C/GFRP加固混凝土梁受弯性能试验研究

通过三根采用不同纤维 (CFRP、C/GFRP和GFRP)正截面加固的混凝土梁和一根对比梁的受弯破坏实验 ,对比研究了C/GFRP层间混杂形式纤维加固梁的受力特点、破坏形态、合理加固方式、梁体应变情况、承载能力、刚度和变形能力 ,试验结果表明 :采用C/GFRP层间混杂形式纤维加固梁在受弯承载力显著提高的前提下表现出了较好的延性 ,这种加固技术切实可行 。

钢骨高强混凝土柱抗震性能敏感性因素的研究

分析了轴压力系数和体积配箍率对钢骨高强混凝土柱抗震延性的影响,得出了满足一定位移延性要求、对应于不同体积配箍率的钢骨高强混凝土柱的轴压力系数限值,指出钢骨形式也是一个重要的影响因素,对于钢骨形式不同的钢骨高强混凝土柱,可适当调整其轴压力系数限值。

光纤端面研磨加工机理研究

给出了研磨光纤时的材料去除机理,选用粒度为微米及亚微米级的金刚石磨料砂纸,在研磨压力为0.48Mpa时,在KE OFP 12型光纤连接器研磨机上对光纤端面进行了研磨实验。结果表明:光纤研磨加工的材料去除存在脆性断裂、半脆性半延性、延性等3种模式。材料去除模式主要取决于磨料的平均粒度,磨料粒度为3μm时,为脆性断裂到延性研磨的临界转换点。并从理论上对结果进行了分析,光纤以延性模式研磨加工时,光纤表面粗糙度Ra可达到纳米级,其表面看不到任何划痕,而光纤以脆性断裂模式研磨加工时,其表面粗糙度只能达到亚微米级,证明材料以延性模式去除是提高光纤表面质量的有效方法。

血清谷氨酸脱氢酶比值对肝癌与肝硬化的差别

血清谷氨酸脱氢酶(glutamate dehydrogenase EC 1.4.1.3 GLD)目前国内临床应用较少,有关检验专著虽有介绍,但临床意义含糊.最近有文献认为,GLD对肝脏疾病监测很有价值[1].我们用Randox试剂GLD 活性2年,认为此试验有助于肝癌与肝硬化的鉴别诊断.现报告如下:

钢筋混凝土超静定结构内力重分布研究中的几个问题

在编辑出版了 CEB-FIP Model Code 90模式规范后,CEB 工作组Ⅱ.2成员所在的几所大学就钢筋延性对转动能力和内力重分布程度的影响开展了更加深入的研究,据作者所了解和参加的工作,在斯图加特大学,主要开展了用焊接钢丝网配筋的钢筋混凝土连续板内力重分布行为的研究,已完成两个系列的试验,其余工作仍在进行中。兹分别简介如下。

恒高温作用后圆钢管混凝土承载力的试验与分析

通过对20个圆形钢管混凝土短柱试件在恒高温作用后的轴压试验,研究了圆形钢管混凝土短柱的轴压力学性能。在分析试验数据的基础上,探讨了试验中对恒温温度(℃)和恒温时间(小时)的选择对研究结果的影响。

高层建筑高强混凝土结构设计和施工中的几点思考

论述高强混凝土在高层建筑中的应用发展。通过分析 ,解决实例工程设计和施工应用中的几个难点 。

Relationship Between Beak Morphological Variables and Body Size and Mantle Length of Male and Female Argentine Shortfin Squid(Illex argentinus)

Beak of cephalopod is an important hard tissue. Understanding the morphology of beak can yield critical infor- mation on the role of cephalopods in the ecosystem. The south patagonic stock of the Argentine shortfin squid, Illex argentinus, is not only one of the most important fishing targets, but also one of the most important species in the marine eco-system of the southwest Atlantic. A total of 430 samples ofL argentinus, including 229 females 103-346mm in mantle length （ML） and 201 males 140-298mm in ML, were collected from the area off the Exclusive Economic Zone of Argentinean waters by Chinese squid jigging vessels during February to May 2007. The morphology of their beaks was evaluated. The relationships between beak morphological variables and ML differed significantly among males and females. They could be best described by loga- rithmic functions for females and linear functions for males except for upper wing length （UWL） and lower rostrum length （LRL）, which followed exponential functions in their relationships with ML. The results showed the sexual dimorphism in the relationship between ML and beak morphology for the south patagonic stock ofL argentinus. However, no significant differ- ence was found between males and females in the relationships of beak morphological variables （except for UWL） versus body weight （BW）, suggesting that the relationship between beak morphological variables and BW can be used for estimating the biomass consumed by their predators.

