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1.
ComputerHandlingofChemicalandBiologicalDataofTraditionalChineseMedicinesCHEChun-taoa**,PaulR.CarlieraandOpheliaC.W.Leeb(aDepa...  相似文献   

2.
The winner of the sixth spectroscopy challenge (published in issue 379/1) is: Xiancui Li, Hong Kong University of Science and Technology, ChinaThe award entitles the winner to select a Springer book from our catalogue up to a value of €75,-. Our Congratulations!  相似文献   

3.
Nondestructive neutron activation analysis employing reactor neutrons and a Ge(Li) gamma-spectrometer has been used to determine the trace element level of air particulates in various areas of Hong Kong. Comparison of the average concentrations of the trace elements of air particulates was made among industrial, heavy-traffic and residential areas. It was found that industrial areas have higher concentrations of Co, Cr, Hg, Mn and Zn, while heavy-traffic areas have very high concentrations of Br. Comparison of the pollution level of Hong Kong with other cities was also made. The average concentrations of Co, Cr, Hg, Zn and Br of air particulates in Hong Kong were found to have higher values than those of other cities. Finally, daily variation of the trace element level in a special area (Hung Hom) had been studied, but no significant variation was found.  相似文献   

4.
Eleven human hair samples were taken from the Chinese residents of Hong Kong for the study of hair trace elemental level and environmental exposures. Absolute neutron activation analysis and Ge(Li) gamma-ray spectrometry were applied in the determination of the trace elemental level. All results are reported in parts per million except for sulfur and oxygen which are reported in percent. The trace element content of hair from a drug addict was found to be considerably different from other sampled people. Comparison of the normal concentrations of the trace elements of the Chinese residents of Hong Kong was made with those from people of various other national, socio-cultural and environmental backgrounds. It was found that together with a few other trace elements, Ni, Sr, Zr and Hg content of the Chinese Residents of Hong Kong show a higher level than those of the other sampled people.  相似文献   

5.
A fluorogen named 1-decyl-1-methyl-2,5-bis{4-[(N,N-diethylamino)methyl]phenyl}-3,4-diphenylsilole (3) was synthesized. It emitted weakly as isolated molecule but strongly as supramolecular aggregate, showing a characteristic behavior of aggregation-induced emission (AIE). The molecules of 3 formed highly emissive nanoparticles in aqueous media, which quickly and selectively marked cytoplasm of HeLa cells and posed no toxicity to the living cells. The fluorogen is thus a promising candidate material for cell imaging as a sensitive, selective and cytocompatible biosensor. Supported by the Research Grants Council of Hong Kong (Grant Nos. 603008, 601608 and 602707), the National Natural Science Foundation of China (Grant No. 20634020) and the CAO GuangBiao Foundation of Zhejiang University.  相似文献   

6.
Electroplating waste water containing copper was treated by means of reverse osmosis (RO) membrane separation on a pilot scale. The copper concentration in the untreated waste water was 340 ppm. After the treatment, the concentration in the treated water was below 4 ppm which is the Hong Kong government discharge limit. It is shown that, by increasing transmembrane pressure drop, metal concentrations in the treated water can be further reduced. This study suggests that larger scale operations on treating electroplating waste water by RO membrane separation is possible and effective. Effects of operating variables including transmembrane pressure drop and temperature on membrane separation performance were studied and explained based on the solution-diffusion model. The present study is part of the recent investigation of industrial waste water management sponsored by the Hong Kong Government. The purpose of this project is to provide guidelines to the local industries for waste minimization which is closely monitored by the Hong Kong legislature.  相似文献   

7.
Nonpolar organic compounds (NPOCs) in ambient particulate matter (PM) commonly include n-alkanes, branched alkanes, hopanes and steranes, and polycyclic aromatic hydrocarbons (PAHs). The recent development of thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) has greatly reduced time and labor in their quantification by eliminating the laborious solvent extraction and sample concentration steps in the traditional approach that relies on solvent extraction. The simplicity of the TD-GCMS methods has afforded us concentration data of NPOCs in more than 90 aerosol samples in two aerosol field studies and 20 vehicular emissions-dominated source samples in Hong Kong over the past few years. In this work, we examine the interspecies relationships between select NPOCs and their concentration ratios to elemental carbon (EC) among the ambient samples and among the source samples. Our analysis indicates that hopanes were mainly from vehicular emissions and they were significantly oxidized in ambient PM. The hopane/EC ratio in ambient samples was on average less than half of the ratio in vehicular emissions-dominated source samples. This highlights the necessity in considering oxidation loss in applying organic tracer data in source apportionment studies. Select PAH/EC ratio–ratio plots reveal that PAHs had diverse sources and vehicular emissions were unlikely a dominant source for PAHs in Hong Kong. Biomass burning and other regional sources likely dominated ambient PAHs in Hong Kong.  相似文献   

