Enhanced measurement precision with continuous interrogation during dynamical decoupling

Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD cycles.We illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein condensate.Sensitivities approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by DD.Our work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.

Microwave interrogation cavity for the rubidium space cold atom clock

The performance of space cold atom clocks（SCACs） should be improved thanks to the microgravity environment in space.The microwave interrogation cavity is a key element in a SCAC.In this paper,we develop a microwave interrogation cavity especially for the rubidium SCAC.The interrogation cavity has two microwave interaction zones with a single feedin source,which is located at the center of the cavity for symmetric coupling excitation and to ensure that the two interaction zones are in phase.The interrogation cavity has a measured resonance frequency of 6.835056471 GHz with a loaded quality factor of nearly 4200,which shows good agreement with simulation results.We measure the Rabi frequency of the clock transition of the rubidium atom in each microwave interaction zone,and subsequently demonstrate that the distributions of the magnetic field in the two interaction zones are the same and meet all requirements of the rubidium SCAC.

Rapid interrogation of special nuclear materials by combining scattering and transmission nuclear resonance fluorescence spectroscopy

The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.

A Calibration Method Based on Linear InGaAs in Fiber Grating Sensors Interrogation System

In accordance with the characteristics of wavelength shift detection in fiber grating sensor interrogation system,the wavelength interrogation system which uses linear InGaAs as the spectrum receiver is proposed.Orientation of optic spectrum line affects the silt of volume phase grating and size of InGaAs photosensitive unit,thus the calibration method is needed.Based on an analysis of InGaAs imaging model,least square curve fitting method is proposed to detect spectrum wavelength and InGaAs photosensitive unit position.The experimental results show that the methods are effective and the demodulation system precision is improved.

Optoelectronic oscillator-based interrogation system for Michelson interferometric sensors

High-performance interrogation systems for optical fiber sensors are extensively required for environmental condition monitoring applications.In this article,we propose and demonstrate a Michelson interferometer(MI)interrogation system based on an optoelectronic oscillator(OEO).The frequency of the OEO is related to the free spectral range(FSR)of the MI.Thus,when the FSR of the MI varies with a change in external physical factors,the frequency of the OEO shifts and can be used for interrogation.We demonstrate that the temperature sensitivity and interrogation resolution are 35.35 MHz/℃and 0.012℃,respectively.Such an OEO-based scheme enables wavelength-to-frequency mapping and promises a wide linear interrogation range,high resolution and high-speed interrogation.

Tensioned Metastable Fluid Detectors in Nuclear Security for Active Interrogation of Special Nuclear Materials―Part B

This paper (constituting Part B) addresses active interrogation for detecting Special Nuclear Materials (SN- Ms) and includes description of the transformational Tensioned Metastable Fluid Detector (TMFD) based method for optimal monitoring. One of the greatest difficulties in detection of SNMs by active interrogation is the task of distinguishing between the probing particles and the secondary particles that indicate the presence of SNMs. The TMFD’s selective insensitivity and γ photon blindness features are advantageous for alleviating this problem. The working principle of the TMFD is discussed along with its applications for security. The experimental work to date involving detection of small quantities of uranium with conventional detectors is discussed along with results of fission neutron detection. Statistically significant detection was achieved within 5 minutes of counting to ascertain and measure conclusive evidence for the presence of a 55g sample of uranium containing 235U. Results of simulations of three active detection techniques utilizing a TMFD system are presented. The process for using the TMFD to discriminate active source particles using timing and energy are described. These simulations indicate that it should be possible to utilize the TMFD system for optimal neutron-based interrogation of SNMs.

A Precision Fiber Bragg Grating Interrogation System Using Long-Wavelength Vertical-Cavity Surface-Emitting Laser

This paper presents the development of a cost-effective precision fiber Bragg grating （FBG） interrogation system using long-wavelength vertical-cavity surface-emitting laser （VCSEL）. Tuning properties of a long-wavelength VCSEL have been studied experimentally. An approximately quadratic dependence of its wavelength on the injection current has been observed. The overall design and key operations of this system including intensity normalization, peak detection, and quadratic curve fitting are introduced in detail. The results show that the system achieves an accuracy of 1.2 pm with a tuning range of 3 nm and a tuning rate of 1 kHz. It is demonstrated that this system is practical and effective by applied in the FBG transformer temperature monitoring.