课堂评价用语的艺术

《新课标》提出了“要充分发挥评价的激励作用，保护学生的自尊心和自信心”的理念。许多教师能积极转变评价理念，在课堂上采用了激励性的评价方式，取得了较好的效果。但是我们也看到有些老师的课堂只有表扬，所有的评价语言都是“好”“很好”“你真棒”，表面上好像符合新课标理念，进行了赏识教育，事实却造成评价语的无效和课堂教学效率低下。笔者结合自己的教学实践就如何进行课堂评价这一问题提出了自己的看法。

Analysis and Consequences of the Pilcomayo River Complexity as International Boundary between Argentina and Paraguay

The War of the Triple Alliance was an international military conflict in South America, fought from 1864 to 1870 between Paraguay and the Triple Alliance of Argentina, Brazil, and Uruguay. In 1939, according to the provisions of the Arb6-Cantilo Treaty, it was established that the international boundary between Argentina and Paraguay passed through the deepest channel of the Pilcomayo River. The natural complexity of the river, plus the condition of acting as international border, led to perform this analysis. The main goal was to implement geo-processing techniques to map the evolution in the drainage pattern, linked to natural processes or human activities from 1951 to today. Satellite imagery and historical maps were integrated upon a Geographic Information System （GIS）; to interpret the changes occurred in the last 60 years along the Pilcomayo River channel which is approximately 20,000 km^2 located in Argentina and Paraguay. The collected information allowed the authors to evaluate and demonstrate the degree of correspondence between the river variation and the topographic position of the international boundary between Argentina and Paraguay, and also to diagnose what could occur in the near future.

Esterase Activities and Biochemical Properties of Lactic Acid Bacteria Isolated from Goat＇s Milk Cheese in Argentina

Twenty-two lactic acid bacteria （LAB） strains isolated from Argentinean goat dairy products were evaluated for its biochemical properties and esterase activities relevant to flavor development. Streptococcus thermophilus （UNSE314）, Lactobacillus （L.） delbrueckii subsp, bulgaricus （UNSE309）, L. rhamnosus （UNSE308）, L. plantarum （UNSE287, UNSE316, UNSE317） and Pediococcus pentosaceus （UNSE315） strains presented high acidifying activity. All strains tested metabolized citrate and produced diacetyl-acetoin in goat milk. Based on these results, 10 strains with the best performance in diverse technological properties were selected to determine esterolytic activity. In all evaluated strains, esterase specific activity （ESA） was detected on ct-naphthyl （ct-NA） acetate and 13-naphthyl （[3-NA） acetate, propionate, eaprylate and ct-NA butyrate. No activity was detected on [3-NA laurate. The highest values were detected when using a-NA instead of fI-NA derivatives as substrate. In Pediocoecus strains, wide variability in ESA were observed, which were species- and strain-specific. These results allow us to select strains with biochemical properties and esterase activities to design starter and adjunct cultures that contribute to flavor development during cheese ripening, thus preserving the typical organoleptic characteristics of Argentinean goat cheeses.

Functionality of Protein Isolates from Argentine Anchovy （Engraulis anchoita） Residue Obtained Using pH Shift Processing

The aim of this study was to obtain a protein isolate from Argentine anchovy （Engraulis anchoita） residue produced using the pH shifting process, with acid and alkaline solubilization and isoelectric precipitation of the protein, and evaluate their functional properties. The lowest solubility was obtained at pH 5 where 8.32% and 2.96% were found for acid and alkali respectively. The highest solubility was obtained at extreme pH. The maximum water holding capacity was presented by the alkaline protein isolate at pH 11 （9.63 g H20/g protein）. The oil holding capacity was 4.20 mL/g protein, 7.26 mL/g of protein for the acid and alkaline protein isolates, respectively. The strain showed higher oil holding capacity in alkaline pH, lower solubility in pH near the protein isoelectric point and a lower capacity to retain water in extreme pH when compared with the acid isolate.

