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| 1 | Selective esterification of glycerol with acetic acid to diacetin using antimony pentoxide as reusable catalyst显示文摘Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides, such as Bi2O3, Sb2O3, Sn O2, Ti O2, Nb2O5 and Sb2O5, was investigated. It was found that in the six investigated metal oxides, only Sb2O5 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%,and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine, which indicated that in the six investigated metal oxides, only Sb2O5 possessed Br?nsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Br?nsted acid sites of Sb2O5. Reusability tests showed that with Sb2O5 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed. | Wenfei Hu Yan Zhang Yizheng Huang Jiaxi Wang Jin Gao Jie Xu | 2015 | Journal of Energy Chemistry2015，24，5： | 2 |
| 2 | Size-resolved effective density of submicron particles during summertime in the rural atmosphere of Beijing, China显示文摘Particle density is an important physical property of atmospheric particles.The information on high time-resolution size-resolved particle density is essential for understanding the atmospheric physical and chemical aging processes of aerosols particles.In the present study,a centrifugal particle mass analyzer(CPMA) combined with a differential mobility analyzer(DMA) was deployed to determine the size-resolved effective density of 50 to 350 nm particles at a rural site of Beijing during summer 2016.The measured particle effective densities decreased with increasing particle sizes and ranged from 1.43 to 1.55 g/cm^3,on average.The effective particle density distributions were dominated by a mode peaked at around 1.5 g/cm^3 for 50 to350 nm particles.Extra modes with peaks at 1.0,0.8,and 0.6 g/cm3 for 150,240,and 350 nm particles,which might be freshly emitted soot particles,were observed during intensive primary emissions episodes.The particle effective densities showed a diurnal variation pattern,with higher values during daytime.A case study showed that the effective density of Aitken mode particles during the new particle formation(NPF) event decreased considerably,indicating the significant contribution of organics to new particle growth. | Kai Qiao Zhijun Wu Xiangyu Pei Qianyun Liu Dongjie Shang Jing Zheng Zhuofei Du Wenfei Zhu Yusheng Wu Shengrong Lou Song Guo Chak K.Chan Ravi Kant Pathak Mattias Hallquist Min Hu | 2018 | Journal of Environmental Sciences2018，30，11： | 2 |
| 3 | Propagating functional dependencies with conditions 显示文摘 | Fan Wenfei Ma Shuai Hu Yanli | 2008 | Proceedings of the VLDB Endownent2008，1，1： | 1 |
| 4 | MDP25 mediates the fine-tuning of microtubule organization in response to salt stress显示文摘Microtubules are dynamic cytoskeleton structures playing fundamental roles in plant responses to salt stress.The precise mechanisms by which microtubule organization is regulated under salt stress are largely unknown.Here,we report that Arabidopsis thaliana MICROTUBULE-DESTABILIZING PROTEIN 25(MDP25;also known as PLASMA MEMBRANEASSOCIATED CATION-BINDING PROTEIN 1(PCaP1))helps regulate microtubule organization.Under salt treatment,elevated cytosolic Ca^(2+) concentration caused MDP25 to partially dissociate from the plasma membrane,promoting microtubule depolymerization.When Ca^(2+) signaling was blocked by BAPTA-AM or LaCl_(3),microtubule depolymerization in wild-type and MDP25-overexpressing cells was slower,while there was no obvious change in mdp25 cells.Knockout of MDP25 improved microtubule reassembly and was conducive to microtubule integrity under long-term salt treatment and microtubule recovery after salt stress.Moreover,mdp25 seedlings exhibited a higher survival rate under salt stress.The presence microtubule-disrupting reagent oryzalin or microtubule-stabilizing reagent paclitaxel differentially affected the survival rates of different genotypes under salt stress.MDP25 promoted microtubule instability by affecting the catastrophe and rescue frequencies,shrinkage rate and time in pause phase at the microtubule plus-end and the depolymerization rate at the microtubule minus-end.These findings reveal a role for MDP25 in regulating microtubule organization under salt treatment by affecting microtubule dynamics. | Peizhi Yang Jingwei Jin Jingru Zhang Dan Wang Xuechun Bai Wenfei Xie Tianming Hu Xuan Zhao Tonglin Mao Tao Qin | 2022 | Journal of Integrative Plant Biology2022，64，6： | 1 |
| 5 | Liquid crystal tunable mm wave frequency selec tive surface 显示文摘 | Hu Wenfei | 2007 | IEEE Mictowave Wireless Components Lett2007，17，9： | 1 |
| 6 | Propagating functional dependencies with conditions显示文摘 | Fan Wenfei Ma Shuai Hu Yanli | 2008 | Proceedings of the VLDB Endowment2008，1，1： | 1 |
