现代汉语否定极性副词“迟迟”的历时考察

"迟迟"作为现代汉语否定极性副词的成员之一,常用于否定句中,其历时的演化面貌尚不明确。"迟迟"由产生初期的多个词义逐渐沿着时间义的方向发展;从整个历时的角度来看,由最初的用在肯定句居多,否定句较少发展成为 "迟迟"肯定句中所占的比重逐渐减少,而在否定句中的比重逐渐增加。这为我们归纳现代汉语否定极性副词常用于否定句的原因提供了一个很好的例证。

A Novel ADC Architecture for Digital Voltage Regulator Module Controllers

The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.

Optimal bandwidth scheduling of networked control systems (NCSs) in accordance with jitter

Network-induced delay and jitter are key factors causing performance degradation and instability of NCSs (networked control systems). The relationships between the sampling periods of the control loops, network-induced delay and jitter were studied aimed at token-type networks. A jitter-dependent optimal bandwidth scheduling algorithm for NCSs is proposed, which tries to achieve a tradeoff between bandwidth occupancy and system performance. Simulation tests proved the effectiveness of this optimal scheduling algorithm.

Delay Compensation Observer with Sliding Mode Controller for Rotary Electro-hydraulic Servo System

The hip’s lower limb exoskeleton essential and most important function is to support human’s payload as well as to enhance and assist human’s motion. It utilizes an electro-hydraulic servo manipulator which is required to achieve precise trajectory tracking and positioning operations. Nevertheless,these tasks require precise and robust control,which is very difficult to attain due to the inherent nonlinear dynamic behavior of the electro-hydraulic system caused by flow-pressure characteristics and fluid volume control variations of the servo valve. The sliding mode controller(SMC)is a widely used nonlinear robust controller,yet uncertainties and delay in the output degrade the closed-loop system performance and cause system instability. This work proposes a robust controller scheme that counts for the output delay and the inherent parameter uncertainties. Namely,a sliding mode controller enhanced by time-delay compensating observer for a typical electro-hydraulic servo system is adapted. SMC is utilized for its robustness against servo system parameters’ uncertainty whereas a time-delay observer estimates the variable states of the controller(velocity and acceleration). The main contribution of this paper is improving on the closed loop performance of the electro hydraulic servo system and mitigating the delay time effects. Simulation results prove the robustness of this controller,which forces the position to track the desired path regardless of the changes of the amount of transport delay of the system’s states. The performance of the proposed controller is validated by repeating the simulation analysis while varying the amount of delay time.

Online Delay-Evaluation Control for Networked Control Systems

This paper presented an evaluation approach of time delays for networked control systems (NCS). An improved scheme based on optimal LQG control was designed to achieve desired performance despite the uncertain delays in the system. The experimental results illustrate the effectiveness of the proposed control design and satisfactory performance of the closed loop system.

An improved method for detection of Edwardsiella tarda by loop-mediated isothermal amplification by targeting the EsrB gene

Edwardsiella tarda is a maj or pathogen in aquatic environments that can cause heavy economic losses. An improved method for quick and accurate detection of E. tarda by loop-mediated isothermal amplification （LAMP） with two additional loop primers was developed by targeting the EsrB gene （EsrI3- LAMP）. In this method, the Mg^2＋ concentration, reaction temperature, and reaction time were optimized to 8 retool/L, 61℃, and 40 min, respectively. The detection limit with the EsrB gene was as low as 10 copies, which is 100 times more sensitive than that of conventional polymerase chain reaction （PCR）. The EsrB-LAMP assay was shown more sensitive and rapid than previously reported LAMP assays targeting the hemolysin gene （hemolysin-LAMP） for detection ofE. tarda. The EsrB-LAMP was also highly specific to E. tarda and had no cross-reaction with 13 other strains of bacteria. The assay can be carried out in a simple heating device and the EsrB-LAMP products can be visually detected by adding fluorescent dye to the reaction mixture. Taken together, the improved EsrB-LAMP diagnostic protocol has the potential for detection ofE. tarda from indoor and outdoor samples.

