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Lingling Feng,Hui Li,Jingmei Jiao,Ding Li,Li Zhou,Jian Wan,Yangsheng Li 한국식물학회 2009 Journal of Plant Biology Vol.52 No.5
Rice cultivar zhonghua11 (Oryza sativa L. ssp. japonica) plants with decreased sedoheptulose-1, 7- bisphosphatase (SBPase) were obtained by transformation with the rice SBPase antisense gene under the control of the maize ubiquitin promoter. The transgenic and wild-type plants were grown at different nitrogen levels (0.1, 1, or 10 mM NH4NO3). Growth rates of the seedlings were measured by the changes in dry weight, and the photosynthetic carbon reduction activities and the potential efficiency of photosystem II were measured by CO2 assimilation and Fv/Fm, respectively. At low N, there are strong effects on growth and photosynthesis when SBPase was reduced by genetic manipulation. Decreased SBPase activity led to a decrease in the amount of starch accumulated in the leaves at all N levels and the decrease was much more prominent in low N than that in high N, but the starch allocation between shoot and root was unaltered. The analysis of chlorophyll fluorescence and SBPase activity indicated that the decrease of growth and photosynthesis at different N levels were not related to the function of PSII but to the activity of SBPase. Western blot analysis showed the content of SBPase in thylakoid membranes was much more than in the stroma fractions in transgenic plants at low N. Results suggested that low N in addition to a 34% decrease in SBPase activity is sufficient to diminish photosynthesis and limit biomass production. Decreased SBPase activity may reduce the N use efficiency of photosynthesis and growth and alter biomass allocation.
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Towards Attacks and Defenses of Anonymous Communication Systems
Tianbo Lu,Puxin Yao1,Lingling Zhao,Yang Li,Feng Xie,Yamei Xia 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1
Anonymous communication system has been hot topic in the field of information security, and attack techniques against anonymous systems are endless. This paper first classifies and summarizes the study of attacks against anonymous communication system in recent years, then analyzes the trend of the research on different attack technologies; secondly, it provides a comparative analysis of defense capability the mainstream anonymous communication system to the various attacks; Finally, combining the advantages and disadvantages of different systems, the authors propose an improved node selection and router forwarding algorithms for anonymous communication systems, and design an architecture of anonymous communications software based on the algorithm.
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Mao, Lingling,Tsai, Hsinhan,Nie, Wanyi,Ma, Lin,Im, Jino,Stoumpos, Constantinos C.,Malliakas, Christos D.,Hao, Feng,Wasielewski, Michael R.,Mohite, Aditya D.,Kanatzidis, Mercouri G. American Chemical Society 2016 Chemistry of materials Vol.28 No.21
<P>Hybrid halide perovskites are emerging semiconducting materials, with a diverse set of remarkable optoelectronic properties. Besides the widely studied three-dimensional (3D) perovskites, two-dimensional (2D) perovskites show significant potential as photovoltaic (PV) active layers while exhibiting high moisture resistance. Here, we report two series of new 2D halide perovskite solid solutions: (HA)Pb1-xSnxI4 and (BZA)(2)Pb1-xSnxI4 (x = 1, 0.75, 0.5, 0.25, 0), where HA stands for the organic spacer histammonium and BZA stands for benzylammonium cations. These compounds are assembled by corner-sharing octahedral [MI6](4-) units stabilizing single-layered, anionic, inorganic perovskite sheets with organic cations filled in between. The optical band gaps are heavily affected by the M-I-M perovksite angles with the band gap steadily decreasing when the angle approaches 180 degrees, ranging from 2.18 eV for (BZA)(2)PbI4 to 2.05 eV for (HA)PbI4. We find an anomalous trend in electronic band gap in the mixed compositions (HA)Pb1-xSnxI4 and (BZA)(2)Pb1-xSnxI4. When Sn substitutes for Pb to form a solid solution, the band gap further decreases to 1.67 eV for (HA)SnI4. The minimum band gap is at x = 0.75 at 1.74 eV. For BZA, the irregular trend is more intense, as all the intermediate compounds (BZA)(2)Pb(1-x)SnxI(4) (x = 0.75, 0.5, 0.25) have even slightly lower band gaps than (BZA)(2)SnI4 (1.89 eV). DFT calculations confirm the pure Pb and Sn compounds are direct band gap semiconductors. Relatively shorter photoluminescence (PL) lifetime in (BZA)2PbI4 than (HA)PbI4 is observed, suggesting faster recombination rates of the carriers. Solution deposited thin films of (HA)PbI4 and (BZA)2PbI4 show drastically different orientations with (HA)PbI4 displaying a perpendicular rather than parallel growth orientation with respect to the substrate, which is more favorable for PV devices. The higher potential in PV applications of the HA system is indicated by device performance, as the champion air stable planar device with the structure ITO/PEDOT:PSS/2D-perovskite/PCBM/Al of (HA)PbI4 achieves a preliminary power conversion efficiency (PCE) of 1.13%, featuring an open-circuit voltage (VOC) of 0.91 V.</P>
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Dewen Kong,Lingling Wang,Feng Fan,Xudong Zhi 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.2
The friction pendulum bearing (FPB) has been widely studied as an effective dry friction sliding isolation device, due to its self-limit and self-reset capability. The refinement finite element models of FPB were applied to column supporting single-layer reticulated domes. The seismic performances of these structures with FPBs were systematically analyzed by finite element software LS-DYNA. Numerical results illustrate that the optimal friction coefficient of FPB increases with increasing earthquake intensity and the optimal range of friction coefficient locates between 0.025 and 0.15. The seismic effects of singlelayer reticulated domes with FPBs are strengthened with the increase of curvature radius, while isolation effect of FPBs has no obvious change as the curvature radius exceeds 1.5 m. Additionally, the parameter selection principles of friction pendulum bearings for column supporting single-layer reticulated domes are given by means of investigating the force of the slider of FPBs and dynamic analysis of single-layer reticulated domes with FPBs.
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Soybean hull functionalized by phosphoric acid for sorption of copper from aqueous solution
Renmin Gong,Lingling Liu,Min Feng,Jiajing Zhao,Xingyan Liu,Shoujun Ni 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.2
One kind of potentially biodegradable cationic sorbent, which bears hydroxyl groups of phosphoric acid as its functional groups, with high sorption capacity of copper was prepared by thermochemically esterifying phosphoric acid (PA) onto soybean hull. Sorption of Cu(Ⅱ) from aqueous solution onto modified soybean hull (MSH) was investigated in a batch system. The sorption experiments were performed under various conditions such as different initial pH, copper concentration, MSH dosage, and contact time. The maximum copper sorption was obtained when initial solution pH≥3.5. The isothermal data of copper sorption fitted the Langmuir model and the sorption process could be described by the pseudo-first-order kinetic model. The maximum sorption capacity (Qm) of MSH for Cu(Ⅱ) was 31.55 mg/g. For 100 mg/l of Cu(Ⅱ) solution, a sorption ratio above 91% could be achieved by 5.0 g/l of MSH. The equilibrium of Cu(Ⅱ) sorption was reached within 50 min. The foreign cation and chelator in Cu(Ⅱ) solution caused decline of Cu(Ⅱ) sorption.
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