化學

Synthesis of halooximes has attracted much attention given their importance as precursors to proline derivatives1, unnatural amino acids2 and a host of alkaloids3. Halooximes have numerous industrial and biological applications 4, for example oxime ethers increases specific channel opening activities, acting as potential targets in drug treatment for various diseases 5, most adrenergic β-receptor blocking compounds also conform to the structure of oxime ethers 6. They also have vitro antifungal activities against certain plants7. A known method for the synthesis of 3 using Me3SiX as a Lewis acid, via intermediate enamines with acyclic/ cyclic bis(oxy)enamines, gives yields between 21-68%. Low yield stems from lack of reaction specificity2. In this work, we investigate coupling nitrogen-oxides with CoBr2 to synthesise halooximes in high yield. Initial cyclic/ acyclic bis(oxy)enamines were prepared by reacting 1 equiv. nitro compound with 2.4 equiv. in excess of dichloromethane under argon atmosphere at a temperature of 0ºC. 2.2 equiv. of TMS-Br was further added and left to stir till thermal equilibrium with room conditions. The cyclic/ acyclic bis(oxy)enamine was isolated upon aqueous work-up, filtration and evaporation. Synthesis of halooximes was carried out by reacting 8mL to 1mmol equiv. of THF and 2 equiv. of CoBr2 under argon atmosphere and left to stir till CoBr2 dissolves. 2mL to 1mmol equiv. of CH2Cl2 was added to 1 equiv. of bis(oxy)enamines. The reaction mixture was left to stir at room temperature for 2 hours, after which aqueous work-up, filtration and evaporation were carried out. Our results are summarized in Table 1. We also obtained relatively high percentage yields for the direct synthesis of bromooximes from cyclic nitronates via a one-pot procedure: Low yield stems from lack of reaction specificity2. In this work, we investigate coupling nitrogen-oxides with CoBr2 to synthesise halooximes in high yield. Initial cyclic/ acyclic bis(oxy)enamines were prepared by reacting 1 equiv. nitro compound with 2.4 equiv. in excess of dichloromethane under argon atmosphere at a temperature of 0ºC. 2.2 equiv. of TMS-Br was further added and left to stir till thermal equilibrium with room conditions. The cyclic/ acyclic bis(oxy)enamine was isolated upon aqueous work-up, filtration and evaporation. Synthesis of halooximes was carried out by reacting 8mL to 1mmol equiv. of THF and 2 equiv. of CoBr2 under argon atmosphere and left to stir till CoBr2 dissolves. 2mL to 1mmol equiv. of CH2Cl2 was added to 1 equiv. of bis(oxy)enamines. The reaction mixture was left to stir at room temperature for 2 hours, after which aqueous work-up, filtration and evaporation were carried out. Our results are summarized in Table 1. We also obtained relatively high percentage yields for the direct synthesis of bromooximes from cyclic nitronates via a one-pot procedure:

Chitin, a polysaccharide common in biocomposites, has an interwoven organic framework that can act as a scaffold for mineralization in natural systems. Acidic amino acids, namely aspartic (Asp) and glutamic (Glu) acids, are the primary active molecules at biomineralisation interphases in mollusks and play an important role in controlling the polymorph and morphology of the associated mineral.\r In this study, chitin was extracted from squid pens and used as a scaffold for crystallization. The chitin scaffold was functionalized with glutamic acid and aspartic acid separately to create an artificial microenvironment for the study of biomineralization of calcium carbonate. The objective was to investigate the usefulness of the extracted chitin to serve as a scaffold for calcium carbonate crystallization, especially the fidelity of the polymorph nucleated to the amino acids and proteins used.

Reflex charging, or burp charge, is a prove method of effectively charging secondary\r batteries under extremely high current. It is commonly used in military and aerospace\r applications where short recharge time and long cell life are essential. Eric C. Darcy, a NASA\r chemical engineer, in his 1998 PhD thesis, ‘Investigation of the response of Ni-MH cells to\r burp charging’, outlined some of the most important theories behind this seemingly\r miraculous technique. However, due to the technical limitations of his equipment, Darcy was\r unable to determine the effects of varied reflex charging frequencies. This research overcame\r this problem by using a purposed built multi-frequency programmable reflex charger\r (PRESTO ALPHA I), and aimed to optimize chemical energy storage by searching for an\r optimum charging frequency.

