《指南针》教学实录及评析

一、导入新课师：（课件展示教材驱动页图）哪位同学能把这幅图的意思讲给大家听听？

指南针

大好春光,最适合的就是跟爸爸妈妈一起去远足啦!出去玩之前要准备好装备,如果是去远一点又不熟悉的地方,那么地图和指南针一定少不了.今天就让我们自己动手做一个指南针吧.

《指南针》

方家以磁石磨针锋，则能指南，然常微偏东，不全南也。水浮多荡摇，指爪及碗唇上皆可为之，运转尤速，但坚滑易坠；不若缕悬为最善。其法，取新纩中独茧缕，以芥子许蜡缀于针腰，无风处悬之，则针常指南。

《指南针》

1．文中与《梵天寺木塔》中“人履其板”的“履”用法相同的一个词语是：___________，可解释为：_______。

指南针为什么不叫指北针

指南针明明有两头，一端指南，一端指北，为什么不叫“指北针”而叫“指南针”呢？

指南针也会“低头”

暑假的一天，我兴高采烈地拿着爸爸给我新买的指南针在家里四处跑。我横跑．竖跑、斜跑，累得满头大汗，气喘吁吁，力图让它改变方向，但是无论怎么做，无论我在哪个方向站立，它仍然意志坚定，指针始终顽固地指向它认准的方向——南方。

Avian magnetic compass:Its functional properties and physical basis

The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and directional conditioning. The respective findings indicate similar functional properties： it is an inclination compass that works only within a functional window around the ambient magnetic field intensity; it tends to be lateralized in favor of the fight eye, and it is wavelength-dependent, requiring light from the short-wavelength range of the spectrum. The underlying physical mechanisms have been identified as radical pair processes, spin-chemical reactions in specialized photopigments. The iron-based receptors in the upper beak do not seem to be involved. The existence of the same type of magnetic compass in only very distantly related bird species suggests that it may have been present already in the common ancestors of all modem birds, where it evolved as an all-purpose compass mechanism for orientation within the home range [Current Zoology 56 （3）： 265-276, 2010].

Performance Analysis of Physical Layer Security over α-η-κ-μ Fading Channels

In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model.

A Precise Localization Method for a High Speed Mobile Robot Using iGS and Dual Compass

This paper proposes a precise localization algorithm for a quickly moving mobile robot.In order to localize a mobile robot with active beacon sensors,a relatively long time is needed,since the distance to the beacon is measured by transmitting time of the ultrasonic signal.The measurement time does not cause a high error rate when the mobile robot moves slowly.However,with an increase of the mobile robot’s speed,the localization error becomes too high to use for accurate mobile robot navigation.Therefore,in this research into high speed mobile robot operations,instead of using two active beacons for localization,an active beacon and dual compass are utilized to localize the mobile robot.This new approach resolves the high localization error caused by the speed of the mobile robot.The performance of the precise localization algorithm is verified by comparing it to the conventional method through real-world experiments.

Experimental Research on the South-Pointing Loadstone Spoon(Sinan)

In the 1940s,Wang Zhenduo王振铎re-created the sinan司南(southpointing loadstone spoon)mentioned in ancient texts.However,subsequent researchers were unsuccessful in their attempts to replicate this design,resulting in longstanding questions over its feasibility.Loadstones with high natural remanent magnetization acquired today resemble the magnetism of those recorded in premodern Chinese documents.By simulating ancient stoneware processing techniques,a loadstone was cut and polished into a spoon shape.It was found that during the course of processing the loadstone spoon,demagnetization was negligible,while after completion,the internal magnetic field was rebalanced due to the change in shape,and the magnetic moment decreased slightly then stabilized for the long term.Experiments of this sort carried out by the author have testified to the enduring and reliable directivity of the resulting loadstone spoon.Paleo-magnetic research indicates that over the past two millennia the horizontal component of the geomagnetic field intensity in northern China underwent a clear M-shaped development.The level in the Qin and Han dynasties is approximately double that of the current day.Using a simulated ancient geomagnetic field,experiments have revealed that multiple methods,such as the“water floating method”and“hanging method,”could manifest a degree of geo-directivity.The comprehensive studies carried out demonstrate that the loadstone spoon is the most optimal among these diverse means for attaining magnetic directivity from the Pre-Qin period(before 221 BCE)to the Tang dynasty(618–907 CE)in view of the availability of loadstone,the state of the geomagnetic field,and existing knowledge and techniques。

