浅谈师范类高校物理化学教学方法

根据物理化学课程的特点,探讨了高等教育师范类物理化学课程教学的有效教学模式。文章从激发学生的学习兴趣、增强教师的业务素质和善用现代化教学手段三方面进行了分析和讨论,探讨物理化学课程教学改革。

Macroalgae in a spring stream in Shanxi Province:composition and relation to physical and chemical variables

Fourteen stream segments were investigated throughout the Xin’an Spring in Shanxi Province, China in 2004. The variation ranges in stream size, current velocity, discharge, dissolved oxygen, and specific conductance were large. Twenty-two macroalgae species were found in the stream. Major divisions in terms of species numbers were Chlorophyta (59.1%), Cyanophyta (22.8%), Xanthophyta (9.1%), Rhodophyta (4.5%) and Charophyta (4.5%). The most widespread species, Cladophora rivularis (50.0%), also Oedogonium sp. (42.9%) and Spirogyra sp. (42.9%) were well represented throughout the stream, whereas another 10 species were found in only one sampling site. Total percentage cover varied from <1% to 90%. Red algae Batrachospermum acuatum and the charophytes Chara vulgaris have the highest percentage cover. Among the parameters analyzed, the stream width, specific conductance and dissolved oxygen were the ones that more closely related to the species number and percentage cover of macroalgal communities. The species number of each site was negatively correlated with dissolved oxygen content. The total percentage cover of the macroalgae was negatively correlated with the stream width and the specific conductance.

Distribution and Assessment of Soil and Land Degradation in Subtropical China—A Case Study of the Dongxi River Basin, Fujian Province *1

Some alternative methods for estimating soil erosion rates rapidly were used to elucidate the relationship between the land use types and land degradation. The 137 Cs content, magnetic susceptibility, aggregate stability, and soil properties were studied in the Dongxi River Basin, a mountainous area of western Fujian. A plot of 137 Cs inventory (Y) against slope angle (X) shows a strong inverse log log relationship ( r = -0.83 ), indicating that much more soil erosion occurs on steeper slopes. Average soil loss (in thickness of top soil per year) in the past 30 years for arable slope crest, arable slopes and tea plantation slopes are 1.6 , 10.4 and 8.0 mm year -1 respectively. The surface layer enrichment factor of magnetic susceptibility (Y) in soil also shows an inverse log log relationship ( r =-0.63), indicating a similar tendency with the relationship between the 137 Cs inventory (Y) against slope angle (X). The physical and chemical properties of soils among different land use types show different degraded characteristics at different significant levels.

Global Bioethical Prevention of the Collision of Biological and Cultural Evolution on Miserable Human Survival

With the cultural myth that science can only determine the way the world ＂is＂ （facts）, while humanities, social sciences, lawyers, philosophers, and theologians must determine the way the world ＂ought to be＂ （values）, those in position of global-, national-, and local-political power make major decisions of the use （or non-use） of scientific knowledge and technology. As a result, the human being has created a non-scientifically based cultural environment that is affecting his ability to survive. In effect, cultural evolution is occurring more rapidly than biological evolution that can adapt to the changes brought about in the physical and psycho-social environments. In a pluralistic cultural world, where each society has generated a different view of human nature and different ethical values, the use, misuse, or non-use of scientific and technological advances are derived from these unscientific views of human nature. Since all life depends on limiting interacting environmental and ecological factors, it is imperative that scientific information be used to govern how to minimize irreversible effects on life-sustaining ecological factors, but also scientific information bearing on understanding human nature ought to be integrated into a ＂global bioethics＂. While ethical values cannot be directly derived from scientific factors, it is also true that human values or our ＂ought＂ cannot be maintained in ignorance or defiance of the facts or the ＂is＂.

