A time-space network-based model for transportation service optimization of China Railway Express

This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of China toward European investment and trade,and in particular,has expanded with the continuous progress of the One Belt and One Road(OBOR)initiative.In addition to improving the service quality of CR Express,the operating costs must be reduced for developing“smart railways”that serve“smart cities”.We propose a dualobjective-based function mathematical optimization model;the satisfaction of the cargo owner is considered,and the timeliness,transportation capacity,and goods category constraints of CR Express transportation are designed.Moreover,we present the normalized equivalent method of the two-objective function of the model.Finally,a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study.

Real-Time Wind Speed Analysis at Wind-Damaged Tower of a Transmission Line

Affected by the Super Typhoon“Mangkhut,”a total of five base towers of a transmission line in the mountainous area of China collapsed.In this paper,a mathematical model is established based on the Shuttle Radar Topography Mission(SRTM)data near the accident tower.The measured wind speed in the plain area under the mountain is used as the calculation boundary condition.The wind speed at the top of the mountain is calculated by using a numerical simulation method.The design wind speed and calculated wind speed at the tower site are compared,and the influence of wind speed on tower position in this wind disaster accident is analyzed.

大学化学虚拟仿真实验教学建设——以水性聚氨酯聚合及超临界连续发泡虚拟仿真实验为例

介绍了水性聚氨酯聚合及超临界连续发泡虚拟仿真实验教学方法。通过三维虚拟仿真技术呈现复杂聚合物合成过程,使学生可以在直观、生动的场景中进行实验,实现真实的实验教学效果,而且在有限的时间内,可进行多次筛选设计实验,大幅度提高了实验效率。此教学方法同时解决了聚合实验材料有毒性危险、实验溶剂不易回收以及实验成本高等问题。此教学方法经过学生实际操作实践后,取得了良好成效。

Hölder Derivative of the Koch Curve

In this paper, we introduce a K Hölder p-adic derivative that can be applied to fractal curves with different Hölder exponent K. We will show that the Koch curve satisfies the Hölder condition with exponent and has a 4-adic arithmetic-analytic representation. We will prove that the Koch curve has exact -Hölder 4-adic derivative.

CMIP6 Evaluation and Projection of Temperature and Precipitation over China

This article evaluates the performance of 20 Coupled Model Intercomparison Project phase 6(CMIP6)models in simulating temperature and precipitation over China through comparisons with gridded observation data for the period of 1995–2014,with a focus on spatial patterns and interannual variability.The evaluations show that the CMIP6 models perform well in reproducing the climatological spatial distribution of temperature and precipitation,with better performance for temperature than for precipitation.Their interannual variability can also be reasonably captured by most models,however,poor performance is noted regarding the interannual variability of winter precipitation.Based on the comprehensive performance for the above two factors,the“highest-ranked”models are selected as an ensemble(BMME).The BMME outperforms the ensemble of all models(AMME)in simulating annual and winter temperature and precipitation,particularly for those subregions with complex terrain but it shows little improvement for summer temperature and precipitation.The AMME and BMME projections indicate annual increases for both temperature and precipitation across China by the end of the 21st century,with larger increases under the scenario of the Shared Socioeconomic Pathway 5/Representative Concentration Pathway 8.5(SSP585)than under scenario of the Shared Socioeconomic Pathway 2/Representative Concentration Pathway 4.5(SSP245).The greatest increases of annual temperature are projected for higher latitudes and higher elevations and the largest percentage-based increases in annual precipitation are projected to occur in northern and western China,especially under SSP585.However,the BMME,which generally performs better in these regions,projects lower changes in annual temperature and larger variations in annual precipitation when compared to the AMME projections.

Redirecting dynamic structural evolution of nickel-contained RuO_(2) catalyst during electrochemical oxygen evolution reaction

Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instability stems from lattice oxygen oxidation,resulting in the oxidation of Ru^(4+) to soluble Ru^(4+)(x>4) species.Herein,we redirect dynamic structural evolution of Ru-based catalysts through introducing oxidized nickel (Ni) components.By virtue of comprehensive structural characterizations,such as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM),X-ray photoelectron spectroscopy (XPS),operando Raman and so forth,it is demonstrated that when the atomic content of Ni exceeds that of ruthenium (Ru),the Ni components can efficiently inhibit the Ru^(4+) oxidation and structural collapse.Density functional theory (DFT) calculations suggest that the introduction of Ni component hinders the formation of oxygen vacancies,and makes lattice oxygen mediated mechanism turn to adsorbate evolution mechanism,which eventually improves the stability.The optimized nickel-contained RuO_(2) catalyst delivers an effective reactivity with an overpotential of less than 215 m V to attain 10 m A cm^(-2) and remarkable stability with only 5 mV increment after 5000 potential cycles.This work provides insights into the origin of dynamic structural evolution of transition-metalmodified RuO_(2) electrocatalysts.

