2005磁波(144)
电磁波谱
NMR:
核磁共振现象、化学位移、γ效应、饱和、弛豫过程、弛豫时间、自旋－晶格弛豫、自旋－自旋弛豫、化学等价核、磁等价核、NOE效应、质子宽带去偶法、偏共振去偶、门控去偶、反转门控去偶
核磁共振现象：化合物吸收的能量与质子发生跃迁时两能级之间的能量差相等时发生的现象。
化学位移：把在一定频率下，处于不同化学环境下的有机化合物中的不同质子，产生NMR的磁场强度不同的现象，称为化学位移。
摩尔吸光系数：浓度为1mol/l，吸收池厚度为1cm时溶液的吸光度值。
IR:
红外活性振动、基频峰、泛频峰、特征峰、相关峰、特征区、指纹区、诱导效应、共轭效应、振动偶合、费米共振、
红外活性振动：瞬间偶极矩变化不为零的振动。
基频峰：当分子吸收一定频率的红外线后，振动能级从基态（V0）跃迁到第一激发态（V1）时所产生的吸收峰，称为基频峰。
质子宽带去偶法：也叫噪音去偶法。是在测定13C谱的同时，用一个包括1H整个进动频率的去偶频带，消除样品中全部1H-13C偶合，使13C谱图呈现一个个单峰。一般说来，在分子中没有对称因素和不含F、P等元素时，往往是分子中有几种化学类型的碳就有几个峰。
偏共振去偶法：偏共振去偶技术是将质子去偶频率放在稍稍偏离质子共振区外，这样得到的谱图，远程偶合不存在，只留下偶合最强的信号并且偶合常数缩小，即所观察到的偶合常数比真实偶合常数小，表观偶合常数的大小与去偶功率和去偶频率偏离共振点的位置有关。
特征区：习惯上把波数在4000～1330cm-1（波长为2.5～7.5μm）区间称为特征频率区，简称特征区。
指纹区：波数在1330～667 cm-1（波长为7.5～15μm）的区域称为指纹区。
诱导效应:分子中引入不同电负性的原子或官能团，通过静电诱导作用，可使分子中电子云密度发生变化，即键的极性发波能量向高能态跃迁的过程连续下去，那么这极微量过剩的低能态氢核就会逐渐减少，吸收信号的强度也随之减弱，最后低能态与高能态的核数趋于相等，使吸收信号完全消失，这种现象为“饱和”现象。
太赫兹波
太赫兹检测技术1 太赫兹波简介电磁波（又称电磁辐射）是由同相振荡且互相垂直的电场与磁场在空间中以波的形式移动，其传播方向垂直于电场与磁场构成的平面，有效的传递能量和动量。
电磁辐射可以按照频率分类，从低频率到高频率，包括有无线电波、微波、红外线、可见光、紫外线、X射线和伽马射线等等。
太赫兹波(Terahert或称太赫兹辐射、T-射线、亚毫米波、远红外，简称THz) 通常指频率在0.1~10THz (1THz=1012Hz)范围内的电磁辐射。
若以应用频率范围的载体为坐标，则太赫兹波位于“雷达”与“人”之间。
是电磁波谱上由电子学向光子学过渡的特殊区域，也是宏观经典理论向微观量子理论的过渡区域。
图1 电磁波谱图Fig1 Electromagnetic spectrumTHz波在无线电物理领域称为亚毫米波，在光学领域则习惯称之为远红外辐射；从能量辐射上看，其大小在电子和光子之间。
在电磁频谱上，THz波段两侧的红外和微波技术已经很成熟，但是THz技术还不完善。
究其原因是因为此频段既不完全适和用光学理论来处理，也不完全适合用微波理论来研究，缺乏有效的产生和检测THz波的手段，从而形成了所说的“THz空隙”。
2 THz辐射研究的发展历史与现状上世纪九十年代以后,超快激光技术的迅速发展,为太赫兹脉冲的产生提供了稳定、可靠的激发光源。
太赫兹波段各种技术的研究才蓬勃发展起来。
与此同时，半导体物理的研究和材料加工工艺的改进也日趋完善，人们在选择与太赫兹辐射研究相关的半导体材料过程中发现半导体材料有着尤为重要的研究价值，且它们都是常用的半导体材料；同时通过掺杂工艺，改善半导体材料的性质，如载流子迁移率、寿命和阻抗都可以控制调整以适应光电器件的要求，这些半导体制作工艺上的发展促进了相关科学技术的发展。
2.1 THz辐射的特点THz技术之所以引起人们广泛的关注，主要是由于太赫兹电磁波独有的特点，各种物质在这一频段的独特响应及其在特定领域中的不可替代性[1]。
电磁干扰
屏蔽效率计算公式
SE=[20lg (fc/o/σ)]-10lg n (fc/o/σ)]其中 fc/o:截止频率 fc/o:截止频率 n:孔洞数目
屏蔽效能
屏蔽体对辐射干扰的抑制能力用屏蔽效能SE 屏蔽体对辐射干扰的抑制能力用屏蔽效能SE (Shielding Effectiveness)来衡量,屏蔽效能的定义: Effectiveness)来衡量,屏蔽效能的定义: 没有屏蔽体时,从辐射干扰源传输到空间某一点(P)的场 没有屏蔽体时,从辐射干扰源传输到空间某一点(P)的场 强 1( 1)和加入屏蔽体后,辐射干扰源传输到空间同一 点(P)的场强 2( 2)之比,用dB(分贝)表示. (P)的场强 )之比,用dB(分贝)表示.
防护建议
1,老人,儿童和孕妇属于电磁辐射的敏感人群, 在有电磁辐射的环境中活动时,应根据辐射频率 或场强特点,选择合适的防护服加以防护.建议 孕妇在孕期,尤其在孕早期,应全方位加以防护, 对于电磁辐射的伤害不能存有侥幸心理. 2,,合理使用电器设备,保持安全距离,减少辐 射危害. 注意多食用富含维生素A,维生素C 注意多食用富含维生素A,维生素C和蛋白质的食 物,加强机体抵抗电磁辐射的能力. 3,平时注意了解电磁辐射的相关知识,增强预防 意识,了解国家相关法规和规定,保护自身的健 康和安全不受侵害
近场反射损耗可按下式计算
R(电)dB=321.8-(20×lg r)-(30×lg f)-[10×lg(/σ)] R(电)dB=321.8-(20× r)-(30× f)-[10× R(磁)dB=14.6+(20×lg r)+(10×lg R(磁)dB=14.6+(20× r)+(10× f)+[10× f)+[10×lg(/σ)] 其中 r:波源与屏蔽之间的距离. SE算式最后一项是校正因子B,其计算公式为 SE算式最后一项是校正因子B B=20lg[-exp(B=20lg[-exp(-2t/σ)] 此式仅适用于近磁场环境并且吸收损耗小于10dB的情况. 此式仅适用于近磁场环境并且吸收损耗小于10dB的情况. 由于屏蔽物吸收效率不高,其内部的再反射会使穿过屏蔽 层另一面的能量增加,所以校正因子是个负数,表示屏蔽 效率的下降情况.
