ii ra đề kiểm tra chất lượng học sinh

... 19775-1 TCVN XXXX:2015 Viện Tiêu chuẩn Chất lượng Việt Nam biên soạn, Bộ Thông tin Truyền thông đề nghị, Tổng cục Tiêu chuẩn Đo lường Chất lượng thẩm định, Bộ Khoa học Công nghệ công bố TCVN XXXX:2015 ... 3.41 Chất lượng (quality) Tồn đặc tính sản phẩm liên quan tới khả thỏa mãn nhu cầu đưa biết đến 13 TCVN XXXX:2015 3.42 Lược đồ chất lượng (quality schema) Lược đồ khái niệm xác đinh khía cạnh chất ... dạng, chất lượng, điều kiện đặc tính khác nhằm tạo thuận lợi cho trình tìm kiếm, truy cập, quản lý lưu trữ liệu 3.30 Biên chung (coboundary) Tập ngun hàm hình học tơ-pơ chiều kích hình học tơ-pơ...

Ngày tải lên: 17/12/2017, 17:27

... người học vào đời) II/ RA ĐỀ KIỂM TRA CHẤT LƯỢNG HỌC SINH I/ Thảo luận ; 1/ Nêu bước cần chuẩn bị trước tiến hành đề kiểm tra chất lượng học sinh 2/Các hình thức đề kiểm tra chất lượng học sinh ... thực • Cấp tổ khối đề kiểm tra háng tháng • Nhà trường đề kiểm tra GHI , GHII , môn TN-XH 4,5 vào cuối HKI cuối HKII Công tác kiểm tra chuyên đề : - Kiểm tra việc thực đề kết học tập nhận xét – ... Chuyên đề : RA ĐỀ KIỂM TRA CHẤT LƯỢNG HỌC TẬP -HỌC SINH I/ Mục đích – yêu cầu • Giúp Gv tự chủ việc kiểm tra chất lượng học tập – từ xây dựng biện pháp nâng cao chất lượng Dạy – Học • Nắm...

Ngày tải lên: 07/05/2015, 20:00

... grating pattern is delineated on the substrate In general, the grating can be placed under the active layer or in the upper cladding layer In DBR lasers, the Bragg grating sections are separated ... spectral width The finite spectral width is mainly due to the random phase of the spontaneous emission that couples into the lasing mode Consequently, the fluctuation in gain broadens the spectral ... concentration and photon energies, the intrinsic linewidth enhancement factor also depends on temperature With decreasing temperature, the change in refractive index with carrier concentration...

Ngày tải lên: 15/12/2013, 04:15

... known as the transparency carrier concentration The above relation gives only a reasonable approximation in a small biasing range when the carrier concentration is comparable to the transparency ... as Ra! b / fc Ea ị1 fv Eb ịị 2:33ị Similarly, the total upward transition rate Rb!a becomes Rb!a / fv Eb ị1 fc Ea ịị 2:34ị As a result, the net effective downward transition rate becomes Ra! b ... system, respectively For uniform incident radiation with energy spectral density &f , the total induced upward transition rate R12 (subscript 12 indicates the transition from the lower energy level...

Ngày tải lên: 15/12/2013, 04:15

... USING THE NEWTON–RAPHSON APPROXIMATION All complex transcendental equations can be expressed in a general form such that WðzÞ ¼ UðzÞ þ j VðzÞ ¼ ð3:17Þ SOLUTIONS OF COMPLEX TRANSCENDENTAL EQUATIONS ... up with a transcendental function 2 ðgLÞ2 þ ð LÞ2 sinh2 ðgLÞ ð1 À r1 Þð1 À r2 Þ þ 2j L ðr1 þ r2 Þ2 ð1 À r1 r2 Þ gL sinh gLÞ coshðgLÞ ¼ ð3:16Þ In the above equation, there are four parameters which ... facet reflection may not be desirable This is because the random corrugation phases at the laser facets will cause extra difficulty in controlling the lasing characteristic Therefore, it is best...

Ngày tải lên: 15/12/2013, 04:15

... includes all electric waves leaving the arbitrary section, whilst matrix V contains those entering the section In both transmission line matrix (TLM) and transfer matrix methods (TMM), matrix U represents ... occurs near the central Bragg wavelength Table 4.2 summarises all laser structures that can be represented by transfer matrices The differences between them are also listed When the grating height ... ðzÀ Þ The transmission gain At of the backward travelling wave can then be expressed as [2] At ¼ ES ðzÀ Þ 1 ¼ ES ðzþ Þ h22 Nþ1 ð4:32Þ When the matrix element h22 approaches zero, the transmission...