CMIP6 Evaluation and Projection of Precipitation over Northern China:Further Investigation

Based on 20 models from phase 6 of the Coupled Model Intercomparison Project(CMIP6),this article explored possible reasons for differences in simulation biases and projected changes in precipitation in northern China among the allmodel ensemble(AMME),“highest-ranked”model ensemble(BMME),and“lowest-ranked”model ensemble(WMME),from the perspective of atmospheric circulations and moisture budgets.The results show that the BMME and AMME reproduce the East Asian winter circulations better than the WMME.Compared with the AMME and WMME,the BMME reduces the overestimation of evaporation,thereby improving the simulation of winter precipitation.The three ensemble simulated biases for the East Asian summer circulations are generally similar,characterized by a stronger zonal pressure gradient between the mid-latitudes of the North Pacific and East Asia and a northward displacement of the East Asian westerly jet.However,the simulated vertical moisture advection is improved in the BMME,contributing to the slightly higher performance of the BMME than the AMME and WMME on summer precipitation in North and Northeast China.Compared to the AMME and WMME,the BMME projects larger increases in precipitation in northern China during both seasons by the end of the 21st century under the Shared Socioeconomic Pathway 5-8.5(SSP5-8.5).One of the reasons is that the increase in evaporation projected by the BMME is larger.The projection of a greater dynamic contribution by the BMME also plays a role.In addition,larger changes in the nonlinear components in the BMME projection contribute to a larger increase in winter precipitation in northern China.

Scalable solid-phase synthesis of defect-rich graphene for oxygen reduction electrocatalysis

Defect-engineered carbon materials have been emerged as promising electrocatalysts for oxygen reduction reaction(ORR)in metal-air batteries.Developing a facile strategy for the preparation of highly active nanocarbon electrocatalysts remains challenging.Herein,a low-cost and simple route is developed to synthesize defective graphene by pyrolyzing the mixture of glucose and carbon nitride.Molecular dynamics simulations reveal that the graphene formation is ascribed to two-dimensional layered feature of carbon nitride,and high compatibility of carbon nitride/glucose systems.Structural measurements suggest that the graphene possesses rich edge and topological defects.The graphene catalyst exhibits higher power density than commercial Pt/C catalyst in a primary Zn-air battery.Combining experimental results and theoretical thermodynamic analysis,it is identified that graphitic nitrogen-modified topological defects at carbon framework edges are responsible for the decent ORR performance.The strategy presented in this work can be can be scaled up readily to fabricate defective carbon materials.

The clinical effects of DC-CIK cells combined with chemotherapy in the treatment of advanced NSCLC

Objective: The aim of the study was to evaluate the safety and therapeutic effects of autologous dendritic cells co-cultured with cytokine-induced killer cells (DC-CIK) combined with chemotherapy in advanced non-small cell lung cancer (NSCLC) patients. Methods: Fifty patients with advanced NSCLC (stages III to IV), who had received therapies in our Center (Department of Biotherapy, Affiliated to Cancer Hospital of Shanxi Medical University, Taiyuan, China) from August 2008 to January 2010, were treated by DC-CIK + chemotherapy as the combined treatment group; fifty advanced NSCLC patients treated with chemotherapy at the same time served as controls. The immunologic function, short-term therapeutic effects, the 1-year survival rate, the life quality, the chemotherapy side effects were compared between the two groups, the safety and therapeutic effects of DC-CIK cells therapy were observed too. Results: There was no obvious change of subsets of T cells in peripheral blood before and after therapy in DC-CIK + chemotherapy group, and IFN-γ was improved after therapy in this group (P < 0.05); in chemotherapy alone group, the ratios of CD3+CD4+, CD3+CD8+, CD3-CD56+ cells and the secretion of IL-2, TNF-α decreased significantly after therapy (P < 0.05); the ratios of CD3+CD8+, CD3+CD56+ were improved after cell culture (P < 0.05). The disease control rate (DCR) of DC-CIK + chemotherapy group was higher than that in the chemotherapy alone group (78.0% vs 56.0%, P < 0.05); the 1-year survival rates of DC-CIK + chemotherapy group and chemotherapy alone group were 50% and 44% respectively, had no significant difference. Compared with chemotherapy alone group, the occurrence of chemotherapy side effects (including bone marrow suppression, nausea and vomiting, peripheral nerve toxicity) was less in the DC-CIK + chemotherapy group (P < 0.05). The physical and appetite were better in DC-CIK + chemotherapy group after therapy. Conclusion: To compare with simple chemotherapy, DC-CIK + chemotherapy for advanced NSCLC is safe and effective, and it can improve patients' life quality and remission rate, and prolong their survival time.

