Potential of eNose Technology for Monitoring Biological CO_(2) Conversion Processes

Electronic nose(eNose) is a modern bioelectronic sensor for monitoring biological processes that convert CO_(2) into valueadded products, such as products formed during photosynthesis and microbial fermentation. eNose technology uses an array of sensors to detect and quantify gases, including CO_(2), in the air. This study briefly introduces the concept of eNose technology and potential applications thereof in monitoring CO_(2) conversion processes. It also provides background information on biological CO_(2) conversion processes. Furthermore, the working principles of eNose technology vis-à-vis gas detection are discussed along with its advantages and limitations versus traditional monitoring methods. This study also provides case studies that have used this technology for monitoring biological CO_(2) conversion processes. eNose-predicted measurements were observed to be completely aligned with biological parameters for R~2 values of 0.864, 0.808, 0.802, and 0.948. We test eNose technology in a variety of biological settings, such as algae farms or bioreactors, to determine its effectiveness in monitoring CO_(2) conversion processes. We also explore the potential benefits of employing this technology vis-à-vis monitoring biological CO_(2) conversion processes, such as increased reaction efficiency and reduced costs versus traditional monitoring methods. Moreover, future directions and challenges of using this technology in CO_(2) capture and conversion have been discussed. Overall, we believe this study would contribute to developing new and innovative methods for monitoring biological CO_(2) conversion processes and mitigating climate change.

Grafting polymeric sulfur onto carbon nanotubes as highly-active cathode for lithium–sulfur batteries

Lithium–sulfur(Li–S)batteries are being explored as promising advanced energy storage systems due to their ultra-high energy density.However,fast capacity fading and low coulombic efficiency,resulting from the dissolution of polysulfides,remain a serious challenge.Compared to weak physical adsorptions or barriers,chemical confinement based on strong chemical interaction is a more effective approach to address the shuttle issue.Herein,we devise a novel polymeric sulfur/carbon nanotube composite for Li–S battery,for which 2,5-dithiobiurea is chosen as the stabilizer of long-chain sulfur.This offers chemical bonds which bridge the polymeric sulfur and carbon nanotubes.The obtained composite can deliver an ultra-high reversible capacity of 1076.2 m Ahg^-1(based on the entire composite)at the rate of 0.1 C with an exceptional initial Coulombic efficiency of 96.2%,as well as remarkable cycle performance.This performance is mainly attributed to the reaction reversibility of the obtained polymeric sulfur-based composite during the discharge/charge process.This was confirmed by density functional theory calculations for the first time.

Interface coupling effects of weakly nonlinear Rayleigh–Taylor instability with double interfaces

Taking the Rayleigh–Taylor instability with double interfaces as the research object,the interface coupling effects in the weakly nonlinear regime are studied numerically.The variation of Atwood numbers on the two interfaces and the variation of the thickness between them are taken into consideration.It is shown that,when the Atwood number on the lower interface is small,the amplitude of perturbation growth on the lower interface is positively related with the Atwood number on the upper interface.However,it is negatively related when the Atwood number on the lower interface is large.The above phenomenon is quantitatively studied using an analytical formula and the underlying physical mechanism is presented.

Quantitative characterization of cell physiological state based on dynamical cell mechanics for drug efficacy indication

Cell mechanics is essential to cell development and function,and its dynamics evolution reflects the physiological state of cells.Here,we investigate the dynamical mechanical properties of single cells under various drug conditions,and present two mathematical approaches to quantitatively characterizing the cell physiological state.It is demonstrated that the cellular mechanical properties upon the drug action increase over time and tend to saturate,and can be mathematically characterized by a linear timeinvariant dynamical model.It is shown that the transition matrices of dynamical cell systems significantly improve the classification accuracies of the cells under different drug actions.Furthermore,it is revealed that there exists a positive linear correlation between the cytoskeleton density and the cellular mechanical properties,and the physiological state of a cell in terms of its cytoskeleton density can be predicted from its mechanical properties by a linear regression model.This study builds a relationship between the cellular mechanical properties and the cellular physiological state,adding information for evaluating drug efficacy.