在這能源短缺的時代，開發替代能源已經成為主要課題。利用光觸媒特性所製成的色素增感型太陽能電池，因二氧化鈦光觸媒受到紫外光照射才產生電子躍遷，吸收光的頻率區域狹小，實用性不高。因此研究氧化鋅、二氧化錫與二氧化鈦混合，是否能提升該電池的轉換效率。藉由各種變因的探討，從中選取最有利的方式，使太陽能電池發揮更大的效益。除了以溫度、電解質、混合比例等因素外，增加電極面積以及串聯均可提高電壓與電流，以增加日常生活的實用性。如不斷的改進發展，諸如電解水、使小燈泡發光，甚至各種小家電用品的使用，都可應用於其中。In times of energy shortage, exploring the alternative energy has already become a main issue. The dye solar photocell is using photocatalyst characteristic. Because the electron transition is caused by lighting up the titanium dioxide photocatalyst by the ultraviolet, the frequency of spectrum is narrow and small. It is thus impractical. Therefore, we research whether or not the mixtures of zinc oxidize and tin oxide with titanium dioxide can improve the conversion efficiency of the dye solar photocell. Through discussion on various kinds of factors, we can choose the best way to make the dye solar cell yield more efficiency. In addition to the factors such as temperature, electrolyte, mixed proportion, etc., increasing the area of electrodes and contact can improve the voltage and electric current. That way we can increase the practicability for daily use. With constant improvement, it can be applied to many kinds of things, such as electrolyzing water, small bulb lights, even small household appliances.

As the most dominant species on planet Earth's surface, humans have become the sole protectors of the planet, in charge of keeping it hospitable for billions of species. However, a swift look around Egypt's streets in contemporary 2007 showed proof of our exploitive use of fossil-fuels. Provoked by such a scene, I set out to discover the negatives of fossil-fuel consumption that more than 2 million websites were ready to detail. The increased CO2 emission, due to fossil-fuel use, is contributing to the greenhouse-effect, causing global-warming and thus leading to climate-change. This affects biodiversity by causing the eventual extinction of species, thus upsetting food-chains and affecting humanity in the long-run. Statistically 40 more years of consumption are left if the current rate-of-consumption persists. My proposal is to use solar-energy as an alternative power-source. Two requirements must be fulfilled: it must hold research potential and shouldn't suffer from problems associated with fossilfuels. 3rd-generation nanocrystalline dye-sensitised solar-cells have a conductive-glass-electrode coated with titanium-dioxide, then a layer of dye on it for light-absorption, electrolyte and finally a counterelectrode coated with graphite.\r In the dye-experiments, dyes extracted from fruits & vegetables, and the wavelengths of visible-lightspectra that they absorb, were examined using a UV-spectrophotometer. The solvent for the extraction-process was tested and ethanol was better than water because it actively extracts the dye while water doesn't help and contains ions that alter the dye's absorption-abilities. I combined 2 dyes: chlorophyll (absorbs the red & violet areas in spectrum) with blackberry (absorbs the green area) thus enabling the solar-cell to absorb the entire spectrum and maximising its power-reading. I investigated whether the dyes should be freshly-mixed or combined earlier (and used every time to build the cell). Freshly-mixing dyes is better because that stops the enzymes that were extracted out with the chlorophyll from denaturing blackberry's anthocyanins and rendering them dysfunctional thus the dyes work better maximising the power. Testing the dye-combination's concentration showed that the 6.25% concentration is the best because it can coat the TiO2 with a single-layer of dye instead of high concentrations that give multiple layers of dye which doesn't give good electron transition or low ones that don't give enough dye which means a lower amount of electrons are being excited and thus less power. In the material-section, anatase and rutile, TiO2's 2 major constituents (structurally identical but with different crystal-orientation), were compared and anatase proved itself better because of its smoother conduction-band. Different anatase particle sizes were examined and the smaller particles (4 nm) were better because of increased surface-area. I investigated the ways of coating the counterelectrode and found that using carbon-paste is the best. Ultimately my solar-cell's power-reading increased from 2.04 nW to 6.41 μW which is 3142 times the initial reading, a dramatic increase for a solar-cell whose size doesn't exceed 4 cm2. This proved the great research potential held by solar-energy. After extensive comparisons between the ups and downs of both fossil-fuels and solar-energy, solar-energy clearly proved itself the perfect alternative for powering our future.

