High level of extra-pair paternity in the socially monogamous Marsh Tits(Poecile palustris)

Background:Extra-pair copulation behavior has been widely studied among socially monogamous birds.Many species revealed high rates of extra-pair paternity.But few of the studies have been carried out in the Asian population.Methods:From 2012 to 2019,we explored the extra-pair paternity of Marsh Tits(Poecile palustris)in Xianrendong National Nature Reserve,Liaoning Province,China.During the study,adult Marsh Tits were captured with mist nets and parental birds,with nest-box traps.Blood samples were taken from the brachial vein.Parentage analyses were carried out using nine highly variable microsatellite loci through Cervus 3.0 software and maximum likelihood approach.Results:Forty-nine offspring(15.08%)from 20 nests(45.45%)were the results of extra-pair fertilization out of a total of 325 offspring in 44 nests.The average extra-pair offspring ratio was 33.54%,with a set varying from 11.11 to 71.43%.Nine extra-pair fathers had been successfully identified,four of whom were the close neighbors of the focus nest while the nests of the remaining five were relatively far.No significant difference was found in the genetic similarity between the social and extra-pair mates of the female,nor in the heterozygosis among the maternal half-siblings.Conclusions:In general,our study proved that the extra-pair paternity in Marsh Tits and its extra-pair mating is independent of the genetic compatibility hypothesis.This complements the understudied bird's extra-pair paternity in Asian area and contributes to the comprehensive insight of birds'extra-pair paternity behaviors.

Obstacle Avoidance Method for a Redundant Manipulator Based on a Configuration Plane

This paper presents a novel approach of obstacle avoidance for redundant manipulators, which is challenging with the considerations of the building of universal kinematics, the formation of dynamics, and the generation of trajectories. A universal approach to deal with obstacle avoidance for the redundant manipulator, that is based on the configuration plane, is presented. The paper also examines common serial robot configurations and introduces a method for classification, partitioning, simplification, and forms of expression used in the workspace to define the configuration plane. This relatively new method is combined with a weighted space vector method to match the configuration plane and solve the inverse kinematics problem. The proposed planner is demonstrated with examples, in which the proposed planner is shown to be capable of providing a smoother trajectory.

Planar Serial Manipulator Motion Synthesis

： This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type, the fast working space solution method, and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target, it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspaee boundary method, an expressing method of the polar coordinate form of work space is then introduced. Finally, according to the form of plane trajectory planning for obstacle avoidance problem, the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.

Design of Heading Fault-Tolerant System for Underwater Vehicles Based on Double-Criterion Fault Detection Method

This paper proposes a heading fault tolerance scheme for operation-level underwater robots subject to external interference.The scheme is based on a double-criterion fault detection method using a redundant structure of a dual electronic compass.First,two subexpansion Kalman filters are set up to fuse data with an inertial attitude measurement system.Then,fault detection can effectively identify the fault sensor and fault source.Finally,a fault-tolerant algorithm is used to isolate and alarm the faulty sensor.The program can effectively detect the constant magnetic field interference,change the magnetic field interference and small transient magnetic field interference,and conduct fault tolerance control in time to ensure the heading accuracy of the system.Test verification shows that the system is practical and effective.

Effect of matrix resin components on properties of the semi-conductive shielding material for high-voltage cable

The semi-conductive shielding layer is an important part of the high-voltage cable,playing a role in uniform electric field and reducing the air gap at the interface.The overall performance of the cable is affected by the semi-conductive shielding layer with different base resin composition.The matrix resins of ethylene-vinyl acetate(EVA),ethylene-ethyl acrylate(EEA)and ethylene-butyl acrylate(EBA)were used to prepare the semi-conductive shielding materials of CB/EVA,CB/EEA and CB/EBA.The influences of different matrix resins on the chemical,electrical,thermal and mechanical properties of the shielding materials were investigated.The results show that CB has the best dispersion in EBA resin and the worst dispersion in EEA resin.The temperature in-flection points of CB/EVA,CB/EEA and CB/EBA shielding materials are 90°C,100°C and 110°C,respectively,and the CB/EBA shielding material has the lowest resistivity and the weakest positive temperature coefficient effect at room temperature.The thermal conductivity of all three matrix resins is smaller than that of the shielding material,the thermal conductivity of CB/EVA and CB/EBA shielding materials show a slow increase with temperature,and the CB/EEA shielding material is the least affected by the tem-perature.The mechanical properties of the three matrix resins and the three shielding materials are EBA>EVA>EEA,among them the stress of CB/EBA shielding material is 31.0 MPa and the strain is 570%.This work has important reference significance for the selection of shielding layer matrix resin and material formulation in engineering applications.