Analysis of a Plasmonic Based Optical Fiber Optrode With Phase Interrogation

Optical fiber optrodes are attractive sensing devices due to their ability to perform point measurement in remote locations. Mostly, they are oriented to biochemical sensing, quite often supported by fluorescent and spectroscopic techniques, but with the refractometric approach considered as well when the objective is of high measurement performance, particularly when the focus is on enhancing the measurand resolution. In this work, we address this subject, proposing and analyzing the characteristics of a fiber optic optrode relying on plasmonic interaction. A linearly tapered optical fiber tip is covered by a double overlay： the inner one - a silver thin film and over it - a dielectric layer, with this combination allowing to achieve, at a specific wavelength range, surface plasmonic resonance （SPR） interaction sensitive Typically, the interrogation of the SPR sensing to the refractive index of the surrounding medium. structures is performed, considering spectroscopic techniques, but in principle, a far better performance can be obtained, considering the reading of the phase of the light at a specific wavelength located within the spectral plasmonic resonance. This is the approach which is studied here in the context of the proposed optical fiber optrode configuration. The analysis performed shows the combination of a silver inner layer with a dielectric titanium oxide layer with tuned thicknesses enables sensitive phase reading and allows the operation of the fiber optic optrode sensor in the third telecommunication wavelength window.

Robust and low-cost interrogation technique for integrated photonic biochemical sensors based on Mach–Zehnder interferometers

We describe and experimentally demonstrate a measuring technique for Mach–Zehnder interferometer(MZI)based integrated photonic biochemical sensors. Our technique is based on the direct measurement of phase changes between the arms of the MZI, achieved by signal modulation on one of the arms of the interferometer together with pseudoheterodyne detection, and it allows us to avoid the use of costly equipment such as tunable light sources or spectrum analyzers. The obtained output signal is intrinsically independent of wavelength, power variations, and global thermal variations, making it extremely robust and adequate for use in real conditions. Using a silicon-on-insulator MZI, we demonstrate the real-time monitoring of refractive index variations and achieve a detection limit of 4.1 × 10^(-6)refractive index units(RIU).

An Interrogation System Based on Two Semiconductor Optical Amplifiers for Weak Fiber Bragg Gratings

An interrogation system based on two semiconductor optical amplifiers for weak fiber Bragg gratings （FBGs） was proposed. The first semiconductor optical amplifier （SOA） was used to modulate the light, and the second SOA separated the reflected signal from the different FBGs through delayed switching. The proposed system has lower insertion loss and higher spatial resolution, and can interrogate the time- and wavelength-division multiplexed FBG array. Up to 50 FBGs, with a reflectivity of 0.2% and a spatial resolution of 5 m along the optical fiber, were distinguished to demonstrate the interrogation system.

Implementation of Interrogation Systems for Fiber Bragg Grating Sensors

The development of two simple methods for wavelength-optical intensity modulation techniques for fiber Bragg grating （FBG） sensors is presented. The performance is evaluated by measuring the strain and temperature. The first method consists of a narrow band source, an optical circulator, an FBG; and a power meter. The source and Bragg reflected signal from the FBG need to be matched to get linear results with good power levels. The source spectral power levels are very critical in this study. The power reflected from a matched reference FBG is fed into the measuring FBG in the second method. Since the FBGs are matched, the entire power is reflected back initially. During the measurement, the change in the measurand causes the reflected power from the sensing FBG to vary. A costly high resolution spectrum analyzer is required only during the characterization of the FBG and source. The performances of two interrogators are compared by measuring the strain and temperature. In the second method, the strain measurements can be made insensitive to the temperature variation by selecting a source with a flat spectrum at the measurement range. Highlights of these methods are the portability, cost effectiveness and better resolution.

Research on the Path of Higher Education Teaching Reform from the Perspective of Big Data

The advent of the digital age has pointed out the direction for the development of higher education.In this paper,the undergraduate course“Science of Interrogation”is taken as the research subject,the challenges of big data teaching reform in universities are analyzed systematically,and concrete measures,such as adhering to the concept of teaching reform under the condition of big data,establishing professional teaching teams,improving the curriculum construction level,emphasizing on being student-centered,and optimizing the reform of the curriculum evaluation system,are proposed to address these challenges.

Wireless Strain Measurement Based on a Microstrip Patch Antenna

Wireless interrogation of a rectangular microstrip patch antenna for strain measurement is investigated by simulations.To analyze the antenna performance,a microstrip line-feeding patch antenna at 10 GHz is designed.A patch antenna wirelessly fed by a horn is proposed to measure the strain.The direction information of strain detected by the patch antenna is also considered.The strain can be detected both in the width and length directions.It is shown that the strain can be measured wirelessly using a standard horn antenna.This kind of wireless strain-sensing technique offers significant potential for wireless structural health monitoring(SHM),especially for high-end equipment.

Interrogating a Fiber Bragg Grating Vibration Sensor by Narrow Line Width Light

A method to interrogate fiber Bragg grating vibration sensor by narrow line width light is demonstrated. The interrogation scheme takes advantage of the intensity modulation of narrow spectral bandwidth light, such as distributed feedback laser, when a reflection or transmission spectrum curve of an fiber Bragg grating （FBG） moves due to the strain which is applied on the sensor. The sensor＇s response to accelerating frequency and amplitude is measured by experiment. The factors which have impacts on the sensitivity of the interrogation system are also discussed.

