Dissipative soliton resonance within different dispersion regimes in a single mode-locked laser

Dissipative soliton resonance(DSR) was previously studied in separated mode-locked fiber lasers within different dispersion regimes including anomalous, near-zero and normal dispersion. Here we propose a method to study DSR in a single mode-locked laser in these different dispersion regimes. This is achieved by virtue of a waveshaper which can control the laser dispersion readily using software, avoiding the usual tedious cutback method. We find that dispersion has a negligible effect on DSR since the pulse duration keeps constant while dispersion is varied. Moreover, we examine the dynamics of DSR on the parameters of the SA including modulation depth and saturation power, and find that the pulse duration can be changed in a large range when the saturation power is decreased. Our numerical simulations could be important to guide relative experimental studies.

Modes of Action of Phytochromes in Establishing Different Phototropic Responsiveness of Maize Coleoptiles

Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended, The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results.

Researches on Classification Features of Rural and Urban Domestic Waste in Tianjin City Under Secondary Classification Mode

In order to investigate the influence of secondary classification mode on waste generation features, this study classified domestic waste generated by 310 rural and urban households at urban areas and Shuigaozhuang Village of Xiqing District into 3 groups： compostable materials, recyclable materials and toxics on the basis of the constructed secondary classification mode of domestic waste. The study focused on waste generation strength and classification features, compared the waste generation features between rural and urban residents, and analyzed the re- lation between waste generation strength and economic and cultural factors. The re- sults indicated that the average generation speed of urban domestic waste was 423.08 g/（d.capita）, and that of rural domestic waste was 629.89 g/（d.capita）, there was significant difference between rural and urban compost generation strength （P= 0.00002）, while the generation strength of recyclable materials and toxics between rural and urban areas had no significant difference （P=0.471 and P=0.099, respec- tively）. Secondary classification mode is an effective source classification mode for domestic wastes and has positive effects on waste reduction and treatment.

Failure Modes for Single-Layer Reticulated Domes Under Impact Loads

The paper presents the theory of Hamilton variation principle which is the current method for impact problem, central difference method which is efficient solution of finite element (FE) method for impact problem and adapts to solve non-linear dynamic problem. And it introduces the ANSYS/LS-DYNA which is the popular FE software for impact problem both at home and abroad. Then it gives solutions for one simple model by analytical method and ANSYS/LS-DYNA respec-tively to validate function of software, and they are consistent. Afterward, it gives model of single-layer Kiewitt reticulated dome with a span of 60 m, and the cylinder impactor, and introduces the contact interface arithmetic, especially the material model of steel (piecewise linear plasticity model) which takes stain rate into account and makes steel failure stress higher under impact loads. The vertical displacement, stress in main members, and the plastic deformation for dome under impact loads were obtained. Then four failure modes (no failure, moderate failure, global failure and slight failure) were summarized according to the rules of dynamic response. And the characteristics of dynamic response for each failure mode were shown.

Dominant modes of geopotential height in the northern hemisphere in summer on interdecadal timescales

Empirical orthogonal function （EOF） analysis is performed on the field of the northem hemisphere geopotential height at 200-hPa using a 54-year （1958-2011） record of summer data on an interdecadal time scale. The first dominant mode, which shows smooth semi-hemispheric variation with maximum action centers in the western hemisphere in the mid-latitudes over the eastern Pacific, North America, and the North Atlantic, is related to global warming. The second mode, which has a pronounced tropical-extratropical alternating pattern with active centers located over the eastern hemisphere from Western Europe across East Asia to the western Pacific, has a close relationship with the Arctic Oscillation. Further analysis results indicate that the two dominant modes show good correlation with the Arctic sea ice concentration （SIC）, with correlation coefficients between these two modes and the first two EOF modes of the Arctic SIC reaching 0.88 and 0.86, respectively.

Preliminary analysis of mode truncation of single-layered reticulated domes under earthquakes

In anti-seismic calculation, the mode truncation is a significant problem to engineers if the mode-superposition response spectrum method is used, which has not been completely solved yet in some large and complex structures such as reticulated domes. In this case, some useful advices, concentrating on the problem above, are expected through a careful and comprehensive investigation of this paper. During the investigation, the authors first point out shortcomings of former researches. Then frequency-spectrum characteristics of single-layered reticulated domes were studied from the perspective of structural responses. During this process, some important results such as the existence of the main resonant section, and the fact that the relative sensitivity of these domes under horizontal and vertical impulse varies with the different R/S ratios were achieved. Furthermore, based on the study of frequency-spectrum characteristics, as well as that of earthquake input, reasonable numbers of mode truncation in single layered reticulated domes with different R/S ratio were presented. Results of case studies prove the mode truncation number proposed is valid.