Ngày tải lên: 15/12/2013, 04:15

... facet reflection at the laser facets is assumed Following the formulation of the transfer matrix method, the overall transfer matrix of the 3PS DFB laser becomes:   y11 ðz5 j z1 Þ y12 ðz5 j z1 ... oscillation, and consequently improve the performance of the spectral linewidth, these structural parameters need to be optimised 5.3.1 Structural Impacts on the Gain Margin To achieve a stable laser ... Coupling Ratio on the Threshold Characteristics In the structural design of DCC DFB lasers, both the coupling ratio ð = Þ and the position of the corrugation play a crucial role in the threshold characteristics...

Ngày tải lên: 15/12/2013, 04:15

... wavelength Internal loss Refractive index at zero injection Carrier concentration at transparency Carrier concentration at threshold Differential index Group velocity at Bragg wavelength Non-linear ... ð6:6Þ where a parabolic model is assumed In this equation, A0 is the differential gain, N0 is the transparency carrier concentration and !0 is the wavelength of the peak gain at transparency gain ... length represented by each transfer matrix becomes much smaller From the Nsectioned DFB laser model, physical parameters such as the carrier concentration and photon concentration are assumed to be...

Ngày tải lên: 15/12/2013, 04:15

... Normalised spontaneous emission spectra of a 3PS DFB LD Figure 7.15 Normalised spontaneous emission spectra of a DCC þ QWS DFB LD SPECTRAL LINEWIDTH 185 Other parameters used are listed in the inset ... number of transfer matrices used and ÁL ¼ L=N is the lengthÀ of each transfer matrix represented From the Á À Á matrix multiplication, matrix elements y22 zj j z1 and y12 zj j z1 at an arbitrary matrix ... change of material gain with carrier concentration which has been demonstrated experimentally using a QWS DFB LD [9] Apart from that, a reduction of the spectral amplitude difference is also shown...

Ngày tải lên: 15/12/2013, 04:15

... propagation simulated by voltage pulses travelling along transmission lines The medium of propagation is represented by the transmission lines – a general or lossy transmission line consists of series ... AND TRANSMISSION-LINE LASER MODELLING (TLLM) TECHNIQUES 29 Wong, W M and Ghafouri-Shiraz, H., Integrated semiconductor laser-transmitter model for microwave-optoelectronic simulation based on transmission-line ... transmission-line laser model 8.4 TRANSMISSION-LINE LASER MODELLING (TLLM) The transmission-line laser model is a wide-bandwidth dynamic laser model that takes into account important considerations...

Ngày tải lên: 15/12/2013, 04:15

... time-averaged spectra of rapidly-modulated semiconductor lasers, IEE Proc Part J Optoelectronics, 132, 34–37, 1985 14 Lowery, A J., Modelling ultra-short pulses (less than the cavity transient ... that the power spectral density given in frequency response is the spectral range of the laser (the laser frequency used in the simulation is that for the 1:55 mm Figure 9.6 Transient response ... DIODE CHARACTERISTICS BASED ON TLLM TLLM FOR DFB LASER DIODES In general, two operations, scattering and connecting, are involved in transmission-line laser modelling The scattering operation takes...

Ngày tải lên: 15/12/2013, 04:15

... suppression ratio (SMSR), which is the ratio of the highest peak to the second highest peak of the transmissivity power Table 10.2 outlines the relationships among the transmission system parameters, ... desired transmission system parameters, filtering properties and counter measures [29–31] Desired transmission (or switching) system parameters Filtering properties for better system parameters ... Solutions of Complex Transcendental Equations using the Newton–Raphson Approximation Transcendental equations will be formed in order to find the threshold gain of DFB LDs [21] In general these equations...

Ngày tải lên: 15/12/2013, 04:15

... that when O ¼ or 2p the transmissivity peaks occur at Æ 11.05 A which gives the ˚ overall filter tuning range of 22.1 A The peak value of transmissivity within this tuning range is almost constant ... wavelength tuning range is 21 A, peak transmissivity ranges Figure 11.12 Power transmissivity versus relative wavelength ð À B Þ for the following different values of O The parameters used are ... The power transmissivities of a few values of O1 and O2 are plotted in Fig 11.18 as a function of the relative wavelength from the Bragg wavelength The figure demonstrates a spectra of high and...

Ngày tải lên: 24/12/2013, 12:17