Plasma-facilitated modification of pumpkin vine-based biochar and its application for efficient elimination of uranyl from aqueous solution

An acrylic modified pumpkin vine-based biochar(p-PVB-PAA) is synthesized by non-thermal plasma-grafting modification of pumpkin vine-based biochar(PVB) for the removal of uranyl from an aqueous solution. Microscopic characterization reveals that compared to PVB the surface of p-PVBPAA has more oxygen-containing functional groups by strong chemical bonding and the specific surface area is increased to 275.3 m^2 g^-1 from 3.8 m^2g^-1. It is found that p-PVB-PAA showed a much higher maximum adsorption capacity for uranyl from aqueous solutions than PVB, which were207.02 mg g^-1 and 67.58 mg g^-1 at pH=5 and 298 K, respectively. Moreover, the adsorption behavior follows a pseudo-second-order kinetics model and the Langmuir adsorption model.Additionally, macroscopic experiments and spectroscopic studies verified that the significantly improved adsorption performance of the p-PVB-PAA is due to surface complexation and electrostatic interactions. Furthermore, the very high removal efficiency and excellent regeneration ability(the percentage of the removal still remained at nearly 90% after five cycles) makes this low-cost, easily obtained, and environmentally friendly material attractive for commercial application.

Plasma-induced grafting of acrylic acid on bentonite for the removal of U(VI) from aqueous solution

Fabrication of reusable adsorbents with satisfactory adsorption capacity and using environmentfriendly preparation processes is required for the environment-related applications. In this study,acrylic acid（AA） was grafted onto bentonite（BT） to generate an AA-graft-BT（AA-g-BT）composite using a plasma-induced grafting technique considered to be an environment-friendly method. The as-prepared composite was characterized by scanning electron microscopy, x-ray powder diffraction, thermal gravity analysis, Fourier transform infrared spectroscopy and Barrett–Emmett–Teller analysis, demonstrating the successful grafting of AA onto BT. In addition, the removal of uranium（VI）（U（VI）） from contaminated aqueous solutions was examined using the as-prepared composite. The influencing factors, including contact time,p H value, ionic strength, temperature, and initial concentration, for the removal of U（VI） were investigated by batch experiments. The experimental process fitted best with the pseudo-secondorder kinetic and the Langmuir models. Moreover, thermodynamic investigation revealed a spontaneous and endothermic process. Compared with previous adsorbents, AA-g-BT has potential practical applications in treating U（VI）-contaminated solutions.

An Improved Combined Power System Utilizing Cold Energy of LNG

In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system simulation and ther^nodynamic analysis were carried out, the Kalina cycle was reorganized by changing the concentration of “basic composition”, so that a better thermal matching in the heat exchanger could be obtained and the irreversibility of the system was decreased. It was found that the Kalina cycle generally used in the bottom of combined power cycle could also be used to recover the cold energy of LNG. The results show that the exergy efficiency of 42.97% is obtained. Compared with the previous system attained the exergy efficiency of 39.76%, the improved system has a better performance.

Autonomous relative optical navigation based on unified modeling of external systematic errors

To solve the problem that external systematic errors of the optical camera cannot be fully estimated due to limited computing resources,a unified dimensionality reduction representation method for the external systematic errors of the optical camera is proposed,and autonomous relative optical navigation is realized.The camera translational and misalignment errors are converted into a three-dimensional rotation error,whose differential model can be established through specific attitude control and appropriate assumption.Then,the rotation error and the relative motion state are jointly estimated in an augmented Kalman filter framework.Compared with the traditional method that estimates the camera translational and misalignment errors,the proposed method reduces the computational complexity in that the estimated state dimension is reduced.Furthermore,as demonstrated by numerical simulation,the estimation accuracy is improved significantly.

C—F Bond Insertion into Indoles with CHBr_(2)F:An Efficient Method to Synthesize Fluorinated Quinolines and Quinolones

A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into indoles using CHBr_(2)F.The simple conditions,readily availability of CHBr_(2)F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and 3-fluoroquinolone.The mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.

