通过对教学督导相关概念进行辨析,对"转动课堂"视域下教学督导的作用及其发挥作用的机制进行分析,寻求"转动课堂"视域下对教学过程督导的具体路径.建立教学督导指导和监督机构,是提高教学质量、加强教学管理工作科学化的需要.

To explore the structure and function of the 555 Schmidt trigger circuit based on the analysis of expansion, the 555 timer 555 timer function, can be found a Schmidt trigger phase output signal uO and uI of the same input signal phase. Introduces the circuit principle, and gives the calculation formula of circuit parameters, comprehensive, quantitative description of the working process of the electric circuit. The innovation of the method is, found 555 Schmidt trigger in new ways, will be conducive to the system structure and design method of 555 Schmidt trigger circuit. For the simulation of several types of phase with the output of 555 Schmidt trigger with Multisim simulation software, the conclusion is proves the correctness of the method.

In order to study systemically the construction of integrating operational circuit and the selection of parameters we deal with the design problems of the integrating operational circuit. Expressions of the output waveform amplitude for square wave input are derived from circuit equations and integral conditions. And the results provide the theoretical basis for the design of the integrating operational circuit. An example is presented to demonstrate the validity, simplicity and practicability of the proposed design method.

Food safety decision is an important content of food safety research. Based on variable precision rough sets model,a method of building decision tree with rules that have definite confidence is proposed for food safety analysis. It is an improvement for decision tree inducing approach presented in traditional methods. Present a new algorithm for constructing decision tree with variable precision weighted mean roughness as the criteria for selecting attribute. The new algorithm used variable precision approximate accuracy instead the approxi-mate accuracy. Noisy data of training sets are considered enough. Limited inconsistency is allowed to existed examples of the positive re-gions. So the decision tree is simplified and its extensive ability is improved and more comprehensible. Experiments show that the algo-rithm is feasible and effective.

The references researching on RC-bridge oscillator often provide technical indicators such as the criterion of oscillation,en-oscillating condition and oscillation frequency without discussing amplitudes of output signals.In this paper,determinants of output amplitudes are studied theoretically and virtual experimentally.It found that the amplitudes of output voltage are determined by values of amplification in en-oscillating condition.In the linear region of a circuit,the larger the amplification in en-oscillating condition exceeds 3,the bigger the amplitude of output voltage is.This study is useful for systemically researching of the construction of oscillator circuits and the selection of parameters.

For experimental verification Flip -flop job characteristics.Here we introduced a method to simu-late the working waves of flip -flop with Multisim.Word generator is used to generate the input signals , such as clock impulse , input data and asynchronous control signals and logical analyzer responds to display all the input and output working waves .This method describes the logical function and changing characteristic of flip -flop visually.The innovation of this method is to settle the question that the working waves of flip -flop are difficult to be analyzed and verified by electronic devices .

In order to study the monostable trigger characteristics.The triggering characteristics of 555 monostable flip-flops,and the relationships between output states and trigging signals are analyzed in detail.The output signals have a frequency division effect on the input signals when the inputs are period impulse signals.The application of monostable flip-flops is widen.Simulation experiments based on Multisim certify the validity of this conclusion.

In a bridge rectifier filter circuit,parameter of filter capacitor is chosen under formula RLC≥(3~5)T/2.It's usually think that the bigger value is better.Simulation experiment with Multisim 10 simulation software is conducted.Waves of output voltage,impulse current flowing through rectifier diode and recovery time are analyzed when the parameters of filter capacitor circuit is changed.The result shows that to increase filter capacitor has little effect on improving waves of output voltage and raising the values of direct current.With the increasing of filter capacitor's value,the time to enter steady state prolongs and impulse current flowing through rectifier diode is rising.The value of filter capacitor should not be too big.

This paper is aimed to investigate simulation experimental technique to analyze differential mono stable flip-flop.With simulation software Multisim 10,working waves of differential mono stable flip-flop are tested.In the test procedure,experimental scheme is given out as well as working processes which include the circuit＇s coming from transient state to stable state,capacitance＇s charging and discharging in transient state,and the circuit＇s reverting to stable state are analyzed.The improvement scheme is drew out to shorten the restoring time.In conclude,working characters of flip-flop can be described intuitively with simulation experimental method which benefits the systematically researching of composition and design of circuits.

In order to find a simple method to design arbitrary synchronous counters,the logic function modification technique in designing any module-N synchronous counters consisting of J-K flip-flops were analyzed.Based on binary synchronous counters composed of J-K flip-flops,a part of the excitation function equations are modified.Thus the state transition sequence can be changed to achieve module-N synchronous counters.Principles for excitation function modification and determination of modified functions are outlined.Self-starting of module-N synchronous counters is also analyzed.This proposed technique is simple,convenient and more practicable.