灿烂紫荆,情满紫圆--论紫砂壶“紫荆同心”的艺术美感与时代意义

紫砂壶艺术重视工艺表现,重视文化内涵,也重视与时代的联系。时值中国共产党百年华诞之际,“紫荆同心”这件紫砂通过精美的艺术设计庆祝了香港回归,用那灿烂盛开的紫荆花装饰象征了两岸及同胞之间深厚的情感,表达了在党的领导下,祝愿国家民族更加和谐,两岸共同繁荣发展的美好愿望。

The Effect of Different Artificial Soil on Urban Non-Point Source Pollution Reduction in the Artificial Rapid Infiltration System

The non-point source pollution posed great risks to the urban water environment which has aroused great concerns. Artificial rapid infiltration systems have been widely used in sewage treatment, which have great environmental and economic values. This study investigated the potential of utilizing artificial rapid infiltration systems on the reduction of urban non-point source pollution. The obtained results showed that the components and composition of artificial soils were vital to the operational performance. The mixture of natural soil, coarse sand and zeolite was ideal for the construction of artificial soils. The permeability coefficient of soils could be improved to 0.166 cm/min at the optimized ratio of 1:1:0.05 (natural soil, coarse sand and zeolite). Also, high removal efficiency for the typical pollutants in rain runoffs (i.e. COD, NH4+-N, TN and TP) could be simultaneous obtained which was above 74% in the artificial rapid infiltration systems. The results demonstrated the effectiveness on the reduction of urban non-point pollution by optimized artificial rapid infiltration system.

An Amorphous 2-Dimensional Barcode

Most existing 2-dimensional barcodes are designed with a fixed shape and clear area.Having a fixed shape and clear area makes the barcode difficult to lay out with other text and pictures.To solve this problem,an amorphous 2-dimensional barcode is presented in this paper.The barcode uses encoding graph units to encode data.There are two key points in a 2-dimensional barcode:One is the encoding graph unit,the other is its encoding rules.Because encoding graph units of a 2-dimensional barcode are surrounded by other graphics,the units should be self-positioned and distinguished from other units.This paper presents an encoding graph unit generation algorithm,which is based on genetic algorithms.Encoding rules of the barcode are also given in this paper.Those rules include data encoding rules and encoding graph unit sequence arrangement rules.Data encoding rules are used to encode data to an encoding graph unit sequence.Encoding graph unit sequence arrangement rules are used to embed the unit sequence in the target picture.In addition to those rules,it also discussed the steps to restore encoding graph unit sequence from a picture.In the experiments section of this paper,an example is provided to encode a string and embed it in a car ad picture by the barcode.According to encoding rules of the barcode,those encoding graphic units can be scattered and embedded in a picture with other graphics,so amorphous 2-dimensional barcode has no fixed shape.Take advantage of this,designer can present a more elegant design to lay out barcodes with other graphic elements.

机构投资者交叉持股能提高会计信息可比性吗?

文章以2008-2017年A股上市公司为样本进行研究,发现交叉持有焦点公司大宗股权的机构投资者越多,焦点公司的会计信息可比性越高;焦点公司的机构大股东持有大宗股权的其他公司越多,焦点公司的会计信息可比性越高。进一步研究发现上述关系在公司信息不对称及代理问题严重时更为显著;中介效应检验的结果表明,机构投资者交叉持股通过减少同行竞争、提高信息披露质量来提高会计信息可比性。

Theoretical and simulation research of hydrodynamic instabilities in inertial-confinement fusion implosions