8.
化学实验评价对于培养学生的创新意识和化学学科实践能力具有重要意义,尝试借鉴香港高中化学学科校本评核方法设计“教、学、评”活动促进学生化学学习和实验能力发展。介绍了香港高中化学学科校本评核框架及准则,以人教版《化学1》(2003年课标本)“铁盐和亚铁盐”为例,结合2017年课标设计实验评价量表,通过实验活动串联教学任务,以期实现教、学、评目标。通过评价反馈,促使更加科学、全面地评估学生的实验能力表现,为教师的化学教学实践提供改进依据。  相似文献   

9.
6种燕窝的傅里叶变换红外光谱法原性状快速鉴别   总被引:32,自引:0,他引:32  
首次利用微钻石ATR探头傅里叶变换红外光谱法(FTIR)无损快速鉴别了6种燕窝。结果表明:印尼燕、越南燕、马来西亚燕、泰国血燕、菲律宾草燕和香港市售燕窝均有自己的红外特征谱,据谱图吸收峰的波数位置和相对峰强度的差异可达到燕窝类同和伪品和鉴别。该方法快速、简便、可靠。  相似文献   

10.
The radioactivity contents in building materials used in Hong Kong were measured to determine the sources of the high indoor radon concentrations observed in local buildings. The radium contents and the radon emanation coefficients of different building materials were measured by high resolution γ-ray spectroscopy using germanium detectors. The radon exhalation rates were measured using scintillation cells by circulating the exhaled radon from building materials and obtaining the initial growth rates. The radium content and the radon exhalation rates of concrete and bricks used in Hong Kong were found to be higher than those in some other countries, resulting in high indoor radon concentrations probably due to the high radioactivity contents in the aggregates, granitic in nature, used in building materials.  相似文献   

11.
 Binding energies of helium, neon and atomic hydrogen encapsulated inside a C20 cage were calculated using an ab initio method at the B3LYP/6-31+G⋆ level of theory. The standard equilibrium constants for the reactions of noble-gas atoms going into the C20 molecular cage have also been studied. The transition states for the reactions of C20 with hydrogen and helium were further obtained with an ab initio method at the B3LYP/6-31+G⋆ level and the rate constants were estimated by using conventional transition-state theory. It was found that the hydrogen and helium atoms are extremely difficult to put into the C20 cage. Once inside the cage, a helium atom can hardly get out, while a hydrogen atom can easily escape from the cage. The results are expected to enrich fullerene science and be helpful for fullerene applications such as storage. Received: 2 November 2002 / Accepted: 19 December 2002 / Published online: 30 April 2003 Correspondence to: R. Q. Zhang, e-mail: aprqz@cityu.edu.hk Acknowledgements. The work described in this paper was jointly supported by a grant from the City University of Hong Kong (project no. 7001222) and a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (project no. 9040633/CityU, 1011/01P].  相似文献   

12.
Germany introduced in 1994 a ban on the import of coloured goods containing azo-dyes that can release carcinogenic aryl amines. Naturally the move aroused great concern from exporters in China and Hong Kong, in particular manufacturers of textile and leathery products.  相似文献   

13.
Desizing wastewaters from the bleaching and dyeing industry of Hong Kong were treated by nanofiltration (NF) membrane separation on a pilot scale in the pressure controlled region. The two brown colored wastewaters had chemical oxygen demand (COD) of 14,000 mg l−1 and 5430 mg l−1, respectively. Permeate flux and COD retention were investigated in relation to transmembrane pressure drop, temperature, and feed-solution concentration. The permeate flux was found to increase significantly with transmembrane pressure drop and to decrease with feed concentration. Higher permeate flux was found for wastewater with higher pH. A minor increase in COD retention was found for the increase in transmembrane pressure drop as well as operating temperature. The COD retention was about 95% for wastewater with pH 10.2, and 80–85% for wastewater with pH 5.5. The difference in the results obtained for the two kinds of wastewater was attributed to their compositional difference that resulted from the desizing operation. Fouling of membrane is not a big concern for the NF membrane tested in treating this type of wastewater. The quality of the permeate is all above the discharge standard for foul sewer in Hong Kong. The experimental results are consistent with the theoretical analysis.  相似文献   

