Correlation method estimation of the modulation signal in the weak equivalence principle test

In a test of the weak equivalence principle （WEP） with a rotating torsion pendulum, it is important to estimate the amplitude of the modulation signal with high precision. We use a torsional filter to remove the free oscillation signal and employ the correlation method to estimate the amplitude of the modulation signal. The data analysis of an experiment shows that the uncertainties of amplitude components of the modulation signal obtained by the correlation method are in agreement with those due to white noise. The power spectral density of the modulation signal obtained by the correlation method is about one order higher than the thermal noise limit. It indicates that the correlation method is an effective way to estimate the amplitude of the modulation signal and it is instructive to conduct a high-accuracy WEP test.

Systematic error suppression scheme of the weak equivalence principle test by dual atom interferometers in space based on spectral correlation

Systematic error suppression and test data processing are very important in improving the accuracy and sensitivity of the atom interferometer(AI)-based weak-equivalence-principle(WEP) test in space. Here we present a spectrum correlation method to investigate the test data of the AI-based WEP test in space by analyzing the characteristics of systematic errors and noises. The power spectrum of the Eotvos coefficient η, systematic errors, and noises in AI-based WEP test in space are analyzed and calculated in detail. By using the method, the WEP violation signal is modulated from direct current(DC) frequency band to alternating current(AC) frequency band. We find that the signal can be effectively extracted and the influence of systematic errors can be greatly suppressed by analyzing the power spectrum of the test data when the spacecraft is in an inertial pointing mode. Furthermore, the relation between the Eotvos coefficient η and the number of measurements is obtained under certain simulated parameters. This method will be useful for both isotopic and nonisotopic AI-based WEP tests in space.

Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity

For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.

Effect of gravity gradient in weak equivalence principle test

A high accuracy test of the weak equivalence principle（WEP） is of great scientific significance no matter whether its result is positive. We analyze the gravity gradient effect which is a main systematic error source in the test of WEP.The result shows that the uncompensated gravity gradient effect from the coupling term of the dominated gravity gradient multipole moment component q_（21） and the relative multipole field component Q_（21） contributes to an uncertainty of 1×10^（-11） on the E otv os parameter. We make a Q_（21） compensation to reduce the effect by about 20 times, and the limit of the test precision due to this coupling is improved to a level of a part in 10^（13）.

Suppression of Coriolis error in weak equivalence principle test using ^85Rb-^87Rb dual-species atom interferometer

Coriolis effect is an important error source in the weak equivalence principle(WEP)test using atom interferometer.In this paper,the problem of Coriolis error in WEP test is studied theoretically and experimentally.In theoretical simulation,the Coriolis effect is analyzed by establishing an error model.The measurement errors of Eotvos coefficient(η)in WEP test related to experimental parameters,such as horizontal-velocity difference and horizontal-position difference of atomic clouds,horizontal-position difference of detectors,and rotation compensation of Raman laser’s mirror are calculated.In experimental investigation,the position difference between^85Rb and^87Rb atomic clouds is reduced to 0.1 mm by optimizing the experimental parameters,an alternating detection method is used to suppress the error caused by detection position difference,thus the Coriolis error related to the atomic clouds and detectors is reduced to 1.1 × 10^-9.This Coriolis error is further corrected by com pensating the rotation of Raman laser's mirror,and the total uncertainty o f rj measurement related to the Coriolis effect is reduced as δη=4.4 × 10^-11.

The Mass-Energy Equivalence Principle in Fluid Dynamics

From Lagrangian formalism as in Classical Field Theory and within the theoretical scheme of the Hamilton-Type Variational Principle, the mass-energy equivalence principle for any fluid is obtained.

On Motion, Its Relativity and the Equivalence Principle

The Equivalence Principle put forward by Albert Einstein is currently undergoing comprehensive revision to determine its degree of accuracy. Notwithstanding, this principle refers to a very specific circumstance, as free-fall;thus in our opinion it cannot be generalised to any other movement in space. This paper refers to the dynamic hypotheses of moving rigid bodies and a particular, structured theory that would establish how such bodies behave when subject to different actions that oblige them to make successive, non-coaxial spins. With respect to bodies subject to acceleration by rotation, we understand that there are indications to identify the prior dynamic state of the moving object and that examples of a violation of the aforementioned Equivalence Principle can be deduced thereof. Based on the findings of this paper and the theory put forward herein, we suggest that an observer can identify the prior situation of absolute rest or absolute non-rotation of a body, thus leading to the conclusion that movement does not necessarily have to be a relative concept. The foregoing leads us to propose that the Equivalence Principle is fully valid for the situation put forward by Albert Einstein, but cannot be generalised to any dynamic situation.