基于主客观环流分型的强降水数值预报MODE检验方法及其在2019年暖季东北地区的应用

本文构建了基于主客观环流分型的强降水数值预报空间检验(MODE)方法框架,并利用该框架对欧洲中期天气预报中心全球模式(ECMWF)和中国气象局区域中尺度数值天气预报模式(CMA_MESO)的2019年暖季东北地区强降水预报进行检验。结果表明,2019年暖季东北地区54个强降水日的环流型可分为:西风槽型(15个)、副热带高压影响型(13个)、急流型(5个)、西部(12个)和东部冷涡型(9个)。其中,西风槽型和急流型以区域性强降水为主,模式对其强降水发生与否的预报能力强,TS评分较高;西部、东部冷涡型强降水的局地性强,模式对其强降水发生与否的预报能力差,TS评分低;副热带高压影响型也以区域性强降水为主,模式对其强降水发生与否的预报能力也比较强,但是对其强降水质心位置、强度、面积等属性预报偏差较大,TS评分也相对较低。另外,从两种模式预报性能对比看,CMA_MESO强降水强度和面积预报较实况普遍偏强,虽然其预报的TS评分一般高于ECMWF,但其对强降水预报的空报率也都比ECMWF大,对强降水的属性预报偏差一致性一般也低于ECMWF,其预报的可订正性整体上不及ECMWF。

Influence of the column-to-beam flexural strength ratio on the failure mode of beam-column connections in RC frames

The column-to-beam flexural strength ratio(CBFSR)has been used in many seismic codes to achieve the strong column-weak beam(SCWB)failure mode in reinforced concrete(RC)frames,in which plastic hinges appear earlier in beams than in columns.However,seismic investigations show that the required limit of CBFSR in seismic codes usually cannot achieve the SCWB failure mode under strong earthquakes.This study investigates the failure modes of RC frames with different CBFSRs.Nine typical three-story RC frame models with different CBFSRs are designed in accordance with Chinese seismic codes.The seismic responses and failure modes of the frames are investigated through time-history analyses using 100 ground motion records.The results show that the required limit of the CBFSR that guarantees the SCWB failure mode depends on the beam-column connection type and the seismic intensity,and different types of beam-column connections exhibit different failure modes even though they are designed with the same CBFSR.Recommended CBFSRs are proposed for achieving the designed SCWB failure mode for different types of connections in RC frames under different seismic intensities.These results may provide some reference for further revisions of the SCWB design criterion in Chinese seismic codes.

On the Symbiotic Modes of SMEs and Large Enterprises Based on Symbiotic Energy and Medium

There are three varieties of symbiotic modes of SMEs and large enterprises based on symbiosis energy,including commensalisms,asymmetry mutualism and symmetry mutualism.The symbiotic mediums(such as stock ownership,contract,trust,etc.) have an important influence on symbiotic modes.From the angle of symbiotic medium view,there are some measures that promote symbiotic modes toward symmetry mutualism,such as optimizing stock ownership structure of subsidiary company,promoting mid-system organization growth,building good faith cultural atmosphere.

一种基于粗糙熵的改进K-modes聚类算法

K-modes聚类算法被广泛应用于人工智能、数据挖掘等领域。传统的K-modes聚类算法有不错的聚类效果,但是存在迭代次数多、计算量大、容易受到冗余属性的干扰等问题,且仅采用简单的0-1匹配的方法来定义2个样本属性值之间的距离,没有充分考虑每个属性对聚类结果的影响。针对上述问题,该文将粗糙熵引入K-modes算法。首先利用粗糙集属性约简算法消除冗余属性,确定各属性的重要程度;然后利用粗糙熵确定每个属性的权重,从而定义新的类内距离。将该文所提算法与传统的K-modes聚类算法分别在4组公开数据集上进行对比试验。试验结果表明,该文所提算法聚类准确率比传统的K-modes聚类算法更高。

Contribution of Mesoscale Eddies to the Subduction and Transport of North Pacific Eastern Subtropical Mode Water