神经递质的可视化荧光检测技术研究进展

神经递质是神经系统中至关重要的组成部分,神经递质释放的时间和空间变化是神经网络中信息处理的核心,可视化监测神经递质的生物传感器是探究各类生理和病理活动的重要工具。文中综述了近年来具有较高时间和空间分辨率的监测神经递质时空分布变化技术的研究进展,介绍了对谷氨酸、多巴胺、γ-氨基丁酸和乙酰胆碱这4类重要的神经递质的检测方法,并归纳总结了各类检测方法的基本原理和优缺点,为设计具有高时空分辨率的神经递质传感器提供一个较为系统的参考。

Andrographolide sulfonate ameliorates lipopolysaccharide-induced acute lung injury in mice by down-regulating MAPK and NF-κB pathways

Acute lung injury(ALI) or acute respiratory distress syndrome(ARDS) is a severe, lifethreatening medical condition characterized by widespread inflammation in the lungs, and is a significant source of morbidity and mortality in the patient population. New therapies for the treatment of ALI are desperately needed. In the present study, we examined the effect of andrographolide sulfonate, a water-soluble form of andrographolide(trade name: Xi-Yan-Ping Injection), on lipopolysaccharide(LPS)-induced ALI and inflammation. Andrographolide sulfonate was administered by intraperitoneal injection to mice with LPS-induced ALI. LPS-induced airway inflammatory cell recruitment and lung histological alterations were significantly ameliorated by andrographolide sulfonate. Protein levels of pro-inflammatory cytokines in bronchoalveolar lavage fluid(BALF) and serum were reduced by andrographolide sulfonate administration. m RNA levels of pro-inflammatory cytokines in lung tissue were also suppressed. Moreover, andrographolide sulfonate markedly suppressed the activation of mitogen-activated protein kinase(MAPK) as well as p65 subunit of nuclear factor-κB(NF-κB). In summary, these results suggest that andrographolide sulfonate ameliorated LPS-induced ALI in mice by inhibiting NF-κB and MAPK-mediated inflammatory responses. Our study shows that water-soluble andrographolide sulfonate may represent a new therapeutic approach for treating inflammatory lung disorders.

钛、镍、铁配合物在硅氢加成反应中的应用

Ti、Ni、Fe配合物作为催化剂广泛应用于有机催化反应中,表现出良好的催化性能,是有机金属催化化学的研究热点之一。本文介绍了近年来非贵金属钛、镍、铁配合物作为催化剂在烯炔烃、含羰基化合物及其他不饱和双键、三键化合物硅氢加成反应中的应用研究成果和进展,分析了这三类催化剂在使用过程中存在的不足,并对其作为催化剂的应用前景进行了展望。

Addressing the environmental risk of persistent organic pollutants in China

The Stockholm Convention on persistent organic pollutants （POPs） was adopted in 2001. This year is the 10th anniversary of the adoption of the Convention. Until now, 22 chemicals or chemical categories have been listed as POPs in the Stockholm Convention. The POPs Research Center was established in Tsinghua University in the same year when the Convention was adopted. In the last ten years, much work has been done by Chinese researchers to understand the environ- mental risk of POPs in China. This article aims to review the recent research progress of our POPs Research Center and some other Chinese researchers＇ studies in addressing the environmental risk of POPs, including the priority screening and inventory study of POPs, monitoring and modeling of POPs pollution and exposure, and environ- mental risk assessment and modeling of POPs. Although great advances in addressing the environmental risk of POPs have been made in recent years, we are still facing quite a few problems, such as data scarcity and uncertainty in environmental risk assessment of POPs. The study on the effect of POPs mixtures is in its infancy and currently POPs are usually assessed from legal perspective by risk assessment of single chemicals. These problems should be well addressed by further efforts. Further studies should also be taken in future to study environment risk of POPs by considering aspects of coupled dynamics between climate processes and POPs. Such sound scientific, riskbased information can support decision-making aiming to effectively minimize the risk level of POPs.

