橡膠鍵鏈結構與自由能的關係
受應力拉伸時，橡膠溫度明顯上升；縮放回原長，橡膠溫度驟降。由文獻得知橡膠內部具有特殊的鍵鍊結構，在一般的情況下，交鏈分子糾結成一團，狀態複雜；受外力拉伸時，交鏈分子依橡膠長度之增加而伸展，排列較為整齊，狀態之複雜度減小。根據熱力學第一定律，當內能變化為零，則外力作功會造成能量變化。在定溫之下，橡膠內能變化為零，當其受應力拉伸，使其內部交鏈分子排列複雜度降低，造成橡膠熵值減小，而有能量（dQ=TdS）的釋出。測量此一能量dQ 變化，即可計算出熵與狀態數之變化The temperature of rubber rises as it is stretched, its temperature comes back again while it restores to its original length. It is known that the rubber is consisted of long-chain molecules, the long-chain molecules strangle each other at normal state, however, they become more order when the rubber is stretched. Based on the 1st law of thermodynamics dU=dQ+dW, The deformation caused by applied force supplies energy to the rubber and reduce its entropy, the heat dQ (=TΔS) released by the reduction of entropy causes the temperature rise of rubber as dU=0. We report the study on the correlation of thermal properties and the molecular network in rubber, from the measurements of temperature change, the changes of entropy and the changes of states’ number were estimated.
Going Dotty: The Distribution and Effects of Rust on Highbush Cranberry
Purpose Every fall, I collect highbush cranberries (Viburnum edule) to make jelly. In 2012, for the first time, I observed highbush cranberry leaves covered in striking patterns of raised purple dots (telia) caused by the pathogenic rust fungus Puccinia linkii. I investigated the distribution and effects of this rust for several reasons: little is known about P. linkii, highbush cranberries are an important food source for wildlife and people, and foliar pathogens may increase with climate change in sub-boreal forests. First, I investigated the patterns of telia within plants. Second, I compared the variation in infection severity among plants, hypothesising that younger plants, those in dense populations, and those in low-elevation riparian areas would be most infected. Finally, I studied the effects of P. linkii on its host, hypothesising that highly infected plants would produce fewer berries and produce berries with less sugar, and that infected leaves would die sooner. Procedures This study investigated P. linkii in mixed coniferous-deciduous forest sites near Smithers, British Columbia. I marked a total of 41 randomly-selected focal V. edule plants in four sites. To examine within-plant patterns of infection, I photographed four leaves of each plant and used a graphic analysis program to examine the size, density and coverage of telia. To assess among-plant patterns, I compared infection severity (5 classes of telia coverage), to three ecological variables: host density within 5m, position on a moisture gradient, and plant maturity. To investigate the effects of P. linkii on its host, I compared infection severity to the number of berries produced, the proportion of malformed and infected berries, and the sugar content of mature berries as measured with a handheld refractometer. I measured leaf mortality in fall. Results P. linkii produced a characteristic pattern within each plant: higher leaves consistently had fewer but bigger telia than lower leaves. Across sites, plants were significantly more infected in areas of high host density. Within sites, young plants and plants and in moister ecosystems were significantly more infected (increases of 1.1 ± 0.2; F1,128=44.8, P
太陽短期活動對地球磁場與大氣溫度異常的影響
This study analyzed how short-term solar activities interact with the earth atmosphere, by using two statistic methods: Diffusion Entropy Analysis (DEA), and Standard Deviation Analysis (SDA). Since solar activities influence the Earth atmosphere in its radiating heat and magnetic field, we use DEA and SDA to calculate the exponents, H and δ, of the scaling law in three time series: “the intensity of solar flare” (representing by SOLAR H-alpha flare index), “magnetic anomaly of magnetosphere” and “sea surface temperature anomaly”. The values of H and δ show the time memory and correlative relationship between the event and next event happening in time series. When H = δ = 0.5, events occur in random. When 0.5
The Interplay of Iron and α-synuclein in mediating Neuroinflammation in Parkinson’s Disease
Neuroinflammation is implicated as a contributive factor to neurodegeneration in Parkinson’s disease (PD). Increased iron accumulation and deposition of -synuclein within Lewy Bodies in PD brains have been observed. It has been hypothesized that unbound iron is able to react with H2O2 to generate free radicals. Using the Divalent Metal Transporter-1 (DMT1) as a vehicle to transport iron into the brain, a DMT1 transgenic mouse model (DTg) was generated to recapitulate iron deposition in PD. The DTg was crossbred with the SNCA (synuclein) transgenic mouse to produce a DMT1_SNCA (BTg) mouse model to study the link between iron, -synuclein and neuroinflammation in PD. Our hypothesis predicts that iron exacerbates -synuclein toxicity by inducing larger inflammatory responses and consequently compromising functions of biomolecules. Our study shows that –synuclein triggers a low-grade inflammatory response by microglia and astrocytes while iron exacerbates -synuclein toxicity by eliciting immunological responses mediated by glia cells in the brain observed both in the DTg and BTg mice. Elevated levels of nitrated proteins were observed in the DTg, suggesting the role of iron in inducing nitrosative stress via upregulation of iNOS in glia cells. With the BTg mice, we hope to understand the effect of iron accumulation as an environmental stressor in aggravating -synuclein toxicity which may lead to the selective demise of dopaminergic neurons.