太赫兹波的几个基本问题
1 太赫兹波特性
太赫兹波的有关研究和应用都离不开两个重要 的特性 : ①光谱特性 在太赫兹波的范围内 , 大多 数化学物质具有吸收特性 , 而在 0 . 3 T Hz 以下的 毫米波和微波范围内 , 则不存在此特性 ; ②传输特 性 在太赫兹波波段 , 大多数材料是透明的 , 或者 是部分透明的 , 而在 3 T Hz 以上的红外范围内 ,
研究太赫兹波在成像 、探测 、传感和通信等所 有的应用系统都离不开基本的太赫兹波能源 。在实 际应用中 , 人们经常要求相关的太赫兹连续波的源 频率可调 , 源强度达到 mW 级以上 , 并且能够在 室温下工作 。目前 , 已经开发的太赫兹连续波源的 方法 有 量 子 级 联 激 光 器 ( QCL ) 、回 波 振 荡 器 (BWO) 和光学混频等 。但是 , 在上述方法中 , 1 ～4 T Hz 的太 赫兹 连续波 源的 功率 太 低 , 见 图 1[4 ] 。因此 , 必须开发出新的 、功率更大的太赫兹 波的连续波源 。
在太赫兹波领域中存在着无限的机会 , 例如在 太赫兹波的电磁波频率范围内 , 其基本周期约为 1 p s , 尤其适合许多重要领域的研究 : 完全受激态原 子的里德伯 ( Rydberg) 态轨道的电子频率是太赫 兹波 ; 小分子的旋转频率是太赫兹波 ; 室温下气态 分子的碰撞时间约 1 p s 等 。因此 , 人们正在努力 降低进入研究太赫兹波的门槛 。
光电子器件的工作频率拓展到太赫兹频率范围 , 也 太赫兹波的加工技术 。
是一种实现方法的尝试 。基于带间跃迁量子机理的 3 .1 太赫兹波加工技术
半导体器件的频率极限高于与半导体能带隙相关器
(1) 铣削 ; (2) 放电加工 ( EDM) , 主要优点是
at2005b技术参数
at2005b技术参数
AT2005B电源的技术参数如下：
1. 最大允许电压：
2. 常用值：5V
3. ⑧脚（CT）：锯齿波振荡电容接入端。
锯齿波振荡器的振荡频率FOSC
由该脚外接电容CT的电容值决定，其计算公式为：Fusc=410×103/()kHz，式中CT的单位为pF。
如CT=2200pF，则Fdsc=410×103/(×2200)=。
4. ⑨脚（C1）、⑩脚（C2）：分别为驱动输出l与驱动输出2。
因为是漏
极开路输出方式，外电路需分别加接上拉电阻R3。
其最大允许漏极电流均
为200mA。
这些技术参数是确保AT2005B电源正常运行的关键因素，对设备的性能和
稳定性起着至关重要的作用。
以上内容仅供参考，如有更专业的技术问题，建议咨询厂家或技术人员。
SF2005中文版(地震测量)
全量程范围 产品
± 4g (带有振荡器) SF2005S.A
± 4g (不带有振荡器) SF2005SN.A 基本 尺寸 A B C D 9 0.46 0.07 0.24 0.11 0.48 0.78 0.48
毫米 24.4 15.0 17.5 11.7 1.7 6.1 2.8 12.2 19.8 12.2
单位
g 峰值 g 峰值 V/g Hz dB ngrms/√Hz dB g 峰值 C ppm/C (re: ±1g) mg g/C (re: ±1g)
SF2005S.A / SF2005SN.A
4 4.5 0.8 (1.6) DC to >1000 114 800 > 40 >1500 -40 to +85 200 ±300 300
电气连接
P1 P2 P3 P4, P8 P5 P6 P7 P9 P10 -Vout +Vout ATST * RTN * OFFSET * XTI * RTN -PWR +PWR 反向输出信号 输出信号 传感器自检输入 返回信号（共同） 用于消除直流偏移 振荡器的输入。N/C for SF2005S 返回 负电源 正电源
V 技术参数
线性输出范围 输出范围 灵敏度 频率响应（全信号） 动态范围(100 Hz BW) 噪音 (10 to 1000 Hz) 交叉轴抑制 冲击极限（0.5ms ½ sine） 工作温度范围 灵敏度温度系数 直流偏移（最大值） 热偏移系数
如无特别说明，所有参数都是在+20°C (+68°F) 和 ±6 to ±15VDC 工作电压的条件下给出。
地球物理
30S.SF2005A.E.03.09
结构/建筑物监测
XCS05XL-4BG144C中文资料
© 2001 Xilinx, Inc. All rights reserved. All Xilinx trademarks, registered trademarks, patents, and disclaimers are as listed at /legal.htm .All other trademarks and registered trademarks are the property of their respective owners. All specifications are subject to change without notice.IntroductionThe Spartan ™ and the Spartan-XL families are a high-vol-ume production FPGA solution that delivers all the key requirements for ASIC replacement up to 40,000 gates.These requirements include high performance, on-chip RAM, core solutions and prices that, in high volume,approach and in many cases are equivalent to mask pro-grammed ASIC devices.The Spartan series is the result of more than 14 years of FPGA design experience and feedback from thousands of customers. By streamlining the Spartan series feature set,leveraging advanced process technologies and focusing on total cost management, the Spartan series delivers the key features required by ASIC and other high-volume logic users while avoiding the initial cost, long development cycles and inherent risk of conventional ASICs. The Spar-tan and Spartan-XL families in the Spartan series have ten members, as shown in T able 1.Spartan and Spartan-XL FeaturesNote: The Spartan series devices described in this data sheet include the 5V Spartan family and the 3.3V Spartan-XL family. See the separate data sheet for the 2.5V Spartan-II family.•First ASIC replacement FPGA for high-volume production with on-chip RAM•Density up to 1862 logic cells or 40,000 system gates •Streamlined feature set based on XC4000 architecture •System performance beyond 80MHz•Broad set of AllianceCORE ™ and LogiCORE ™ predefined solutions available •Unlimited reprogrammability •Low cost•System level features-Available in both 5V and 3.3V versions -On-chip SelectRAM ™ memory -Fully PCI compliant-Full readback capability for program verificationand internal node observability -Dedicated high-speed carry logic -Internal 3-state bus capability-Eight global low-skew clock or signal networks -IEEE 1149.1-compatible Boundary Scan logic -Low cost plastic packages available in all densities -Footprint compatibility in common packages•Fully supported by powerful Xilinx development system -Foundation Series: Integrated, shrink-wrapsoftware-Alliance Series: Dozens of PC and workstationthird party development systems supported-Fully automatic mapping, placement and routing Additional Spartan-XL Features• 3.3V supply for low power with 5V tolerant I/Os •Power down input •Higher performance •Faster carry logic•More flexible high-speed clock network•Latch capability in Configurable Logic Blocks •Input fast capture latch•Optional mux or 2-input function generator on outputs •12 mA or 24 mA output drive •5V and 3.3V PCI compliant •Enhanced Boundary Scan •Express Mode configuration •Chip scale packagingSpartan and Spartan-XL Families Field Programmable Gate ArraysDS060 (v1.6) September 19, 2001Product Specification T able 1: Spartan and Spartan-XL Field Programmable Gate Arrays1.Max values of Typical Gate Range include 20-30% of CLBs used as RAM.2DS060 (v1.6) September 19, 2001General OverviewSpartan series FPGAs are implemented with a regular, flex-ible, programmable architecture of Configurable Logic Blocks (CLBs), interconnected by a powerful hierarchy of versatile routing resources (routing channels), and sur-rounded by a perimeter of programmable Input/Output Blocks (IOBs), as seen in Figure 1. They have generous routing resources to accommodate the most complex inter-connect patterns.The devices are customized by loading configuration data into internal static memory cells. Re-programming is possi-ble an unlimited number of times. The values stored in thesememory cells determine the logic functions and intercon-nections implemented in the FPGA. The FPGA can either actively read its configuration data from an external serial PROM (Master Serial mode), or the configuration data can be written into the FPGA from an external device (Slave Serial mode).Spartan series