Determination of the thermal noise limit in test of weak equivalence principle with a rotating torsion pendulum

Thermal noise is one of the most fundamental limits to the sensitivity in weak equivalence principle test with a rotating torsion pendulum. Velocity damping and internal damping are two of many contributions at the thermal noise, and which one mainly limits the torsion pendulum in low frequency is difficult to be verified by experiment. Based on the conventional method of fast Fourier transform, we propose a developed method to determine the thermal noise limit and then obtain the precise power spectrum density of the pendulum motion signal. The experiment result verifies that the thermal noise is mainly contributed by the internal damping in the fiber in the low frequency torsion pendulum experiment with a high vacuum. Quantitative data analysis shows that the basic noise level in the experiment is about one to two times of the theoretical value of internal damping thermal noise.

Design and Evaluation of a Differential Accelerometer for Drop-Tower Equivalence Principle Test with Rotating Masses

A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measurement is performed by placing the two concentric masses of very different momenta in a vacuum drop capsule which is falling freely in the Earth＇s gravitational field. A nonzero output of the differential aeeelerometer is an indication of possible violation of new equivalence principle （NEP）. We present the conceptual design of a modified free-fall NEP experiment which can be performed at the Belting drop tower. Design and evaluation of the differential accelerometer with a hybrid electrostatic/magnetic suspension system are presented to accommodate for operation on ground and drop-tower tests. Details specific to the measurement uncertainty are discussed to yield an NEP test accuracy of 7.2×10^-9.

Nutational Oscillatory Effect of the Test Body in Space Equivalence Principle Experiments

The significance of quadrupole gravitational force is discussed for test mass in equivalence principle (EP), and the angular moment acting on a cylindrically symmetrical body due to quadrupole force is calculated, which will result in nutational oscillatory effect. The oscillations contain a perturbation with the same frequency of EP violation signal, which is mitigated by two different methods as in Galileo Galilei (GG) mission and μSCOPE. In GG the sensor for readout is sensitive to differential forces in the orbital plane perpendicular to spin axis of test cylinders. In order to mitigate the nutational oscillatory effect, test mass should be rapidly rotated with the spin axis. However, in μSCOPE, the readout sensitive axis is the symmetry axis in the orbital plane. This nutational oscillation will produce a second order effect in the rotation amplitude at twice the signal frequency, and could be subtracted easily, too.

EQUIVALENT-EFFECT PRINCIPLE AND THE TRANSLATION OF ENGLISH AND CHINESE BRAND NAMES

Translation of brand names is a kind of intercultural communication,which involves regional cultures,consumer psychology,aesthetic interest and some other factors. It is important to achieve the pragmatic equivalence in the brand name translation. This paper first briefly goes over equivalent-effect principles and the features of brand and brand names. Then it analyses the characteristics of English and Chinese brand names and discusses five approaches to the translation of brand names--literal translation;transliteration; mixed translation; flexible translation and zero translation.

The principle of minimization of the equivalent load for design of launching vertical shiplift

Launching vertical shiplift is a type of shiplifts which have the advantages in characteristics of dynamics and statics, safety and simplicity in operation. But their applications are limited as the scales of mechanical equipments are too large. This paper puts forward the principle of minimization of the equivalent load for the general layout design of launching vertical shiplifts, based on the analysis of the load probability of the main hoists and their key mechanical equipments. The principle aims at determining the optimal weight of counterweight so that the equivalent loads of the main hoists of shiplifls are minimized, and larger ships are permitted to pass through. The theory and method presented in this paper have been applied in the design of the first step and third step shiplifts of the Goupitan Hydro Power Station. This has resulted in the breakthrough of the design and manufacture of launching vertical shiplifts so that the ships with tonnage of 500 t can pass through hydro dams for this type of shiplifts, comparing with the largest launching shiplift in Yantan Hydro Power Station with the 250 t shiplift.