在這篇報告中，特別針對了凝膠的機制去做探討，以許多的實驗數據，再輔以凝膠的基本定義，去臆測各種有關於凝膠的老化機制，並藉由其過程中推斷出一些有趣的性質： 1. 當膠體內水分含量不同，與凝結後的醇類膠體有相當的影響。 2. 凝膠老化後形成的結晶形狀，因凝膠溶質、溶液內互溶性的不同，形成了不同凝聚程度的絮聚現象。 3. 同種陰陽離子在不同碳數的醇類凝膠中，因為與水溶液的互溶性也有所不同，間接影響了凝膠的形成速度，這對於安定來說，包含了很大的意義存在。 4. 對於其老化的速度，會因其安定程度而有所影響。 5. 老化後的溶液內的陰陽離子濃度，會直接影響其再次安定與老化的情形。 In this report, we especially do the discussion to the mechanism of the gel. With a lot of experimental data and the basic definition of gel, we conjecture various kinds of aging mechanism about the gel, and infer some interesting problems from its course: 1. Moisture content in the gel effect the gel’s quality after alcohol condensed greatly. 2. Because of dissolving difference between the alcohol and the other substances, crystallization forms after the gel aged have formed different degrees phenomenon of gathered. 3. The same kind of negative and positive ion among the alcohol gel that have different carbon atoms. Because of dissolving difference between the ions and the solution, the ions influence forming speed of gel indirectly. To being stable of the gel, this phenomenon includes very great meaning. 4. Stable degree of the gel can influence its speed of aging. 5. The consistency of negative and positive ion in the aging solution of the gel can influence its stable and aging situation again directly.

本研究首先利用NaOH 將PAN 薄膜改質形成PAA 水膠膜表面，進一步與異丙胺鍵結形成NIPAAm 結構，以做為藥物傳輸的載體。反應所得之PNIPAAm 薄膜其溫度轉換點為34 °C 其pH 敏感性介於pH 5 至10 之間，實驗進行進一步於34 °C將PNIPAAm 薄膜浸入共軛亞麻油酸(CLA)中，取出後置入4 oC 二次水中，最後測試經改質接枝後PAN 薄膜於膽固醇、三酸甘油酯的吸收效果，並以化學冷光儀分析改質接枝後PAN 薄膜其抗氧化效率。結果顯示改質接枝之PNIPAAm 薄膜於包埋CLA 其對於血液中膽固醇及三酸甘油酯有明顯的吸收效率，此外對血液中的自由基也有明顯較未改質之PAN 薄膜穩定的趨勢。A thin layer of poly(N-isopropyl acrylamide) (pNIPAAm) was synthesized in situ on the surface of hydrolyzed polyacrylonitrile (PAN) membrane. This thin layer exhibited both pH response due to the poly(acrylic acid) moiety and temperature response due to the pNIPAAm moiety. The swelling behavior of the membranes was evaluated under various temperatures and pH. The curve of the swelling ratio for the PAN-NIPAAm showed a lower critical solution temperature (LCST). Then conjugated linoleic acid (CLA) was loaded into the pNIPAAm layer. The effects of CLA on the blood coagulation and oxidative stress were evaluated using human blood. The level of reactive oxygen species (ROS) was measured by chemiluminescence (CL) method to evaluate the oxidative stress. Furthermore, the removal of bacterial endotoxin (lipopolysaccharide, LPS) by CLA-loaded PAN-NIPAAm was measured with ELISA. The results show that the LCST swelling curve was at 37°C. In addition, the swelling ratio increased by 71% when the pH increased from 5 to 10. The concentration of LPS can be reduced by CLA-loaded PAN-NIPAAm 2.1 and 1.2 5 times of that by unmodified PAN and PAN-NIPAAm membranes, respectively. In addition, the level of ROS against CLA-loaded PAN-NIPAAm was reduced significantly than that against unmodified PAN and PAN-NIPAAm. Therefore CLA-loaded PAN-NIPAAm membrane could offer protection for patients against oxidative stress and could also inhibit LPS for clinical applications