Plasmonic Au Decorated Single-crystal-like TiO2-NaYF4 Mesoporous Microspheres for Enhanced Broadband Photocatalysis

Single-crystal-like TiO2 mesoporous microspheres have been reported with high photocatalytic activity under ultraviolet light （UV light） because of their high specific surface areas and single-crystal-like channel walls. In this work, plasmonic gold nanoparticles （Au NPs） and fl-NaYF4： Yb3＋, Er3＋ upconversion nanoparticles （UCNPs） were composited with single-crystal-like TiO2 mesoporous microspheres through a series of facile approaches, aiming at broadening response region of solar light from UV to visible and near infrared light and enhancing the photocata- lyric activity further. The structure was rationally designed by modifying the pore size of TiO2 mesoporous micro- spheres so as to anchor plasmonic Au NPs, and covering β-NaYF4： Yb3＋, Er3＋ with SiO2 in order to embed UCNPs into TiO2 mesoporous microspheres via hydrophilic interaction. This work studied the attribution of Au NPs and UCNPs to photocatalysis and found out that combining Au NPs and certain amount of UCNPs with single-crystal- like TiO2 mesoporous microspheres in a monolithic architecture would bring enhanced broadband photocatalytic activity under simulated solar light. Consequently, the composite photocatalyts containing 150 mg UCNPs showed a significant enhancement in reaction rate, which was 36.02% higher than commercial P25 and 85.09% higher than pure TiO2 mesoporous microspheres under simulated solar light.

Clinical phenotype features and genetic etiologies of 38 children with progressive myoclonic epilepsy

Background:Progressive myoclonic epilepsy(PME)is a group of neurodegenerative diseases with genetic heterogeneity and phenotypic similarities,and many cases remain unknown of the genetic causes.This study is aim to summarize the clinical features and study the genetic causes of PME patients.Methods:Sanger sequencing of the target gene,Next Generation Sequencing(NGS)panels of epilepsy,trio-based Whole Exome Sequencing(WES)and detection of cytosine-adenine-guanine(CAG)repeat number were used to investigate the genetic causes of PME patients.Results:Thirty-eight children with PME whose seizure onset age ranged from 3 months to 12 years were collected from February 2012 to November 2019 in three hospitals in Beijing,China.The seizure types included myoclonic seizures(n=38),focal seizures(n=19),generalized tonic-clonie seizure(GTCS)(n=13),absence seizures(n=4),atonic seizures(n=3),epileptic spasms(n=2)and tonic seizures(n=1).Twenty-seven cases were sporadic and 11 had family members affected.Established PME-related genes were identified in 30 out of 38(78.9%)patients who had either recessively inherited or de novo heterozygous mutations.Among these 30 cases,there were 12 cases(31.6%)of neuronal ceroid lipofuscinoses(the causing gene contains TPP1,PPT1,CLN5,CLN6 and MFSD8),two cases of sialidosis(the causing gene is NEU1),two cases of neuronopathic Gaucher disease(the causing gene is GBA),one case of spinal muscular atrophy-progressive myoclonic epilepsy(the causing gene is ASAH1),four cases of KCNC1 mutation-related PME,four cases of KCTD7 mutation-related PME,two cases of TBC1D24 mutation-related PME,one case of GOSR2 related PME,and two of dentatorubral-pallidoluysian atrophy(the causing gene is ATN1).In total,13 PME genes were identified in our cohort.The etiology was not clear in eight patients.Conclusion:PME is a group of clinically and genetically heterogeneous diseases.Genetic diagnosis was clear in 78.9%of PME patients.Various of genetic testing methods could increase the rate of genetic diagnosis.Neuronal ceroid lipofuscinoses(NCL)is the most common etiology of PME in children.Nearly one third PME children were diagnosed with NCL.GOSR2 related PME was in our cohort in Asia for the first time.

