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991.
The thermal transition behavior of poly(bis(p-fluorophenoxy)phosphazene) was studied as a representative aryloxy-substituted poly(organophosphazene) using X-ray diffraction, differential thermal analysis and density measurements. The crystal structure of-form contained in as-cast film had marked paracrystalline disorder. The crystal phase transformed into the mesophase atT(1) (110 140 °C). The structure of the-form observed in the mesophase was a representative hexagonal-packing of macromolecular chains which rotate around the chain axes. When the mesophase was cooled to room temperature, a more ordered crystal phase of the-form could appear. The most ordered crystal structure of the-form has a monoclinic unit cell with the following lattice parameters: a=18.9, b=13.2, c=4.90 Å, and=77°. The chain conformation is nearly planar cis-trans, which has been observed commonly in poly(organophosphazenes). The macroscopic deformation of the film sample was also examined, taking into account the microscopic deformation of the lamellar crystal due to the crystal-mesophase transition. 相似文献
992.
关于圆内亚纯函数幅角分布的一个结果 总被引:2,自引:0,他引:2
王凤竹 《纯粹数学与应用数学》1995,11(1):121-126
本文得到如下结果:若f(z)为|z|<1内ρ(0<ρ<∞)级亚纯函数,则存在点e^i∞(0≤θ<2π),使得对于任意ε>0,任意正整数K以及|z|<1内任意两个级小于ρ的亚纯函数a(z),b(z) 相似文献
993.
Let be a lattice of finite height. The correspondence between closure operators and ∧-subsemilattices is well known. Here we investigate what type of number-valued function is induces a ∧-subsemilattice ; and if so, what kind of . Conversely, what type of function is induced by what type of (or cl). Several results known for matroids, greedoids, or semimodular lattices are generalized. 相似文献
994.
S. O. Juriaans I. B. S. Passi Dipendra Prasad 《Proceedings of the American Mathematical Society》2005,133(2):415-423
In this paper we study the groups whose integral group rings have hyperbolic unit groups . We classify completely the torsion subgroups of and the polycyclic-by-finite subgroups of the group . Finally, we classify the groups for which the boundary of has dimension zero.
995.
Toshisuke Maruyama 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2007,83(7):181-191
To estimate the amount of evapotranspiration in a river basin, the “short period water balance method” was formulated. Then, by introducing the “complementary relationship method,” the amount of evapotranspiration was estimated seasonally, and with reasonable accuracy, for both small and large areas. Moreover, to accurately estimate river discharge in the low water season, the “weighted statistical unit hydrograph method” was proposed and a procedure for the calculation of the unit hydrograph was developed. Also, a new model, based on the “equivalent roughness method,” was successfully developed for the estimation of flood runoff from newly reclaimed farmlands. Based on the results of this research, a “composite reservoir model” was formulated to analyze the repeated use of irrigation water in large spatial areas. The application of this model to a number of watershed areas provided useful information with regard to the realities of water demand-supply systems in watersheds predominately dedicated to paddy fields, in Japan. 相似文献
996.
Thanikan Sukaram Petcharat Sirisakwisut Jitnapa Sirirak Duangjai Nacapricha 《International journal of environmental analytical chemistry》2018,98(10):907-920
Crude aqueous extract from the orchid ‘Dendrobium Sonia earsakul’ was utilised as a natural product reagent in flow injection analysis (FIA) incorporating a gas diffusion unit (GD) for the determination of ammonia nitrogen. Sample solution was injected into a NaOH donor stream to generate ammonia gas (NH3). In the GD unit, NH3 diffused across a PTFE gas-permeable membrane into the acceptor stream of the orchid extract. As the result, the aqueous orchid reagent became more alkaline and its colour changed from purple to green. The change in the colour of orchid acceptor correlated with the concentration of ammonia nitrogen in the sample and its absorbance monitored by a spectrophotometer at 600 nm. Ammonia nitrogen in chemical fertiliser samples and wastewater samples from agricultural fields were determined and reported as %N (w/w) and mg N L?1, respectively. For chemical fertilisers which contained high content of ammonia nitrogen, a flow rate of 1.0 mL min?1 and injection volume of 100 µL were used with a linear range of 5–40 mmol L?1 and detection limit of 2.12 mmol L?1. However, a higher sensitivity was required for wastewater samples having low ammonia nitrogen content. The flow rate was reduced to 0.3 mL min?1 and the injection volume increased to 1000 µL. As a result, detection limit of 0.76 mmol L?1 was achieved with linear range of 1–5 mmol L?1. The results of our method agreed well with that using the OPA method employing fluorescence detection. 相似文献
997.