A molecular cobaloxime cocatalyst and ultrathin FeOOH nanolayers co-modifiedBiVO_(4) photoanode for efficient photoelectrochemical water oxidation

BiVO_(4) has been attracting a lot of interest in photoelectrochemical (PEC) water oxidation due to its efficient solar absorption and appropriate band positions.So far,sluggish water oxidation kinetics and fast photogenerated charge recombination still hinder the PEC performance ofBiVO_(4) .In this study,a novel PEC photoanode was designed by depositing ultrathin FeOOH nanolayers on the surface of nanoporousBiVO_(4) electrode,followed by modification with a cobaloxime (Co(dmgH)_(2)(4-COOH-py)Cl) molecular cocatalyst.Under irradiation of a 100 mW cm^(-2)(AM 1.5G) Xe lamp,the photocurrent density of the cobaloxime/FeOOH/BiVO_(4) composite photoanode reached 5.1 mA cm^(-2)at 1.23 V vs.RHE in 1.0 M potassium borate buffer solution (pH=9.0).The onset potential of the optimal cobaloxime/FeOOH/BiVO_(4) photoanode exhibited a 460 m V cathodic shift relative to bareBiVO_(4) .In addition,the surface charge injection efficiency of the composite photoanode reached~80%at 1.23 V vs.RHE and the incident photon-to-current efficiency (IPCE) reached~88%at 420 nm.

The degradation of oxadiazon by nonthermal plasma with a dielectric barrier configuration

To explore the feasibility of a degradation approach by non-thermal plasma and the corresponding degradation pathways,studies on the oxadiazon removal in synthetic wastewater by a dielectric barrier discharge plasma reactor were investigated.The loss of the nitro group,dechlorination and ring cleavage is mainly involved in the non-thermal plasma degradation pathways of oxadiazon in a solution based on the OES and LC-MS analysis.Detection of EC25 and the production of the chlorine ion and nitrate ion further demonstrate the feasibility and validity of the approach.The conditions with a proper applied voltage,solution flow rate,oxygen flow rate,and solution pH contribute to the plasma degradation processes with a degradation ratio of over 94%.

DNA damage-mediated cellular senescence promotes hand-foot syndrome that can be relieved by thymidine prodrug

Hand-foot syndrome(HFS)is a widely recognized dose-limiting cutaneous toxicity effect of fluoropyrimidine chemotherapy agents that impairs clinical benefits and treatment outcomes.Even though the cause and pathophysiology of HFS are relatively widely reported,how the toxicity of fluoropyrimidine translates into persistent inflammation has not been studied.Additionally,prevention and treatment strategies for HFS based on its mechanistic occurrence and development are scarce.In our study,we demonstrated that cGAS-STING signaling pathway-mediated cellular senescence played a critical role in the inflammatory reaction and provided a therapeutic solution for HFS.Mechanistically,DNA damage,as the primary cytotoxic cause,in keratinocytes induces cell cycle arrest,activates the cGAS-STING signaling pathway,and subsequently mediates cellular senescence,ultimately fueling a robust secondary inflammatory response that results in HFS.More importantly,the thymidine prodrug thymidine diacetate was proven to be effective in preventing HFS by compensating for thymidylate deficiency to facilitate the replication and repair of DNA and thus causing the escape from cellular senescence.These data highlight the importance of DNA damage-mediated cellular senescence in the etiology of HFS and provide a potential therapeutic anchor point for fluoropyrimidine-induced HFS.

Can software-defined vehicles never roll over:A perspective of active structural transformation

The revolution of physical structure is highly significant for future software defined vehicles(SDV).Active structural transformation is a promising feature of the next generation of vehicle physical structure.It can enhance the dynamic performance of vehicles,thus providing safer and more comfortable ride experiences,such as the ability to avoid rollover in critical situations.Based on the active structural transformation technology,this study proposes a novel approach to improve the dynamic performance of a vehicle.The first analytical motion model of a vehicle with active structural transformation capability is established.Then,a multi-objective optimization problem with the adjustable parameters as design variables is abstracted and solved with an innovative scenario specific optimization method.Simulation results under different driving scenarios revealed that the active transformable vehicle applying the proposed method could significantly improve the handling stability without sacrificing the ride comfort,compared with a conventional vehicle with a fixed structure.The proposed method pipeline is defined by the software and supported by the hardware.It fully embodies the characteristics of SDV,and inspires the improvement of multiple types of vehicle performance based on the concept of“being defined by software”and the revolution of the physical structure.