Evaluation of new IPSS-Molecular model and comparison of different prognostic systems in patients with myelodysplastic syndrome

A risk-adapted treatment strategy is of crucial importance in patients with myelodysplastic syndromes(MDS).Previous risk prognostic scoring systems did not integrate molecular abnormalities.The new IPSS-Molecular(IPSS-M)model,combing genomic profiling with hematologic and cytogenetic parameters,was recently developed to evaluate the associations with leukemia-free survival(LFS),leukemic transformation,and overall survival(OS).However,it has not yet been widely validated in clinics.This study aims to further validate the prognostic power of IPSS-M based on real-world data and to compare the prognostic value of different scoring systems in patients with MDS.IPSS-M Web calculator was used to calculate a tailored IPSS-M score of the enrolled patient(N=255),and the risk category was defined correspondingly.We next compared the IPSS-M prognostic power to that of IPSS,IPSS-R,and WPSS.We found that IPSS-M risk classification was statistically significant for 3-year OS and LFS.Compared with other tools,IPSS-M was superior in sensitivity and accuracy for 3-year OS and LFS.The mapping C-index between IPSS-R and IPSS-M categories resulted in improved discrimination across the OS,but not LFS and leukemic transformation.The result of different treatment options indicated that allogeneic hematopoietic stem cell transplantation(allo-HSCT)can result in a better OS than those without allo-HSCT.In conclusion,IPSS-M was a valuable tool for risk stratification compared with other risk prognostic scoring systems.However,more studies should be conducted to explore the appropriate treatment options for different groups stratified by IPSS-M.

Research progress of semiconductive shielding layer of HVDC cable

As an indispensable part of high-voltage direct current(HVDC)cable,the semiconductive shielding layer plays the role of uniforming electric field in the cable.However,cable shielding materials>35 kV mainly rely on foreign imports in China,which belongs to the technical weak issues in the field of electrical materials.At present,there are few systematic reports on semiconductive shielding material of HVDC cable.In the work,the mechanisms of charge conduction and thermal conduction of semiconductive material have been introduced.Effect of raw material,carbon black content and the second conductive filler on the resistance characteristics of the semiconductive layer,the charge accumulation characteristics of the insulating layer and the interface characteristics have been studied.A kind of semiconductive layer as a high voltage terminal charge emission method has been proposed to study charge emission from the semiconducting layer to the insulation layer.This work can provide theoretical guidance for the research of semiconductive shielding materials.

Effect of temperature on electric-thermal properties of semiconductive shielding layer and insulation layer for high-voltage cable

A semi‐conductive shielding layer plays an important role in the uniform electric field for a high‐voltage cable.The electric‐thermal properties of the semi‐conductive layer and insulation layer directly affect the overall insulation performance of the cable.The physicochemical performances of semi‐conductive composites are firstly analysed herein.Furthermore,electric‐thermal properties of the semi‐conductive layer and insulation layer are discussed.The experimental results show that the thermal conductivity of the commercial semi‐conductive layer is about twice that of the insulation layer,owing to the effect of carbon black.The thermal expansion coefficient of the insulation layer rises from 1.86×10^(−4)/K at 25℃ to 3.20×10^(−4)/K at 90℃.By contrast,the semi‐conductive layer begins to slowly decline at a certain temperature,and decreases signif-icantly to 2.25×10^(−4)/K at 80℃,owing to the effect of ethylene‐vinyl acetate copolymer(EVA).The electrical experiments show that the resistivity of semi‐conductive composite gradually rises with an increase in temperature,and gradually declines with an increase in the carbon black content.The dc breakdown strength of the composite structure of the semi‐conductive layer/insulation layer decreases significantly with an increase in tem-perature,decreasing from 307 kV/mm at 25℃ to 203 kV/mm at 90℃.At four typical temperatures,the breakdown strength reaches the maximum value when the carbon black content is 25 phr.It is about 15%and 19%higher than carbon black contents of 20 and 30 phr.These findings have reference significance for high‐voltage cable breakdown fault analysis and material selection in cable design.

Review of interface tailoring techniques and applications to improve insulation performance

Interfaces between different materials,for instance,electrode-dielectrics and vacuum/air/SF6‐insulators and oilpaper,are universal in high‐voltage insulation systems.Targeted tailoring of the interfacial properties,e.g.chemical structures,micro‐/nanoscale morphology,the charge injection barrier,trap states,and surface conductivity,is thought to be an effective approach to improve insulation properties such as breakdown and flashover strength,corona/tracking resistance,and wettability.In this article,the authors review recent progress in interface tailoring methods and their application to improve various insulation properties.The potential application scenarios of interface tailoring in different facilities are first summarised,and the desired insulation properties of various applications are highlighted.Interface tailoring methods are classified as physical/chemical surface modification and surface coating(inorganic,organic and composite),and the features of different techniques are described in detail.The structure-property relationships between interfacial states and various microscopic parameters such as charge injection barrier,trap distribution and surface conductivity are discussed together with the tailoring mechanisms for different insulation properties.Finally,the future development prospects of interface tailoring methods and their applications,e.g.multi-functional coating and stimuli-response smart coating,are presented.