抗冻结沥青混凝土路面国内外研究现状与进展

我国北方地区冬季气候寒冷,路面积雪结冰对公路发展和交通安全运营的制约因素越来越受到各界人士的关注。抗冻结路面作为清除路面冰雪的有效措施,可以保障道路畅通和行车安全,避免交通事故的发生,提高道路通行能力和运营效益。综述了抗冻结沥青混凝土路面国内外研究现状与进展,重点介绍了化学类、物理类及物理化学类抗冻结路面。

The physicochemical properties of some imidazolium-based ionic liquids and their binary mixtures

The density, viscosity and conductivity of ionic liquids （ILs）, 1-octyl-3-methylimidazolium tetrafluoroborate （[omim][BF4]）, 1-octyl-3-methylimidazolium chloride （[omim][C1]）, 1-hexyl-3-methylimidazolium tetrafluoroborate （[hmim] BF4]）, 1-hexyl- 3-methylimidazolium chloride （[hmim][C1]）, 1-hexyl-3-methylimidazolium hexafluorophosphate （[hmim][PF6]）, and the [omim][BF4] ＋ [omim][Cl], [hmim][BF4] ＋ [hmim][C1], and [hmim][PF6] ＋ [hmim][C1] binary mixtures were studied at dif- ferent temperatures. It was demonstrated that the densities of both the neat ILs and their mixtures varied linearly with temper- ature. The density sensitivity of a binary mixture is between those of the two components. The excess molar volumes （l/e） of [hmim][BF4] ＋ [hmim][C1] and [hmim][PF6] ＋ [hmim][C1] mixtures are positive in the whole composition range. For [omim][BF4] ＋ [omim][C1], the VE is also positive in the [omirn][C1]-rich region, but is negative in the [omim][BF4]-rich re- gion. The viscosity or conductivity of a mixture is in the intermediate of those of the two neat ILs. For all the neat ILs and the binary mixtures studied, the order of conductivity is opposite to that of the viscosity. The Vogel-Tammann-Fulcher （VTF） equations can be used to fit the viscosity and conductivity of all the neat ILs and the binary mixtures. The neat ILs and their mixtures obey the Fractional Walden Rule very well, and the values of the Walden slopes are all smaller than unit, indicating obvious ion associations in the neat ILs and the binary mixtures.

Studies on abacavir-induced hypersensitivity reaction:a successful example of translation of pharmacogenetics to personalized medicine

Abacavir is an effective nucleoside analog reverse transcriptase inhibitor used to treat human immunodeficiency virus(HIV) infected patients.Its main side effect is hypersensitivity reaction(HSR).The incidence of the HSR is associated with ethnicity among patients exposed to abacavir,and retrospective and prospective studies show a significantly increased risk of abacavir-induced HSR in human leukocyte antigen(HLA)-B*57:01-carrying patients.Immunological studies indicated that abacavir interacts specifically with HLA-B*57:01 and changed the binding specificity between the HLA molecule and the HLA-presented endogenous peptide repertoire,leading to a systemic autoimmune reaction.HLA-B*57:01 screening,combined with patch testing,had clinically predictive value and cost-effective impact in reducing the incidence of abacavir-induced HSR regardless of the HLA-B*57:01 prevalence in the population.Therefore,the US Food and Drug Administration(FDA) and international HIV treatment guidelines recommend a routine HLA-B*57:01 screening prior to abacavir treatment to decrease false positive diagnosis and prevent abacavir-induced HSR.The studies of abacavir-induced HSR and the implementation of the HLA-B*57:01 screening in the clinic represent a successful example of the use of pharmacogenetics for personalized diagnosis and therapy.

Study of Substrate and Physico-Chemical Base Classification of the Rivers of Nepal

The rivers in Nepal are classified in terms of geographical regions but a more scientific classification such as on the ba-sis of morphology is clearly lacking. This study was done in 9 rivers namely Jhikhukhola of the Koshi system, Aandhikhola, Arungkhola, East Rapti, Karrakhola, Seti and main channel Narayani of the Gandaki system, and two independent systems within Nepal, Bagmati and Tinau. Among the morphologies, river bed or the substratum was taken as the main variable for the analysis which was categorized into 7 types as rocks, boulders, cobbles, pebbles, gravels, sand and silt. There were 23 sampling sites each with 2 stretches of around 100m in those rivers. The data were taken as a percentage, and to avoid biases it was observed visually by the same person for a complete year in every season. With 23 sites each with 2 stretches and 4 replicates corresponding to 4 seasons, there are altogether 184 observations, each termed as a case, that constitute this work. Canonical Discrimination Analysis (CDA) which is most suitable when the data pool is huge was applied to see if the rivers studied distinguish themselves in terms of its morphology. The result was remarkably successful and was close to the established regional classification of the rivers. This kind of river classification has great application in the utilization, conservation and restoration of the most important natural re-source of the country.