This study investigates the contribution of mesoscale eddies to the subduction and transport of North Pacific Eastern Subtropical Mode Water(ESTMW)using the high-frequency output of an eddy-resolved ocean model spanning the period 1994–2010.Results show that the subduction induced by mesoscale eddies accounts for about 31%of the total subduction of ESTMW formation.The volume of ESTMW trapped by anticyclonic eddies is slightly larger than that trapped by cyclonic eddies.The ESTMW trapped by all eddies in May reaches up to about 2.8×1013m3,which is approximately 16%of the total ESTMW volume.The eddy-trapped ESTMW moves primarily westward,with its meridional integration at 18°–30°N reaching about 0.17Sv,which is approximately 18%of the total zonal ESTMW transport in this direction,at 140°W.This study highlights the important role of eddies in carrying ESTMW westward over the northeastern Pacific Ocean.

Does the incubator control mode influence outcomes of low-birth-weight neonates during the first days of life and at hospital discharge?

Background: The thermal environment surrounding neonates in closed incubators can be regulated via two different modes: skin servocontrol mode (SSC) and air temperature control mode (ATC). These produce different patterns of incubator air and infant body temperatures. Objective: To assess the effects of incubator control mode on clinical outcomes of low-birth-weight-infants during the first days of life and at hospital discharge. Methods: 52 low-birth-weight neonates were nursed over ten days in closed incubators functioning either with SSC mode (n = 29), or with ATC mode (n = 23). Results: The anthropomorphic characteristics of the two groups of neonates were homogenous (gestational age = 29.4 ± 1.4 vs. 29.9 ± 1.2 weeks and birthweight = 1214 ± 347 vs. 1263 ±292 gin the SSC-group and the ATC-group, respectively) and the caregiving (energy and fluid intakes, ventilator assistance and drug administration) did not differ statistically. Daily means of incubator air temperature were similar in the SSC and the ATC-group, however, the SSC mode resulted in more variable incubator air temperature but more stable skin abdominal temperature whereas the reverse was found when using the ATC mode. Those differences had no impact on the body weight of the neonates or their clinical outcomes at hospital discharge which were not statistically different. Conclusion: The clinical outcomes do not differ depending on the incubator control mode after the first ten days of life and at hospital discharge.

Operation Modes and Control Schemes for Internet-Based Teleoperation System with Time Delay

Teleoperation system plays an important role in executing task under hazard environment. As the computer networks such as the Internet are being used as the communication channel of teleoperation system, varying time delay causes the overall system unstable and reduces the performance of transparency. This paper proposed twelve operation modes with different control schemes for teleoperation on the Internet with time delay. And an optimal operation mode with control scheme was specified for teleoperation with time delay, based on the tradeoff between passivity and transparency properties. It experimentally confirmed the validity of the proposed optimal mode and control scheme by using a simple one DOF master-slave manipulator system.

Stepwise Ecological Restoration:A framework for improving restoration outcomes

Ecosystem degradation is one of the critical constraints for the sustainable development of our planet.However,recovering an ecosystem to a pre-impairment condition is often not practical.The International Restoration Standards provide the first framework for practical guidance on what constitutes the process of ecological repair and how this repair process can be influenced to improve net ecological benefits.In these Standards,Restorative Continuum is highlighted and it recognises that many do not,yet there is still value in aspiring to improvements to the highest extent possible,with some sites potentially being able to be improved in a stepwise manner.Here we elaborate on these Standards by providing a cross-ecosystem theoretical framework of Stepwise Ecological Restoration(STERE)for promoting higher environmental benefits.STERE allows the selection of suitable restorative modes by considering the degree of degradation while encouraging a transition to a higher state.These models include environmental remediation for completely modified and degraded ecosystems,ecological rehabilitation for highly modified and degraded ecosystems,and ecological restoration for degraded native ecosystems.STERE requires selecting tailored restorative modes,setting clear restorative targets and reference ecosystems,applying a systematic-thinking approach,and implementing a continuous monitoring program at all process stages to achieve a resilient trajectory.STERE allows adaptive management in the context of climate change,and when the evidence is available,to“adapt to the future”to ensure climate resilience.The STERE framework could assist in initiating and implementing restoration projects worldwide,especially in developing countries.