FPGAs can be used where hardware must be adapted to different user applications. FPGAs are ideal for shortening design and development cycles, and also offer a cost-effective solution for production rates well beyond 50,000 systems per month.Figure 1: Basic FPGA Block DiagramSpartan series devices achieve high-performance, low-cost operation through the use of an advanced architecture and semiconductor technology. Spartan and Spartan-XL devices provide system clock rates exceeding 80MHz and internal performance in excess of150MHz. In contrast to other FPGA devices, the Spartan series offers the most cost-effective solution while maintaining leading-edge per-formance. In addition to the conventional benefit of high vol-ume programmable logic solutions, Spartan series FPGAs also offer on-chip edge-triggered single-port and dual-port RAM, clock enables on all flip-flops, fast carry logic, and many other features.The Spartan/XL families leverage the highly successful XC4000 architecture with many of that family’s features and benefits. T echnology advancements have been derived from the XC4000XLA process developments.Logic Functional DescriptionThe Spartan series uses a standard FPGA structure as shown in Figure1, page2. The FPGA consists of an array of configurable logic blocks (CLBs) placed in a matrix of routing channels. The input and output of signals is achieved through a set of input/output blocks (IOBs) forming a ring around the CLBs and routing channels.•CLBs provide the functional elements for implementing the user’s logic.•IOBs provide the interface between the package pins and internal signal lines.•Routing channels provide paths to interconnect the inputs and outputs of the CLBs and IOBs.The functionality of each circuit block is customized during configuration by programming internal static memory cells. The values stored in these memory cells determine the logic functions and interconnections implemented in the FPGA.Configurable Logic Blocks (CLBs)The CLBs are used to implement most of the logic in an FPGA. The principal CLB elements are shown in the simpli-fied block diagram in Figure2. There are three look-up tables (LUT) which are used as logic function generators, two flip-flops and two groups of signal steering multiplexers. There are also some more advanced features provided by the CLB which will be covered in the Advanced Features Description, page13.Function GeneratorsTwo 16x1 memory look-up tables (F-LUT and G-LUT) are used to implement 4-input function generators, each offer-ing unrestricted logic implementation of any Boolean func-tion of up to four independent input signals (F1 to F4 or G1 to G4). Using memory look-up tables the propagation delay is independent of the function implemented.A third 3-input function generator (H-LUT) can implement any Boolean function of its three inputs. Two of these inputs are controlled by programmable multiplexers (see box "A" of Figure2). These inputs can come from the F-LUT or G-LUT outputs or from CLB inputs. The third input always comes from a CLB input. The CLB can, therefore, implement cer-tain functions of up to nine inputs, like parity checking. The three LUTs in the CLB can also be combined to do any arbi-trarily defined Boolean function of five inputs.4DS060 (v1.6) September 19, 2001A CLB can implement any of the following functions:•Any function of up to four variables, plus any second function of up to four unrelated variables, plus any third function of up to three unrelated variablesNote: When three separate functions are generated, one of the function outputs must be captured in a flip-flop internal to the CLB. Only two unregistered function generator outputs are available from the CLB.•Any single function of five variables•Any function of four variables together with some functions of six variables•Some functions of up to nine variables.Implementing wide functions in a single block reduces both the number of blocks required and the delay in the signal path, achieving both increased capacity and speed. The versatility of the CLB function generators significantly improves system speed. In addition, the design-software tools can deal with each function generator independently.This flexibility improves cell usage.Flip-FlopsEach CLB contains two flip-flops that can be used to regis-ter (store) the function generator outputs. The flip-flops and function generators can also be used independently (see Figure 2). The CLB input DIN can be used as a direct input to either of the two flip-flops. H1 can also drive either flip-flop via the H-LUT with a slight additional delay.The two flip-flops have common clock (CK), clock enable (EC) and set/reset (SR) inputs. Internally both flip-flops are also controlled by a global initialization signal (GSR) which is described in detail in Global Signals: GSR and GTS ,page 20.Latches (Spartan-XL only)The Spartan-XL CLB storage elements can also be config-ured as latches. The two latches have common clock (K)and clock enable (EC) inputs. Functionality of the storage element is described in Table 2.Figure 2: Spartan/XL Simplified CLB Logic Diagram (some features not shown)Clock InputEach flip-flop can be triggered on either the rising or falling clock edge. The CLB clock line is shared by both flip-flops.However, the clock is individually invertible for each flip-flop (see CK path in Figure 3). Any inverter placed on the clock line in the design is automatically absorbed into the CLB. Clock EnableThe clock enable line (EC) is active High. The EC line is shared by both flip-flops in a CLB. If either one is left discon-nected, the clock enable for that flip-flop defaults to the active state. EC is not invertible within the CLB. The clock enable is synchronous to the clock and must satisfy the setup and hold timing specified for the device.Set/ResetThe set/reset line (SR) is an