Yuuki Komoto Yasuomi Yamazaki Dr. Yusuke Tamaki Madoka Iwane Prof.Dr. Tomoaki Nishino Prof. Dr. Osamu Ishitani Prof. Dr. Manabu Kiguchi Dr. Shintaro Fujii 《化学:亚洲杂志》2018,13(10):1297-1301
Single‐molecule junctions are of particular interest in molecular electronics. To realize molecular electronic devices, it is crucial that functional single‐molecule junctions are connected to each other by using joint units on the atomic scale. However, good joint units have not been reported because controlling the charge transport directions through the junctions is not trivial. Here, we report a joint unit that controls and changes the charge transport directions through the junctions, by using a ruthenium–tris‐bipyridine (RuBpy) complex. The RuBpy single‐molecule junction was fabricated with scanning tunnelling microscopy‐based break junction techniques. The RuBpy single‐molecule junction showed two distinct high and low conductance states. The two states were characterized by the conductance measurement, the correlation analysis, and the comparative experiment of bipyridine (Bpy), which is the ligand unit of RuBpy. We demonstrate that the Ru complex has multiple charge transport paths, where the charge is carried vertically and horizontally through the complex depending on the path. 相似文献
998.
Jinying Liu Feng Yuan Xiaoyu Ma Dang‐i Y. Auphedeous Changli Zhao Chuntai Liu Changyu Shen Prof. Chuanliang Feng 《Angewandte Chemie (International ed. in English)》2018,57(22):6475-6479
Although helical nanofibrous structures have great influence on cell adhesion, the role played by chiral molecules in these structures on cells behavior has usually been ignored. The chirality of helical nanofibers is inverted by the odd–even effect of methylene units from homochiral l ‐phenylalanine derivative during assembly. An increase in cell adhesion on left‐handed nanofibers and weak influence of cell behaviors on right‐handed nanofibers are observed, even though both were derived from l ‐phenylalanine derivatives. Weak and negative influences on cell behavior was also observed for left‐ and right‐handed nanofibers derived from d ‐phenylalanine, respectively. The effect on cell adhesion of single chiral molecules and helical nanofibers may be mutually offset. 相似文献
999.
ZHUANG Bo-Tao PAN Bing-Hua HUANG Liang-Ren HE Ling-Jie CHEN Peng-Cheng SUN Hao-Feng PAN Guo-Hua 《结构化学》1998,(1)
1INTRODUCTIONThechemistryofMo--S,Fe--SandMo-Fe--Sclustercomplexeshasincreasinglyinterestedchemistsandbioinorganicchemistssincetheexistenceofmetal-sulfurbondinginmetalenzymes,especiallytheFe--Mo--Sclusterastheactivecenterinni-trogenase,wasdiscovered.Recently,aninterestingFe--SstructuralunitFeZSZ(CO),t'3,hasbeeningoodglancesofpeopleandthechemistryofthemetalclustercompoundscontainingFe,S,(CO),-unitshasbeenfocusedbygreatattentionbecausei)FeZSZ(CO)6isanironsourceforthesynthesisofMo-… 相似文献
1000.
Two series of new liquid crystailine polymers with T-shaped two-dimensional mesogenicunits were synthesized by low temperature solution polycondensations of 4-substituted N-2, 5- dihydroxybenzylidene aniline monomers with different diacyl dichlorides. The polymerswere found to be nematic and shown liquid crystailine behavior. The melting temperatureT_m and the clearing temperature T_i of the polymers change regularly with varying of themonomer structures. 相似文献