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1.
Recently, we developed a convenient microfluidic droplet generation device based on vacuum‐driven fluid manipulation with a piezoelectric diaphragm micropump. In the present study built on our previous work, we investigate the influence of settings applied to the piezoelectric pump, such as peak‐to‐peak drive voltage (Vp‐p) and wave frequency, on droplet generation characteristics. Stepwise adjustments to the drive voltage in ±10‐Vp‐p increments over the range of 200?250 Vp‐p during droplet creation revealed that the droplet generation rate could be reproducibly controlled at a specific drive voltage. The droplet generation rate switched within <0.5 s after the input of a new voltage. Although the droplet generation rate depended on the drive voltage, this setting had almost no influence on droplet size. The frequency over the selected range (50?60 Hz) did not markedly influence the droplet generation rate or droplet size. We show that the current fluid manipulation system can be conveniently used for both droplet generation and for rapid droplet reading, which is required in many microfluidic‐based applications. 相似文献
2.
D3h‐Symmetric Porphyrin‐Based Rigid Macrocyclic Ligands for Multicofacial Multinuclear Complexes in a One‐Nanometer‐Sized Cavity 下载免费PDF全文
Yohei Ohkoda Akane Asaishi Tomoya Namiki Tomoaki Hashimoto Midori Yamada Koichiro Shirai Yuta Katagami Dr. Tomoaki Sugaya Prof. Makoto Tadokoro Prof. Akiharu Satake 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(33):11745-11756
The one‐step synthesis of D3h‐symmetric cyclic porphyrin trimers 1 composed of three 2,2′‐[4,4′‐bis(methoxycarbonyl)]bipyridyl moieties and three porphyrinatozinc moieties was achieved from a nickel‐mediated reductive coupling of meso‐5,15‐bis(6‐chloro‐4‐methoxycarbonylpyrid‐2‐yl)porphyrinatozinc. Although cyclic trimers 1 were obtained as a mixture that included other cyclic and acyclic porphyrin oligomers, an extremely specific separation was observed only for cyclic trimers 1 when using columns of silica gel modified with pyrenylethyl, cyanopropyl, and other groups. Structural analysis of cyclic trimers 1 was carried out by means of NMR spectroscopy and X‐ray crystallography. Treatment of an η3‐allylpalladium complex with a cyclic trimer gave a tris(palladium) complex containing three η3‐allylpalladium groups inside the space, which indicated that the bipyridyl moieties inside the ring could work as bidentate metalloligands. 相似文献
3.
Cuixia Cui Yong Gao Dr. Jun Li Chao Yang Meng Liu Prof. Dr. Huile Jin Prof. Dr. Zhenhai Xia Prof. Dr. Liming Dai Prof. Dr. Yong Lei Prof. Dr. Jichang Wang Prof. Dr. Shun Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(20):8002-8007
Although tremendous efforts have been devoted to understanding the origin of boosted charge storage on heteroatom-doped carbons, none of the present studies has shown a whole landscape. Herein, by both experimental evidence and theoretical simulation, it is demonstrated that heteroatom doping not only results in a broadened operating voltage, but also successfully promotes the specific capacitance in aqueous supercapacitors. In particular, the electrolyte cations adsorbed on heteroatom-doped carbon can effectively inhibit hydrogen evolution reaction, a key step of water decomposition during the charging process, which broadens the voltage window of aqueous electrolytes even beyond the thermodynamic limit of water (1.23 V). Furthermore, the reduced adsorption energy of heteroatom-doped carbon consequently leads to more stored cations on the heteroatom-doped carbon surface, thus yielding a boosted charge storage performance. 相似文献
4.
采用Cundari和Stevens等推导的有效芯势对镧系金属一氢化物进行了理论计算,以探讨镧系金属元素与氢的相互作用。结果表明所有镧系金属一氢化物基态时理论上是稳定的,最稳定的是SmH,最不稳定的是DyH;键长计算结果显示,基态时镧系金属一招兵买马花物有独立王国 收缩现象发生;红外振动频率理论计算值与实验结果一致;成键轨道中,金属原子轨道的贡献主要是s轨道和d轨道:从CeH至ErH(GdH)例外)随着外层电子的增加s轨道成分逐渐增大d轨道成分逐渐减小;从TmH和LuH(包括GdH),成键轨道中金属原子轨道的贡献主要是d轨道,约为90%;约大多数镧系金属一氧化物的成键轨道中金属原子轨道f成分小于1%。 相似文献
5.