Stochastic Resonance of a Periodically Driven Bistable System with Two Different Kinds of Time Delays

In this paper, we study the phenomenon of stochastic resonance （SR） in a periodically driven bistable system with correlations between multiplicative and additive white noise terms when there, are two different kinds of time delays existed in the deterministic and fluctuating forces, respectively. Using the small time delay approximation and the theory of signal-to-noise ratio （SNR） in the adiabatic limit, the expression of SNR is obtained. The effects of the delay time T in the deterministic force, and the delay time 8 in the fluctuating force on SNR are discussed. Based on the numerical computation, it is found that： （i） There appears a reentrant transition between one peak and two peaks and then to one peak again in the curve of SNR when the value of the time delay θ is increased. （ii） SR can be realized by tuning the time delay T or 8 with fixed noise, i.e., delay-induced stochastic resonance （DSR） exists.

Influences of different diluents on ignition delay of syngas at gas turbine conditions：A numerical study

Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition delay of syngas in temperature range of 900-1400 K and at pressures of 10 and 30 atm respectively.In high temperature range,comparing with N_2 dilution,adding H_2O and CO_2 can significantly inhibit autoignition of syngas because they have higher collision efficiencies in reaction H + O_2(+ M) = HO_2(+ M).As for low temperature conditions,adding H_2O can increase reactivity of syngas,especially under high pressure,because of its high collision efficiency in reaction H_2O_2(+ M) = 2OH(+ M).Comparing with different dilution rates shows that for syngas and operating conditions in this paper,adding N_2 mainly influences temperature rising process of syngas combustion,thus inhibiting reactivity of syngas.In addition,this paper calculated ignition delay of syngas at different equivalence ratios(φ= 0.5,1.0).Higher equivalence ratio(φ≤1) means that less air(especially N_2) needs to be heated,thus promoting ignition of syngas,

lon migration suppression mechanism via 4-sulfobenzoic acid monopotassium salt for 22.7%stable perovskite solar cells

The deep-level traps at grain boundaries(GBs)and halide ion migration are quite challenging for further enhancement of the stability and efficiency of perovskite solar cells(PSCs)as well as for the elimination of notorious hysteresis.Herein,we report a large-sized strongly coordinated organic anion GB anchoring strategy for suppressing ion migration and passivating defects in planar PSCs.The practical implementation of this strategy involves the incorporation of potassium salts containing a large-sized organic counter anion(4-sulfobenzoic acid monopotassium salt,SAMS)into the perovskite precursor.It has been found that anions within SAMS can be firmly anchored at GBs due to the strong coordination interaction between C=O and/or S=O at both ends of bulky anion and undercoordinated Pb^(2+)and/or halide vacancies,along with the hydrogen bond between–OH and formamidinium.SAMS can not only passivate shallowlevel defects but also cause more effective passivation of the deep-level defects.The GB manipulation strategy results in a reduced defect density,an increased carrier lifetime as well as suppressed ion migration,which in turn contributed to enhanced efficiency and stability of PSCs together with a thorough elimination of hysteresis.As a result,the SAMSmodified device with an outstanding fill factor of 0.84 delivers a significant improvement in efficiency(22.7%)in comparison with the control device(20.3%).The unencapsulated modified device demonstrates only little degradation after 1320 h at 60℃.

Delay-induced firing behavior and transitions in adaptive neuronal networks with two types of synapses

In this paper, we study delay-induced firing behavior and transitions in adaptive Newman-Watts networks of thermosensitive neurons with electrical or chemical synapses. It is found that electrical and chemical synapse time delay-induced firing behavior and transitions differ significantly. In the case of electrical synapses, the bursts for a fixed delay involve equal number of spikes in each burst, and for certain time delays the firing can be inhibited. However, in the case of chemical synapses the bursts for a fixed delay involve different numbers of spikes in each burst, and no firing inhibition is observed. It is also shown that larger growth rates of adaptive coupling strength or larger network randomness can enhance the synchronization of bursting in the case of electrical synapses but reduce it in the case of chemical synapses. These results show that electrical and chemical synapses have different effects on delay-induced firing behavior and dynamical evolution. Compared to electrical synapses, chemical synapses might be more beneficial to the generation of firing and abundant firing transitions in adaptive and delayed neuronal networks. These findings can help to better understand different firing behaviors in neuronal networks with electrical and chemical synapses.

