脉诊七步法在中医学生带教中的应用

脉诊是中医四诊之一,独具特色,是中医师最核心的技术。但由于脉诊难于学习和掌握,使中医学生脉诊技能的培养效果不佳。我们在临床实践中总结的脉诊七步法,使学生由浅入深,便于操作。脉诊七步法分别从脉位、脉体、脉势、迟数、滑涩5个方面,与三部九候进行组合分析,及特殊脉象甄别,使初学者易于掌握,易入门径,中医医学生反映良好。

Decay rates and time lags of heat conduction in building construction under field conditions

The field measurements of decay rates and time lags of heat conduction in a building construction taken in Nanjing during the summer of 2001 are presented.The decay rates and time lags are calculated according to the frequency responses of the heat absorbed by the room＇s internal surfaces,inside surface temperature,indoor air temperature and outdoor synthetic temperature.The measured results match very well with the theoretical results of the zeroth and the first order values of the decay rates and time lags of heat conduction in the building construction,but the difference between the measured values and the theoretical values for the second order is too great to be accepted.It is therefore difficult to accurately test the second order value.However,it is still advisable to complete the analysis using the zeroth-and the first-orders values of the decay rates and time lags of heat conduction in building construction under field conditions,because in these cases the decay rates of heat conduction reach twenty which meets the requirements of engineering plans.

2.5Gb/s/ch 0.18μm CMOS Data Recovery Circuit

A 2.5Gb/s/ch data recovery （DR） circuit is designed for an SFI-5 interface. To make the parallel data bit-synchronization and reduce the bit error rate （BER） ,a delay locked loop （DLL） is used to place the center of the data eye exactly at the rising edge of the data-sampling clock. A single channel DR circuit was fabricated in TSMC＇s standard 0. 18μm CMOS process. The chip area is 0. 46mm^2. With a 2^32 - 1 pseudorandom bit sequence （PRBS） input,the RMS jitter of the recovered 2.5Gb/s data is 3.3ps. The sensitivity of the single channel DR is less than 20mV with 10-12 BER.

Time-stamped predictive functional control for networked control systems with random delays

The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.

Data Aggregation Scheduling with Guaranteed Lifetime and Efficient Latency in Wireless Sensor Networks

In scenarios of real-time data collection of long-term deployed Wireless Sensor Networks （WSNs）, low-latency data collection with long net- work lifetime becomes a key issue. In this paper, we present a data aggregation scheduling with guaran- teed lifetime and efficient latency in WSNs. We first Construct a Guaranteed Lifetime Mininmm Ra- dius Data Aggregation Tree （GLMRDAT） which is conducive to reduce scheduling latency while pro- viding a guaranteed network lifetime, and then de-sign a Greedy Scheduling algorithM （GSM） based on finding the nmzximum independent set in conflict graph to schedule he transmission of nodes in the aggregation tree. Finally, simulations show that our proposed approach not only outperfonm the state-of-the-art solutions in terms of schedule latency, but also provides longer and guaranteed network lifetilre.

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.

Factors determining delay in relaparotomy for anastomotic leakage after colorectal resection

AIM： To analyze the time interval （‘delay＇） between the first occurrence of clinical parameters associated with anastomotic leakage alter colorectal resection and subsequent relaparotomy. METHODS： In 36 out of 289 consecutive patients with colorectal anastomosis, leakage was confirmed at relaparotomy. The medical records of these patients were retrospectively analysed and type and time of appearance of clinical parameters suggestive of anastomotic leakage were recorded. These parameters included heart rate, body temperature, local or generalized peritoneal reaction, leucocytosis, ileus and delayed gastric emptying. Factors influencing delay of relaparotomy and consequences of delayed recognition and treatment were determined. RESULTS： First documentation of at least one of the predefined parameters for anastomotic leakage was alter a median interval of 4 ± 1.7 d alter the operation. The median number of days between first parameter（s） associated with leakage and relaparotomy was 3.5 ± 5.7 d. The time interval between the first signs of leakage and relaparotomy was significantly longer when a weekend was included （4.2 d vs 2.4 d, P = 0.021） or radiological evaluation proved to be false-negative （8.1 d vs 3.5 d, P = 0.007）. No significant association between delay and number of additional relaparotomies, hospital stay or mortality could be demonstrated.CONCLUSION： An intervening weekend and negative diagnostic imaging reports may contribute to a delay in diagnosis and relaparotomy for anastomotic leakage. That delay was more than two days in two-thirds of the patients.

