Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Xiang, J." wg kryterium: Autor


Wyświetlanie 1-7 z 7
Tytuł:
Improvements in timber production of Chinese fir (Cunninghamia lanceolata) per unit forest area in China via tree breeding: Status and challenges
Autorzy:
Zhou, B.
Peng, D.
Zhao, Q.
Yangnan, S.
Yang, S.
Yang, F.
Qu, G.
Tang, W.
Ou, J.
Xiang, W.
Xiang, J.
Deng, X.
Powiązania:
https://bibliotekanauki.pl/articles/2077649.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Cunninghamia lanceolata
genetic improvement
timber volumes per unit forest area
wood properties
proposals
recommendations
Opis:
Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] is a fast-growing tree species that is widely planted for timber production in southern China. Many high-quality breeding systems for Chinese fir have been developed using genetic methods. Here, we systematically review progress in increasing Chinese fir timber volumes per unit forest area in China, using genetic methods. We comprehensively assess the objec- tives, strategies, and primary accomplishments of the first to fourth generations of a Chinese fir breeding program. Furthermore, we propose a genetic improvement program and protocol for Chinese fir, and out- line several recommendations with respect to the main challenges associated with using genetic methods to increase timber yields. Finally, we present a series of proposals to increase Chinese fir timber production in China. This review offers insight into genetic improvements that have increased timber volumes of Chi- nese fir over four generations of breeding, and provides direction for future genetic improvements to wood properties.
Źródło:
Dendrobiology; 2020, 83; 43-51
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applications of Density Matrix Renormalization Group to Problems in Magnetism
Autorzy:
Gehring, G. A.
Bursill, R. J.
Xiang, T.
Powiązania:
https://bibliotekanauki.pl/articles/1953163.pdf
Data publikacji:
1997-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.60.-i
11.10.Gh
Opis:
The application of real space renormalization group methods to quantum lattice models has become a topic of great interest following the development of the density matrix renormalization group by White. This method has been used to find the ground and low-lying excited state energies and wave functions of quantum spin models in which the form of the ground state is not clear, for instance because the interactions are frustrated. It has also been applied to fermion problems where the tendency for localization due to the strong Coulomb repulsion is opposed by the lowering of the kinetic energy which occurs as a result of electron transfer. The approach is particularly suitable for one-, or quasi-one-dimensional problems. The method involves truncating the Hilbert space in a systematic and optimised manner. Results for the ground state energy are thus variational bounds. The results for low-lying energies and correlation functions for one-dimensional systems have unprecedented accuracy and the method has become the method of choice for solving one-dimensional quantum spin problems. We review the method and results obtained for the spin-1 chain with biquadratic exchange as well as the spin-1/2 model with competing nearest and next nearest neighbour exchange will be described. More recently, the density matrix renormalization group has been applied to reformulate the coupling constant renormalization group approach which is appropriate for the study of critical properties. This approach has been applied to the anisotropic spin-1/2 Heisenberg chain. Finally, we discuss recent work which has borne promising applications in two dimensions - the Ising model and the two-dimensional Hubbard model.
Źródło:
Acta Physica Polonica A; 1997, 91, 1; 105-119
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical generation of ultra-wideband signals with a reconfigurable spectral notch-band
Autorzy:
Xiang, P.
Chen, Y.
Chen, D.
Zhao, J.
Powiązania:
https://bibliotekanauki.pl/articles/174353.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultra-wideband (UWB)
ultra-wideband over fiber
notch-band
interference avoidance
Opis:
A novel method for optical generation of ultra-wideband signals with a reconfigurable spectral notch-band is proposed. In the proposed system, ultra-wideband signals are generated in the optical domain and an optical tunable delay line is deployed to introduce a notch-band to the spectral profile of the generated ultra-wideband signals, which can effectively avoid the signal interference between ultra-wideband signals and pre-planned narrowband wireless signals used in wireless local area networks (WLAN). A theoretical model describing the proposed system is derived; the optical generation and fiber transmission of ultra-wideband signals with a reconfigurable notch-band are demonstrated via computer simulations.
Źródło:
Optica Applicata; 2014, 44, 3; 411-419
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detonation Performance of Four Groups of Aluminized Explosives
Autorzy:
Xiang, D.-L.
Rong, J.-L.
He, X.