Directed Current Induced by an Symmetrically ac Force Coexisting with a Time-Delayed Feedback

We study the transport of overdamped Brownian particles in a symmetricaJly periodic potential in the presence of an asymmetrically ac driving force and a time-delayed feedback. It is found that for low frequencies, the average velocity can be negative by changing the driving amplitude, for high frequencies, there exists an optimized driving amplitude at which the average velocity takes its maximum value. Additionally, there is a threshold value of driving amplitude below which no directed transport can be obtained for high frequencies. For the large value of the delay time, the average velocity is independent of the delay time.

Relative position determination of a lunar rover using the biased differential phase delay of same-beam VLBI

When only data transmission signals with a bandwidth of 1 MHz exist in the rover, the position can be obtained using the differential group delay data of the same-beam very long baseline interferometry (VLBI). The relative position between a lunar rover and a lander can be determined with an error of several hundreds of meters. When the guidance information of the rover is used to determine relative position, the rover's wheel skid behavior and integral movement may influence the accuracy of the determined position. This paper proposes a new method for accurately determining relative position. The differential group delay and biased differential phase delay are obtained from the same-beam VLBI observation, while the modified biased differential phase delay is obtained using the statistic mean value of the differential group delay and the biased phase delay as basis. The small bias in the modified biased phase delay is estimated together with other parameters when the relative position of the rover is calculated. The effectiveness of the proposed method is confirmed using the same-beam VLBI observation data of SELENE. The radio sources onboard the rover and the lander are designed for same-beam VLBI observations. The results of the simulations of the differential delay of the same-beam VLBI observation between the rover and the lander show that the differential delay is sensitive to relative position. An approach to solving the relative position and a strategy for tracking are also introduced. When the lunar topography data near the rover are used and the observations are scheduled properly, the determined relative position of the rover may be nearly as accurate as that solved using differential phase delay data.

Dynamics of electric activities in neuron and neurons of network induced by autapses

The effect of autapse on adjusting the membrane of potentials of neuron is described by imposing a time-delayed feedback on the membrane of neuron in a close loop type,and the Hindmarsh-Rose(HR)neuron under autapse is investigated.Firstly,the electric activity of single HR neuron under electric autapse and chemical autapse is investigated.It is found that quiescent neuron is activated due to appropriate time delay and feedback gain in the autapse,and the autapse plays an important role in waking up neuron.The parameter region for periodic,chaotic activity of neuron under autapse is calculated in a numerical way,and transition from spiking to bursting is observed by increasing the feedback gain and time delay carefully.Furthermore,the collective electric activities of neurons in a ring network is investigated and abundant electric activities are observed due to the competition between the autapse and the time-delayed coupling between adjacent neurons in the network,and time delay in coupling between neurons also plays an important role in enhancing synchronization in the network.

Methods for optical phase retardation measurement:A review

Optical-phase-retardation elements are widely used in many fields.Accurate measurement of their phase retardation is crucial to the practical effect of the element's processing and application.The development and present situation of the methods for optical phase retardation measurement are reviewed,with the wave plate,the most typical phase-retardation element,as an example.The latest research progress in this field is introduced;the principles and characteristics of individual measurement method are summarized and discussed.Three new methods based on laser frequency splitting or laser feedback are presented in detail,in which the laser is not only regarded as a light source but also plays a role of sensor.Moreover,no standard wave plates are needed and arbitrary phase retardation can be measured.Traceability,high precision and high repeatability are achieved as well.