Inertial fusion energy （IFE） has been considered a promising, nearly inexhaustible source of sustainable carbon-free power for the world＇s energy future. It has long been recognized that the control of hydrodynamic instabilities is of critical importance for ignition and high-gain in the inertial-confinement fusion （ICF） hot-spot ignition scheme. In this mini-review, we summarize the progress of theoretical and simulation research of hydrodynamic instabilities in the ICF central hot-spot implosion in our group over the past decade. In order to obtain sufficient understanding of the growth of hydrodynamic instabilities in ICF, we first decompose the problem into different stages according to the implosion physics processes. The decomposed essential physics pro- cesses that are associated with ICF implosions, such as Rayleigh-Taylor instability （RTI）, Richtmyer-Meshkov instability （RMI）, Kelvin-Helmholtz instability （KHI）, convergent geometry effects, as well as perturbation feed-through are reviewed. Analyti- cal models in planar, cylindrical, and spherical geometries have been established to study different physical aspects, including density-gradient, interface-coupling, geometry, and convergent effects. The influence of ablation in the presence of preheating on the RTI has been extensively studied by numerical simulations. The KHI considering the ablation effect has been discussed in detail for the first time. A series of single-mode ablative RTI experiments has been performed on the Shenguang-II laser facility. The theoretical and simulation research provides us the physical insights of linear and weakly nonlinear growths, and nonlinear evolutions of the hydrodynamic instabilities in ICF implosions, which has directly supported the research of ICF ignition target design. The ICF hot-spot ignition implosion design that uses several controlling features, based on our current understanding of hydrodynamic instabilities, to address shell implosion stability, has been briefly described, several of which are novel.

Removal of benzotriazole by heterogeneous photoelectro-Fenton like process using ZnFe_2O_4 nanoparticles as catalyst

ZnFe2O4 nanoparticles （ZFNPs） were developed as catalyst for the degradation of benzotriazole （BTA） by heterogeneous photoelectro- Fenton （PE-Fenton） like process. ZFNPs were prepared by a co-precipitation process and then characterized with transmission electron microscopy （TEM）, X-ray fluorescence （XRF）, X-ray diffraction （XRD） and BET surface area. Using such ZFNPs as catalyst, the degradation of BTA was investigated. Due to the high catalytic activity of ZFNPs, PE-Fenton like process showed efficient degradation of BTA. The influencing factors such as pH, dosage of ZFNPs, applied potential and initial concentration of BTA were systematically investigated. Under the optimum conditions, 91.2% of BTA was removed after 180 rain treatment.

Genome editing and animal models

Transgenic technology allows a gene of interest to be introduced into the genome of a laboratory animal,and provides an extremely powerful tool to dissect the molecular mechanisms of disease.Transgenic mouse models made by microinjection of DNA into zygotic pronuclei in particular have been widely used by the genetics community for 30 years.However,it remains a rather crude approach:injected sequences randomly insert in multiple copies as concatamers,they can be mutagenic,and they have variable or silenced expression depending on the site of integration,a phenomenon called position effects.As a result,multiple lines are required in order to confirm appropriate transgene expression.This can be partially overcome by flanking transgenes with insulator sequences to protect the transgene from the influence of the surrounding regulatory elements.Large(\300 kb)BACbased transgenic vectors have also been shown to be more resistant to position effects.However,animals carrying extra copies of fairly large regions of the genome could have unpredictable phenotypes.The most effective method used to control for position effects is to target transgene insertion to specific genomic loci,the so-called targeted transgenesis;for instance,the fast,site-specific transgenic technology Targatt TM.The purpose of this review is to provide an overview on the current existing methods for making targeted transgenic mouse models.

Friction and Wear Behavior of Resin/Graphite Composite under Dry Sliding

The friction and wear behavior of resin/graphite composite has been investigated using a pin-on-disc configuration under dry sliding condition. The results showed that the resin/graphite composite exhibited much better mechanical and tribological properties compared with the unimpregnated graphite. The friction coefficient was reduced by addition of furan resin, which could also prevent the'dusting' wear at loads more than 15 MPa. The steady and lubricated transfer film was easily formed on the counterpart surface due to the interaction of furan resin and wear debris of graphite, which was useful to reduce the wear rate of the resin/graphite composite. The composite is highly promising for mechanical sealing application and can be used at high load for long time sliding.