Necrotic Incompatibility in Crosses of Bread Wheats in Argentina

Abstract： Synthetic wheats are the product of the cross between Triticum turgidum L. var. durum and T. tauschii. The 7＇. tauschii has shown excellent resistance to diseases, salinity, and drought, However, these synthetic wheats are also carriers of genes that produce varying degrees of necrosis, which is expressed as death of tissues in the hybrids （F l） generated from crosses with other bread wheats Necrotic incompatibility is a gradual premature leaf death in certain bread wheat F1 plants and it is caused by the interaction of two genes Nel and Ne2. In this paper 40 hybridizations with T. tauschii in the genetic constitution of some of the two parents made in 2006 and 2007 are presented, and their respective F1 planted at the CEI Barrow （Chacra Experimental de Barrow）. The plants that showed necrotic incompatibility had less growth than the normal F1 at tillering. Symptoms appeared at the beginning of tillering, remaining in that state and till jointing but they never headed. Out of the 16 Argentinean commercial cultivars evaluated, seven had the Ne allele in its genetic constitution and therefore showed necrotic incompatibility, whereas nine of them did not have the NE allele and their F 1 developed normally.

Consumers＇ Perceptions about Food Quality Attributes and Their Incidence in Argentinean Organic Choices

The objective of this paper is to analyze consumers＇ perceptions about risk and quality attributes of food consumption; and to evaluate the incidence of these factors when buying organic products in the Argentinean domestic market. Data derives from a food consumption survey on organic and non-organic consumers conducted in Buenos Aires City, Argentina, in April 2005.The Lancaster model （1966） provided the theoretical basis. The results yielded by the estimated logistic model suggest that consumers with higher educational level, who eat healthy food, and consider food control organisms as ＂inefficient＂ are more likely to buy organic products. A high percentage of consumers read and trust label information in Argentina. This has interesting policy implications to promote differentiated and high value products, and to reduce information asymmetries.

Argentinean Commercial Malbec Wines： Regional Sensory Profiles

Sensory evaluation was performed on 32 commercial Malbec wines （2008 and 2009 vintages） produced in five provinces of Argentina. Wines from different areas in Mendoza （the most important producer of Malbec） were also included to test possible differences within this province. Ten key attributes were first recognized by descriptive analyses and then carefully evaluated by a trained sensory panel composed of 10 judges. Among the aroma and flavour attributes the analyses focused on plum, red fruits, white pepper, bell pepper, and floral. Three attributes of taste （acidity, astringency, and bitterness） and two attributes of color （red and blue-purple hues） were also analyzed. Statistical differences and similarities in sensory data were tested using analysis of variance （ANOVA）, multiple means comparisons by least significant difference test （Fisher LSD）, and principal component analysis （PCA）. ANOVA and Fisher LSD tests of sensory data showed significant differences （P 〈 0.05） for 6 out of 10 wine attributes： plum, floral, red fruits, astringency, red and blue- purple hues.

Effective approaches to extending medium-term forecasting of persistent severe precipitation in regional models

A set of methods designed to improve （i.e.extend） the medium-term forecasting of persistent severe rainfall （PSR） events in China using the regional Weather Research and Forecasting model are summarized.Simulations show that achieving a more efficient use of large-scale atmospheric variations of the global model and retaining small-scale features in the regional model are critical for better forecasting PSR events.For precipitation,the larger the magnitude and longer the lead time,the more significant the improvement-especially for the methods of spectral nudging and updated initial conditions.In terms of large-scale circulation,the anomaly correlation coefficient can be distinctly improved for 1-5-day lead times by adopting the spectral nudging technique,whereas lateral boundary filtering results in marked improvement for 7-11-day lead times.

