海上结构物的Ringing现象

介绍近年来新发现的海上结构物在高海况下遇到的一种现象─—ringing高频共振响应现象及这一现象现有的研究成果，包括该现象的发现过程、特征、产生的机理及研究方法等。提出了研究ringing现象的一种可能的新方法。

Two phenomena: Honji instability, and ringing of offshore structures

Honji instability and ringing of offshore structrures are two different phenomena. Honji instability occurs at a circular cylinder in transverse periodic finite motion in a water tank. It is superposed on the streaming flow induced by the cylinder’s boundary layer. Its oscillation period is half of the period of the cylinder oscillation. Finite volume calculations of the filtered Navier-Stokes equations visualize the three-dimensional instability, where fluid particles transported by the circumferencial roll pairs exhibit a periodic mushroom-like pattern. Force is the same with and without the Honji instability. The large eddy simulation calculations for high Reynolds number support a drag coefficient in accordance with the Stokes-Wang solution below separation and conform with experimental measurements of the damping force on a harmonically oscillating cylinder. Ringing of offshore structures are vibrations which appear at natural frequencies and concern fatigue. It is generated by a higher harmonic force oscillating with frequency being 3-4 times the fundamental wave frequency. Together with a strong inertia load in phase with the incoming wave’s acceleration, a secondary load cycle appears in strong seas when the wave crest leaves the structure; this occurs about 1/4 wave period after the main force peak, it starts when the wave crest is about one cylinder radius behind the cylinder, lasts for about 15-20 percent of the wave period and has a magnitude up to 11 % of the peak-to-peak total force. It is a gravity effect and appears in strong irregular seas when kA > 0.18 and um/√gD > 0.4 (k wavenumber, A amplitude, um maximal wave induced velocity, g acceleration of gravity, D cylinder diameter).

Multiscale anisotropic diffusion for ringing artifact suppression in geophysical deconvolution data

Ringing artifact degradations always appear in the deconvolution of geophysical data. To address this problem, we propose a postprocessing approach to suppress ringing artifacts that uses a novel anisotropic diffusion based on a stationary wavelet transform （SWT） algorithm. In this paper, we discuss the ringing artifact suppression problem and analyze the characteristics of the deconvolu- tion ringing artifact. The deconvolution data containing ringing artifacts are decomposed into different SWT sub- bands for analysis, and a new multiscale adaptive aniso- tropic filter is developed to suppress these degradations. Finally, we demonstrate the performance of the proposed method and describe the experiments in detail.

Numerical Study of the High-Frequency Wave Loads and Ringing Response of A Bottom-Hinged Vertical Cylinder in Focused Waves

This paper presents a numerical study on the high-frequency wave loads and ringing response of offshore wind turbine foundations exposed to moderately steep transient water waves.Input wave groups are generated by the technique of frequency-focusing,and the numerical simulation of focused waves is based on the NewWave model and a Fourier time-stepping procedure.The proposed model is validated by comparison with the published laboratory data.In respect of both the wave elevations and the underlying water particle kinematics,the numerical results are in excellent agreement with the experimental data.Furthermore,the local evolution of power spectra and the transfer of energy into higher frequencies can be clearly identified.Then the generalized FNV theory and Rainey’s model are applied respectively to calculate the nonlinear wave loads on a bottom-hinged vertical cylinder in focused waves.Resonant ringing response excited by the nonlinear high-frequency wave loads is found in the numerical simulation when frequency ratios(natural frequency of the structure to peak frequency of wave spectra)are equal to 3–5.Dynamic amplification factor of ringing response is also investigated for different dynamic properties(natural frequency and damping ratio)of the structure.

Object Picture of Electromagnetic Quasinormal Ringing for a Stringy Black Hole

We investigate the evolution of an electromagnetic field in the spacetime of a stringy black hole.The objectpicture of the quasinormal ringing has been obtained by the finite difference method.Compared with a Schwarzschildblack hole,the results show that the electromagnetic field damps more slowly for a stringy black hole.

Prevalence of Ringing Delusion among Mobile Phone Users

The exponential application of mobile technology has led to a concern about implications of electromagnetic radiation on human health. As we are aware that mobile phone radiates EMR when users communicate to others and that time subscribers of the device are regularly exposed nearby 40% - 50% of total mobile irradiation. We analyzed the risk of "Ringing Delusion" among normal users, moderate users and heavy users when compared to low users. Although the "Ringing Delusion" has not been added in medical terminology but we found frequently such kind of symptoms among mobile phone users. "Ringing Delusion" may be considered as an imagination of ringing voice from cellular phone. The risk was also compared between urban and rural, male and female and adult and children population. The information was gathered through well designed questionnaires for cellular user’s demographic and social characteristics, adopted safety measures and calling duration. Prevalence of “Ringing Delusion” among rural users was higher than the urban users. A trend for the risk was also observed in male users in comparison to female. Study may support innovators to re-examine health effects of mobile phones.