Polypropylene microplastics alter the cadmium adsorption capacity on different soil solid fractions

Microplastics(MPs)are widely present in a variety of environmental media and have attracted more and more attention worldwide.However,the effect of MPs on the interaction between heavy metals and soil,especially in soil solid fraction level,is not well understood.In this study,batch experiments were performed to investigate the adsorption characteristics of Cd in bulk soil and three soil solid fractions(i.e.particulate organo matter(POM),organic-mineral compounds(OMC),and mineral)with or without polypropylene(PP)MPs.The results showed that the addition of PP-MPs reduced the Cd adsorption capacity of the bulk soil in aqueous solution,and the effects varied with PP-MPs dose and aging degree.Whereas,the responses of the three fractions to PP-MPs were different.In presence of PP-MPs,the POM and OMC fractions showed negative adsorption effects,while the mineral fraction showed positive adsorption.For the bulk soil,POM and OMC fractions,the adsorption isotherm fitted to the Langmuir model better than the Freundlich model,whereas,the Freundlich isotherm model was more fitted for the mineral fraction.Combined with the comprehensive analysis of the partitioning coefficients,XRD and FTIR results,it was found that OMC fraction extremely likely play a leading role in the bulk soil adsorption of Cd in this study.Overall,the effect of MPs on adsorption capacity of the bulk soil for Cd may be determined by the proportion of POM,OMC,and mineral fractions in the soil,but further confirmation is needed.

Mechanical Response of Conductor on Round Core(CORC)Cables Under Electromagnetic Force

The conductor on round core(CORC)cables are fabricated with multilayer high-temperature superconductor tapes,which are helically wound around a circular central former.The large Lorentz force will be generated by the transport current in CORC cables under high magnetic field,which will affect the stress and strain distributions of tapes in the cables and the performance of superconducting tape.This paper establishes a two-dimensional axisymmetric model to analyze the mechanical response of CORC cables subjected to the Lorentz force and analyzes the influence of air gaps on stress and strain distributions inside the cables.The T-A method is used to calculate the distributions of current density,magnetic field and the Lorentz force in CORC cables.The mechanical response of CORC cables is analyzed by applying the Lorentz force as an external load in the mechanical model.The direction of electromagnetic force is analyzed in CORC cables with and without shielding current,and the results show that the shielding current can lead to the concentration of electromagnetic force.The maximum stress and strain occur on both sides of the superconducting tapes in the cables with shielding current.Reducing the size of air gaps can reduce the stress and strain in the superconducting layers.The analysis of mechanical response of CORC cables can play an important role in optimizing the design of CORC cables and improving transmission performance.

Grafting polysulfides into a functional N-halo compound for high-performance lithium—sulfur battery

Due to its high energy density,lithium-sulfur(Li-S)battery is considered as the most promising candidate for the energy storage systems,but its practical application is hindered by the dissolution of lithium polysulfides in the electrolyte.In this work,N-bromophthalimide(C8H4NO2Br,NBP),an aromatic molecule with carbophilic,sulfiphilic,lithiophilic,and solvophilic nature,is introduced into active graphene(AG)to fabricate the sulfur composite cathode.The carbophilic NBP is anchored readily on the AG surface viaπ−πstacking interaction.During discharging,the dissolved lithium polysulfide anion(LiS−n)is grafted into the sulfiphilic NBP spontaneously via SN2 substitution reaction to form C8H4NO2SnLi,which brings the dissolved LiS−n back to the AG surface in the composite cathode.Moreover,the lithiophilic and solvophilic nature of NBP improve the wettability of the porous composite cathode,and the electrolyte molecule is easily penetrated into the micro-mesopores of AG to facilitate the diffusion of the electrolyte.Thus,NBP,as a multi-functional compound in Li-S battery,can immobilize LiS−n and enhance the diffusion of the electrolyte.The above features of NBP endow the sulfur composite cathode with improved electrochemical performance in the cycling stability.