Biomarkers of neurodegenerative disorders: How good are they?

Biomarkers are very important indicators of normal and abnormal biological processes. Specific changes in pathologies, biochemistries and genetics can give us comprehensive information regarding the nature of any particular disease. A good biomarker should be precise and reliable, distinguishable between normal and interested disease, and differential between different diseases. It is believed that biomarkers have great potential in predicting chances for diseases, aiding in early diagnosis, and setting standards for the development of new remedies to treat diseases. New technologies have enabled scientists to identify biomarkers of several different neurodegenerative diseases. The followings, for instance, are only a few of the many new biomarkers that have been recently identified: the phosphorylated tau protein and aggregated β-amyloid peptide for Alzheimer’s disease (AD), α-synuclein contained Lewy bodies and altered dopamine transporter (DAT) imaging for Parkinson’s disease (PD), SOD mutations for familial amyotrophic lateral sclerosis (ALS), and CAG repeats resulted from Huntington’s gene mutations in Huntington’s disease (HD). This article will focus on the most-recent findings of biomarkers belonging to the four mentioned neurodegenerative diseases.

Investigation of Argentinean Plant Extracts for Their Antibacterial Activity

Plants of Baccharis （Asteraceae） genus are commonly known in Argentina as ＂carqueja＂. The antimicrobial activity and minimal inhibitory concentration of B. articulata, B. trimera and B. crispa aqueous and ethanolic extracts were evaluated by using the micro-well dilution method. Previously, the components of extracts were analyzed by spectroscopial means. Gram-positive bacteria were more sensitive to Baccharis species extracts than Gram-negative bacteria. Out of 3 plant species, B. trimera showed significant antibacterial activity and aqueous and ethanolic extracts were active against Staphylococcus aureus （MIC = 2,500 μg/mL and 1,250 μg/mL, respectively） and Listeria monocytogenes （MIC = 625 μg/mL and 625 μg/mL, respectively）. All ethanolic extracts inhibited the growth of the selected Gram-positive （MIC values ranged between 625 μg/mL and 1,250 μg/mL）. Therefore, all Gram-negative bacteria were resistant to the ethanolic and aqueous extracts tested. One flavone, genkawanin, was identified from the three ethanolic extracts as the responsible of antibacterial activity. Two terpenes, hawtriwaic acid and bacrispine, were identified from ethanolic extract of B. crispa and B. trimera as the responsibles of antibacterial activity. These preliminary studies corroborated the antimicrobial activity of the selected plants used in folklore medicine. Therefore, they could be potential sources of new antimicrobial agents used in treatment of infectious diseases.

Composition and Thermal Behavior of Oils from Native Seeds and Fruits of Argentina and Uruguay

The purpose of this work was to study the thermal characterization of oils extracted from native seeds and fruits of the Argentina, Uruguayan region. This is important because it＇s necessary to find new applications for food industry. Uruguayan wild cardoon seed, Argentinian wild papaya seeds, Argentinian avocado pulp, Argentinian cherimoya seeds, Argentinian grapeseeds and four commercial brands of chia oils were studied. The thermal behaviors of the oils were analyzed on a differential scanning calorimetry （DSC）, TA Instrument, Q20 model equipped with an intercooler. These oils＇ thermal profiles presented differences, which are related to the compositions of fatty acids and triacylglycerols. The thermogram for the chia oil, with a high content of linolenic acid, presented a very important peak at about -40 ℃; whereas, the papaya oil with an oleic acid content of 74%, showed a peak at about -3 ℃. When comparing the thermal behaviors of these oils to commercial brand oils, it was found that the chia oil is similar to the flaxseed oil, the papaya similar to the olive oil and the avocado similar to the rice bran oil. The avocado oil, in particular, presents high solid content at cold store or winter temperatures, which would make its use in those conditions difficult （for example, a cosmetic cream or gourmet oil）. In conclusion, the thermal behavior of one oil sample as determined by DSC provides valuable information with regards to the possible use of new oils of American origin as replacement of usual commercial others.