Powiązania:
https://bibliotekanauki.pl/articles/358148.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
aluminized explosive
detonation pressure
detonation velocity
heat of detonation
KHT code
Opis:
The detonation performances of TNT-, RDX-, HMX-, and RDX/AP-based aluminized explosives were examined through detonation experiments. The detonation pressure, velocity, and heat of detonation of the four groups of aluminized explosives were measured. Reliability verification was conducted for the experimental results and for those calculated with an empirical formula and the KHT code. The test results on detonation pressures and velocities were in good agreement with the predicted values when aluminum (Al) particles were considered inert. The experimental heat of detonation values exhibited good consistency with the predicted values when a certain proportion of Al particles was active. Ammonium perchlorate (AP) can effectively reduce the detonation pressure and improve the heat of detonation for the RDX/AP-based aluminized explosive. A comparison of the current test results and literature data shows that errors may exist in early test data. The test data presented in this study allow for an improved understanding of the detonation performance of the four groups of aluminized explosives.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 903-915
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Underwater Explosion Performance of RDX/AP-based Aluminized Explosives
Autorzy:
Xiang, D.
Rong, J.
He, X.
Feng, Z.
Powiązania:
https://bibliotekanauki.pl/articles/358616.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
UNDEX
RDX/AP-based aluminized explosives
detonation
shock wave
Al/O ratio
Opis:
To understand the underwater explosion (UNDEX) performance of RDX/AP-based aluminized explosives, six formulations of the explosives were prepared, with Al content varying from 30% to 55% and ammonium perchlorate (AP) content from 45% to 20%. A series of UNDEX tests that used a 1 kg cylindrical charge was conducted underwater at a depth of 4.7 m. The pressure histories of the shock wave produced at different positions and the bubble periods were measured. The coefficients of the similarity law equation for the shock wave parameters were fitted with experimental data. The effect of the aluminum/oxygen (Al/O) ratio on the performance of the energy output structure for RDX/AP-based aluminized explosives is discussed. The bubble motion during UNDEX was simulated using MSC.DYTRAN software, and the radius-time curves of the bubbles were determined. The results show that AP influences the detonation reaction mechanism of RDX/AP-based aluminized explosives, which causes different UNDEX performances. The bubble energy of the RDX/AP-based aluminized explosive was higher than that of RDX-based and HMX-based aluminized explosives.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 1; 60-76
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generation of chirped microwave signal with any central frequency based on a nonuniformly spaced finite impulse response filter
Autorzy:
Chen, D.
Wang, R.
Pu, T.
Xiang, P.
Fang, T.
Zheng, J.
Xiong, J.
Powiązania:
https://bibliotekanauki.pl/articles/174334.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
microwave photonics
microwave photonic filter
chirped microwave signal
dual drive Mach–Zehnder modulator
Opis:
A novel optical approach to generating a chirped microwave signal by using a nonuniformly spaced finite impulse response filter is proposed and demonstrated. In this scheme, a narrowband Gaussian pulse is used as the original chirped-free signal, which is easy to be acquired. To eliminate the need of a wideband chirped-free signal, a mixer and a radio frequency signal are used to up-convert the spectrum of the original Gaussian signal. Therefore, the required frequency response can be calculated and reconstructed by a finite impulse response filter with nonuniformly spaced taps. Besides, a dual drive Mach–Zehnder modulator is used to realize single sideband modulation of the chirpedfree signal. Thus, the transfer function induced by the fiber dispersion is eliminated and the chirped microwave signal with any central frequency can be generated. In this paper, a design example of a filter with a central frequency of 10GHz is provided, and generation of the target chirped microwave signal is also demonstrated by numerical simulations.
Źródło:
Optica Applicata; 2016, 46, 3; 399-408
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical and Scintillation Properties of $Bi_{4}(Ge_{x}S_{1-x})_{3}O_{12}$ Single Crystal
Autorzy:
Xiao, X.
Xu, J.
Lu, B.
Cai, W.
Zhang, Y.
Shen, H.
Yang, B.
Xiang, W.
Powiązania:
https://bibliotekanauki.pl/articles/1399369.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.10.Fq
61.05.C-
78.20.Ci
78.70.Ps
Opis:
The solid solution crystals, $Bi_{4}(Ge_{x}Si_{1-x})_{3}O_{12}$ (BGSO) with x=0, 0.05, and 0.15, have been grown by the modified vertical Bridgman method. The as-grown crystals show 80% of transmittance with an absorption edge of 285 nm. The relative light yields of BGSO crystals are found to be 7.2%, 6.3%, and 4.2% of CsI(Tl) crystal for x=0, 0.05, and 0.15, respectively. The energy resolutions of these crystals are 18.9%, 21.3%, and 24.7%, respectively, with PMT for 662 keV gamma rays at room temperature when exposed to $\text{}^{137}Cs$ γ -ray. The scintillation performance of BGSO crystals clearly deteriorates with the increase of Ge content. However, the appropriate number of germanium ions doped to BSO crystal can improve its crystallization behavior and effectively restrain component segregation. It is expected that large size crystals of BGSO will be grown and applied to the dual readout calorimeter in the nearest future.
Źródło:
Acta Physica Polonica A; 2015, 127, 3; 854-858
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies