536 research outputs found
Arboridia tridentata Song & Li
No full text<i>Arboridia tridentata</i> Song & Li <p>(Fig. 27)</p> <p> <i>Arboridia tridentata</i> Song & Li, 2013: 240</p> <p> <b>Specimens examined.</b> holotype male, CHINA, Yunnan, Lanping, 14-VIII-2006, coll. Q.Z. Song; 1 paratype male, CHINA, Yunnan, Pianma, at light, 14-VIII-2006, coll. Q.Z. Song (GUGC). <b>Distribution.</b> China (Yunnan).</p>Published as part of <i>Song, Yue-Hua & Li, Zi-Zhong, 2015, Review of the genus Arboridia Zachvatkin (Hemiptera: Cicadellidae: Typhlocybinae), with description of two new species from China, pp. 584-592 in Zootaxa 3990 (4)</i> on page 591, DOI: 10.11646/zootaxa.3990.4.7, <a href="http://zenodo.org/record/238915">http://zenodo.org/record/238915</a>
Arboridia paraprocessa Song & Li
No full textArboridia paraprocessa Song & Li (Fig. 23) Arboridia paraprocessa Song & Li, 2013: 239 Specimens examined. holotype male, 2 paratype males, CHINA, Henan, Mt. Wangwu, 21 -VIII- 2008, coll. Q.Z. Song; 5 paratype males, 3 paratype females, CHINA, Guizhou, Mayanghe National Nature Reserve, at light, 28 - IX- 2007, coll. Y.H. Song (GUGC). Distribution. China (Henan, Guizhou).Published as part of Song, Yue-Hua & Li, Zi-Zhong, 2015, Review of the genus Arboridia Zachvatkin (Hemiptera: Cicadellidae: Typhlocybinae), with description of two new species from China, pp. 584-592 in Zootaxa 3990 (4) on page 591, DOI: 10.11646/zootaxa.3990.4.7, http://zenodo.org/record/23891
Arboridia reniformis Song & Li
No full text<i>Arboridia reniformis</i> Song & Li <p>(Fig. 24)</p> <p> <i>Arboridia reniformis</i> Song & Li, 2013: 234</p> <p> <b>Specimens examined.</b> holotype male, CHINA, Yunnan Prov., Lanping, 08-VIII-2006, coll. Q.Z. Song (GUGC). <b>Distribution.</b> China (Yunnan).</p>Published as part of <i>Song, Yue-Hua & Li, Zi-Zhong, 2015, Review of the genus Arboridia Zachvatkin (Hemiptera: Cicadellidae: Typhlocybinae), with description of two new species from China, pp. 584-592 in Zootaxa 3990 (4)</i> on page 591, DOI: 10.11646/zootaxa.3990.4.7, <a href="http://zenodo.org/record/238915">http://zenodo.org/record/238915</a>
Influence of Zr alloying on the mechanical properties, thermal stability and oxidation resistance of Cr-Al-N coatings
No full textCr–Al–N coatings with Zr alloying (Zr contents from 0 to 29.5 at.%) were deposited by d.c. reactive magnetron sputtering. The chemical composition and the morphology of as-deposited coatings were characterized, and the phase structure, mechanical properties and wear resistance of the coatings before and after thermal annealing were analyzed and evaluated. With the increase of Zr content, both Cr and N contents decrease whereas Al shows a growing trend. Low Zr (<26.9 at.%) coatings are stoichiometric and present a fcc NaCl-type B1 structure with columnar morphology, while high Zr (?26.9 at.%) coatings are in N deficiency and have low crystallinity degree. The alloying of low contents of Zr improves the coating hardness and H/E ratio; however, for low ordered coatings these properties decrease significantly. After thermal annealing, fcc structure is kept in low Zr films whereas the crystalline degree is improved in the high Zr ones and their mechanical properties were slightly improved. Two coatings were selected for further testing, representatives of low (CrAlZr5N) and high (CrAlZr27N) Zr contents. The onset oxidation temperature is ?900 °C and 600 °C for CrAlZr5N and CrAlZr27N coatings, respectively. Mainly Cr2O3 is formed on low Zr coatings whereas mixed oxides of ZrO2 and Cr2O3 are detected on CrAlZr27N sample after thermal exposure. In all tribological tests, low Zr coating presents lower wear rate than the CrAlZr27N coating. In general, the addition of very high Zr contents (>20 at.%) with N deficiency markedly weakens the mechanical properties and the oxidation resistance of Cr–Al–Zr–N coatings
Influence of trimethylsilane flow on the microstructure, mechanical and tribological properties of CrSiCN coatings in water lubrication
No full textCrSiCN coatings with different silicon and carbon contents were deposited on silicon wafers and 316L stainless steels using unbalanced magnetron sputtering via adjusting trimethylsilane (TMS) flow, and their microstructure and mechanical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectrons spectroscopy (XPS) and nano-indenter, respectively. The tribological properties of CrSiCN coatings sliding against SiC balls in water were investigated using ball-on-disk tribometer. The results showed that the CrSiCN coatings had fine composite microstructure consisting of nanocrystallites of Cr(C, N) crystal and amorphous phases such as a-Si3N4 and a-C(a-CNx). The typical columnar structures changed from fine cluster to coarse ones when the Si content was beyond 3.4 at.%. With an increase in the TMS flow, the hardness and Young's modulus of Corsican coatings all first increased, and then rapidly decreased, but the compressive stress in the coatings varied in the range of 2.8–4.8 GPa. When the TMS flow was 10 sccm, the CrSiCN coatings exhibited the highest hardness of 21.3 GPa and the lowest friction coefficient (0.11) and wear rate (8.4 × 10-8 mm3/N m). But when the TMS flow was beyond 15 sccm, the tribological properties of CrSiCN coatings in water became poor
