尔定律．方法已应用于催化剂中微量铂（Ⅳ）的测定．

西藏错那县扎西通美寺杜康大殿十六罗汉壁画初探

扎西通美寺杜康大殿保存有16世纪中期绘制的十六罗汉壁画,作为早期勉唐派作品的珍贵遗存,既是西藏十六罗汉绘画流变研究的关键性作品,更是汉藏文化与美术交流的典型。将扎西通美寺杜康大殿十六罗汉壁画与卫藏地区早于它的几组十六罗汉绘塑作品进行图像特征的比对与分析,说明其图像源自“永乐样式”的罗汉绘画,并通过在此进一步的风格分析,揭示其并非是“永乐样式”罗汉绘画风格的复制与再现,而是藏族画师依据本民族文化与审美特质的主动创造,是对“永乐样式”罗汉图像进行的转译与本土化再创造。

新型吡啶偶氮试剂质子化行为的分光光度法研究

应用分光光度法研究了两种新型吡啶偶氮二甲氨基苯胺类化合物在溶液中的离解平衡，测定了各级离解常数．结果表明，这两种化合物在溶液中均存在着三级离值分别为：ＰＫα１＝－４．５６，ＰＫα２＝１．０７，ＰＫα３＝５．１０．２－（５－溴－２－吡啶偶氮）－５－二甲氨基苯胺（记作５－Ｂｒ－ＰＡＤ－ＭＡ）的ＰＫα值分别为ＰＫα１＝－４．２５，ＰＫα２＝１．７１；ＰＫα３＝５．８８．

双波长叠加2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯胺分光光度法同时测定铑和钯的研究

提出了以 2 ( 5 硝基 2 吡啶偶氮 ) 5 二甲氨基苯胺 ( 5 NO2 PADMA)作为铑、钯同时测定的新光度试剂。研究发现 ,钯、铑与试剂分别在 0 3～ 3 9mol/L高氯酸介质及 pH5 2 5～ 6 75近中性介质中 ,形成稳定络合物 ,向铑络合物中加入强酸酸化 ,该络合物不仅不被分解 ,且吸收红移、吸光度增大。作者还发现 ,铑、钯与试剂形成的络合物 ,均呈现两个强弱不等的吸收峰 ,强峰分别位于 62 0nm和 62 1nm处 ,弱峰分别位于 575nm和 584nm处。其各自的强弱峰对应的吸光度之和与溶液中铑、钯的含量具有良好的线性关系。利用双波长叠加的方法测得铑、钯的表观摩尔吸光系数分别为 2 57× 1 0 5 和 1 58×1 0 5 ,灵敏度分别为单波长测定的 1 85倍和 1 68倍。本文基于二者显色酸度的差异 ,同时又采用双波长叠加使灵敏度提高而建立了铑、钯同时测定的新方法 ,灵敏度高 ,选择性好 ,操作简便 ,用于合成样品中微量铑、钯的测定 ,结果满意。

新显色剂2－（5－硝基－2－吡啶偶氮）－5－二甲氨基苯胺与钯显色反应的研究及其应用

用新合成的偶氮试剂２－（５－硝基－２－吡啶偶氮）－５－二甲氨基苯胺（５－ＮＯ＿２－ＰＡＤＭＡ）研究了光度法测定他的反应条件。结果表明，在０．４５～１．２ｍｏｌ／Ｌ盐酸介质中，钯与试剂形成稳定的蓝色配合物，其最大吸收波长位于６２１ｎｍ处，表观摩尔吸收系数为９．４×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），配合成的组成为Ｐｄ：５－ＮＯ＿２－ＰＡＤＭＡ＝１：２，钯浓度在０～１０μｇ／１０ｍＬ范围内符合比尔定律。本方法是目前测定钯的高灵敏度和高选择性体系之一。用于含钯分子筛及二次合金管理样－８８中微量钯的测定，结果满意。

2－（3，5－二氯－2－吡啶偶氮）－5－二甲氨基苯胺与铂（Ⅳ）显色反应的研究

研究了２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺与铂（Ⅳ）的显色反应，在ｐＨ３．５～６．０醋酸－醋酸钠介质中，沸水浴加热２５ｍｉｎ，试剂与铂（Ⅳ）形成１：４的紫色配合物，再提高酸度至２．９～４．０ｍｏｌ／Ｌ盐酸溶液，其最大吸收峰红移至６３０ｎｍ，灵敏度显著提高，表现摩尔吸光系数ε＿（６００）＝７．０×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），铂含量在０～３２μｇ／２５ｍＬ范围内符合比耳定律。大多数常见金属离子不干扰测定，所拟方法操作简便，用于催化剂中微量铂的测定。

以2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺作螯合剂浊点萃取-激光热透镜光谱法测定水中痕量钴

钴是生命体必需的微量元素,研究建立水样中钴的测定方法具有重要意义。在pH5.0的醋酸-醋酸钠缓冲介质中,于60℃水浴中加热10min,螯合剂2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺(5-Br-PADMA)与钴(Ⅱ)反应生成配位比为2∶1的疏水性螯合物Co(Ⅱ)-5-BrPADMA,其最大吸收波长位于611nm,用非离子表面活性剂TritonX-114为萃取剂进行浊点萃取(CPE),将该疏水性螯合物萃取到表面活性剂胶束相中,在相分离之后,以0.45mL2mol/L HCl-乙醇溶液溶解胶束相,转入光程为5mm的自制石英吸收池中,以单模He-Ne激光器(λ=632.8nm)做激发和探测光束进行热透镜光谱法(TLS)测定,建立了浊点萃取-激光热透镜光谱法(CPE-TLS)测定超痕量钴的方法。在优化条件下,热透镜光谱信号强度与钴(Ⅱ)质量浓度在0.40~6.0ng/mL范围内呈良好的线性关系,相关系数为0.9978,检出限为0.05ng/mL。按富集前后溶液体积比值计算其浓缩因子为22。将实验方法用于湖水和温泉水中钴含量的测定,结果的相对标准偏差(RSD,n=6)小于4%;结果与电感耦合等离子体质谱法(ICP-MS)基本一致;加标回收率在96%~101%之间。

2-(5-氰基-2-吡啶偶氮)-5-二甲氨基苯胺与钴的显色反应及其应用

对2-(5-氰基-2-吡啶偶氮)-5-二甲氨基苯胺(5-CN-PADMA)与钴的显色反应进行了探讨,并将其应用于实际样品中钴的测定。实验表明,在pH 4.5的HAc-NaAc缓冲溶液中,钴与5-CN-PADMA形成稳定的络合物,其最大吸收峰位于543nm,经1.2mol/L高氯酸酸化后,该络合物转化成一种较稳定的蓝色络合物,并呈现两个吸收峰,分别位于570nm和609nm。在优化的实验条件下,钴质量浓度在0.04～0.60μg/mL内与其在570mm和609nm处的吸光度加和呈线性关系,线性相关系数为0.999 8,表观摩尔吸光系数ε为1.99×105 L·mol^(-1)·cm^(-1)。将该体系应用于镍矿和钯钴炭催化剂中微量钴的测定,结果与火焰原子吸收光谱法一致,相对标准偏差(RSD,n=6)为0.50%～0.60%。