Tandem hydroalkylation and deoxygenation of lignin-derived phenolics to synthesize high-density fuels

Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.

Conversion of lignin oil and hemicellulose derivative into high-density jet fuel

Synthesizing high-density fuel from lignocellulose can not only achieve green and low-carbon development,but also expand the feedstock source of hydrocarbon fuel.Here,we reported a route of producing high-density fuel from lignin oil and hemicellulose derivative cyclopentanol through alkylation and hydrodeoxygenation,HY with SiO_(2)/Al_(2)O_(3) molar ratio of 5.3 was screened as the alkylation catalyst in the reaction of model phenolic compounds and mixtures,and the reaction conditions were optimized to achieve conversion of phenolic compounds higher than 87%and selectivity of bicyclic and tricyclic products higher than 99%.Then two phenolic pools simulating the composition of two typic lignin oils were studied to validate the alkylation and analyze the competition mechanism of phenolic compounds in mixture system.Finally,real lignin oil from depolymerized of beech powder was tested,and notably80%of phenolic monomers in the oil were converted into fuel precursor.After hydrodeoxygenation,the alkylated product was converted to fuel blend with a density of 0.91 g/mL at 20℃and a freezing point lower than-60℃,very promising as high density fuel.This work provides a facile and energyefficient way of synthesizing high-performance jet fuel directly from lignocellulosic derivatives,which decreases processing energy consumption and improve the utilization rate of feedstock.

Survey on vehicle map matching techniques

With the development of location‐based services and Big data technology,vehicle map matching techniques are growing rapidly,which is the fundamental techniques in the study of exploring global positioning system(GPS)data.The pre‐processed GPS data can provide the guarantee of high‐quality data for the research of mining passenger’s points of interest and urban computing services.The existing surveys mainly focus on map‐matching algorithms,but there are few descriptions on the key phases of the acquisition of sampling data,floating car and road data preprocessing in vehicle map matching systems.To address these limitations,the contribution of this survey on map matching techniques lies in the following aspects:(i)the background knowledge,function and system framework of vehicle map matching techniques;(ii)description of floating car data and road network structure to understand the detailed phase of map matching;(iii)data preprocessing rules,specific methodologies,and significance of floating car and road data;(iv)map matching algorithms are classified by the sampling frequency and data information.The authors give the introduction of open‐source GPS sampling data sets,and the evaluation measurements of map‐matching approaches;(v)the suggestions on data preprocessing and map matching algorithms in the future work.

Subcellular Localization of APX1 Protein in Arabidopsis thaliana

To predict the subcellular location of ascorbate peroxidase 1 （ APX1 ） protein in Arabidopsis thaliana, a plasmid expressing APXl-enbance green fluores- cent protein （EGFP） fusion protein was constructed, transformed into Agrobacterium tumefaciens GV3101, and transiently expressed in tobacco leaves. The localization of APX1 protein in the cells was determined by detecting the distribution of the fusion protein in tobacco epidermal cells. The results showed APX1 protein was mainly distributed in the cytoplasm of the plant.

双侧闭口型压型钢板混凝土组合构件轴压力学性能研究

双侧闭口型压型钢板混凝土组合构件由两侧放置的闭口型压型钢板和内部填充混凝土组成,内嵌于混凝土中的闭口型板肋既可作为钢板与混凝土之间的连接件,保证两者的共同工作,又能有效降低钢板的宽厚比,提高闭口型压型钢板的屈曲承载力。相比传统的双钢板混凝土组合构件,双侧闭口型压型钢板混凝土组合构件无需额外的连接件即可实现钢板和混凝土的共同工作,增加了施工的便利性和高效性,同时保持了双钢板-混凝土组合构件的性能优势,在工程中具有广阔的应用前景。采用有限元方法分析了闭口型压型钢板混凝土组合构件在轴压荷载作用下的受力全过程,包括混凝土截面的应力分布、压型钢板板带的应力发展过程及屈曲性能;通过试验结果和理论分析明确了板肋在混凝土中的嵌固作用;研究了压型钢板布置形式、混凝土强度等级、钢材屈服强度、钢板厚度(板带宽厚比)和构件厚度等参数对双侧闭口型压型钢板混凝土组合构件轴压性能影响规律。通过对双侧闭口型压型钢板混凝土组合构件受力全过程的分析,可以得到以下结论:闭口型板肋将压型钢板分成若干个板带,各板带单独发生受压屈曲,改变了钢板整体受压屈曲的方式;混凝土能够对嵌入的闭口型板肋提供足够的嵌固作用,使得压型钢板与混凝土能够共同工作;嵌入混凝土中的闭口型板肋为压型钢板板带提供了可靠的边缘嵌固和支撑,使得闭口型压型钢板仅在板带上发生局部弹性屈曲,且能够发展屈曲后强度,压型钢板板带的屈曲后强度可以采用有效宽度法计算;闭口型板肋嵌于混凝土中使得板肋附近混凝土的应力分布不均匀,并对两侧板肋之间的混凝土产生一定的约束作用,但截面上并未形成明显的约束区和非约束区;双侧闭口型压型钢板混凝土组合构件轴压承载力可由混凝土抗压承载力和考虑屈曲后强度的压型钢板承载力叠加获得;压型钢板布置方式对构件的轴压承载力没有明显影响,构件各组成部分的材料强度、墙体厚度和压型钢板厚度对其轴压承载力和延性影响明显。

Safety and feasibility of laparoscopic surgery for colorectal and gastric cancer under the Chinese multi-site practice policy:admittance standards of competence are needed

Background:The multi-site practice(MSP)policy has been practiced in China over 10 years.This study aimed to investigate the safety and feasibility of performing laparoscopic surgery for colorectal cancer(LSCRC)and gastric cancer(LSGC)under the Chinese MSP policy.Methods:We collected and analysed the data from 1,081 patients who underwent LSCRC or LSGC performed by one gastrointestinal surgeon in his original hospital(n=573)and his MSP institutions(n=508)between January 2017 and December 2020.Baseline demographics,intraoperative outcomes,post-operative recovery,and pathological results were compared between the original hospital and MSP institutions,as well as between MSP institutions with and without specific competence(surgical skill,operative instrument,perioperative multi-discipline team).Results:In our study,690 patients underwent LSCRC and 391 patients underwent LSGC.The prevalence of post-operative complications was comparable for LSCRC(11.5%vs 11.1%,P=0.89)or LSGC(15.2%vs 12.6%,P=0.46)between the original hospital and MSP institutions.However,patients in MSP institutions without qualified surgical assistant(s)and adequate instruments experienced longer operative time and greater intraoperative blood loss.The proportion of patients with inadequate lymph-node yield was significantly higher in MSP institutions than in the original hospital for both LSCRC(11.5%vs 21.2%,P<0.01)and LSGC(9.8%vs 20.5%,P<0.01).Conclusion:For an experienced gastrointestinal surgeon,performing LSCRC and LSGC outside his original hospital under the MSP policy is safe and feasible,but relies on the precondition that the MSP institutions are equipped with qualified surgical skills,adequate operative instruments,and complete perioperative management.