asynchronous active High con-trol of the flip-flop. SR can be configured as either set or reset at each flip-flop. This configuration option determines the state in which each flip-flop becomes operational after configuration. It also determines the effect of a GSR pulse during normal operation, and the effect of a pulse on the SR line of the CLB. The SR line is shared by both flip-flops. If SR is not specified for a flip-flop the set/reset for that flip-flop defaults to the inactive state. SR is not invertible within the CLB.CLB Signal Flow ControlIn addition to the H-LUT input control multiplexers (shown in box "A" of Figure 2, page 4) there are signal flow control multiplexers (shown in box "B" of Figure 2) which select the signals which drive the flip-flop inputs and the combinatorial CLB outputs (X and Y).Each flip-flop input is driven from a 4:1 multiplexer which selects among the three LUT outputs and DIN as the data source.Each combinatorial output is driven from a 2:1 multiplexer which selects between two of the LUT outputs. The X output can be driven from the F-LUT or H-LUT, the Y output from G-LUT or H-LUT .Control SignalsThere are four signal control multiplexers on the input of the CLB. These multiplexers allow the internal CLB control sig-nals (H1, DIN, SR, and EC in Figure 2 and Figure 4) to be driven from any of the four general control inputs (C1-C4 in Figure 4) into the CLB. Any of these inputs can drive any of the four internal control signals.T able 2: CLB Storage Element FunctionalityLegend:XDon ’t careRising edge (clock not inverted).SR Set or Reset value. Reset is default.0*Input is Low or unconnected (default value)1*Input is High or unconnected (default value)Figure 3: CLB Flip-Flop Functional Block Diagram6DS060 (v1.6) September 19, 2001The four internal control signals are:•EC: Enable Clock•SR: Asynchronous Set/Reset or H function generator Input 0•DIN: Direct In or H function generator Input 2•H1: H function generator Input 1.Input/Output Blocks (IOBs)User-configurable input/output blocks (IOBs) provide the interface between external package pins and the internal logic. Each IOB controls one package pin and can be con-figured for input, output, or bidirectional signals. Figure 6shows a simplified functional block diagram of the Spar-tan/XL IOB.IOB Input Signal PathThe input signal to the IOB can be configured to either go directly to the routing channels (via I1 and I2 in Figure 6) or to the input register. The input register can be programmed as either an edge-triggered flip-flop or a level-sensitive latch. The functionality of this register is shown in Table 3,and a simplified block diagram of the register can be seen in Figure 5.Figure 4: CLB Control Signal InterfaceFigure 5: IOB Flip-Flop/Latch Functional BlockDiagramTable 3: Input Register FunctionalityX Don ’t care.Rising edge (clock not inverted).SR Set or Reset value. Reset is default.0*Input is Low or unconnected (default value)1*Input is High or unconnected (default value)The register choice is made by placing the appropriate library symbol. For example, IFD is the basic input flip-flop (rising edge triggered), and ILD is the basic input latch (transparent-High). Variations with inverted clocks are also available. The clock signal inverter is also shown in Figure5 on the CK line.The Spartan IOB data input path has a one-tap delay ele-ment: either the delay is inserted (default), or it is not. The Spartan-XL IOB data input path has a two-tap delay ele-ment, with choices of a full delay, a partial delay, or no delay. The added delay guarantees a zero hold time with respect to clocks routed through the global clock buffers. (See Glo-bal Nets and Buffers, page12 for a description of the glo-bal clock buffers in the Spartan/XL families.) For a shorter input register setup time, with positive hold-time, attach a NODELAY attribute or property to the flip-flop.The output of the input register goes to the routing channels (via I1 and I2 in Figure6). The I1 and I2 signals that exit the IOB can each carry either the direct or registered input signal.The 5V Spartan input buffers can be globally configured for either TTL (1.2V) or CMOS (VCC/2) thresholds, using an option in the bitstream generation software. The Spartan output levels are also configurable; the two global adjust-ments of input threshold and output level are independent. The inputs of Spartan devices can be driven by the outputs of any 3.3V device, if the Spartan inputs are in TTL mode. Input and output thresholds are TTL on all configuration pins until the configuration has been loaded into the device and specifies how they are to be used. Spartan-XL inputs are TTL compatible and 3.3V CMOS compatible. Supported sources for Spartan/XL device inputs are shown in Table4.Spartan-XL I/Os are fully 5V tolerant even though the V CC is 3.3V. This allows 5V signals to directly connect to the Spar-tan-XL inputs without damage, as shown in Table4. In addi-tion, the 3.3V V CC can be applied before or after 5V signals are applied to the I/Os. This makes the Spartan-XL devices immune to power supply sequencing problems.Figure 6: Simplified Spartan/XL IOB Block Diagram8DS060 (v1.6) September 19, 2001Spartan-XL V CC ClampingSpartan-XL FPGAs have an optional clamping diode con-nected from each I/O to V CC . When enabled they clamp ringing transients back to the 3.3V supply rail. This clamping action is required in 3.3V PCI applications. V CC clamping is a global option affecting all I/O pins.Spartan-XL devices are fully 5V TTL I/O compatible if V CC clamping is not enabled. With V CC clamping enabled, the Spartan-XL devices will begin to clamp input voltages to one diode voltage drop above V CC . If enabled, TTL I/O com-patibility is maintained but full 5V I/O tolerance is sacrificed.The user may select either 5V tolerance (default) or 3.3V PCI compatibility. In