| 2501. |
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| 2502. |
- Wang, Jinpeng, et al.
(författare)
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Metabolic engineering for increased lipid accumulation in Yarrowia lipolytica – A Review
- 2020
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 313
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Forskningsöversikt (refereegranskat)abstract
- Current energy security and climate change policies encourage the development and utilization of bioenergy. Oleaginous yeasts provide a particularly attractive platform for the sustainable production of biofuels and industrial chemicals due to their ability to accumulate high amounts of lipids. In particular, microbial lipids in the form of triacylglycerides (TAGs) produced from renewable feedstocks have attracted considerable attention because they can be directly used in the production of biodiesel and oleochemicals analogous to petrochemicals. As an oleaginous yeast that is generally regarded as safe, Yarrowia lipolytica has been extensively studied, with large amounts of data on its lipid metabolism, genetic tools, and genome sequencing and annotation. In this review, we highlight the newest strategies for increasing lipid accumulation using metabolic engineering and summarize the research advances on the overaccumulation of lipids in Y. lipolytica. Finally, perspectives for future engineering approaches are proposed.
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| 2503. |
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| 2504. |
- Wang, Jingjing, et al.
(författare)
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Thermodynamic and diffusion kinetic studies of the Fe-Co system
- 2017
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Ingår i: Calphad. - : Elsevier. - 0364-5916 .- 1873-2984. ; 58, s. 82-100
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Tidskriftsartikel (refereegranskat)abstract
- The phase equilibria, thermodynamic properties and diffusion mobilities of the Fe-Co system were carefully assessed through the CALPHAD methods. As an indispensable tool, the first-principles calculations were carried out to study the magnetic moments and the enthalpies of mixing of the bcc_A2, bcc_B2, fcc_A1 and hcp_A3 phases as well as the point defect types of the bcc_B2 phase. In order to verify the heat capacities reported in the literature, new measurements were conducted in a high-temperature calorimetric apparatus using the three-dimensional calorimetric method. Because of the revision of the thermodynamic parameters in the present work, the diffusion mobilities for the fcc_Al phase were reassessed. The diffusion mobilities for the bcc_A2 phase were established for the first time based on the experimental diffusion coefficients. For the low temperature bcc_B2 phase, the diffusion couple experiments conducted in the present work show that the diffusion process is sluggish and the interdiffusion coefficients are difficult to determine. Therefore the tracer diffusivities of Co and Fe in the Fe-Co alloys were used to assess the diffusion mobilities for the bcc_B2 phase, while the composition-distance profile of one diffusion couple was served as a validation of its diffusion mobilities.
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| 2505. |
- Wang, Jun-Zhi, et al.
(författare)
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An analytical study on artesian flow conditions in unconfined-aquifer drainage basins
- 2015
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Ingår i: Water resources research. - : American Geophysical Union (AGU). - 0043-1397 .- 1944-7973. ; 51:10, s. 8658-8667
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Tidskriftsartikel (refereegranskat)abstract
- Although it has been reported that flowing artesian wells could be topographically controlled, there is no quantitative research on artesian flow conditions in unconfined aquifers. In this study, the water table, which has a lower amplitude than the land surface, is damped from the topography and used as the boundary condition to obtain the analytical solution of hydraulic head of a unit basin with a single flow system. The term artesian head is defined to characterize the condition of flowing artesian wells. The zone with positive artesian head is called artesian zone while with negative artesian head is nonartesian zone. The maximum artesian head and the size of artesian zones are found to increase with the damping factor and the anisotropy ratio, and decrease with the ratio of basin width to depth and the depth-decay exponent of hydraulic conductivity. Moreover, the artesian head increases with depth nearby the valley and decreases with depth near by the divide, and the variation rates are influenced by the decay exponent and the anisotropy ratio. Finally, the distribution of flowing artesian wells and the artesian head measurements in different depths of a borehole in a small catchment in the Ordos Plateau, Northwestern China is used to illustrate the theoretical findings. The change in artesian head with depth was used to estimate the anisotropy ratio and the decay exponent. This study opens up a new door to analyze basin-scale groundwater flow.
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| 2506. |
- Wang, Jun-Zhi, et al.