Synthesis of novel nanomaterials and their application in efficient removal of radionuclides

With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment. Nanomaterials have been considered as the potential candidates for the effective and selective removal of radionuclides from aqueous solutions under complicated conditions because of their high specific surface area, large amounts of binding sites, abundant functional groups, pore-size controllable and easily surface modification. This review mainly summarized the recent studies for the synthesis, fabrication and surface modification of novel nanomaterials and their applications in the efficient elimination and solidification of radionuclides,and discussed the interaction mechanisms from batch experiments, spectroscopy analysis and theoretical calculations. The sorption capacities with other materials, advantages and disadvantages of different nanomaterials are compared, and at last the perspective of the novel nanomaterials is summarized.

基于YOLOv5的移动机器人动态视觉SLAM算法研究

移动机器人在未知环境中,通过同步定位与地图构建(SLAM)技术,实现了精准的自身定位功能。目前大多数视觉SLAM系统均假设环境是静态的,但在实际应用中,由于大量动态目标的存在,严重影响机器人的定位与建图精度。为改善这一情况,本文基于ORB-SLAM3系统提出一种鲁棒的动态视觉SLAM系统,其融合YOLOv5深度学习方法,以减少动态目标的影响。并在公共TUM数据集和真实场景中测试本文算法的性能,结果表明:本文算法与ORB-SLAM3相比,具有更高的鲁棒性。

Novel phthalimides regulating PD-1/PD-L1 interaction as potential immunotherapy agents

Programmed cell death 1(PD-1)/programmed cell death ligand 1(PD-L1)have emerged as one of the most promising immune checkpoint targets for cancer immunotherapy.Despite the inherent advantages of small-molecule inhibitors over antibodies,the discovery of small-molecule inhibitors has fallen behind that of antibody drugs.Based on docking studies between small molecule inhibitor and PD-L1 protein,changing the chemical linker of inhibitor from a flexible chain to an aromatic ring may improve its binding capacity to PD-L1 protein,which was not reported before.A series of novel phthalimide derivatives from structure-based rational design was synthesized.P39 was identified as the best inhibitor with promising activity,which not only inhibited PD-1/PD-L1 interaction(IC_(50)=8.9 nmol/L),but also enhanced killing efficacy of immune cells on cancer cells.Co-crystal data demonstrated that P39 induced the dimerization of PD-L1 proteins,thereby blocking the binding of PD-1/PD-L1.Moreover,P39 exhibited a favorable safety profile with a LD_(50)>5000 mg/kg and showed significant in vivo antitumor activity through promoting CD8^(+)T cell activation.All these data suggest that P39 acts as a promising small chemical inhibitor against the PD-1/PD-L1 axis and has the potential to improve the immunotherapy efficacy of T-cells.

Arctic sea ice thickness variations from CryoSat-2 satellite altimetry data

Arctic sea ice plays an important role in Earth's climate and environmental system.Sea ice thickness is one of the most important sea ice parameters.Accurately obtaining the sea ice thickness and its changes has great significance to Arctic and global change research.Satellite altimeters can be used to derive long-term and large-scale changes in sea ice thickness.The leads detection is vital in sea ice thickness estimation by using satellite altimetry.Different leads detection methods are compared with remote sensing images,and results show that the detection method that uses waveform parameters can obtain improved results.The model for the conversion of freeboard to thickness is optimized by considering the incomplete penetration of snow for radar altimeters.We derive the estimates of the Arctic sea ice thickness for November 2010 to December 2019 by using the CryoSat-2 altimetry data.The sea ice thickness from the IceBridge and draft data from the upward-looking sonar are used to validate our thickness results.Validations show that the accuracy of our thickness estimates is within 0.2 m.Variations in the Arctic sea ice thickness are analyzed using the PIOMAS model and air and sea surface temperatures.A sharp increase in sea ice thickness is found in 2014.