Reproductive Behaviors and Pairing Modes of Odontotermes fomosanus(Shiraki)Alates

[ Objectives ] To study the reproductive behaviors and the effect of different pairing modes on the developmental status of incipient colonies＇of Odontote- rmes fomosanus （Shiraki）. [ Methods ] We observed the reproductive behaviors of male alates, female Mates and mated alates respectively. Male and female Mates had 9 pairing modes and founded 170 incipient colonies under laboratory conditions. The effect of pairing mode on incipient colonies＇ developmental status was ana- lyzed. [ Results ] Two peaking hours of mating activity within the daily circadian rhythm of Mate activity appeared from 09：00 to 10：00, and from 21：00 to 22：00, respectively. Courtship behavior before mating consisted of touching with antennae, connecting into a ring （head-to-end）, and licking. The reproductive behavior （ calling, pairing, tandem, mating and oviposition） of nestmate pairs was different to that of non-nestmate pairs. The pairing time of non-nestmate pairs was signifi- candy longer than that of alates paired with siblings （P 〈 0.05 ）. The non-swarming alates could mate with swarming or non-swarming Mates and lay fertile eggs which hatched successfully. However, the survival rate of colonies founded by non-swarming alates was very low. The death rate of incipient colonies was in the range of 0.61% -0. 99% after three months, while the death rate of the colonies founded by swarming alates was in the range of 0.22% -0.58%. Females that had been experimentally prevented from mating could lay eggs, but the eggs did not hatch. [ Conclusion] There are two distinct hourly peaks of mating activity within each 24 hour period. Incipient colonies founded by outbreeding have the highest probability of survival.

Effects of spot size on the operation mode of Ga As photoconductive semiconductor switch employing extrinsic photoconductivity

To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.

UAV-assisted data collection for wireless sensor networks with dynamic working modes

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application scenarios.In this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy threshold.Besides,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous WSN.We aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate constraint.To this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster heads.Then we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation procedure.Numerical results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

Adaptive Trajectory Tracking Control for Nonholonomic Wheeled Mobile Robots:A Barrier Function Sliding Mode Approach

The trajectory tracking control performance of nonholonomic wheeled mobile robots(NWMRs)is subject to nonholonomic constraints,system uncertainties,and external disturbances.This paper proposes a barrier function-based adaptive sliding mode control(BFASMC)method to provide high-precision,fast-response performance and robustness for NWMRs.Compared with the conventional adaptive sliding mode control,the proposed control strategy can guarantee that the sliding mode variables converge to a predefined neighborhood of origin with a predefined reaching time independent of the prior knowledge of the uncertainties and disturbances bounds.Another advantage of the proposed algorithm is that the control gains can be adaptively adjusted to follow the disturbances amplitudes thanks to the barrier function.The benefit is that the overestimation of control gain can be eliminated,resulting in chattering reduction.Moreover,a modified barrier function-like control gain is employed to prevent the input saturation problem due to the physical limit of the actuator.The stability analysis and comparative experiments demonstrate that the proposed BFASMC can ensure the prespecified convergence performance of the NWMR system output variables and strong robustness against uncertainties/disturbances.

Validation of the current and pressure coupling schemes with nonlinear simulations of TAE and analysis on the linear stability of tearing mode in the presence of energetic particles

Both current and pressure coupling schemes have been adopted in the hybrid kinetic–magnetohydrodynamic code CLT-K recently.Numerical equivalences between these two coupling schemes are strictly verified under different approximations.First,when considering only the perturbed distribution function of energetic particles(EPs),the equivalence can be proved analytically.Second,when both the variations of the magnetic field and the EP distribution function are included,the current and pressure coupling schemes numerically produce the same result in the nonlinear simulations.On this basis,the influences of co-/counter-passing and trapped EPs on the linear stabilities of the m/n=2/1 tearing mode(TM)have been investigated(where m and n represent the poloidal and toroidal mode numbers,respectively).The results of scanningβh of EPs show that the co-passing and trapped EPs are found to stabilize the TM,while the counter-passing EPs tend to destabilize the TM.The behind(de)stabilization mechanisms of the TM by EPs are carefully analyzed.Furthermore,after exceeding critical EP betas,the same branch of the high-frequency mode is excited by co-/counterpassing and trapped EPs,which is identified as the m/n=2/1 energetic particle mode.

Real-Time 4-Mode MDM Transmission Using Commercial 400G OTN Transceivers and All-Fiber Mode Multiplexers

Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.