In our experiment, the novel hydrothermal-galvanic couple method is used to produce nanostructured TiO2 thin film. Compared with the traditional hydrothermal method, whose process is conducted under high temperature and high pressure, the hydrothermal-galvanic couple method is a thermally and electrochemically driven process. The titanium atom is gradually oxidized on the surface driven by potential difference, and eventually become nanostructured TiO2. The advantages of the hydrothermal-galvanic couple method are numerous： they are simple, environment-friendly and energy-saving. Experimental parameters include time, concentration and types of solution. The hydrothermal method is used for comparison. By the cross-section and surface pictures of Field-emission scanning electron microscopy (FE-SEM), we can clearly observe that there is obvious change on the titanium surface, along with increased thickness and altered surface structure. The film of hydrothermal-galvanic couple method is thicker than that of hydrothermal method. Thickness increases with time and concentration as well. Both the hydrophile and decomposition of methylene blue examination indicate that the product on the surface contains photocatalyst-like feature.我們利用新穎水熱-化學電池法製備奈米級二氧化鈦薄膜。相較於一般傳統水熱法高溫高壓的製程，水熱-化學電池法結合了熱能與化學電能，讓鈦原子在電位差的驅動下於表面逐步氧化，最終形成奈米級二氧化鈦粒子，具備簡易、環保、省能的優點。實驗參數包括時間、濃度、溶液種類，並以水熱法作為對照組。由FE-SEM 橫截面圖及表面圖可清楚看到鈦的表面有明顯變化，膜厚增加、表面結構改變；以水熱-化學電池法所得的薄膜明顯較水熱法厚，而其厚度隨著濃度及時間的增加也有增加的趨勢，由試片親水性測試與亞甲基藍吸光度測試，皆顯示試片的表面產物具有類似光觸媒的性質。

洗滌用的界面活性劑分散系，沾在吸管可吹成泡，沾在框上則生成特定形體的薄膜；兩種不同現象，依據各自的性質原理，分別設計為可測量的裝置，研討表面張力與濃度間的關係，發現『兩泡連通法』，測量的靈敏度較佳，並且；薄膜總面積法則會因為框的形不同，測得薄膜總面積與表面張力大小的變化趨勢不一樣，而且數據誤差都比『兩泡連通法』大。市售的洗劑有肥皂與合成清潔劑兩類，它們溶於水的分散系，表面張力與濃度大小的變化趨勢正好相反；肥皂的濃度愈大表面張力愈大，合成清潔劑的濃度愈小表面張力愈大。這種現象發生的原因，和分散質是否含苯環結構無關。用數位照相輔助毛細管上升法，觀測『兩泡連通法』標準液的張力與濃度關係，數據顯示兩泡連通法與毛細管上升法，兩者比較各種分散系張力與濃度大小的結果相同。因此，用『兩泡連通法』比較不同分散系張力大小是簡便生動的可行方法。The dispersion of surfactant used for the purpose of cleasing,if dipped on a blowpipe,can be blown into bubbles and,if dipped on a frame,will form a certain shape of membrane.For these two different situations,according to the principle of their quality,measuringdevices can be respectively designed to explore the relation of surfact tension to its concentrate.It is discovered that,with the measuring device of the Two Bubble Connection Method,the sensitivity measured is better;and that,because of the difference of the structures of the frames,the total area of the membrane and the change trend of the degree of the surface tension will also be different and the probable error of the measured digits is always larger and it is not easy to find regularity. For the two categories of dispersion,soaps on the market and synthesis detergent,when they are measured with the Two Bubble Connection Method about the relationship of their surface tension to the degree of their concentrate,the trend of change is exactly opposite.The surface tension and concentrate of the category of soap are in right proportion whereas,for synthesis detergent used for cleaning bowls and plater and washing clothes,when its concentrate is less,its surface tension is more intense.Based on the findings of this study,the concentrate and the change trend of the degree of tension have no connection with whether there is benzene structure in the solvent. With the Capillary Rise Method assisted by digital photography to observe the relation of the tension of standard solution to the concentrate,we have found that they totally correspond to the result measured with the Two Bubble Connection Method designed in this study.