Numerical study on the laser ablative Rayleigh-Taylor instability

The laser ablative Rayleigh-Taylor instability plays an important role in the ignition of inertial refinement fusion.An accurate simulation of this process is important to control the growth of flow instability during the implosion.In this paper,taking the simulations of the hydrodynamics,the laser energy deposition and the electronic thermal conductivity into consideration,a massively parallel laser ablative Rayleigh-Taylor instability code based on Euler method is developed.Some open source codes are used to improve the code development efficiency.The accuracy of the hydrodynamics simulation is tested by an analytical theory about the weakly nonlinear Rayleigh-Taylor instability with double interfaces.The benchmark of an one dimensional heat conductivity is used to test the accuracy of the thermal conductivity simulation.The laser ablative plane target and the laser ablative Rayleigh-Taylor instability are used to test the reliability of the code on the simulation of the whole laser ablative process.It is shown that the confidence of our numerical simulation code is high and the code framework we designed is effective.It can be a basis on studying the problems about the laser ablative instability in inertial refinement fusion.

Fish Density Estimation with Multi-Scale Context Enhanced Convolutional Neural Network

With the development of fishery industry,accurate estimation of the number of fish in aquaculture waters is of great importance to fish behavior analysis,bait feeding and fishery resource investigation.In this paper,we propose a method for fish density estimation based on the multi-scale context enhanced convolutional network,which could map a fish school image taken at any angle to a density map,and calculate the number of fish in the image finally.In order to eliminate the influence of camera perspective effect and image resolution on density estimation,multi-scale filters are utilized in a convolutional neural network to process fish image in parallel.And then,the context enhancement module is merged in the network structure to help the network understand the global context information of the image.Finally,different feature maps are merged together to construct the density map of fish school images,and finally get the number of fish in the image.In order to make the effectiveness of our method valid,we test the proposed method on DlouDataset.The results show that the proposed method has lower mean square error and mean absolute error,which is helpful to improve the accuracy of the fish counting in dense fish school images.

Infrared broadband nonlinear optical limiting technology based on stimulated Brillouin scattering in As_(2)Se_(3) fiber

A novel infrared broadband nonlinear optical limiting[NOL]technology based on stimulated Billouin scattering(SBS)in As_(2)Se_(3) fiber is proposed.The As_(2)Se_(3) fiber alows a weak infrared laser to pass through,but blocks an intense laser with the same wavelength due to the SBS effect.This NOL technology has been experimentally proved to have excellent NOL per-formance for incident pulsed lasers with a typical infrared wavelength of 3.6μm.The linear transmissions of 1 m and 0.5 m As_(2)Se_(3) fibers are higher than 90%,and the lowest nonlinear transmissions are reduced to 0.89%and 1.23%,respectively.

资本市场开放缓解了企业的投融资期限错配吗?——基于“沪深港通”交易制度的经验证据

投融资期限错配是诱发金融风险的重要因素。本文基于“沪深港通”交易制度实施这一准自然实验场景,深入探讨资本市场开放对企业投融资期限错配的影响及其作用机制。研究发现,资本市场开放显著改善了标的企业的投融资期限错配,这主要是依靠缓解融资约束与抑制管理层非理性行为来实现的。进一步研究发现,资本市场开放对投融资期限错配的改善作用在信息环境较差、内部治理水平较低的公司样本中更加显著;并且资本市场开放能够显著降低投融资期限错配导致的债务违约风险。本文为继续推进资本市场开放、降低流动性风险提供了理论支持和经验证据。

Distributed state estimation for linear timeinvariant dynamical systems:A review of theories and algorithms

Distributed state estimation is of paramount importance in many applications involving the large-scale complex systems over spatially deployed networked sensors.This paper provides an overview for analysis of distributed state estimation algorithms for linear time invariant systems.A number of previous works are reviewed and a clear classification of the main approaches in this field are presented,i.e.,Kalman-filter-type methods and Luenberger-observer-type methods.The design and the stability analysis of these methods are discussed.Moreover,a comprehensive comparison of the existing results is provided in terms of some standard metrics including the graph connectivity,system observability,optimality,time scale and so on.Finally,several important and challenging future research directions are discussed.