COMPUTATION OF DIVERGING SUMS BASED ON A FINITE NUMBER OF TERMS
No full textWe propose a numerical method that permits us to compute the sum of a diverging series from only the first N terms by generalizing the traditional Borel technique. The method is rather robust and can be used to recover the ground state energy from the diverging perturbation theory for quantum field theoretical systems that are spatially constrained. Surprisingly, even the corresponding eigenvectors can be generated despite the intrinsic non-perturbative nature of bound state problems. [1-3] This work has been supported by the NSF, NSFC and Research Corporation. [1] C. Lisowski, S. Norris, R. Pelphrey, E. Stefanovich, Q. Su, R. Grobe, Ann. Phys. 373, 456 (2016). [2] Q.Z. Lv, S. Norris, R. Pelphrey, Q. Su, R. Grobe, Comp. Phys. Comm. 219, 1 (2017). [3] Q.Z. Lv, S. Dong, C. Lisowski, R. Pelphrey, Y.T. Li, Q. Su and R. Grobe, Phys. Rev. A 97, 053416 (2018)
Climatic changes indicated by trace elements in the Chagelebulu stratigraphic section, Badain Jaran Desert, China, since 150 kyr BP
No full textOPTIMAL SUPERCRITICAL POTENTIALS FOR THE ELECTRON-POSITRON PAIR-CREATION RATE
No full textWe examine the steady state electron-positron pair creation rate for supercritical electric potentials with arbitrary spatial dependence. The numerical optimization algorithms predict that the set of external fields that can maximize the production rate for positrons with a given energy take non-trivial spatial shapes. We explain the underlying physical mechanisms based on a remarkably simple analytical model that exploits resonances among the negative energy eigenstates of the Dirac Hamiltonian. The results are rather encouraging from an experimental perspective as they suggest that one does not require unachievable infinitely large fields to maximize the possible pair creation yield. In fact, in many cases smaller electric fields lead surprisingly to larger yields for given energy ranges. This work [1-7] has been supported by the NSF, NSFC, Research Corporation, and the China Scholarship Council program. [1] Q.Z. Lv, J. Unger, Y.T. Li, Q. Su and R. Grobe, Euro. Phys. Lett. 116, 40003 (2016). [2] Q.Z. Lv, J. Unger, Y.T. Li, Q. Su and R. Grobe, Phys. Rev. A 95, 023416 (2017). [3] N.D. Christensen, J. Unger, S. Pinto, Q. Su and R. Grobe, Ann. Phys. 389, 239 (2018). [4] S. Dong, R. Flores, J. Unger, Q. Su and R. Grobe, Phys. Rev. E 98, 012221 (2018). [5] J. Unger, S. Dong, R. Flores, Q. Su and R. Grobe, Laser Phys. (in press). [6] J. Unger, S. Dong, R. Flores, Q. Su and R. Grobe, Phys. Rev. A (in press). [7] J. Unger, S. Dong, Q. Su and R. Grobe, Phys. Rev. A (submitted)
INFINITE DIMENSIONAL OPTIMIZATION APPLIED TO PAIR CREATION FROM THE VACUUM
No full textWe examine the electron-positron pair creation process from the vacuum for general time-dependent external fields. By applying the framework of optimal control theory, we determine those temporal pulse shapes, that can maximize the final number of created positrons for a given set of momenta. In the perturbative regime of sufficiently small pulse energies or short interaction times, we obtain analytical forms that match the computational data of the optimal fields for the chosen sets of momenta. [1-7] This work has been supported by the NSF, NSFC and Research Corporation. [1] Q.Z. Lv, J. Unger, Y.T. Li, Q. Su and R. Grobe, Euro. Phys. Lett. 116, 40003 (2016). [2] Q.Z. Lv, J. Unger, Y.T. Li, Q. Su and R. Grobe, Phys. Rev. A 95, 023416 (2017). [3] N.D. Christensen, J. Unger, S. Pinto, Q. Su and R. Grobe, Ann. Phys. 389, 239 (2018). [4] S. Dong, R. Flores, J. Unger, Q. Su and R. Grobe, Phys. Rev. E 98, 012221 (2018). [5] J. Unger, S. Dong, R. Flores, Q. Su and R. Grobe, Laser Phys. (in press). [6] J. Unger, S. Dong, R. Flores, Q. Su and R. Grobe, Phys. Rev. A (in press). [7] J. Unger, S. Dong, Q. Su and R. Grobe, Phys. Rev. A (submitted)
Heat capacities and thermodynamic properties of Co(AIP)(BPY)(0.5)center dot H2O (n)center dot 2nH(2)O
No full textHeat capacities and thermodynamic properties of Co(AIP)(BPY)(0.5)center dot H2O (n)center dot 2nH(2)
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