綠色陶土分子篩-污染大剋星
現今日常生活充斥著有機污染物，然而處理含有有機污染物的廢水需要極高的成本，有鑑於此，我們參考Fenton Reaction，從成本、毒性、活化能、操作方便性、二次污染及經濟效益的多方考量下，選擇以分子篩來固定鐵、鈷、鎳、錳、鋅之金屬離子，並決定以鐵分子篩為研究主軸，並探討其催化過氧化氫對有機物的分解。鑒於粉末狀的分子篩容易流失，我們以陶土固定分子篩，製作成反應杯槽，發現了分子篩與陶土的結合性。接著藉由二氧化碳感測器及光譜儀來感測有機物的分解速率，在控制溫度，濃度等條件下，探討分解有機物的反應及其反應時的特性。由實驗結果得知，分子篩能有效分解簡單醇類、氯仿、四氯化碳及indigo。使用0.35克陶土鐵分子篩，1M 以下的雙氧水50ml，其分解異丙醇所生成二氧化碳的速率可達0.34-0.55ppm/sec 之間（3.1-4.9×10-9mol/sec），此外有機氯化物分解後生成無毒性的氯離子；indigo染料分解後褪色。本實驗證實，陶土鐵分子篩：一、可以重複使用；二、可在較低濃度環境下運作；三、在酸性較弱環境下運作；四、可在低溫環境下運作(10℃)；五、不須對大量鐵離子做沉澱回收的工作（此五點優於Fenton Reaction）。相較於TAML 等人工合成的催化劑雖有避免污染的優點，但卻有無法重複使用的缺點，綜合以上幾點看來，陶土鐵分子篩在操作方便性及經濟與環境保護上具有相當的潛力及價值。With organic pollutants everywhere and the high cost to dispose of them, this study, a two-stage experiment, aimed first to evaluate the efficiency of zeolite with different metal ions and then to compare their rates in reacting to the decomposition of organic matter with hydrogen peroxide as the catalyst. Since zeolite powder can be easily washed away, we tested zeolite with clay to hold such metal ions as Fe, Co, Ni, Mn, and Zn and finally used the Argillaceous Fe-zeolite for its superiority on the basis of cost, toxin, activation energy, easy operation, and contamination. A carbon dioxide sensor and a spectrometer for visible light were used to measure the decomposition rate of organic matter under controlled temperature and resolution concentrations. The results of the experiments showed that zeolite achieved excellent effects in decomposing organic chlorides such as lower alcohols, chloroform, and carbon tetrachloride. When 0.35g of zeolite and less than 1M of hydrogen peroxide resolution were used the rate of carbon dioxide production reached 0.34-0.35 ppm/sec (3.1-4.9x10-9 mol/sec). The decomposition of organic chloride produced nontoxic Cl and the indigo dye faded after it was decomposed. Our experiments proved that Argillaceous Fe-zeolite has the following five advantages over Fenton Reaction. First, it can be reused. Second, it performed well at lower concentrations. Third, it worked well under weak acid conditions. Fourth, it worked at a lower temperature (20℃). And finally, there was no need to recycle a large amount of Fe ions. Argillaceous Fe-zeolite was also found to be superior to TAML, which has the advantage of avoiding contamination but is not reusable. The above observation and discussion demonstrate that Argillaceous Fe-zeolite possesses very significant value in terms of easy application, economy, and environmental protection.