both cases negative voltage is clamped to one diode voltage drop below ground.Spartan-XL devices are compatible with TTL, LVTTL, PCI 3V, PCI 5V and LVCMOS signalling. The various standards are illustrated in Table 5.Additional Fast Capture Input Latch (Spartan-XL only)The Spartan-XL IOB has an additional optional latch on the input. This latch is clocked by the clock used for the output flip-flop rather than the input clock. Therefore, two different clocks can be used to clock the two input storage elements.This additional latch allows the fast capture of input data,which is then synchronized to the internal clock by the IOB flip-flop or latch.T o place the Fast Capture latch in a design, use one of the special library symbols, ILFFX or ILFLX. ILFFX is a trans-parent-Low Fast Capture latch followed by an active High input flip-flop. ILFLX is a transparent Low Fast Capture latch followed by a transparent High input latch. Any of the clock inputs can be inverted before driving the library element,and the inverter is absorbed into the IOB.IOB Output Signal PathOutput signals can be optionally inverted within the IOB,and can pass directly to the output buffer or be stored in an edge-triggered flip-flop and then to the output buffer. The functionality of this flip-flop is shown in T able 6.T able 4: Supported Sources for Spartan/XL InputsT able 5: I/O Standards Supported by Spartan-XL FPGAsTable 6: Output Flip-Flop Functionality X Don ’t careRising edge (clock not inverted). SR Set or Reset value. Reset is default.0*Input is Low or unconnected (default value)1*Input is High or unconnected (default value)Z3-stateOutput Multiplexer/2-Input Function Generator (Spartan-XL only)The output path in the Spartan-XL IOB contains an addi-tional multiplexer not available in the Spartan IOB. The mul-tiplexer can also be configured as a 2-input function generator, implementing a pass gate, AND gate, OR gate, or XOR gate, with 0, 1, or 2 inverted inputs.When configured as a multiplexer, this feature allows two output signals to time-share the same output pad, effec-tively doubling the number of device outputs without requir-ing a larger, more expensive package. The select input is the pin used for the output flip-flop clock, OK.When the multiplexer is configured as a 2-input function generator, logic can be implemented within the IOB itself. Combined with a Global buffer, this arrangement allows very high-speed gating of a single signal. For example, a wide decoder can be implemented in CLBs, and its output gated with a Read or Write Strobe driven by a global buffer. The user can specify that the IOB function generator be used by placing special library symbols beginning with the letter "O." For example, a 2-input AND gate in the IOB func-tion generator is called OAND2. Use the symbol input pin labeled "F" for the signal on the critical path. This signal is placed on the OK pin — the IOB input with the shortest delay to the function generator. Two examples are shown in Figure7.Output BufferAn active High 3-state signal can be used to place the out-put buffer in a high-impedance state, implementing 3-state outputs or bidirectional I/O. Under configuration control, the output (O) and output 3-state (T) signals can be inverted. The polarity of these signals is independently configured for each IOB (see Figure6, page7). An output can be config-ured as open-drain (open-collector) by tying the 3-state pin (T) to the output signal, and the input pin (I) to Ground.By default, a 5V Spartan device output buffer pull-up struc-ture is configured as a TTL-like totem-pole. The High driver is an n-channel pull-up transistor, pulling to a voltage one transistor threshold below V CC. Alternatively, the outputs can be globally configured as CMOS drivers, with additional p-channel pull-up transistors pulling to V CC. This option, applied using the bitstream generation software, applies to all outputs on the device. It is not individually programma-ble.All Spartan-XL device outputs are configured as CMOS drivers, therefore driving rail-to-rail. The Spartan-XL outputs are individually programmable for 12mA or 24mA output drive.Any 5V Spartan device with its outputs configured in TTL mode can drive the inputs of any typical 3.3V device. Sup-ported destinations for Spartan/XL device outputs are shown in Table7.Three-State Register (Spartan-XL Only)Spartan-XL devices incorporate an optional register control-ling the three-state enable in the IOBs. The use of the three-state control register can significantly improve output enable and disable time.Output Slew RateThe slew rate of each output buffer is, by default, reduced, to minimize power bus transients when switching non-criti-cal signals. For critical signals, attach a FAST attribute or property to the output buffer or flip-flop.Spartan/XL devices have a feature called "Soft Start-up," designed to reduce ground bounce when all outputs are turned on simultaneously at the end of configuration. When the configuration process is finished and the device starts up, the first activation of the outputs is automatically slew-rate limited. Immediately following the initial activation of the I/O, the slew rate of the individual outputs is deter-mined by the individual configuration option for each IOB. Pull-up and Pull-down NetworkProgrammable pull-up and pull-down resistors are used fortying unused pins to V CC or Ground to minimize power con-sumption and reduce noise sensitivity. The configurablepull-up resistor is a p-channel transistor that pulls to V CC.The configurable pull-down resistor is an n-channel transis-tor that pulls to Ground. The value of these resistors is typi-cally 20KΩ − 100KΩ (See "Spartan DC Characteristics Figure 7: AND and MUX Symbols in Spartan-XL IOB10DS060 (v1.6) September 19, 2001Over Operating Conditions" on page 43.). This high value makes them