Land deformation monitoring in mining area with PPP-AR

The mining area deformation monitoring theory and method using precise point positioning （PPP） ambi- guity resolution （AR） were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay （CPD） was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.

Exponential stability for networked control systems based on the model of nonlinear discrete-time system with time-varying delay

An uncertain nonlinear discrete-time system model with time-varying input delays for networked control systems (NCSs) is presented. The problem of exponential stability for the system is considered and some new criteria of exponential stability are obtained based on norm inequality methods. A numerical example is given todemonstrate that those criteria are useful to analyzing the stability of nonlinear NCSs.

Effect of Phosphate on Zinc Transport in Lou Soil

A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input. The effects of phosphate and temperature on zinc transport were studied through analysing the diffusion-dispersion coefficients (D) and the retardation factor (R) obtained by the program CXTFIT. The results showed that D decreased and R increased with increasing concentration of phosphate so that it was difficult for zinc to break through the soil column, and zinc stopped to break through the column at high temperature. One order equation, double constant equation and the Elovich equation were all suitable for the description of zinc dynamica. Effects of phosphate and temperature on zinc transport were further confirmed by the analysis on pseudo-thermodynamic parameters of zinc transport.

H_∞ Control Based on LMIs for a Class of Time-delay Switched Systems

The problem of H∞ stability analysis and control synthesis of switched systems with delayed states under arb/trary switchirg laws is considered. By means of Lyapunov function and linear matrix inequality tools, sufficient ctmdition of H∞ stability is presented in terms of linear matrix inequalities. Furthermore, the robust H∞ control synthesis via state feedback and output feedack is studied. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.

Sliding mode control of solid state transformer using a three-level hysteresis function

The solid state transformer(SST) can be viewed as an energy router in energy internet. This work presents sliding mode control(SMC) to improve dynamic state and steady state performance of a three-stage(rectifier stage, isolated stage and inverter stage) SST for energy internet. SMC with three-level hysteresis sliding functions is presented to control the input current of rectifier stage and output voltage of inverter stage to improve the robustness under external disturbance and parametric uncertainties and reduce the switching frequency. A modified feedback linearization technique using isolated stage simplified model is presented to achieve satisfactory regulation of output voltage of the isolated stage. The system is tested for steady state operation, reactive power control, dynamic load change and voltage sag simulations, respectively. The switching model of SST is implemented in Matlab/ Simulink to verify the SST control algorithms.

Effect of car-body lower-center rolling on aerodynamic performance of a high-speed train

The interaction between the car-body vibration and aerodynamic performance of the train becomes more prominent motivated by the vehicle’s light-weighting design.To address this topic,this study firstly analyzes the posture characteristics of the car-body based on the previous full-scale test results.And then the aerodynamic performance under different vibration cases(different car-body roll angles)is studied with an improved delayed detached eddy simulation(IDDES).The results revealed that car-body rolling had a significant impact on the aerodynamic behavior of bogies,which significantly increased the lateral force and yaw moment of a bogie and further may have aggravated the operational instability of the train.The unbalanced distribution of the longitudinal pressure on both sides of the bogie caused by the car-body rolling motion was the primary cause for the bogie yaw moment increase.The tail vortex of the train was also affected by the car-body rolling,resulting in vertical jitter.

A DYNAMIC CROSS-LAYER DATA QUEUE MANAGEMENT APPROACH BASED ON PRIORITY FOR DELAY-TOLERANT MOBILE SENSOR NETWORKS

This paper presents a Dynamic Cross-layer Data Queue Management approach (DC-DQM) based on priority to address the priority deviation problem in Delay-Tolerant Mobile Sensor Networks (DT-MSNs). Receiver-driven data delivery scheme is used for fast response to data transfers, and a priority based interaction model is adopted to identify the data priority. Three interactive parameters are introduced to prioritize and dynamically manage data queue. The experimental results show that it can ameliorate data delivery ratio and achieve good performance in terms of average delay.