(författare)
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On the use of late-time peaks of residence time distributions for the characterization of hierarchically nested groundwater flow systems
- 2016
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Ingår i: JOURNAL OF HYDROLOGY. - : Elsevier. - 0022-1694. ; 543, s. 47-58
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies on the characterization of hierarchically nested groundwater flow systems have mainly been based on the spatial distribution analyses of groundwater pathways. In this paper, by considering the discrete nature of the temporal behavior induced by different hierarchical flow systems, a new approach is proposed. The core of this approach is to use the critical residence times defined by the late-time peaks of residence time distributions (RTDs) to divide the groundwater flow field into local, intermediate and regional systems as described by Toth (1963). We first introduce Tothian basins of a 2D cross section and a 3D domain as synthetic test cases. The feasibility of the approach is demonstrated by comparing the partitioning results given by the dividing streamlines associated with internal stagnation points in the 2D Tothian basin and by the hydraulic connections between recharge and discharge zones in the 3D Tothian basin. Then, the Dosit River Watershed in Northwestern China is introduced as a field case study. Using the calibrated 3D groundwater flow model, one distinct late-time peak is identified from the RTD and indicates that the Dosit River Watershed can generally be regarded as a two-order nested flow structure with local and regional flow systems. This approach can be used to identify the volumes occupied by different orders of flow systems in 3D, and therefore opens up a new perspective in the study of the 3D nature of basin-scale groundwater flow.
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| 2507. |
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| 2508. |
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| 2509. |
- Wang, Kai, et al.
(författare)
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EXTENDED RELATIVISTIC CONFIGURATION INTERACTION AND MANY-BODY PERTURBATION CALCULATIONS OF SPECTROSCOPIC DATA FOR THE N 6 CONFIGURATIONS IN Ne-LIKE IONS BETWEEN Cr XV AND Kr XXVII
- 2016
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Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 226:2
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Tidskriftsartikel (refereegranskat)abstract
- Level energies, wavelengths, electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transition rates, oscillator strengths, and line strengths from combined relativistic con guration interaction and many-body perturbation calculations are reported for the 201 ne-structure states of the 2s22p6, 2s22p53l, 2s2p63l, 2s22p54l, 2s2p64l, 2s22p55l, and 2s22p56l con gurations in all Ne-like ions between Cr XV and Kr XXVII. Calculated level energies and transition data are compared with experiments from the National Institute of Standards and Technology (NIST) and CHIANTI databases, and other recent benchmark calculations. The mean energy difference with the NIST experiments is only 0.05%. The present calculations signi cantly increase the amount of accurate spectroscopic data for the n > 3 states in a number of Ne-like ions of astrophysical interest. A complete data set should be helpful for analyzing new observations from solar and other astrophysical sources, and is also likely to be useful for modeling and diagnosing a variety of plasmas, including astronomical and fusion plasma.
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| 2510. |
- Wang, Kewei, et al.
(författare)
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Fairness-aware Location and Hybrid Beamforming Optimization in IRSs-aided Cell-free MIMO System
- 2023
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Ingår i: 2023 IEEE/CIC International Conference on Communications in China, ICCC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Intelligent reflecting surface/Reconfigurable intelligent surface (IRS/RIS) and cell-free networks have been proposed as revolutionary technologies for beyond fifth-generation (B5G) and sixth-generation (6G) communication, which may significantly improve the connection quality and coverage to meet future communication demand for extremely massive connectivity and high reliability. In this paper, we proposed a low-complexity fractional programming (FP) based fairness-aware location and hybrid beamforming optimization method in IRSs-assisted cell-free MIMO systems. The minimum rate of user (UE) was optimized by jointly optimizing the passive beamforming in IRSs, location of IRSs, and transmit beamforming at base stations (BSs). Different from previous works, which required solving many feasible second-order cone program (SOCP) and semi-definite relaxation (SDR) problems in each iteration, our algorithm only needs to solve SOCP and SDR once in each iteration. The convergence of the proposed algorithm is validated by numerical results and our proposed method can improve the minimum rate by approximately 51% compared with FP transmit beamforming with random phase shift of IRS.
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