Ringing cancellation in Carr-Purcell-Meiboom-Gill-type sequences

We propose a four-step phase cycling scheme that can cancel ringings from both the excitation and the refocusing pulses in Carr-Purcell-Meiboom-Gill(CPMG)measurements.It allows accurate measurements of the first echo with short echo spacing tE,yielding improved precision of porosity,permeability,and fluid type identification in porous media study,at a cost of~25%signal reduction.In our example,we achieved tE=100 ms on a 6.8 MHz unilateral NMR sensor without using a Q-switch.These methods can be integrated in all nuclear magnetic resonance(NMR)protocols using CPMG,such as relaxation(T1,T2)and diffusion measurements,and do not require additional hardware(e.g.,Qswitches)to cancel ringing(although it can be used with a Q-switch to further reduce residual ringing).

Online Tills Ringing Out

A LAPTOP, a broadband connection and a pile of express delivery orders are all clues that 26-year-old Qu Wen was no longer a member of the nine-to-five white collar brigade. Three years after graduating, 0u now manages an online store on Taobao, China＇s fast-growing online shopping bazaar, selling handbags, cosmetics, accessories and other goods. Her online store now has three employees, and daily turnover surpassing 10,000 yuan （$1.612）. Last year. the entrepreneur also opened a retail outlet in her hometown in Shandong Province.

Investment Bells Ringing

It＇s just been over half a year since Kenya inaugurated its standard gauge railway, but already the transport system is seeing heavy demand from travelers between Nairobi and Mombasa.

Africa Is Ringing in the Changes

Sales show that Chinese mobile phone manufacturers have dialed into what African consumers really need by Gui Gui WHEN Guan Yazhou visited Tanzania’s Kariakoo market for the first time in late 2009,he couldn’t help but be impressed.Today,the 29-year-old mobile phone engineer can still remember how surprised he was at seeing the extent to which Tecno,a Chinese mobile phone brand,had blanketed the area in advertising material.

Ringing in the Changes Unprecedented State Council restructuring sees creation, cuts and merges of ministries

China＇s Xinhua News Agency calls it the ＂biggest government reshuffle in years＂ in what is seen as a dra matic continuation of the previous seven rounds of cabinet restructuring that began in 1982.

Ringing spectroscopy in the magnomechanical system

The ringing phenomenon has been studied in optical whispering gallery mode(WGM)resonators and can be used to sense the ultrafast process in spectroscopy.Here we observe the ringing phenomenon in a magnomechanical system for the first time,which is induced by the interference between the microwave photons converted from the damped phonons and the probing microwave photons.This interference eventually appears as a transparency window even along with the ringing phenomenon in the measured microwave reflection spectrum,which is influenced by the scanning speed and the input power.Then,the ringing spectroscopy is used to measure the coupling strength between the magnon and phonon modes,and outline the displacement profile of𝑆1,2,2 mechanical mode in a YIG microsphere,demonstrating the theoretical analysis.In addition,the ring-up spectroscopy is developed in our magnomechanical system,laying the foundation for fast sensing based on mechanical motion.

Soundscape of the West Lake Scenic Area with profound cultural background—a case study of Evening Bell Ringing in Jingci Temple,China

From the case study of Evening Bell Ringing at Nanping Hill,one of the West Lake Cultural Landscapes in Hangzhou,China,we investigated the soundscape of a scenic area with a profound cultural background.First,we conducted the soundscape physical index of the area in both winter and spring seasons to analyze its objective graphical expression.Second,we focused on people's reactions to the soundscape in order to obtain a subjective evaluation of each component in the soundscape and integrated environment.Then,the relationship between the objective data and the subjective evaluation was analyzed.Finally,the impacts of the natural environment,history,and cultural factors on the evaluation of the Jingci Temple soundscape were studied.It was found that natural sounds,cultural sounds,and historic sounds were widely acclaimed in people's subjective feelings,which indicated the close relationships among historical and cultural background,soundscape,and natural environment.Thus,the conclusion was made that soundscape should be consistent with the local natural environment and the historical and cultural background.

Suppressing ringing caused by large photomultiplier tube signals

We describe here the characteristic features of the ringing we observed following large PMT signals in the Daya Bay reactor antineutrino experiment. We conclude that the ceramic capacitors used in the circuitry of the PMT bases and the HV-signal decouplers are the primary cause for this ringing. We present some possible schemes to reduce the ringing when replacing these ceramic capacitors is not feasible.

ON POTENT ELEMENTS AND PSEUDO CLEAN RINGS

In this paper,potent index of an element and pseudo clean rings are considered.Some properties and examples of pseudo clean rings are given.We also show that Zm is pseudo clean for every 2≤m∈Z and pseudo clean rings are clean.Furthermore,we prove pseudo clean rings are directly finite and have stable range one.

