29 research outputs found
The genome of the Hi5 germ cell line from Trichoplusia ni, an agricultural pest and novel model for small RNA biology
We report a draft assembly of the genome of Hi5 cells from the lepidopteran insect pest, Trichoplusia ni, assigning 90.6% of bases to one of 28 chromosomes and predicting 14,037 protein-coding genes. Chemoreception and detoxification gene families reveal T. ni-specific gene expansions that may explain its widespread distribution and rapid adaptation to insecticides. Transcriptome and small RNA data from thorax, ovary, testis, and the germline-derived Hi5 cell line show distinct expression profiles for 295 microRNA- and \u3e 393 piRNA-producing loci, as well as 39 genes encoding small RNA pathway proteins. Nearly all of the W chromosome is devoted to piRNA production, and T. ni siRNAs are not 2 -O-methylated. To enable use of Hi5 cells as a model system, we have established genome editing and single-cell cloning protocols. The T. ni genome provides insights into pest control and allows Hi5 cells to become a new tool for studying small RNAs ex vivo
A hybrid physical-data approach for solving dynamic optimal power flow considering uncertainties and different topology configurations
The security and economy of power system operation or planning are threatened by various uncertain factors, including the unpredictability of renewable energy, the variation of topology configurations, and significant load fluctuation. It is a challenge to solve dynamic optimal power flow efficiently for the operation and planning of power system considering uncertainties on both Renewable generation and Load, as well as different Topology configurations (RLT-DOPF). For fast solving the RLT-DOPF problem, we propose a hybrid physical-data approach using a physics-driven method — two-stage robust optimization approach based on an improved uncertainty set, and a data-driven method combined the Graph convolutional network with Long short term memory named GL-DOPF. The two-stage robust optimization approach can supply robust solutions for the RLT-DOPF problem under various topology configurations. Then the GL-DOPF model is trained using a training dataset that includes robust solutions. The solutions for RTL-DOPF are available with the trained GL-DOPF model and an AC power flow calculation fast. Simulations on IEEE 30/300-bus systems show that the speedup of the proposed hybrid physical-data approach is x25/29 as compared to a robust optimization method for RLT-DOPF under almost the same accuracy and the solutions for RTL-DOPF are feasible and robust. The training dataset for GL-DOPF generated from the proposed two-stage robust optimization model is less conservative than the original RO models and can cover the prediction errors of uncertainties. The effectiveness and robustness of the proposed hybrid physical-data approach for the RLT-DOPF problem clearly outperform
Efficient Hydrogenolysis of Guaiacol over Highly Dispersed Ni/MCM-41 Catalyst Combined with HZSM-5
A series of MCM-41 supported Ni catalysts with high metal dispersion was successfully synthesized by simple co-impregnation using proper ethylene glycol (EG). The acquired Ni-based catalysts performed the outstanding hydrogenolysis activity of guaiacol. The effects of the synthesis parameters including drying temperature, calcination temperature, and metal loading on the physical properties of NiO nanoparticles were investigated through the use of X-ray diffraction (XRD). The drying temperature was found to significantly influence the particle sizes of NiO supported on MCM-41, but the calcination temperature and metal loading had less influence. Interestingly, the small particle size (≤3.3 nm) and the high dispersion of NiO particles were also obtained for co-impregnation on the mixed support (MCM-41:HZSM-5 = 1:1), similar to that on the single MCM-41 support, leading to excellent hydrogenation activity at low temperature. The guaiacol conversion could reach 97.9% at 150 °C, and the catalytic activity was comparative with that of noble metal catalysts. The hydrodeoxygenation (HDO) performance was also promoted by the introduction of acidic HZSM-5 zeolite and an 84.1% yield of cyclohexane at 240 °C was achieved. These findings demonstrate potential applications for the future in promoting and improving industrial catalyst performance
乙二醇促进制备高分散的cosio2催化剂及其催化乳酸乙酯转化为12丙二醇的气相加氢活性
Highly dispersed Co catalysts supported on SiO_2 were prepared in the presence of ethylene glycol(EG) by co-impregnation and tested in the vapor-phase hydrogenolysis of ethyl lactate to 1,2-propanediol.The synthesis parameters of Co metal loading,ratio o
乙二醇促进制备高分散的Co/SiO_2催化剂及其催化乳酸乙酯转化为1,2-丙二醇的气相加氢活性
Highly dispersed Co catalysts supported on SiO_2 were prepared in the presence of ethylene glycol(EG) by co-impregnation and tested in the vapor-phase hydrogenolysis of ethyl lactate to 1,2-propanediol.The synthesis parameters of Co metal loading,ratio o
Promotion of Ni/MCM-41 Catalyst for Hydrogenation of Naphthalene by co-Impregnation with Polyols
The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols (ethylene glycol, glycerol, xylitol, sorbitol and glucose), were investigated by hydrogenation of naphthalene. Compared with the conventional wetness impregnation, addition of moderate polyols into the metal nitrate aqueous solution could enhance interaction with support surface, resulting in formation of very small NiO particle size (<5 nm), high dispersion of the active phase and significant catalytic activity. Particle size of Ni~0 decreased from 36.1 nm to below 5 nm; meanwhile the complete hydrogenation of naphthalene was dependent on the Ni~0 particle size. The hydrogenation activities of the catalysts prepared by co-impregnation with polyols were very high with 100% conversion even at low temperature of 55 oC