6.
钨(Ⅵ)的富集与检测方法研究进展 总被引:1,自引:0,他引:1
检测W(Ⅵ)对环境科学和生命科学研究具有积极意义。本文就1991年以来国内外W(Ⅵ)的富集手段,检测方法概况作一综述,其中包括,荧光光谱法,分光光度法,原子发射光谱法,质谱法,动力学方法,极普法,化学发光法,中子活化分析及联用技术等。 相似文献
7.
8.
Yasufumi Hashimoto 《Journal of Number Theory》2007,122(2):324-335
In [P. Sarnak, Class numbers of indefinite binary quadratic forms, J. Number Theory 15 (1982) 229-247], it was proved that the Selberg zeta function for SL2(Z) is expressed in terms of the fundamental units and the class numbers of the primitive indefinite binary quadratic forms. The aim of this paper is to obtain similar arithmetic expressions of the logarithmic derivatives of the Selberg zeta functions for congruence subgroups of SL2(Z). As applications, we study the Brun-Titchmarsh type prime geodesic theorem and the asymptotic formula of the sum of the class number. 相似文献
9.
XPS measurement revealed that the original state of TiO2 was changed to Ti2O3 and TiO by ion bombardment. TiO2 decreased and Ti2O3 increased at the initial stage. TiO increased at a later stage than Ti2O3. Each of them saturated after enough sputtering time.A formulation was proposed in order to explain the change of XPS spectra for oxides as a function of ion sputtering time. This formulation was based on reaction equations that contain two reduction processes (from TiO2 to Ti2O3 and from Ti2O3 to TiO), and sputtering effects. Using four fitting parameters (two reduction coefficients, sputtering yield and information depth), the present formula was fitted to the experimental results. The fitting results agree satisfactorily with the experimental results. The calculation shows that the reduction coefficient from TiO2 to Ti2O3 is about ten times larger than that from Ti2O3 to TiO. This calculation predicts that surface composition of an oxide that is changed by ion bombardment will reach a different value depending on its bulk composition. Moreover, the present formulation can determine the chemical states of compounds changed by ion bombardment. 相似文献
10.
Mat Rasol Awang Hassan Hamdani Mutaat Mohd. Shukri Mahmud Wan Badrin Wan Husain Tajuddin Osman Khomsaton Abu Bakar Asmahwati Kassim Zal U''yun Wan Mahmud Ishak ManafTamikazu Kume Shoji Hashimoto 《Radiation Physics and Chemistry》1993,42(4-6):611-616
In solid state fermentation, Pleurotus sajor-caju has been found to be able to degrade at least 30% oil palm empty Fruit Bunch (EFB) fibre leaving 70 % useful materials. Conditions under which fermentation carried out were investigated. It was found that, in the temperature range between 25– 28 °C, relative ph between 6–8, moisture between 60–70 % and medium composition of CaCO3: rice bran 2 %: 5 % were the optimum conditions. The results showed in fermented products that, there were substantial reduction in cellulosic component such as Crude Fiber (CF, 18 %); Acid Detergent Fibre (ADF, 45 %), Neutral Detergent Fibre (NDF, 61 %) and Acid Detergent Lignin (ADL, 14 %). However, Crude Protein (CP, 10%) increased resulted from single cell protein enrichment of mycelial microbial mass. The mass reductions of substrate in fermentation process corresponds to the CO2 released during fermentation. Hence, attributable to the decreased in content of CF, ADF, NDF, and ADL. The digestibility study has also been carried out to determine the useful level of this product to ruminant. Aflatoxin content was detected low in both the initial substrates and products. Based on nutritional value and low content of aflatoxin, the product is useful as a source of roughage to ruminant. 相似文献