unsuitable as wired-AND pull-up resistors.After configuration, voltage levels of unused pads, bonded or unbonded, must be valid logic levels, to reduce noise sensitivity and avoid excess current. Therefore, by default,unused pads are configured with the internal pull-up resistor active. Alternatively, they can be individually configured with the pull-down resistor, or as a driven output, or to be driven by an external source. To activate the internal pull-up, attach the PULLUP library component to the net attached to the pad. To activate the internal pull-down, attach the PULL-DOWN library component to the net attached to the pad.Set/ResetAs with the CLB registers, the GSR signal can be used to set or clear the input and output registers, depending on the value of the INIT attribute or property. The two flip-flops can be individually configured to set or clear on reset and after configuration. Other than the global GSR net, no user-con-trolled set/reset signal is available to the I/O flip-flops (Figure 5). The choice of set or reset applies to both the ini-tial state of the flip-flop and the response to the GSR pulse.Independent ClocksSeparate clock signals are provided for the input (IK) and output (OK) flip-flops. The clock can be independently inverted for each flip-flop within the IOB, generating eitherfalling-edge or rising-edge triggered flip-flops. The clock inputs for each IOB are mon Clock EnablesThe input and output flip-flops in each IOB have a common clock enable input (see EC signal in Figure 5), which through configuration, can be activated individually for the input or output flip-flop, or both. This clock enable operates exactly like the EC signal on the Spartan/XL CLB. It cannot be inverted within the IOB.Routing Channel DescriptionAll internal routing channels are composed of metal seg-ments with programmable switching points and switching matrices to implement the desired routing. A structured,hierarchical matrix of routing channels is provided to achieve efficient automated routing.This section describes the routing channels available in Spartan/XL devices. Figure 8 shows a general block dia-gram of the CLB routing channels. The implementation soft-ware automatically assigns the appropriate resources based on the density and timing requirements of the design.The following description of the routing channels is for infor-mation only and is simplified with some minor details omit-ted. For an exact interconnect description the designer should open a design in the FPGA Editor and review the actual connections in this tool.The routing channels will be discussed as follows;•CLB routing channels which run along each row and column of the CLB array.•IOB routing channels which form a ring (called a VersaRing) around the outside of the CLB array. It connects the I/O with the CLB routing channels.•Global routing consists of dedicated networks primarily designed to distribute clocks throughout the device with minimum delay and skew. Global routing can also be used for other high-fanout signals.CLB Routing ChannelsThe routing channels around the CLB are derived from three types of interconnects; single-length, double-length,and longlines. At the intersection of each vertical and hori-zontal routing channel is a signal steering matrix called a Programmable Switch Matrix (PSM). Figure 8 shows the basic routing channel configuration showing single-length lines, double-length lines and longlines as well as the CLBs and PSMs. The CLB to routing channel interface is shown as well as how the PSMs interface at the channel intersec-tions.T able 7: Supported Destinations for Spartan/XL OutputsNotes:1.Only if destination device has 5V tolerant inputs.CLB InterfaceA block diagram of the CLB interface signals is shown in Figure9. The input signals to the CLB are distributed evenly on all four sides providing maximum routing flexibility. In general, the entire architecture is symmetrical and regular. It is well suited to established placement and routing algo-rithms. Inputs, outputs, and function generators can freely swap positions within a CLB to avoid routing congestion during the placement and routing operation. The exceptions are the clock (K) input and CIN/COUT signals. The K input is routed to dedicated global vertical lines as well as four single-length lines and is on the left side of the CLB. The CIN/COUT signals are routed through dedicated intercon-nects which do not interfere with the general routing struc-ture. The output signals from the CLB are available to drive both vertical and horizontal channels.Programmable Switch MatricesThe horizontal and vertical single- and double-length lines intersect at a box called a programmable switch matrix (PSM). Each PSM consists of programmable pass transis-tors used to establish connections between the lines (see Figure10).For example, a single-length signal entering on the right side of the switch matrix can be routed to a single-length line on the top, left, or bottom sides, or any combination thereof, if multiple branches are required. Similarly, a dou-ble-length signal can be routed to a double-length line on any or all of the other three edges of the programmable switch matrix.Single-Length LinesSingle-length lines provide the greatest interconnect flexibil-ity and offer fast routing between adjacent blocks. There are eight vertical and eight horizontal single-length lines associ-ated with each CLB. These lines connect the switching matrices that are located in every row and column of CLBs. Single-length lines are connected by way of the program-mable switch matrices, as shown in Figure10. Routing con-nectivity is shown in Figure8.Single-length lines incur a delay whenever they go through a PSM. Therefore, they are not suitable for routing signals for long distances. They are normally used to conduct sig-nals within a localized area and to provide the branching for nets with fanout greater than one.Figure 8: Spartan/XL CLB Routing Channels and Interface Block DiagramFigure 9: CLB Interconnect Signals。