Wilson's disease in two siblings from Ecuador:Two case reports

BACKGROUND Wilson's disease(WD)is a rare metabolic disorder of copper accumulation in organs such as liver,brain,and cornea.Diagnoses and treatments are challenging in settings,where advanced diagnostic tests are unavailable,copper chelating agents are frequently scarce,healthcare professionals lack disease awareness,and medical follow-ups are limited.Prompt diagnoses and treatments help prevent complications,improve patients’quality of life,and ensure a normal life expectancy.The clinical presentations and outcomes of WD can vary within a single family.CASE SUMMARY We present the cases of two siblings(19 and 27 years)from a consanguineous family in rural Ecuador,diagnosed as having WD during a family screening.The male patient,diagnosed at age 19 after his brother’s death from acute liver failure,presented with compensated cirrhosis,neurological symptoms,and bilateral Kayser-Fleischer rings.He developed progressive neurological deterioration during an irregular treatment with D-penicillamine due to medication shortages.His condition improved upon switching to trientine tetrahydrochloride,and his neurological symptoms improved over an 8-year period of follow-ups.The female patient,diagnosed at age 10,exhibited only biochemical alterations.Her treatment history was similar;however,she remained asymptomatic without disease progression over the same follow-up period.We discuss the potential influence of epigenetic mechanisms and modifier genes on the various phenotypes,emphasizing the need for research in these areas to optimize therapeutic strategies.CONCLUSION Our patients’medical histories show how early diagnosis and treatment can prevent disease progression;and,how suboptimal treatments impact disease outcomes.

Mapping the landscape of gastric signet ring cell carcinoma:Overcoming hurdles and charting new paths for advancement

BACKGROUND In recent years,the global prevalence of gastric cancer(GC)has witnessed a progressive decrease,accompanied by a step-growth in the incidence of gastric signet ring cell carcinoma(GSRCC).As precision medicine concepts progress,GSRCC,a distinct sub-type of GC,has drawn considerable attention from researchers.However,there still persist some controversies regarding the associated research findings.AIM To summarize the current obstacles and potential future directions for research on GSRCC.METHODS To begin with,all literature related to GSRCC published from January 1,2004 to December 31,2023 was subjected to bibliometric analysis in this article.Additionally,this paper analyzed the research data using CiteSpace,GraphPad Prism v8.0.2,and VOSviewer,which was obtained from the Web of Science Core Collection database.The analysis results were visually represented.RESULTS This study provided a comprehensive overview of the statistical characteristics of the 995 English articles related to GSRCC,including cited references,authors,journals,countries,institutions,and keywords.The popular keywords and clusters contain"prognosis","survival","expression","histology",and"chemotherapy".CONCLUSION The prognosis,precise definition and classification,as well as chemoresistance of GSRCC,continue to be crucial areas of ongoing research,whose directions are closely tied to advancements in molecular biology research on GSRCC.

Ringing in the New

Tradition and the contemporary blend in Spring Festival celebrations No matter where they are or what they are doing, the Spring Festival lurese very Chinese to their family like

Alarm Bells Are Ringing

As China prepares for a battle against H5N1 bird flu, health authorities are tracking new global developments of the virus Since a highly pathogenic strain of the bird flu virus made the leap from birds to humans in Hong Kong in 1997, the threat of an all-out pandemic has never been more serious than right now. Having spread to 15 countries, from Iraq to Austria and then into Nigeria in the past month alone, the total number of countries with a confirmed presence of the virus has risen to more than 30. A...

A 16-bit 18-MSPS flash-assisted SAR ADC with hybrid synchronous and asynchronous control logic

This paper presents a 16-bit,18-MSPS(million samples per second)flash-assisted successive-approximation-register(SAR)analog-to-digital converter(ADC)utilizing hybrid synchronous and asynchronous(HYSAS)timing control logic based on an on-chip delay-locked loop(DLL).The HYSAS scheme can provide a longer settling time for the capacitive digital-to-analog converter(CDAC)than the synchronous and asynchronous SAR ADC.Therefore,the issue of incomplete settling or ringing in the DAC voltage for cases of either on-chip or off-chip reference voltage can be solved to a large extent.In addition,the fore-ground calibration of the CDAC’s mismatch is performed with a finite-impulse-response bandpass filter(FIR-BPF)based least-mean-square(LMS)algorithm in an off-chip FPGA(field programmable gate array).Fabricated in 40-nm CMOS process,the proto-type ADC achieves 94.02-dB spurious-free dynamic range(SFDR),and 75.98-dB signal-to-noise-and-distortion ratio(SNDR)for a 2.88-MHz input under 18-MSPS sampling rate.