Influence of Dark Energy on Gravitational Time Delay

We investigate the gravitational time delay of light in the Schwarzschild black hole space-time surroundedby quintessence.With the analysis and numerical methods,we find that the gravitational time delay of light in theSchwarzschild black hole space-time surrounded by quintessence increases when the normalization factor c increases,andthat the gravitational time delay also decreases when the quintessential state parameter ω_q increases.

Nonlinear characteristics and functional analysis of masseter electromyography

The C-C method was adopted to analyze the nonlinear characteristics of masseter electromyography （EMG） signals and the chaotic degree by the largest Lyapunov exponent （LLE） of different genders and sides. First, the embedding dimension and the delay time were obtained through this method, then the phase space was reconstructed to resume the chaotie attractor and determine the LLE. The result shows that the trajectory of attractor is denser than Chen＇s attractor, and the LLE is positive, which means that not only the signal has the character of chaos, but also the chaotic degree of masseter EMG is relatively high. According to the value of the LLE, the chaotic degree of men＇s masseter EMG is higher than that of women＇s; when the dentition is normal, the chaotic degree of two sides is almost the same. Then, a conclusion can be deduced that if the LLE of both sides are in great difference, the unilateral mastication is likely to exist, which means that the nonlinear characteristics of masseter EMG can be applied to predict the unilateral mastication.

Guaranteed cost sampled-data control for uncertain nonlinear time-varying delay system

The robust guaranteed cost sampled-data control was studied for a class of uncertain nonlinear systems with time-varying delay. The parameter uncertainties are time-varying norm-bounded and appear in both the state and the input control matrices. By applying an input delay approach, the system was transformed into a continuous time-delay system. Attention was focused on the design of a robust guaranteed cost sampled-data control law which guarantees that the closed-loop system is asymptotically stable and the quadratic performance index is less than a certain bound for all admissible uncertainties. By applying Lyapunov stability theory, the theorems were derived to provide sufficient conditions for the existence of robust guaranteed cost sampled-data control law in the form of linear matrix inequalities (LMIs), especially an optimal state-feedback guaranteed cost sampled-data control law which ensures the minimization of the guaranteed cost was given. The effectiveness of the proposed method was illustrated by a simulation example with the asymptotically stable curves of system state under the initial condition of x(0)=[0.679 6 0].

Global exponential stability of interval neural networks with a fixed delay

The problem of the global exponential robust stability of interval neural networks with a fixed delay was studied by an approach combining the Lyapunov-Krasovskii functional with the linear matrix inequality (LMI). The results obtained provide an easily verified guideline for determining the exponential robust stability of delayed neural networks. The theoretical analysis and numerical simulations show that the results are less conservative and less restrictive than those reported recently in the literature.

Global Attractivity for a Differential Delay Model

This paper considers the scalar differential delay equation x（t） -μ x（t）-f（x（t-τ））, where f（x） is a decreasing continuous function. By proving that all solutions will beultimately in some interval, we give tile conditions under which the unique equilibrium pointof the differential delay equation is globally attractive.

Research on a High-Precision Delay Circuit in Data Acquisition Systems

This paper presents a novel precision delay circuit design for high-speed data acquisition systems. Many studies have suggested that various advanced electronic measurement apparatuses require that the delay circuit should have a high precision and a short delay interval. Practically, however, such measurement apparatuses are low in preci- sion and long in delay interval at present. The structure and function of a data acquisition system is introduced first; then the principle of ramp-based precision delay circuits and the digitally programmable delay generator is studied and the precision delay circuit is designed. The authors also demonstrated 8-bit programmable delay circuits with a timing pre- cision of 10 ps. Therefore the programmable precision delay circuit here presented has a higher precision, shorter inter- val and more detectable function than any other precision delay circuit.