Sorbitol transformation into aromatics: A comparative evaluation of Ni/HZSM-5 and Ni/H beta
Aromatics including benzenes, olefins and naphthalenes derived from renewable biomass are of great importance on the potential substitution for diminishing fossil fuels. In this work, aromatics from biomass-derived sorbitol by hydrogenation and aromatization was investigated over the Ni/HZSM-5 and Ni/H beta catalysts in a fixed-bed reactor. The testing results showed that all the catalysts revealed 100% of sorbitol conversion, while the formation of aromatics and carbon species were various during the catalytic processing of sorbitol. The selectivity of aromatics was found to be 53.2% and 17.1% over the Ni/HZSM-5(38) and Ni/H beta catalyst, respectively. In addition, the catalysts were characterized by N-2 physical adsorption, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), H-2 temperature-programmed reduction (H-2-TPR), and temperature-programmed desorption of ammonia (NH3-TPD) techniques. The characterization results revealed that the Ni/HZSM-5(38) catalyst contained the optimum acidic sites and the structural property, which favor the hydrogenation and aromatization of sorbitol in the reaction. (C) 2015 Elsevier Ltd. All rights reserved
Mitochondrial DNA diversity and demographic history of Black-boned chickens in China
Black-boned chickens (Gallus domesticus, herein abbreviated BBCs) are well known for their unique appearance and medicinal properties and have a long breeding history in China. However, the genetic diversity and demographic history of BBCs remain unclear. In this study, we analyzed 844 mitochondrial DNA D-loop sequences, including 346 de novo sequences and 498 previously published sequences from 20 BBC breeds. We detected a generally high level of genetic diversity among the BBCs, with average haplotype and nucleotide diversities of 0.917 ± 0.0049 and 0.01422, respectively. Nucleotide diversity was highest in populations from Southwest China (0.01549 ± 0.00026), particularly in Yunnan Province (0.01624 ± 0.00025). Significant genetic divergence was detected between most breeds, particularly between Yunnan chickens and those from all other provinces. Haplogroups F and G had the highest levels of genetic diversity and were restricted to Southwest China, particularly Yunnan Province. Based on neutrality tests and mismatch distribution analyses, we did not obtain evidence for rapid population expansions and observed similar demographic histories in BBCs and local non-BBCs. Our results suggest that Chinese BBCs have complex breeding histories and may be selected in situ from local domestic chickens. These results improve our understanding of the genetic heritage and breeding histories of these desirable chickens
One-pot aqueous phase catalytic conversion of sorbitol to gasoline over nickel catalyst
The carbon chain extension and hydrodeoxygenation steps play critical roles in the high-energy-density hydrocarbons production. In this paper, a systematic study had been carried out to investigate one-pot aqueous phase catalytic conversion of sorbitol to gasoline (STG) over bifunctional Ni-based catalysts. Characterization technologies of N-2 physisorption, X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and NH3 temperature-programmed desorption (NH3-TPD) were used to study the textural properties, phase compositions, acid behavior and morphologies of the catalysts. The catalytic performances were tested in a fixed bed reactor. It was found that the physically mixed Ni/HZSM-5 and Ni/silica-gel (mesoporous SG) catalyst realized the carbon chain extension and exhibited excellent performances on hydrodeoxygenation (HDO) reaction (46.9% of gasoline (C5-C12) yield and 45.5% of C7-C12 hydrocarbons in the gasoline products). Especially, the temperature of STG (553-593 K) was lower obviously than that of the traditional methanol to gasoline (MTG) process (623-773 K). It provided a novel transformation of sorbitol to long-chain alkanes by one-pot process over the bifunctional catalyst (Ni@HZSM-5/SG), wherein hydrodeoxygenation, ketonization and aldol condensation steps were integrated. (C) 2015 Elsevier Ltd. All rights reserved
Jet-Fuel Range Hydrocarbons from Biomass-Derived Sorbitol over Ni-HZSM-5/SBA-15 Catalyst
Aromatics and cyclic-hydrocarbons are the significant components of jet fuel with high energy-density. However, conventional technologies for bio-fuel production cannot produce these products without further aromatization and isomerization. In this work, renewable liquid fuel with high content of aromatics and cyclic-hydrocarbons was obtained through aqueous catalytic conversion of biomass sorbitol over Ni-HZSM-5/SBA-15 catalyst. Texture characteristics of the catalyst were determined by physisorption of N2, which indicated its bimodal pore structures were microporous (HZSM-5, pore width: 0.56 nm) and mesoporous (SBA-15, pore width: 8 nm). The surface acidity included weak and strong acid sites, predominantly Lewis type, and was further confirmed by the NH3-TPD and Py-IR analysis. The catalytic performances were tested in a fixed-bed reactor under the conditions of 593 K, WHSV of 0.75 h−1, GHSV of 2500 h−1 and 4.0 MPa of hydrogen pressure, whereby oil yield of 40.4 wt. % with aromatics and cyclic-hydrocarbons content of 80.0% was obtained