2005年高考全国卷3理综物理(含答案)
2005年高考全国卷3综合能力测试物理部分二、选择题(本题包括8 小题。
每小题给出的四个选项中，有的只有一个选项正确，有的有多个选项正确)l4．如图所示，一物块位于光滑水平桌面上，用一大小为F 、方向如图所示的力去推它，使它以加速度a 右运动。
若保持力的方向不变而增大力的大小，则 A . a 变大 B .不变C ．a 变小D . 因为物块的质量未知，故不能确定a 变化的趋势15．氢原子的能级图如图所示。
欲使一处于基态的氢原子释放出一个电子而变成氢离子，该氢原子需要吸收的能量至少是 A . 13.60eV B .10.20eV C . 0.54 eV D . 27. 20eV16．如图，闭合线圈上方有一竖直放置的条形磁铁，磁铁的N 极朝下。
当磁铁向下运动时（但未插入线圈内部），A ．线圈中感应电流的方向与图中箭头方向相同，磁铁与线圈相互吸引B ．线圈中感应电流的方向与图中箭头方向相同，磁铁与线圈相互排斥 C. 线圈中感应电流的方向与图中箭头方向相反，磁铁与线圈相互吸引 D ．线圈中感应电流的方向与图中箭头方向相反，磁铁与线圈相互排斥17.水平放置的平行板电容器与一电池相连。
在电容器的两板间有一带正电的质点处于静 止平衡状态。
现将电容器两板间的距离增大，则A ．电容变大，质点向上运动B ．电容变大，质点向下运动C ．电容变小，质点保持静止D ．电容变小，质点向下运动18．两种单色光由水中射向空气时发生全反射的临界角分别为θ1、θ2。
用n1、n 2分别表示水对两单色光的折射率，v1、v2分别表示两单色光在水中的传播速度A . n l＜n2、v1＜v2 B.n l＜n2、v1>v2 C.n l>n2、v1＜v2 D.n l>n2、v1>v219. 一定质量的气体经历一缓慢的绝热膨胀过程。
设气体分子向的势能可忽略，则在此过程中A．外界对气体做功，气体分子的平均动能增加C．气体对外界做功，气体分子的平均动能增加B．外界对气体做功，气体分子的平均动能减少D．气体对外界做功，气体分子的平均动能减少20．一列简谐横波在x轴上传播，某时刻的波形图如图所示，a 、b 、c为三个质元，a 正向上运动。
2005年代中国地区地磁场及其长期变化球冠谐和分析解读
第５４卷第３期２０１１年３月地球物理学报ＣＨＩＮＥＳＥＪＯＵＲＮＡＩ。
ＯＦＧＥＯＰＨＹＳＩＣＳＶ０１．５４，Ｎｏ．３Ｍａｒ．，２０１１陈斌，顾左文，高金田等．２００５．０年代中国地区地磁场及其长期变化球冠谐和分析．地球物理学报，２０１１，５４（３）：７７１～７７９，ＤＯＩ：１０．３９６９／ｊ．ｉｓｓｎ．０００１－５７３３．２０１１．０３．０１７ＣｈｅｎＢ，ＧｕＺＷ，ＧａｏＪＴ，ｅｔａ１．ＡｎａｌｙｓｅｓｏｆｇｅｏｍａｇｎｅｔｉｃｆｉｅｌｄａｎｄｉｔｓｓｅｃｕｌａｒｖａｒｉａｔｉｏｎｏｖｅｒＣｈｉｎａｆｏｒ２００５．０ｅｐｏｃｈｕｓｉｎｇＳｐｈｅｒｉｃａｌＣａｐＨａｒｍｏｎｉｃｍｅｔｈｏｄ．ＣｈｉｎｅｓｅＪ．Ｇｅｏｐｈｙｓ．（ｉｎＣｈｉｎｅｓｅ），２０１１，５４（３）：７７１＂－＇７７９，ＤＯＩ：１０．３９６９／ｊ．ｉｓｓｎ．０００１—５７３３．２０１１．０３．０１７２００５．０年代中国地区地磁场及其长期变化球冠谐和分析陈斌，顾左文，高金田，袁洁浩，狄传芝中国地震局地球物理研究所，北京１０００８１摘要国家地磁图作为描述一个国家领域内地磁场空间分布的基础科技产品，其选用的模型计算方法应准确合理地反映标准年代上地磁场空间分布及未来５年的地磁场长期变化趋势．本文应用球冠谐和（ｓｃＨ）方法，对中国地区１１１９个野外地磁测点和３６个地磁台的观测数据进行了计算，获得了２００５．０标准地磁年代中国地区地磁正常场及其异常场空间分布，建立了２００５～２０１０年中国地区地磁场长期变化球冠谐和模型．结果表明，ＩＧＲＦ描述的中国地区地磁场偏差幅度约为５’（Ｄ、Ｄ或１００ｎＴ（Ｆ），由于新的、空间分辨率更高的地磁测量数据参与计算，球冠谐和方法描述的２００５．０地磁图能较ＩＧＲＦ更细致地描述地磁场的空间分布，具备稳定运用在中国地磁图的编制出版工作中的能力．关键词地磁图，球冠谐和方法，中国地区ＩＸ）Ｉ：１０．３９６９／１．ｉｓｓｎ．０００１—５７３３．２０１１．０３．０１７中图分类号Ｐ３１８收稿日期２０１０－０７－０５，２０１０－０９－１８收修定稿ＡｎａｌｙｓｅｓｏｆｇｅｏｍａｇｎｅｔｉｃｆｉｅｌｄａｎｄｉｔｓｓｅｃｕｌａｒｖａｒｉａｔｉｏｎｏｖｅｒＣｈｉｎａｆｏｒ２００５．０ｅｐｏｃｈｕｓｉｎｇＳｐｈｅｒｉｃａｌＣａｐＨａｒｍｏｎｉｃｍｅｔｈｏｄＣＨＥＮＢｉｎ，ＧＵＺｕｏ—Ｗｅｎ，ＧＡＯＪｉｎ－Ｔｉａｎ，ＹＵＡＮＪｉｅ－Ｈａｏ，ＤＩＣｈｕａｎ－ＺｈｉＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＣｈｉｎａＥａｒｔｈｑｕａｋｅＡｄｍｉｎｉｓｔｒａｔｉｏｎ，Ｂｅｉｊｉｎｇ１０００８１，ＣｈｉｎａＡｂｓｔｒａｃｔＡｓａｂａｓｉｃｔｅｃｈｎｏｌｏｇｉｃａｌｐｒｏｄｕｃｔｄｅｓｃｒｉｂｉｎｇｔｈｅｇｅｏｍａｇｎｅｔｉｃｓｐａｔｉａｌｄｉｓｔｒｉｂｕｔｉｏｎ，ｔｈｅｎａｔｉｏｎａｌｇｅｏｍａｇｎｅｔｉｃｃｈａｒｔｓｈｏｕｌｄｃｈｏｏｓｅａｐｐｒｏｐｒｉａｔｅｍｅｔｈｏｄｔＯｔｒｕｌｙｄｅｓｃｒｉｂｅｔｈｅｇｅｏｍａｇｎｅｔｉｃｆｉｅｌｄｏｎｓｔａｎｄａｒｄｅｐｏｃｈａｎｄｉｔｓｖａｒｉａｔｉｏｎｆｏｒｃｏｍｉｎｇ５ｙｅａｒｓ．ＷｅｕｓｅｄｔｈｅＳｐｈｅｒｉｃａｌＣａｐＨａｒｍｏｎｉｃ（ＳＣＨ）ｍｅｔｈｏｄｔＯｃａｌｃｕｌａｔｅｔｈｅｇｅｏｍａｇｎｅｔｉｃｄａｔａａｔ１１１９ｓｉｔｅｓａｎｄ３６ｏｂｓｅｒｖａｔｏｒｉｅｓｉｎＣｈｉｎａｏｎ２００５．０ｅｐｏｃｈ．ａｎｄｏｂｔａｉｎｅｄｔｈｅｎｏｒｍａｌａｎｄａｂｎｏｒｍａｌｇｅｏｍａｇｎｅｔｉｃｓｐａｔｉａｌｓｔｒｕｃｔｕｒｅｉｎＣｈｉｎａａｎｄｂｕｉｌｔａｎＳＣＨｍｏｄｅｌｆｏｒｇｅｏｍａｇｎｅｔｉｃｓｅｃｕｌａｒｖａｒｉａｔｉｏｎｉｎＣｈｉｎａｆｏｒ２００５～２０１０ｅｐｏｃｈ．ＴｈｅｒｅｓｕｌｔｓｈａｖｅｓｈｏｗｅｄｔｈａｔｔｈｅｅｒｒｏｒｏｆｇｅｏｍａｇｎｅｔｉｃｆｉｅｌｄｂｙＩＧＲＦｃｏｕｌｄｂｅ５７ｆｏｒｄｅｃｌｉｎａｔｉｏｎａｎｄｉｎｃｌｉｎａｔｉｏｎａｎｄ１００ｎＴｆｏｒｔｏｔａｌｉｎｔｅｎｓｉｔｙ．Ｂｙｕｓｉｎｇｂｅｔｔｅｒｒｅｓｏｌｕｔｉｏｎａｎｄｎｅｗｅｒｇｅｏｍａｇｎｅｔｉｃｄａｔａ，ｔｈｅｇｅｏｍａｇｎｅｔｉｃｃｈａｒｔｏｎ２００５．０ｅｐｏｃｈｕｓｉｎｇＳＣＨｍｅｔｈｏｄｓｈｏｕｌｄｂｅｂｅｔｔｅｒｔｏｄｅｓｃｒｉｂｅｔｈｅｓｐａｔｉａｌｓｔｒｕｃｔｕｒｅｏｆｇｅｏｍａｇｎｅｔｉｃｆｉｅｌｄ．ＴｈｉｓｍｅｔｈｏｄｓｈｏｕｌｄｂｅｕｓｅｄｉｎｃｏｍｐｉｌｉｎｇＧｅｏｍａｇｎｅｔｉｃＣｈａｒｔｆｏｒＣｈｉｎａｓｔａｂｌｙ．ＫｅｙｗｏｒｄｓＧｅｏｍａｇｎｅｔｉｃｃｈａｒｔ，ＳｐｈｅｒｉｃａｌＣａｐＨａｒｍｏｎｉｃ（ＳＣＨ）ｍｅｔｈｏｄ，Ｃｈｉｎａ基金项目科技部公益性专项“２００５．０中国地磁图”与科技部基础性专项“地球现代磁场监测与地磁基本数据积累”联合资助．作者简介陈斌，男，１９７９年生，助理研究员，２００５年毕业于中国科学院武汉物理与数学研究所，主要从事地磁测量及地磁研究工作．Ｅ－ｍａｉｌ・．ｃｈａｍｐｉｏｎ＿ｃｈｂ＠１２６．ｔｏｍＭ＃＃ｍ｛“（ｃｈⅢｓｆＪＧｅｏｐｈｙｓ１引言国家地磁圉作为描述个国家领域内地破场空问分布的基础科技产品，每瓦车十年缩｛５Ｉ出版一期‘”其工作模式为：妆取国家疆域内和周边地Ⅸ地磁场绝对测量数据．升“地磋要素等值线和等坐线的形式绘制成图，以描述国采垭域内地磁场的空间分布和时间变化这涉及如何根据空间离散的地磁场测量数据．以相当的精崖和分辨力对地磁场的空间分布进行连续描述的技术同题区域地磁场模型计算便是解决这一技术问题的有效方法我国的第～代全国地磁图制作于１９５０年代，即《】９５００中国地盛图》其后共计出版了七代中国地磁图在最新的《２００５０中国地磁图》之前，主要运用毒勒多项式方法建立地磁场空同分布厦其长期变化模型”””安振昌等（１９９３）将球冠谐和方法引＾中国地Ⅸ地磁模型的计算．由于璋冠谐和方法满足内濂磁场是位场的位势理论的要求ｔ并且能给出地碰场的三维结构．可以表示不同高度或不同深度处地磁场的分布．而且地磁场三个独立要素ｘ、ｙ、ｚ求解于一个ｌａｐｌａｃｅ方程，因此各个地磁要素的分布基奉不会出现相互矛盾的现象这些都是泰勒多项式模型不具备的优点”“此外．璋冠谐和方法与同际地磁参考场（ＩＧＲＦ）采用的球谐方法有良好的理沦悱删所以．我们选择璋冠谐和方法作为龇ｎ０年代中心地区地磁场的主要模型计算方法．井臆卅于《２００５０中闽地磁图》的编制《２００５０中国地磁图》及相关模型描述的是２００５ｏ邙代地球士磁场和部分岩石圈磁场在中国地区的分布状态与ＩＧＲＦ相似，不同年代的地球主磁场和岩石圈磁场的空间分布会发生一定的变化－但选种变化必须合理、有规律，即相临地磁年代．相同地区的地磁图应反映地磁场壹化的“传承性”或研“稳定性”ｔ否则便是出现了不窖忽视的错误或疏蠲例如．原始观耐数据空间分布的较大变化或嫠异．或数据赴理过程的不合理．或模型计算方法和边界约束条件使用的不科学等在此方面．ＩＧＲＦ和世界酷场模型（ＷｏｒｌｄＭａｇｎｅｔｉｃＭｏｄｅｌ，ｗＭＭ）无疑树立丁彳Ｉ｝好的范例２２００５．０年代中国及邻近地区地磁场球冠谐和分析２．Ｉ敲据来谭噩处理２００２－２００４年期间．在中国大砧地区共进行了１１１９个野外地破三分量测点的测量工作．测点的空间分布如图１所示在中国大陆东部的平均测点坷距约为７０ｋｍｔ在中国大陆西部的平均测点间距约为１５０ｋｍ此外，还使用了中国地震局地碰台站网目Ｉ２０惦ｏ‘ｐ目＆ｔ目目＊■＾Ｈ￥ｏ№ｍ自＊一●＂＊ｎｍｄ＾Ｆｉｇ１Ｔｈｅｓｕｒｖｅｙｓｉｔｅｓｋ７Ｒ一￥ｎｅｌｌｃ［ｈｅｒｌｆｏｒＣｈｉｎａ。
14导电性和磁性
第十四讲导电性和磁性2005年7月6日第一部分、导电性1、电子的传导：例子：Na金属中的电子传导：Na的bcc结构2、金属中的电子传导：（1）自由电子气模型电子在离子附近的速度变化电子电子间的排斥作用电子浓度：'M N Z N A m v ρ=(2)电导率的计算:欧姆定律: I=V/R (I:电流; V:点势差; R:电阻。
)去除尺寸的影响，引入电流密度J，电阻率ρ，电导率σ。
引入定义：J=I/A，ε(电场强度)=V/L，则有：R=（Lρ）/A为方便，定义电导率σ=1/ρ。
欧姆定律可变形为:J=σετεv m e dt dv m **−−=0**=−−=τεv m e dt dv m 当：ετ*m e v −=有：ετετ*2*))(()(mNe m e Ne v Ne J =−−=−=*2m Ne τσ='M N Z N A m v ρ=电子浓度：*2m τNe =σ对一般金属而言，σ约为5×107(欧姆·米)-1，τ的值约为10-14s 。
一般电子的运动速度是v=106m ·s -1，所以平均自由程l=10-8m=102Å。
为原子距离的20倍左右。
(3) 金属导电性随温度的变化倒易FCC Copper（4）导电性和能带（5）能带理论对导电性解释的局限性：电导率做为晶格常数a的函数实际上，a非常大时，晶体中电子的真正轨道不再是离域化的布洛赫函数形式。
它们是以格点为中心的定域化轨道，这使库伦能减弱。
由于轨道是定域化的，如同自由原子的情况一样，因此电导降为零。
注意，即使能级仍为能带形式，且能带半充满。
但由于电子轨道变成定域化的，因此也不导电。
3、半导体中电流的传导：（1）典型半导体的种类：A、IV族元素半导体体，如：C（金刚石）、Si、Ge和α-Sn(灰锡)。
四配位，金刚石fcc格子结构。
B、III-V族化合物，最著名的有GaAs和InSb，此外还有GaP、InAs、GaSb等等。
2005年度《热机技术》目录汇总
2005年度《热机技术》目录汇总
无
【期刊名称】《热机技术》
【年(卷),期】2005(000)004
【总页数】3页(P71-73)
【作者】无
【作者单位】无
【正文语种】中文
【中图分类】TK
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电磁波谱 PPT课件 课件2 人教课标版
五、紫外线
5nm～370nm
由德国物理学家里特于1801 年首先发现的
荧光效应 化学作用 杀菌消毒 感光技术、医用消毒等
防紫外线雨伞
六、X射线和γ射线
X射线：10－8m~10－12m γ射线：小于10－10m
X射线由德国物理学家W.K.伦琴于 1895年发现
穿透力很强
X射线和γ射线的应用