Clinical Practice Guideline on Acupuncture and Moxibustion:Adult Major Depressive Disorder(Mild-Moderate Degree):Determination of clinical questions

Determining clinical questions is fundamental to the development of clinical practice guidelines(CPGs),which bridges the initial phases and the final recommendations.It is essential for evidence retrieval and the formulation of recommendations.The scientific rigor and precision in determination of clinical questions directly influence the future implementation and applicability of guidelines.In 2020,the World Federation of Acupuncture-Moxibustion Societies initiated the project of clinical practice guideline on acupuncture and moxibustion for adult major depressive disorder(mild-moderate degree)to address clinical and medical decision-making issues in acupuncture treatment for adult mild to moderate major depressive disorder.This CPG provides systematic recommendations based on clinical evidence,patient values,and other factors,aiding decision-makers,clinicians,and patients in selecting appropriate interventions.This paper discusses and analyzes the determination process of clinical questions,and the related issues during the development of this guideline,aiming to provide a reference for determining clinical questions and developing CPGs in the field of acupuncture and exploring more scientific tools and methods for determining clinical questions in future CPGs.

World Federation of Acupuncture-Moxibustion Societies(WFAS)Clinical Practice Guideline on Acupuncture and Moxibustion:Allergic Rhinitis recommendation summaries

Clinical Practice Guideline on Acupuncture and Moxibustion:Allergic Rhinitis was revised and released by the Standards Working Committee of World Federation of Acupuncture-Moxibustion Societies(WFAS)on October 9,2023.This is the first clinical practice guideline(CPG)on acupuncture and moxibustion for allergic rhinitis approved by an international academic organization,which provides evidence-based recommendations and the practical therapeutic protocols for acupuncture practitioners globally.This CPG was developed by following Grades of Recommendation,Assessment,Development,and Evaluation(GRADE)methodology,and the principles of the World Health Organization Handbook for Guideline Development.The members in the guideline development group(GDG)were from different countries,with different professions,and they played a critical role in the development of clinical questions,recommendations,and therapeutic protocols.Recommendations are the core of a CPG and the direct answers to clinical questions,due to which this article focuses on the recommendations of this CPG.The recommendations were developed by using the modified Delphi method and the GRADE grid rules,based on the updated systematic reviews of clinical evidence.A total of 15 recommendations for 15 clinical questions were developed in this CPG,including one strong recommendation for intervention based on high-quality evidence,three conditional recommendations for either the intervention or the comparison based on very low quality of evidence,and 11 conditional recommendations for the intervention based on very low quality of evidence.

World Federation of Acupuncture-Moxibustion Societies(WFAS)Clinical Practice Guidelines on Acupuncture and Moxibustion:Female Urinary Incontinence recommendation summaries

Urinary incontinence(UI)is common in women and affects the quality of life in female patients severely.But the clinical consideration and treatment are insufficient.Acupuncture and-moxibustion has been proposed as a potentially effective intervention for female UI.Hence,the World Federation of Acupuncturemoxibustion Societies(WFAS)have initiated a project to develop the clinical practice guideline(CPG)on acupuncture and moxibustion for female UI towards global acupuncture practitioners.The CPG was developed according to the Grades of Recommendation,Assessment,Development,and Evaluation(GRADE)methodology,referring to the principles of the World Health Organization Handbook for Guideline Development.During the development of the CPG,the guideline development group(GDG)played an important role,which is composed of multi-national and multi-disciplinary experts.The clinical questions,recommendations and therapeutic protocols were all formulated by GDG using the modified Delphi method and basing on the results of the latest systematic review.This article focuses on the recommendations in the CPG.The CPG contains ten recommendations for ten clinical questions,including nine conditional recommendations for the intervention,one conditional recommendations for either the intervention or the comparison.The CPG also provides one conventional filiform needle therapy protocol,two deep puncturing stimulation on lumbosacral acupoints therapy protocols,and four moxibustion therapy protocols,extracted from the included clinical evidence of this CPG.