Cooperative Principle and the Equivalent Effect in Translation

The cooperative principle is an important theory of pragmatics,concerning how to maximally achieve communicative goal.While translation serves as a communicative medium,it should also observe the conversational rules—cooperative principle to achieve the equivalent effect.This paper tries to explore the issue from the perspective of cooperative principle.

STUDY OF THE EQUIVALENT THEOREM OF GENERALIZED VARIATIONAL PRINCIPLES IN ELASTICITY

The relations of all generalized variational principles in elasticity are studied by employing the invariance theorem of field theory. The infinitesimal scale transformation in field theory was employed to investigate the equivalent theorem. Among the results found particularly interesting are those related to that all generalized variational principles in elasticity are equal to each other. Also studied result is that only two variables are independent in the functional and the stress-strain relation is the variational constraint condition for all generalized variational principles in elasticity. This work has proven again the conclusion of Prof. Chien Wei-zang.

The Application of the Principle of the Equivalent Effect in the Translation of Metaphors

American linguist and translator Eugene Nida put forward the principle of equivalent effect, which states clearly that the same information, though expressed by two different languages, must have the equivalent effect on the SL receptors as well as on the TL readers. The article will mainly discuss the translation of metaphors by the principle of equivalent effect.

A General View of the Equivalence Between Chinese and English

This paper briefly presents a study of the relationship between English and Chinese, which is put forward from the point of the equivalence in both languages. By observing and analyzing the examples in the parts of full equivalence and partial equivalence, we can surely conclude that English and Chinese have close relationship with each other. However, the equivalence reflected in the languages is, to some extent, greatly influenced by their respective culture, which still needs us to do more research about it.

TIME-TEMPERATURE-STRESS EQUIVALENCE AND ITS APPLICATION TO NONLINEAR VISCOELASTIC MATERIALS

Stress-dependence of the intrinsic time of viscoelastic materialsis investigated. The influence of stress level on the intrinsic timeis considered to be similar to that of temperature, pressure, solventcon- centration, damage and physical aging. Thetime-temperature-stress equivalence principle is proposed, byemploying which, the creep curves at different temperatures andstress level can be shifted into a master curve at referencetemperature and stress level.

Linear-regression models and algorithms based on the Total-Least-Squares principle

In classical regression analysis, the error of independent variable is usually not taken into account in regression analysis. This paper presents two solution methods for the case that both the independent and the dependent variables have errors. These methods are derived from the condition-adjustment and indirect-adjustment models based on the Total-Least-Squares principle. The equivalence of these two methods is also proven in theory.

Translation of Cultural Terms Under the Functional Equivalence Theory

Different countries and different nationalities have different cultures.There are differences between them as each culture has its characteristics.Therefore,as their different value,aesthetic taste,region and custom,different cultures assign different meanings to words.According to Tytler,the translation of cultural terms should follow the three principles of translation and adopt reasonable translation methods:retention method,transference translation method,transliteration method,hybrid method,approximation method,interpretation method and implication presentation method,to overcome the translation barriers caused by cultural differences and achieve the translation effect of functional equivalence proposed by Nida.

Equivalence between a Gravity Field and an Unruh Acceleration Temperature Field as a Possible Clue to “Dark Matter”

Einstein’s equivalence principle allows one to compare the magnitudes of a gravitational acceleration field with the magnitudes of a field of Unruh acceleration temperatures. The validity of such a comparison is demonstrated by using it to derive the effective Hawking black body radiation at a Schwarzschild black hole horizon. One can then extend the black hole thought experiment to a Hawking-Unruh temperature equation expressed in terms of the Schwarzschild radius. This follows an inverse radius law rather than an inverse radius-squared law. Following a brief discussion of current theoretical failures to explain galactic rotation curves, the Unruh acceleration temperature equations are brought together to show how a rotating supermassive black hole galactic system should follow an inverse radius rule of centripetal gravitational force and centripetal acceleration. This result appears to indicate that galactic observations currently attributed to dark matter may in part be attributed to classical Newtonian dynamics superimposed on a relativistic rotating system powered by a supermassive black hole.