Directive Function of Cooperative Principle in Trial Language

This paper aims to study the embodiment and directive function of Cooperative Principle in trial process. By analyzing dialogues in the sample trial transcript, the author will find out the embodiment of Cooperative Principle in trial language, and draw a conclusion that the Cooperative Principle is important to direct the judge to discriminate if the suspect is cooperative, which helps the interrogation succeed.

A Case Report:Traditional Chinese Medicine for Curing Psychosomatic Tinnitus Symptoms

Patients with tinnitus are associated with adverse psychological reactions to varying degrees.Psychological interventions are currently the primary treatment to help patients eliminate negative responses to tinnitus.Traditional Chinese medicine uses four diagnostic methods or consultations.Interrogation is one such method.Through consultation,doctors can analyze the causes of tinnitus in patients,collect an accurate description,and assess the severity of the condition.At the same time,when doctors ask about other symptoms in a guided manner,they help patients refocus their attention to the symptoms so that their perception of tinnitus is changed,the vicious circular thinking patterns are broken,and their quality of life improves.When the patient understands why the physician establishes a medical plan,they are willing to cooperate actively and participate in a constructive doctor-patient relationship.This article analyzes the clinical methods and techniques of diagnosing tinnitus patients from the vantage of psychosomatic medicine,which has particular significance for the clinical treatment of tinnitus.

Emily Dickinson:An Interrogator of Death and Immortality

Emily Dickinson is widely regarded as one of American's premier poets of the nineteenth century.In both style and content,her verse was,"revolutionary" in her day.Owing to the deep exploration of death and immortality,Emily Dickinson has become a puzzle in literary.As show in her poems,Dickinson's spiritual journey led her from na?ve nature-mysticism through disappointment,to a sacramental approach to immortality afterlife and further discouragement,culminating in a mature attitude of faithful unknowing and even more interrogating the immortality.This paper will base on the theory of the death and immortality through common people's fear to death,the essence of death,the significance of death to show the poetess's whole life-childhood,love,life condition,spiritual contradiction,and mainly her skeptical concept of death and immortality.

The Usages of“Ji(几)”in Yulin Dialect

In Yulin dialect,there are three usages of“ji(几)”:interrogative pronouns,numerals,and degree adverbs.When used as an interrogative pronoun,it is generally used to inquire about the number and degree where the inquiry number is generally small,but the number can be large when it is used in asking about age.When used as a number,it can represent not only integers between one and ten,but also decimal part.When used as a degree adverb,there are rich syntactic formats such as“ji(几)+verb”,“ji(几)+adjective”,different formats indicating different meanings.Compared with Mandarin,the usage of Yulin dialect“ji(几)”is more diverse.We also analyze the use of“ji(几)”from a diachronic perspective and finally we propose that due to the reanalysis of the syntactic format and the change of semantics,the“ji(几)”is further grammaticalized from interrogative pronoun to degree adverb.

Academic Study of Religion in Universities, Southwest Nigeria： In Search of Social Identity/Relevance

Social theorists have engaged religion as a social agent and submitted that it has the capacity to foster positive and negative changes in the society. Milton Yinger, Emile Durkheim, and Karl Marx lead the pack among other sociologists. The need to therefore interrogate religion as an agent of social engineering cannot be overemphasized normatively and functionally. One of the implications of such engagement is that religion; study and practice need to respond to issues in the society. Basic challenges facing the Nigerian nation are issues of poverty, diseases, corruption, and illiteracy. However, in Nigerian universities, the situation posits that religion is studied with theological intentions based on the curriculum bequeathed by the missionaries that laid the foundation for the academic study of religion in Nigeria leading to exclusive and reductionist approaches to its study. There is also government policy that placed emphasis on science and management courses for development. The situation has led to reduction in students＇ enrolments for the study of religion in Nigerian universities. Therefore, this paper seeks explanations for the non-functional design（s） of the curriculum for the academic study of religion in universities, southwest of Nigeria. Descriptive and analytic methods were adopted in the study to pursue the thesis that the academic study of religion in Nigeria should be rebranded and repackaged to respond and interrogate social challenges/problems, such as the scourge of HIV/AIDS plaguing the society thereby recreating a new social identity and relevance for its study.

The Cartography of Focus and Interrogative Projections inǸjò`-Kóo

Researches on cartography have made universal predictions on the hierarchies of functional projections in language.Based on this assumption,the structural maps established by Rizzi(1997,2001b)for the left-peripheral elements suggest very strongly that Interrogative dominates Focus.Nevertheless,a straight-jacket adoption of this proposed hierarchical order to account for these left-peripheral projections inǸjò`-Kóo would be counterintuitive.Therefore,leaning on empirical and theoretical evidence,the paper calls to question the universality of the cartographers’claim,and argues that the opposite of the view is true ofǸjò`-Kóo.The paper adopts fieldwork method for data elicitation and descriptive approach as well as minimalist program for analysis of data.Data used in this study were elicited from purposively selected native speakers based on language proficiency.Data were acquired with syntactic checklist and structured interviews,and were subjected to interlinear and qualitative analysis.