Provoked by the intention of studying simulation experiment of working waves in capacitor filter circuits, Multisim 10 software is applied to simulation testing and the scheme for experiment is provided. When the parameter of filter capacitors are set to different values, variation of working waves and performance of circuits are analyzed. It is concluded that simulation experiment can be used to describe visually the characteristic of capacitor filter circuit and to research systemically the component of circuit and parameter selection of circuit element.

This paper analyses the operation relationships in differential input scaling operational circuit.It is pointed,the value of scale factors of input signals is limited when the input resistances reach balance in input ends.Based on in-depth analysis of the relationships between scale factors and balance conditions,the improved program is proposed to allow input signals to participate operation in arbitrary number.Then the design methods and procedures of this universal appliance circuit are given.

Multisim simulation methods of composing a modulo-N counter by 4-bit integrated binary counter 74LS161 are introduced.The waveform is used to display both the counting processes of counter and the processes that transition state forming asynchronous reset signals.Four-trace oscilloscope to synchronously display clock pulse signals,asynchronous reset signals and the overlap of output signals.Transition state and time delay of asynchronous reset signals are analyzed.A bug in Multisim 10,that clock trigger mode of 74LS161 counter is mistake,is pointed out,and the correction is given.This method settles the question that the working waveforms of counters are difficult to be analyzed and verified by electronic devices.

A noninverting input scaling circuit with random scaling coefficient is given in this paper.The relationships of scaling coefficient with balance resistor and feedback resistor are analyzed.The purpose of paper is to explore the variation of composition forms of in-phase scaling operation circuit when the scaling coefficient is arbitrary.It's concluded that when the resistance is equilibrium in the input port and input signal scaling coefficients are greater than 1,equal to 1 and less than 1,noninverting input scaling operation circuit can be simplified.The innovation of this method is that the balance condition of input resistance in operational circuits is converted to the scaling coefficients so that the form of simplified circuit can be directly determined.The application scope of noninverting input scaling operation circuits is extended.

The method is that applying Multisim to analyze the state transition of flip-flop.The word generator of simulation software which can reflect the characteristic of state transition and the logic function is used to generate signals such as clock pulse,input data and asynchronous control.Well the logic analyzer is employed to synchronously display the input and output waves of flip-flop,which make the state change of flip-flop be described intuitively.This method settles the question that the working waves of flip-flop are hard to test and verify by electronic devices.

States transition in twisted ring counter working progress is analyzed.A new design scheme that the logic function modification is made to excitation function in any counter is put forward,where this scheme does not conflict with the right shift and back cycling shift rules.In present framework design,the only solution needs to be worked out is that the excitation function for the first flip-flop.The method is modified while remaining the inside structure of right shift register invariant.It is aimed to explore the logic function modification of self-correction in twisted ring counters.The method is to minimize the excitation function with next state Karnaugh map,to check the next state values in invalid state and to carry out self-correction synchronously.Design progress of twisted ring counter is simplified.

In logic circuit design,transformation for logic function expression is essential for realizing special logic function with limited logic gates.An exploration is made to gain all kinds of logic function starting from AND-OR expression.The method and process to some usual logic function expressions are derived as well as to changing stander AND-OR expression based on special minterms into XOR expression.It's concluded that the method is simple and convenient,and design efficiency could be promoted.

Sequential characteristic between input signals and output signals in 555 timer base circuit is proposed.Design method of 555 monostable flip-flops is researched based on state diagram which reflects sequential characteristic.Input method,voltage altitude and lasting time of external trigger signals are analyzed.Timing unit in RC circuit and charge and discharge process of capacitance are discussed.New design methods are given.These design methods are verified by Multisim simulation as well as realistic hardware experiments.

To explore the simulation experiment technology of the working waves of flip-flop,the method of applying Multisim to analyze the working wave of flop-flop is introduced.The word generator in multisim simulation software is used to generate signals such as clock pulse,input data and asynchronous control,and the logic analyzer is employed to synchronously display the input and output waves of flip-flop.How to set the word generator is also discussed in several typical trigger modes for different logic functions. As a conclusion,logic functions and states change of flip-flop can be depicted intuitively and vividly.This method settles the question that the working waves of flip-flop are hard to test and verify by electronic devices.

The design technique of multi-input sequential logic circiut based on multiplexer and D flip-flops is introduced to investigate a simple method to realize the multi-input sequential logic circiut,which D flip-flops are combined with multiplexer.Taking the present states as the data multiplexer to select input variables and the output functions of the data multiplexer as the input signals of D flip-flops,the multi-input sequential network with the functions of storage and selection is composed.The input variables are selected according to the present states of D flip-flops,the transformation direction of the next states of D flip-flops is determined by the selected variables.The combination of these two components is suitable to the realization of the mutual exclusion multi-variable sequential logic circuit.The function simplification is unnecessary in design process.This is a new method to design sequential logic circuits.