World Federation of Acupuncture-Moxibustion Societies Clinical Practice Guideline on Acupuncture-Moxibustion:Non-Specific Low Back Pain recommendation summaries

Clinical Practice Guideline on Acupuncture and Moxibustion:Nonspecific low back pain was revised and released by the Standards Working Committee of World Federation of Acupuncture-Moxibustion Societies(WFAS)on October 9,2023.This is the first clinical practice guideline(CPG)on acupuncture and moxibustion for nonspecific low back pain approved by an international academic organization,which provides the evidence-based recommendations and practical therapeutic protocols for international acupuncture practitioners.This CPG was developed by following Grades of Recommendation,Assessment,Development,and Evaluation(GRADE)methodology,and the Principles of the World Health Organization Handbook for Guideline Development.The guideline development group(GDG)from different countries,with different professions,played a critical role in the formulation of clinical questions,recommendations,and therapeutic protocols.Recommendations are the key content of a CPG and the direct answers to clinical questions.Hence,this article focuses on the recommendations of this CPG.The recommendations were formulated using the modified Delphi method and the GRADE grid rules,based on the updated systematic reviews of clinical evidence.A total of seven recommendations for ten clinical questions were formulated in this CPG,including one conditional recommendation for either the intervention or the comparison based on very low quality of evidence,and six conditional recommendations for the intervention based on very low quality of evidence.

Full process of recommendation formulation for clinical practice guidelines:Taking World Federation of Acupuncture-Moxibustion Societies Clinical Practice Guideline on Acupuncture and Moxibustion:Allergic Rhinitis as an example

The formulation of recommendations is a crucial step in the development of clinical practice guidelines,which requires tools provided by the GRADE methodology.These tools include the evidence quality assessment tool,the evidence summary tool,and the evidence-to-decision(EtD)framework.Although there is a methodologically guided standard pathway for formulating recommendations in clinical practice guidelines,it remains unclear how to translate this theoretical pathway into the practical process for formulating recommendations and what the specific steps in this process entail.Therefore,this paper takes the World Federation of Acupuncture-Moxibustion Societies Clinical Practice Guidelines on Acupuncture and Moxibustion:Allergic Rhinitis as an example to detail the full process of formulating recommendations and summaries it into a three-step method.Step one:Collect original materials from different sources to create EtD table.Step two:Distribute and collect EtD table,and preliminarily gather the recommendation voting results.Step three:Organize"salami-slicing pattern"guideline development group consensus meeting to formulate recommendations.The three-step method for formulating recommendations in clinical practice guidelines fully utilizes the GRADE EtD table to provide guideline development group with decision-making foundation and reference from multiple dimensions,including the importance of clinical questions,balance of benefits and harms,quality of evidence,resource required,values and preferences,health equity,acceptability,and feasibility.This approach enhances the scientific and practical nature of guideline recommendations.This paper provides a standard operating procedure to formulate recommendations for the incoming clinical practice guidelines,which aims to establish a standard pathway for the formulation of acupuncture clinical practice guideline recommendations.

Clinical practice guidelines of acupuncture-moxibustion for cervical spondylotic radiculopathy

On the basis of relevant literature and evidence, Clinical Practice Guidelines of Acupuncture-moxibust^on .for Cervical 5pondyloffc Radiculopathy has been formulated according to the quality of evidences and by adopting the method of Grades of Recommendations Assessment, Development and Evaluation （GRADE）, in which the objective of guidelines formulation, the scope of application of the guidelines, the principle of acupuncture-moxibustion treatment of cervical spondylotic radiculopathy, the time for intervention and different acupuncture-moxibustion regimens, etc. were specified.