14.
A high throughput thermal gravimetric method was developed to measure the carbonaceous aerosols and particulates collected on filters. Representative portions or the whole piece of a loaded or blank filter was sampled and conditioned at 105±5 °C for 4 h to drive away water moisture. The sample was then treated at 550±10 °C for 4 h. After each of the heat treatment steps, the sample was conditioned in a humidity and temperature-controlled cabinet for 12 h till constant weight. The weight of the filter before and after the heated treatment was measured and the weight difference between the treatment at 550 and 105 °C was calculated as the weight of the carbon containing substances (CCS). Reference chemical standards and certified reference materials SRM 1649a and 1650a were used to validate the method. CCS concentrations of real aerosol samples collected in the city of Hong Kong during the summer of 2001 were also measured, compared and correlated with the concentrations of total carbon (TC), elemental carbon (EC) and organic carbon (OC) of the samples determined using a thermal optical transmittance (TOT) method as specified in NIOSH method 5040. The weight of organic compounds in airborne particulate matters is usually estimated by multiplying the weight of TC, which is determined by thermal/thermal optical methods, by a factor of 1.2 or 1.4. To this end, a correction factor of approximately 1.6 was found to relate TC to the measured values of CCS in aerosol samples collected in the urban atmosphere of Hong Kong. The proposed procedure for measurement of CCS is simple, easy to follow and requires simple laboratory instrumentation. Typically, the analysis of more than 100 filter samples can be completed within three working days with minimal attention.  相似文献   

15.
The arsenic concentrations were determined by neutron activation analysis in some popular dried seafood and dried algae consumed in Hong Kong. It was found that dried scallop was the least contaminated, while most of the samples of dried shrimp, dried oyster and dried mussel contained arsenic less than the maximum permissible concentration (MPC). Dried squid was found to contain the highest arsenic and every sample measured contained arsenic higher than the MPC. Action to be taken was recommended.  相似文献   

16.
The immune modulating effects of selected herbs deserve careful studies to gain evidence-based support for their further development. We have been working hard on many items of medicinal herbs to gain insight into their immunomodulatory effects relevant to cancer treatment in particular, while infection control is not excluded. Nine of them have been selected to give the results of our exploration on their biological, particularly immunomodulatory activities. Since Hong Kong people especially favor one medicinal mushroom, viz. Coriolus versicolor, a number of clinical trials using Coriolus for cancer-related studies are included in this review. While immune modulation platforms are being built for relevant studies, a brief account on the research targets and related procedures are given.  相似文献   

17.
From the 95% ethanol extract of the Hong Kong liverwort, Marchantiapaleacea, guided by bioactivity directed isolation, two novel isoriccardinquinones A and B were obtained together with previously known marchantin C, isoriccardin C and phenanthrene derivative, 2-hydroxy-3,7-dimethoxyphenanthrene. The structures of the new compounds were established by high field spectroscopic methods, including 2D NMR techniques.  相似文献   

18.
香港海域毒性微藻Alexandium tamarense的麻痹性贝毒研究   总被引:2,自引:0,他引:2  
对从香港海域底坭分离并培养的毒性微藻塔玛亚历山大藻(Alexandiumtamareuse)的毒性和麻痹性贝毒素的组成进行研究。由生物试验测得其毒性为4.11×10-6MU/cell,用高效液相色谱分析毒素的组成,结果表明所含麻痹性贝毒成分主要是膝沟藻毒素-2(GTX2),含量为94.13pg/cell,本研究所用的微藻毒素提取方法和高效液相色谱分析方法都比较容易和有效。  相似文献   

19.
Chiralligandsplayacrucialroleinasymmetriccatalysis .Todateavarietyofligandshavebeensynthe sizedandprovedtobeeffective .Amongthemtheligands1withbothcoordinateatomsatbenzenering positionsshowgoodtoexcellentasymmetricinductionincatalyticasymmetricreactions …  相似文献   

20.
Ultrahigh performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) was utilized to develop a rapid, sensitive and reliable method without solid phase extraction (SPE) pre-concentration for trace analysis of 11 pharmaceuticals and personal care products (PPCPs) in in?uent and ef?uent from municipal wastewater treatment plants (WWTPs). This method not only shortened the analysis time but also reduced analysis cost significantly by omitting SPE process and avoiding the consumption of SPE cartridge. Detection parameters for UHPLC–MS/MS analysis were optimized, including sample pH, eluent, mobile phase (solvent and additive), column temperature, and ?ow rate. Under the optimal conditions, all analytes were well separated and detected within 8.0 min by UHPLC–MS/MS. The method quantification limits (MQLs) for the 11 PPCPs ranged from 0.040 to 88 ng L−1 and from 0.030 to 90 ng L−1 for influent and effluent, respectively. The matrix effect was systematically investigated and quantified for different types of samples. The analysis of in?uent and ef?uent samples of two WWTPs in Hong Kong revealed the presence of 11 PPCPs, including acyclovir, benzophenone-3, benzylparaben, carbamazepine, ethylparaben, fluconazole, fluoxetine, methylparaben, metronidazole, propylparaben, and ranitidine. Their concentrations ranged from 9.1 to 1810 ng L−1 in influent and from 6.5 to 823 ng L−1 in effluent samples collected from Hong Kong WWTPs.  相似文献   

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