1、再长的路一步一步得走也能走到终点，再近的距离不迈开第一步永远也不会到达。 2、从善如登，从恶如崩。 3、现在决定未来，知识改变命运。 4、当你能梦的时候就不要放弃梦。 5、龙吟八洲行壮志，凤舞九天挥鸿图。 6、天下大事，必作于细；天下难事，必作于易。 7、当你把高尔夫球打不进时，球洞只是陷阱；打进时，它就是成功。 8、真正的爱，应该超越生命的长度、心灵的宽度、灵魂的深度。 9、永远不要逃避问题，因为时间不会给弱者任何回报。 10、评价一个人对你的好坏，有钱的看他愿不愿对你花时间，没钱的愿不愿意为你花钱。 11、明天是世上增值最快的一块土地，因它充满了希望。 12、得意时应善待他人，因为你失意时会需要他们。 13、人生最大的错误是不断担心会犯错。 14、忍别人所不能忍的痛，吃别人所不能吃的苦，是为了收获别人得不到的收获。 15、不管怎样，仍要坚持，没有梦想，永远到不了远方。 16、心态决定命运，自信走向成功。 17、第一个青春是上帝给的；第二个的青春是靠自己努力的。 18、励志照亮人生，创业改变命运。 19、就算生活让你再蛋疼，也要笑着学会忍。 20、当你能飞的时候就不要放弃飞。 21、所有欺骗中，自欺是最为严重的。 22、糊涂一点就会快乐一点。有的人有的事，想得太多会疼，想不通会头疼，想通了会心痛。 23、天行健君子以自强不息；地势坤君子以厚德载物。 24、态度决定高度，思路决定出路，细节关乎命运。 25、世上最累人的事，莫过於虚伪的过日子。 26、事不三思终有悔，人能百忍自无忧。 27、智者，一切求自己；愚者，一切求他人。 28、有时候，生活不免走向低谷，才能迎接你的下一个高点。 29、乐观本身就是一种成功。乌云后面依然是灿烂的晴天。 30、经验是由痛苦中粹取出来的。 31、绳锯木断，水滴石穿。 32、肯承认错误则错已改了一半。 33、快乐不是因为拥有的多而是计较的少。 34、好方法事半功倍，好习惯受益终身。 35、生命可以不轰轰烈烈，但应掷地有声。 36、每临大事，心必静心，静则神明，豁然冰释。 37、别人认识你是你的面容和躯体，人们定义你是你的头脑和心灵。 38、当一个人真正觉悟的一刻，他放弃追寻外在世界的财富，而开始追寻他内心世界的真正财富。 39、人的价值，在遭受诱惑的一瞬间被决定。 40、事虽微，不为不成；道虽迩，不行不至。 41、好好扮演自己的角色，做自己该做的事。 42、自信人生二百年，会当水击三千里。 43、要纠正别人之前，先反省自己有没有犯错。 44、仁慈是一种聋子能听到、哑巴能了解的语言。 45、不可能！只存在于蠢人的字典里。 46、在浩瀚的宇宙里，每天都只是一瞬，活在今天，忘掉昨天。 47、小事成就大事，细节成就完美。 48、凡真心尝试助人者，没有不帮到自己的。 49、人往往会这样，顺风顺水，人的智力就会下降一些；如果突遇挫折，智力就会应激增长。 50、想像力比知识更重要。不是无知，而是对无知的无知，才是知的死亡。 51、对于最有能力的领航人风浪总是格外的汹涌。 52、思想如钻子，必须集中在一点钻下去才有力量。 53、年少时，梦想在心中激扬迸进，势不可挡，只是我们还没学会去战斗。经过一番努力，我们终于学会了战斗，却已没有了拼搏的勇气。因此，我们转向自身，攻击自己，成为自己最大的敌人。 54、最伟大的思想和行动往往需要最微不足道的开始。 55、不积小流无以成江海，不积跬步无以至千里。 56、远大抱负始于高中，辉煌人生起于今日。 57、理想的路总是为有信心的人预备着。 58、抱最大的希望，为最大的努力，做最坏的打算。 59、世上除了生死，都是小事。从今天开始，每天微笑吧。 60、一勤天下无难事，一懒天下皆难事。 61、在清醒中孤独，总好过于在喧嚣人群中寂寞。 62、心里的感觉总会是这样，你越期待的会越行越远，你越在乎的对你的伤害越大。 63、彩虹风雨后，成功细节中。 64、有些事你是绕不过去的，你现在逃避，你以后就会话十倍的精力去面对。 65、只要有信心，就能在信念中行走。 66、每天告诉自己一次，我真的很不错。 67、心中有理想 再累也快乐 68、发光并非太阳的专利，你也可以发光。 69、任何山都可以移动，只要把沙土一卡车一卡车运走即可。 70、当你的希望一个个落空，你也要坚定，要沉着！ 71、生命太过短暂，今天放弃了明天不一定能得到。 72、只要路是对的，就不怕路远。 73、如果一个人爱你、特别在乎你，有一个表现是他还是有点怕你。 74、先知三日，富贵十年。付诸行动，你就会得到力量。 75、爱的力量大到可以使人忘记一切，却又小到连一粒嫉妒的沙石也不能容纳。 76、好习惯成就一生，坏习惯毁人前程。 77、年轻就是这样，有错过有遗憾，最后才会学着珍惜。 78、时间不会停下来等你，我们现在过的每一天，都是余生中最年轻的一天。 79、在极度失望时，上天总会给你一点希望；在你感到痛苦时，又会让你偶遇一些温暖。在这忽冷忽热中，我们学会了看护自己，学会了坚强。 80、乐观者在灾祸中看到机会；悲观者在机会中看到灾祸。
AFG-2005
范围
5Hz~150MHz
精确度
时基精确度±1count
时基
±20ppm(23℃±5℃)，热机30分钟
分辨率
最大分辨率：对于1Hz，100nHz；对于100MHz，0.1Hz
输入阻抗
1MΩ/150pf
灵敏度
≤35mVrms(5Hz~100MHz)；≤45mVrms(100MHz~150MHz)
存储/调取
调变频率
2mHz~20kHz(Int)；DC~20kHz(Ext)
偏差
DC~最大频率
FSK
载波波形
正弦波、方波、三角波
调变波形
50%占空比方波
内部频率
2mHz~20kHz
频率范围
0.1Hz~最大频率
扫描
扫描时间
1ms~500s
波形种类
正弦波、方波、三角波
扫描形态
线性或对数
开始/截止频率
0.1Hz~最大频率
精确度
设定值的±1%±1mVpp；(1kHz,＞10mVpp)
分辨率
0.1mV或3位
平坦度
±1% (0.1dB)≤100kHz；±3% (0.3dB)≤；±5% (0.4dB)≤12MHz；
±20% (2dB)≤20MHz；±5% (0.4dB)≤25MHz；(正弦波1kHz)
单位
Vpp，Vrms，dBm
0.1Hz~5MHz
0.1Hz~12MHz
0.1Hz~25MHz
三角波/锯齿波
1MHz
分辨率
0.1Hz
稳定度
±20ppm
老化率
±1ppm/year
误差容忍
＜10mHz
输出特性
幅值范围
2005杭州重点中学高二物理期终考试模拟练习
高二（下）物理期终模拟练习班级＿＿＿＿；学号＿＿＿＿＿；姓名＿＿＿＿；成绩＿＿＿＿＿一、选择题（第题只有一个选项符合题意，第题3分）1、19世纪60年代，在理论上预言了电磁波存在的科学家是（）A. 麦克斯韦B. 牛顿C. 赫兹D. 惠更斯2、某品牌电动自行车的铭牌如下：根据此铭牌中的有关数据，可知该车的额定转速约为（）A.15km/hB.18km/hC.20km/hD.25km/h3、若某种实际气体分子间的作用力表现为引力，下列关于一定质量的该气体内能的大小，与气体体积和温度关系的说法( )①如果保持其体积不变，温度升高，内能增大②如果保持其体积不变，温度升高，内能减小③如果保持其温度不变，体积增大，内能增大④如果保持其温度不变，体积增大，内能减小A.②③B.①④C.①③D.②④4、过量接收电磁辐射有害人体健康。
按照有关规定，工作场所受到的电磁辐射强度（单位时间内垂直通过单位面积的电磁辐射能量）不得超过某一临界值W。
若某无线电通讯装置的电磁辐射功率为P，则符合规定的安全区域到该通讯装置的距离至少为（）A．B．C．D．5、一带电粒子射入一固定在O点的点电荷的电场中，粒子运动的轨迹如图1所示，图中实线是同心圆弧，表示电场的等势面，不计重力，可以判断（）A．此粒子由a到b，电场力做功，由b到c，粒子克服电场力做功B．粒子在b点的电势能一定大于在a点的电势能C．粒子在c点的速度和在a点的速度相等D ．等势面a 比等势面b 的电势高6、如图所示，M 是一小型理想变压器，接线柱a 、b 接在电压u ＝311sin314t (V)的正弦交流电源上，变压器右侧部分为一火警报警系统原理图，其中R 2为用半导体热敏材料制成的传感器，电流表A 2为值班室的显示器，显示通过R 1的电流，电压表V 2显示加在报警器上的电压(报警器未画出)，R 3为一定值电阻。
当传感器R 2所在处出现火警时，以下说法中正确的是：( )A ．A 1的示数不变，A 2的示数增大B ．V 1的示数不变，V 2的示数减小C ．V 1的示数不变，V 2的示数增大D ．A 1的示数不变，A 2的示数减小7、下列关于超重、失重现象的描述中，正确的是（ ）A ．电梯正在减速上升，人在电梯中处于超重状态B ．列车在水平直轨道上加速行驶，车上的人处于超重状态C ．在国际空间站内的宇航员处于失重状态D ．荡秋千时当秋千摆到最低位置时，人处于失重状态8、摆球质量相同的甲、乙两个单摆，它们在同地摆动时的振动图象如图所示。
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2005年大学物理（磁、振动和波）期中考试试卷(144A)
2005.11.9
班级_________姓名_________学号___________得分__________
注意：（1）试卷共二张。
（2）填空题空白处若写上关键式子，可参考给分。
计算题要列出必要的方程和解题的关键步骤。
（3）不要将订书钉拆掉。
(4)第4页是草稿纸。
一、填空题（共60分） 1、（本小题5分）边长为a 2的等边三角形线圈（如图所示），通有电流I ，则线圈中心处的磁感强度的大小为________________，方向为________________.
2、（本小题4分）一磁场的磁感强度为k c j b i a B
++= (SI)，则通过一半径为R ，开口向
z 轴正方向的半球壳表面的磁通量的大小为____________Wb ．
3、（本小题6分）一点电荷带有电荷量为C 100.810-⨯=q ，以速度m/s 100.35
⨯=v 在半径为m 1000.63
-⨯=R 的圆周上，作匀速率圆周运动.则该点电荷在轨道中心处所产生的磁感强度大小=B __________________，该点电荷轨道运动的磁矩大小=m p ___________________．(170m H 104--⋅⨯=πμ)
4、（本小题6分）图示为三种不同的磁介质的H B ~关系曲线，其中虚线表示的是H B 0μ=的关系．说明a 、b 、c 各代表哪一类磁介质的
H B ~关系曲线：
a 代表______________________________的H B ~关系曲线．
b 代表______________________________的H B ~关系曲线．
c 代表______________________________的H B ~关系曲线． 5、（本小题6分）如图所示，在一长直导线L 中通有电流I ，ABCD 为一
矩形线圈，它与L 皆在纸面内，且AB 边与L 平行．
（1）矩形线圈在纸面内向右移动时，线圈中感应电动势方 向为________________________________．
（2）矩形线圈绕AD 边旋转，当BC 边已离开纸面正向外运
动时，线圈中感应动势的方向为_________________________． I
L
C
6、（本小题3分）一无铁芯的长直螺线管，在保持其半径和总匝数不变的情况下，把螺线管拉长一些，则它的自感系数将____________________．（填：增大、不变或减小）
7、（本小题6分）图示为一圆柱体的横截面，圆柱体内有一均匀电场E
，其方向垂直纸面向内，E 的大小随时间t 线性增加，P 为柱体内与轴线相距为r 的一点则 （1）P 点的位移电流密度的方向为____________． （2）P 点感生磁场的方向为____________． 8、（本小题4分）两个同方向同频率的简谐振动，其振动表达式分别为：
)2
15c o s (10621π+⨯=-t x (SI) ， )5c o s
(10222t x -π⨯=- (SI) 它们的合振动的振辐为_____________,初相为____________．
9、（本小题5分）一平面简谐波沿Ox 轴正方向传播，波长为λ．若如图P 1点处质点的振
动方程为)2c o s (1ϕν+=t A y π，则P 2点处质点的振动方程为_________________________________；
与P 1点处质点振动状态相同的那些点的位置是___________________________． 10、（本小题5分）如图所示, 两相干波源S 1与S 2相距3λ/4，λ为波长．设
两波在S 1 S 2连线上传播时，它们的振幅都是A ，并且不随距离变化．已知
在该直线上在S 1左侧各点的合成波强度为其中一个波强度的4倍，则两波
源应满足的相位条件是_________________________．
11、（本小题5分）一声源的振动频率为S ν，相对于空气以S v 的速率运动，在其运动方向上有一相对于空气为静止的接收器R ．设声波在空气中的传播速度为v ，则接收器R 接收到的声波频率R ν = _______________________________．
12、（本小题5分）在真空中沿着负z 方向传播的平面电磁波的磁场强度为：
)/(2cos 50.1λνz t H x +=π (SI)，则它的电场强度为y E = ____________________． （真空介电常量F/m 1085.8120-⨯=ε，真空磁导率 H /m
10470-⨯=πμ）
O P 1 P 2
二、计算题（共40分）
1、（本小题8分）两同方向简谐振动的表达式为：
)6
10cos(31π
+
=t x ，)10cos(222ϕ+=t A x . （21x x 、的单位为厘米）
若合成振动振幅cm 3=A ，相位ϕ与1ϕ之差6
1π
ϕϕ=-，则振动2x 的初相位2ϕ为
多少？
2、（本小题10分）在绳上传播的入射波表达式为)2cos(1λ
πωx
t A y +=，入射波在0
=x 处反射，反射端为固定端．设反射波不衰减，求驻波表达式.
3、（本小题12分）如图，半径为a ，带正电荷且线密度是λ (常量)的半圆以角速度ω绕轴O O '''匀速旋转．求： (1) O 点的B
；
(2) 旋转的带电半圆的磁矩m p
．
(积分公式 π=⎰π
21
d s i n 0
2
θθ)
4、（本小题10分）在半径为R 的圆柱形空间存在着轴向均匀磁场（如图）有一长为2R 的导体棒在垂直磁场的平面内以速度v
横扫过磁场，
若磁感强度B 以 0d d >t
B
变化，试求导体棒在如图所示的位置处时，棒上的感应电动势．。