TD-AltBOC:A new COMPASS B2 modulation

AltBOC(15,10) is the baseline of COMPASS B2 signal modulation.It is a BOC-like signal having different PN codes in the lower and the upper main split lobes,which allow one signal service per lobe.The two lobes can be received and processed separately like two BPSK(10) signals,or coherently processed to achieve better performance.Interoperability among COMPASS B2,Galileo E5 and GPS L5 is also achievable using AltBOC modulation.However,Galileo's 4-code AltBOC has drawbacks such as low efficiency and great receiver complexity.This paper presents a new modulation type named TD-AltBOC (Time Division AltBOC).The signal generation scheme and receiving method are presented,and are compared with AltBOC in the areas of power spectrum,ranging accuracy,anti-multipath performance,anti-interference performance,processing flexibility and complexity.Analysis results show TD-AltBOC has similar spectrum characteristics,interoperability,flexibility and anti-interference performance with AltBOC.When the frontend bandwidth is more than 50 MHz,TD-AltBOC can achieve better ranging accuracy and anti-multipath performance.It also has such advantages as high efficiency and low receiver complexity.TD-AltBOC could be a good solution to COMPASS B2 navigation signal.

A new unequal-weighted triple-frequency first order ionosphere correction algorithm and its application in COMPASS

As the introduction of triple-frequency signals in GNSS,the multi-frequency ionosphere correction technology has been fast developing.References indicate that the triple-frequency second order ionosphere correction is worse than the dual-frequency first order ionosphere correction because of the larger noise amplification factor.On the assumption that the variances of three frequency pseudoranges were equal,other references presented the triple-frequency first order ionosphere correction,which proved worse or better than the dual-frequency first order correction in different situations.In practice,the PN code rate,carrier-to-noise ratio,parameters of DLL and multipath effect of each frequency are not the same,so three frequency pseudorange variances are unequal.Under this consideration,a new unequal-weighted triple-frequency first order ionosphere correction algorithm,which minimizes the variance of the pseudorange ionosphere-free combination,is proposed in this paper.It is found that conventional dual-frequency first-order correction algorithms and the equal-weighted triple-frequency first order correction algorithm are special cases of the new algorithm.A new pseudorange variance estimation method based on the three carrier combination is also introduced.Theoretical analysis shows that the new algorithm is optimal.The experiment with COMPASS G3 satellite observations demonstrates that the ionosphere-free pseudorange combination variance of the new algorithm is smaller than traditional multi-frequency correction algorithms.

Study of SAR imaging with COMPASS signal

A concept of space-surface bistatic synthetic aperture radar (SS-BSAR) passive imaging system is proposed,which is parasitic on the signal of COMPASS Navigation Satellite System (CNSS).The feasibility is demonstrated by analyzing the signal ambiguity function and the range resolution as well as the system topology.Due to the multiple peaks of signal in the auto-correlation function,a new correlation is used to remove the side-peaks.A double-channel receiver is employed to receive the direct satellite signal and the ground reflected signal.The direct signal is a reference signal in range compression,and may also be used for transmitter-receiver signal synchronization.The reflected signal is raw data collected for imaging.Then,a modified range-Doppler imaging algorithm is derived based on the system geometric models and BSAR imaging principle.The proposed algorithm is verified via signal simulation.The work in this paper is of great value to the further use of COMPASS signal,as well as other global navigation satellite signals in passive imaging.

Integrity analysis of COMPASS and other GNSS combined navigation

The integrity requirement should be satisfied when GNSS is used in aviation.There are now two ways for integrity monitoring,that is,receiver autonomous integrity monitoring(RAIM) and GNSS integrity channel(GIC) based on augmentation system.The rapid development of the Beidou satellite navigation system(COMPASS) will significantly improve the satellite geometry.Besides,the effects of first order ionosphere delay will be mitigated by the combination of GNSS multi-frequency signals.The availability of RAIM will be enhanced,which makes it possible to provide a worldwide seamless integrity service for aviation by using RAIM.The contribution of COMPASS to the availability of RAIM is analyzed by simulation;and the integrity requirement of which aviation approaching phrase can be satisfied when using COMPASS single system and its combination with other satellite navigation system is analyzed.Moreover,the influence of user range accuracy(URA) of COMPASS on integrity performance is discussed.