| 7 | Simultaneous bioimaging of MMP-2 and MMP-7 via Au-Se constructed fluorescence nanoprobe显示文摘Au-Se bond strategy has been applied to construct fluorescence nanoprobe that is being used to simultaneously dual-image the tumor markers matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-7(MMP-7)in vitro.The two Se-terminating ligand peptide chains respectively labeled with fluorescein isothiocyanate(FITC)and 5-Carboxytetramethylrhodamine(5-TAMRA)dyes are attached to the surface of Au nanoparticles(NPs).The nanoprobe can be specifically cut off by MMP-2 and MMP-7 respectively to carry out significant enhanced fluorescence recovery for simultaneously imaging both markers.The nanoprobe not only displays high selectivity and sensitivity towards MMP-2 and MMP-7,but also has strong anti-interference stability against biothiols and enhanced fidelity for avoiding'false positive'results.This approach offers new perspectives in designing tumor-related early diagnosis approaches and also provides strategies for clinical applications. | Xiaonan Gao Wenfei Guo Lulu Jiang Bo Hu Xiaojun Liu Kehua Xu Bo Tang | 2020 | Science China Chemistry2020，63，1： | 1 |
| 8 | Fabrication and characterisation of barium strontium titanate thick film device structures for microwave applications 显示文摘 | ZHANG Don HU Wenfei MEGGS C | 2007 | J Eur Ceram Soc2007，7，2： | 1 |
| 9 | Liquid Crystal Tunable mm Wave Frequency Selective Sur- face显示文摘 | HU Wenfei DICKIE R CAHILL R | 2007 | IEEE Microwave and Wireless Components Letters2007，17，9： | 1 |
| 10 | Building a Post-Layout Simulation Performance Model with Global Mapping Model Fusion Technique显示文摘Building a post-layout simulation performance model is essential in closing the loop of analog circuits, but it is a challenging task because of the high-dimensional space and expensive simulation cost. To facilitate efficient modeling, this paper proposes a Global Mapping Model Fusion(GMMF) technique. The key idea of GMMF is to reuse the schematic-level model trained by the Artificial Neural Network(ANN) algorithm, and combine it with few mapping coefficients to build the post-simulation model. Furthermore, as an efficient global optimization algorithm,differential evolution is applied to determine the optimal mapping coefficients with few samples. In GMMF, only a small number of mapping coefficients are unknown, so the number of post-layout samples needed is significantly reduced. To enhance practical utility of the proposed GMMF technique, two specific mapping relations, i.e., linear or weakly no-linear and nonlinear, are carefully considered in this paper. We conduct experiments on two topologies of two-stage operational amplifier and comparator in different commercial processes. All the simulation data for modeling are obtained from a parametric design framework. A more than 5 runtime speedup is achieved over ANN without surrendering any accuracy. | Zhikai Wang Wenfei Hu Sen Yin Ruitao Wang Jian Zhang Yan Wang Zuochang Ye | 2022 | Tsinghua Science and Technology2022，27，3： | 0 |
| 11 | An Early-Stop Adjoint Transient Sensitivity Analysis Method for Objective Functions Associated with Many Time Points显示文摘Transient sensitivity analysis aims to obtain the gradients of objective functions(circuit performance)with respect to design or variation parameters in a simulator,which can be widely used in yield analysis and circuit optimization,among others.However,the traditional method has a computational complexity of O(N^(2))for objective functions containing circuit states at N time points.The computational complexity is too expensive for large N,especially in time-frequency transform.This paper proposes a many-time-point sensitivity method to reduce the computational complexity to O(N)in multiparameter many-time-point cases.The paper demonstrates a derivation process that improves efficiency by weighting the transfer chain and multiplexing the backpropagation process.We also proposed an early-stop method to improve efficiency further under the premise of ensuring accuracy.The algorithm enables sensitivity calculation of performances involving thousands of time points,such as signal-to-noise and distortion ratio and total harmonic distortion,with significant speed improvements. | Wenfei Hu Sen Yin Liang Wang Chunxue Liu Zhikai Wang Zuochang Ye Yan Wang | 2023 | Tsinghua Science and Technology2023，28，3： | 0 |
| 12 | Dealloying of an amorphous TiCuRu alloy results in a nanostructured electrocatalyst for hydrogen evolution reaction显示文摘Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was performed to prepare a freestanding nanostructured hydrogen evolution reaction(HER)catalyst.The effect of dealloying and addition of Ru to TiCu alloys on the microstructure and HER properties under alkaline conditions was investigated.3 at.%Ru addition in Ti_(40)Cu_(60) decreases the overpotential to reach a current density of 10mA cm^(-2) and Tafel slope of the dealloyed samples to 35 and 34mV dec−1.The improvement of electrocatalytic properties was attributed to the formation of a nanostructure and the modification of the electronic structure of the catalyst.First-principles calculations based on density function theory indicate that Ru decreases the Gibbs free energy of water dissociation.This work presents a method to prepare an efficient electrocatalyst via dealloying of amorphous alloys. | Jinsen Tian Yuanchao Hu Wenfei Lu Jiahua Zhu Xiaodi Liu Jun Shen Gang Wang Jan Schroers | 2023 | Carbon Energy2023，5，8： | 0 |
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