Genomes of 12 fig wasps provide insights into the adaptation of pollinators to fig syconia

Figs and fig pollinators are one of the few classic textbook examples of obligate pollination mutualism.The specific dependence of fig pollinators on the relatively safe living environment with sufficient food sources in the enclosed fig syconia implies that they are vulnerable to habitat changes.However,there is still no extensive genomic evidence to reveal the evolutionary footprint of this long-term mutually beneficial symbiosis in fig pollinators.In fig syconia,there are also non-pollinator species.The non-pollinator species differ in their evolutionary and life histories from pollinators.We conducted comparative analyses on 11 newly sequenced fig wasp genomes and one previously published genome.The pollinators colonized the figs approximately 66.9 million years ago,consistent with the origin of host figs.Compared with nonpollinators,many more genes in pollinators were subject to relaxed selection.Seven genes were absent in pollinators in response to environmental stress and immune activation.Pollinators had more streamlined gene repertoires in the innate immune system,chemosensory toolbox,and detoxification system.Our results provide genomic evidence for the differentiation between pollinators and nonpollinators.The data suggest that owing to the long-term adaptation to the fig,some genes related to functions no longer required are absent in pollinators.

Development and clinical advancement of small molecules for ex vivo expansion of hematopoietic stem cell

Hematopoietic stem cell(HSC) transplantation is the only curative therapy for many diseases.HSCs from umbilical cord blood(UCB) source have many advantages over from bone marrow.However,limited HSC dose in a single CB unit restrict its widespread use.Over the past two decades,ex vivo HSC expansion with small molecules has been an effective approach for obtaining adequate HSCs.Till now,several small-molecule compounds have entered the phase Ⅰ/Ⅱ trials,showing safe and favorable pharmacological profiles.As HSC expansion has become a hot topic over recent years,many newly identified small molecules along with novel biological mechanisms for HSC expansion would help solve this challenging issue.Here,we will give an overview of HSC biology,discovery and medicinal chemistry development of small molecules,natural products targeting for HSC expansion,and their recent clinical progresses,as well as potential protein targets for HSC expansion.

Static aeroelasticity analysis of a rotor blade using a Gauss-Seidel fluid-structure interaction method

The present study introduces a Gauss-Seidel fluid-structure interaction(FSI)method including the flow solver,structural statics solver and a fast data transfer technique,for the research of structural deformation and flow field variation of rotor blades under the combined influence of steady aerodynamic and centrifugal forces.The FSI method is illustrated and validated by the static aeroelasticity analysis of a transonic compressor rotor blade,NASA Rotor 37.An improved local interpolation with data reduction(LIWDR)algorithm is introduced for fast data transfer on the fluid-solid interface of blade.The results of FSI calculation of NASA Rotor 37 show that when compared with the radial basis function(RBF)based interpolation algorithm,LIWDR meets the interpolation accuracy requirements,while the calculation cost can be greatly improved.The data transmission time is only about 1%of that of RBF.Moreover,the iteration step of steady flow computation within one single FSI has little impact on the converged aerodynamic and structural results.The aerodynamic load-caused deformation accounts for nearly 50%of the total.The effects of blade deformation on the variations of aerodynamic performance are given,demonstrating that when static aeroelasticity is taken into account,the choke mass flow rate increases and the peak adiabatic efficiency slightly decreases.The impact mechanisms on performance variations are presented in detail.

Regulated adsorption sites using atomically single cluster over biochar for efficient elemental mercury uptake

Carbon-based materials have been widely used in gaseous pollutant removal because of their sufficient surface functional groups;however,its removal efficiency for elemental mercury(Hg^(0))is low.In this study,we fabricated biomass using a chelated coupled pyrolysis strategy and further constructed the regulated adsorption sites for gaseous Hg^(0) uptake.A series of Mnδ-N_(2)O_(2)/BC with different manganese cluster sizes demonstrated that manganese clusters anchored on biochar acted as highly active and durable adsorbents for Hg^(0) immobilization,which increased the adsorption efficiency of Hg^(0) by up to 50%.Shrimp-and crab-based biochar adsorbents exhibited excellent Hg^(0) removal because of their chitosan-like structure.In particular,small Mn clusters and oxygen species around the defect led to a boost in the Hg^(0) adsorption by carbon.The results of density functional theory calculation revealed that the presence of oxygen in the carbon skeleton can tune the electrons of small-sized Mn clusters,thereby promoting the affinity of mercury atoms.The newly developed Mnδ-N_(2)O_(2)/BC_(shrimp) had an adsorption capacity of 7.98-11.52 mg g^(−1) over a broad temperature range(50-200℃)and showed a high tolerance to different industrial flue gases(H_(2)O,NO,HCl,and SO_(2)).These results provide novel green and low-carbon disposal methods for biomass resource utilization and industrial Hg^(0) emission control.