Operando generated copper‐based catalyst enabling efficient electrosynthesis of 2,5‐bis(hydroxymethyl)furan

Electrocatalytic upgrading of biomass-derived platform molecules has emerged as a sustainable and environmentally benign route to produce high-value chemicals.The main challenge lies in developing efficient catalysts for the selective activation of designated chemical bonds in the presence of various reducible groups.This work demonstrated a high-efficiency electrochemical conversion of 5-hydroxymethylfurfural(HMF)to 2,5-bis(hydroxymethyl)furan(BHMF),an important industrial synthetic reagent.A highly porous Cu-based catalyst was developed that achieved nearly 100%BHMF selectivity and long-term stability.Through comprehensive operando and ex-situ structural characterizations,an electrochemically generated catalyst with abundant Cu/Cu2O interfaces was identified as a catalytically active phase for HMF conversion.Deuterated BHMF,with the potential to produce deuterated drugs,was also synthesized using D2O as the deuterium source.Density functional theory calculations show that the Cu/Cu2O interface structure exhibits relatively low energy barriers for the hydrogenation of HMF to BHMF.This work provides insights into the origin of electrocatalytic hydrogenation activity and highlights the promising potential of the electrocatalytic synthesis of high-value chemicals.

Preparation of photoluminescent carbon dots-embedded polyelectrolyte microcapsules

Two types of photoluminescent carbon dots （CDs）-embedded polyelectrolyte （PE） microcapsules were successfully prepared via the layer-by-layer （LbL） assembly approach on sacrificial templates. For the first type, the PE microcapsules with CDs embedded in the cavity were produced from assembly of five pairs of poly（sodium 4-styrensulfonate） （PSS） and poly（allylamine hydrochloride） （PAH） on CDs-pre-loaded meso-porous silica. For the second type, the PE microcapsules with CDs embedded in the wall were made of CDs and PAH, which were derived from SiO2 particles as templates. Microscope images confirmed the introduction of CDs into the two CDs-embedded microcapsules. These two microcapsules also retained the optical properties of free CDs. Photoluminescence spectra revealed that the two types of microcapsules had excitation-dependent photoluminescence behavior. When the excitation wavelength changed from 280 to 340nm, photoluminescence emission peak of the PE microcapsules with CDs embedded in the cavity shifts from 369 to 377 nm, while for microcapsules with CDs embedded in the wall, emission peak shifts from 367 to 390 nm. Due to low toxicity, good hydrophilicity and photoluminescence properties of CDs, these two kinds of photo-luminescent microcapsules have competitive potential for application in carriers for imaging, drug delivery and biosensors.

Numerical simulation on the frosting and heat transfer characteristics of plate-fin heat exchanger considering confinement effect

In refrigerating industry,frost commonly deposits on the confined cold surfaces of heat exchangers,which affects the heat transfer performance.Along the confined flow path of the heat exchanger,the frosting at downstream is affected by the parameters from the upstream.In this study,a numerical model considering the confinement effect has been proposed to predict frosting characteristics in plate-fin heat exchanger.Convection-diffusion equations for humid air and empirical correlations for local frost density are employed in the numerical prediction.Frosting behavior and heat transfer in the confined channel are investigated with different humid air parameters and cold surface temperatures.The results indicate that frost thickness in the confined channel is thicker than that in open space under the same inlet parameters.The frost layer is thicker and fluffier along the confined channel.In addition,the air temperature difference between inlet and outlet of the confined channel enlarges with frosting.Under the same average temperature of upper and lower surfaces,the heat and mass transfer of frosting are enhanced with diminishing temperature difference of upper and lower surfaces.In such condition,frosting is mainly influenced by the cold surface with the lower temperature.

Carbon nanotubes coated with platinum nanoparticles as anode of biofuel cell

A hybrid system of carbon nanotubes （CNTs） coated with poly （amidoamine） （PAMAM） dendrimer- encapsulated platinum nanoparticles （Pt-DENs） and glucose oxidase （GOx） was prepared through the layer-by-layer （LbL） self-assembly approach and then used as anode in enzyme-based biofuel cells （BFCs）. The assembly process was monitored by C-potential measurement, and the as-resulted Pt-DENs/CNTs nanocomposites were characterized by transmission electron microscopy （TEM）. The performance of electrodes modified by Pt-DENs/CNTs was also investigated by electrochemical impedance spectroscopy （EIS） and cyclic voltammetry （CV）. We found that the Pt-DENs]CNTs could enhance the electron trans- fer between the redox centers in enzyme and the electrode surfaces. Furthermore, by employing the Pt-DENs/CNTs modified electrodes as anode, the enzyme-based BFCs operated in a solution containing glucose generated an open-circuit voltage of approximately 640.0 mV and a maximum current density of about 90.0 μA/cmx, suggesting that Pt-DENs/CNTs may serve as an alternative anode to previously used noble metals in BFC applications.