Out-of-plane elastic buckling load and strength design of space truss arch with a rectangular section

The out-of-plane stability of the two-hinged space truss circular arch with a rectangular section is theoretically and numerically investigated in this paper.Firstly,the flexural stiffness and torsional stiffness of space truss arches are deduced.The calculation formula of out-of-plane elastic buckling loads of the space truss arch is derived based on the classical solution of out-of-plane flexural-torsional buckling loads of the solid web arch.However,since the classical solution cannot be used for the calculation of the arch with a small rise-span ratio,the formula for out-of-plane elastic buckling loads of space truss arches subjected to end bending moments is modified.Numerical research of the out-of-plane stability of space truss arches under different load cases shows that the theoretical formula proposed in this paper has good accuracy.Secondly,the design formulas to predict the out-of-plane elastoplastic stability strength of space truss arches subjected to the end bending moment and radial uniform load are presented through introducing a normalized slenderness ratio.By assuming that all components of space truss circular arches bear only axial force,the design formulas to prevent the local buckling of chord and transverse tubes are deduced.Finally,the bearing capacity design equations of space truss arches are proposed under vertical uniform load.

Effect of graphene modified semi-conductive shielding layer on space charge accumulation in insulation layer for high-voltage direct current cable

Space charge accumulation in the insulation layer of high-voltage direct current(HVDC)cable is one of the key factors restricting the development of HVDC cable.The inner semi-conductive layer as an important structure of cable will affect the charge accumu-lation characteristics in the insulation layer.This work intends to explore the method of modifying the semi-conductive layer with graphene,to suppress charge accumulation in the insulation layer.First,the semi-conductive layer with different contents of Graphene(G)and carbon black(CB)are prepared.Second,the morphology and surface roughness of the cross section are analysed.Further,the effects of the semi-conductive layer on space charge accumulation of the insulation layer are studied by pulsed electro-acoustic method and thermal stimulation depolarisation current method.The experimental re-sults show that a moderate amount of graphene replacing CB can effectively reduce charge accumulation in the insulation layer and inhibit positive temperature coefficient(PTC)effect at the same time.The surface roughness of specimens decreases with the increase of G content from 0 to 3 phr(parts per hundreds of resin),when the CB content decreases from 25 to 10 phr,the surface roughness of specimen increases.The resistivity test shows that doping G can significantly inhibit the PTC effect of the semi-conductive layer.The volume resistivity of the semi-conductive layer decreases with the increase of G content and CB content.In addition,charge accumulation of the insulation layer rises and then drops under the action of the semi-conductive layer.

DC breakdown characteristics of XLPE/BNNS nanocomposites considering BN nanosheet concentration,space charge and temperature

Breakdown failure in insulation material is one of the key problems that threaten the safe operation of high-voltage direct current cable.In this work,the effect of boron nitride nanosheets(BNNSs)concentration,space charge and temperature on DC breakdown strength have been explored.Cross-linked polyethylene(XLPE)/BNNS nanocomposites were prepared by the melt blending method,and the basic characteristics of nanoparticles and composite were characterised.The experimental results indicate that DC breakdown strength of nanocomposite can be effectively improved when a small amount of BN nanosheet is doped into the matrix.The breakdown strength of the sample reaches the maximum value of 407.52 kV/mm when BNNS content is 0.5 wt%,which is about 33%higher than that of pure XLPE.Further,the effect of space charge on the breakdown of nanocomposites has been studied by pre-injecting charges.For the samples with different BNNS contents,all the breakdown strength present ascending trend when the polarity of the applied voltage is the same as that of the pre-injected charges.Besides,it can be found that the breakdown strength of the XLPE/BNNSs composite decreases significantly at 50°C,which is due to more charge accumulation at 50°C.It reaches 2.06×10^(−8)C which increases by about 2.2 times than the room temperature.

Dipeptide： from gel to chiral crystal

Crystallization in gel media is an important strategy for the growth of organic, inorganic and protein crystals, The suppression of sedimentation, convection currents and nucleation afforded by the viscous property of gel media are beneficial for obtaining crystals with improved physical properties such as fewer defects, better optical auality, and larger size.