基于双流体模型的尊村泵站双吸离心泵泥沙磨损

黄河尊村二级泵站的高效稳定运行一直都受水泵的泥沙磨损问题制约,其影响因素包括过泵水流的泥沙体积分数和泥沙粒径.采用双流体模型对尊村二级泵站的双吸离心泵内水沙两相流进行数值模拟,在模型中考虑了颗粒动态尺度对颗粒湍动扩散系数的影响,以及颗粒的惯性和湍动对相间阻力的影响;采用Oka磨损模型计算了泵内泥沙磨损.模拟了由4种典型泥沙体积分数和4种典型泥沙粒径组合成的16种入口泥沙工况,在此基础上研究了入口泥沙体积分数和泥沙粒径对泵内磨损的影响规律.结果表明,不同泥沙条件下该泵发生严重磨损的区域主要位于叶片和蜗壳,其中叶片中后部和蜗壳隔舌的磨损最为严重.随着入口泥沙体积分数增加,叶片和蜗壳的磨损速率呈线性趋势上升;随着泥沙粒径的增加,叶片和蜗壳的磨损速率呈现小幅度增加,且磨损速率增长斜率随粒径增加逐渐放缓.根据该结果,可采取措施降低过泵水流中的泥沙体积分数和泥沙粒径以缓解双吸离心泵内的泥沙磨损.

广西山地农业化背景下鸟类多样性比较

随着农业用地需求增加,生物多样性受到严重威胁并急剧下降。为探讨农业化对鸟类多样性的影响,本文在2020年10月至2021年10月期间,对广西大瑶山、大明山、十万大山3个国家级自然保护区以及周边农田区域内鸟类进行了调查。研究选取森林、近地农田(距离森林较近的农田)、远地农田(距离森林较远的农田)3种生境,布设样点共计180个,并在不同季节(春、夏、秋、冬)对鸟类多样性进行了调查。结果如下:(1)3种生境物种累积曲线呈先快速上升,后变为渐近线或增速放缓趋势,各生境实际调查鸟类物种数与预测值比例均大于60%,表明鸟类调查充分;(2)共记录到鸟类196种,隶属于14目54科,其中雀形目鸟类占比最高(71.4%)。不同生境记录到鸟类种数从多到少依次为:森林(103)、近地(101)、远地(94);(3)相似性分析结果表明,森林与近地农田和远地农田间鸟类相似性差异都较大,近地与远地间鸟类群落更为相似;(4)3种生境鸟类群落Shannon-Wiener多样性指数在不同季节里均表现为:远地>近地>森林;(5)广义线性混合模型结果显示,两种农田生境鸟类多样性显著高于森林,而近地和远地农田生境间鸟类多样性无显著差异。研究结果表明,虽然森林鸟类多样性较低,但对其特有种具有较高的保护作用;尽管鸟类对农田生境表现出更高的喜好,但农田内人为干扰较为频繁,缺乏相关的保护措施,应加强对农田鸟类的保护。

Ozonated graphene oxides as high efficient sorbents for Sr(Ⅱ) and U(Ⅵ) removal from aqueous solutions

Ozone was used to oxidize graphene oxides （GO） to generate ozonated graphene oxides （OGO） with higher oxygen-containing functional groups. The as-prepared OGO was characterized by Fourier transformed infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS）. Based on the results of potentiometric acid-base ti- trations, the total carboxylic acid concentration on OGO surface was calculated to be 3.92 retool/g, which was much higher than that on GO surface. The results of adsorption experiments indicated that the adsorption capacities of OGO for Sr（II） and U（VI） removal were improved significantly after ozonization.