Impact of initial fluctuations and nuclear deformations in isobar collisions

Relativistic isobar^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zrcollisions have revealed intricate differences in their nuclear size and shape,inspiring unconventional studies of nuclear structure using relativistic heavy ion collisions.In this study,we investigate the relative differences in the mean multiplicityR_(<Nch>)and the secondR_(ε2)and third-order eccentricityR_(ε3)between isobar collisions using initial state Glauber models.It is found that initial fluctuations and nuclear deformations have negligible effects on R_(<Nch>)in most central collisions,while both are important for the R_(ε2)and R_(ε3),the degree of which is sensitive to the underlying nucleonic or sub-nucleonic degree of freedom.These features,compared to real data,may probe the particle production mechanism and the physics underlying nuclear structure.

Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations:a functional magnetic resonance imaging study

AIM:To study functional brain abnormalities in patients with hypertensive retinopathy(HR)and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations(fALFFs)method.METHODS:Twenty HR patients and 20 healthy controls(HCs)were respectively recruited.The age,gender,and educational background characteristics of the two groups were similar.After functional magnetic resonance imaging(fMRI)scanning,the subjects’spontaneous brain activity was evaluated with the fALFF method.Receiver operating characteristic(ROC)curve analysis was used to classify the data.Further,we used Pearson’s correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR.RESULTS:The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus(RO-MFG)and right lingual gyrus.In contrast,the values of fALFFs in the left middle temporal gyrus(MTG),left superior temporal pole(STP),left middle frontal gyrus(MFG),left superior marginal gyrus(SMG),left superior parietal lobule(SPL),and right supplementary motor area(SMA)were higher in the HR group.The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group(P<0.001).The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores(r=0.9232;P<0.0001)and depression scores(r=0.9682;P<0.0001).CONCLUSION:fALFF values in multiple brain regions of HR patients are abnormal,suggesting that these brain regions in HR patients may be dysfunctional,which may help to reveal the pathophysiological mechanisms of HR.

Experimental study on temperature fluctuations on plate surface induced by coaxial-jet flow

In nuclear reactors,temperature fluctuations of fluids may cause fatigue damage to adjacent structures;this is referred to as thermal striping.Research on thermal striping in the upper plenum has mainly focused on fluid fields.Few experimental studies have been reported on solid structures in a fluid field with a coaxial jet.This study entailed an experimental study of the temperature fluctuations in the fluid and on a plate surface caused by a coaxial jet.The temperature fluctuations of the fluid and plate surfaces located at different heights were analyzed.The cause of the temperature fluctuation was analyzed using a transient temperature distribution.The results show that the mixing of the hot and cold fluids gradually becomes uniform in the positive axial direction.The average surface temperatures tended to be consistent.When the jet reaches the plate surface,the swing of the jet center,contraction and expansion of the cold jet,and changes in the jet shape result in temperature fluctuations.The intensity of the temperature fluctuation was affected by the position.More attention should be paid when the plate is located at a lower height,and between the hot and cold-fluid nozzles.

Influence of blood glucose fluctuations on chemotherapy efficacy and safety in type 2 diabetes mellitus patients complicated with lung carcinoma

BACKGROUND Patients with type 2 diabetes mellitus(T2DM)have large fluctuations in blood glucose(BG),abnormal metabolic function and low immunity to varying degrees,which increases the risk of malignant tumor diseases and affects the efficacy of tumor chemotherapy.Controlling hyperglycemia may have important therapeutic implications for cancer patients.AIM To clarify the influence of BG fluctuations on chemotherapy efficacy and safety in T2DM patients complicated with lung carcinoma(LC).METHODS The clinical data of 60 T2DM+LC patients who presented to the First Affiliated Hospital of Ningbo University between January 2019 and January 2021 were retrospectively analyzed.All patients underwent chemotherapy and were grouped as a control group(CG;normal BG fluctuation with a mean fluctuation<3.9 mmol/L)and an observation group(OG;high BG fluctuation with a mean fluctuation≥3.9 mmol/L)based on their BG fluctuations,with 30 cases each.BGrelated indices,tumor markers,serum inflammatory cytokines and adverse reactions were comparatively analyzed.Pearson correlation analysis was performed to analyze the correlation between BG fluctuations and tumor markers.RESULTS The fasting blood glucose and 2-hour postprandial blood glucose levels in the OG were notably elevated compared with those in the CG,together with markedly higher mean amplitude of glycemic excursions(MAGE),mean of daily differences,largest amplitude of glycemic excursions and standard deviation of blood glucose(P<0.05).In addition,the OG exhibited evidently higher levels of carbohydrate antigen 19-9,carbohydrate antigen 125,carcinoembryonic antigen,neuron-specific enolase,cytokeratin 19,tumor necrosis factor-α,interleukin-6,and highsensitivity C-reactive protein than the CG(P<0.05).Pearson analysis revealed a positive association of MAGE with serum tumor markers.The incidence of adverse reactions was significantly higher in the OG than in the CG(P<0.05).CONCLUSION The greater the BG fluctuation in LC patients after chemotherapy,the more unfavorable the therapeutic effect of chemotherapy;the higher the level of tumor markers and inflammatory cytokines,the more adverse reactions the patient experiences.

A Statistical Method for Characterizing CMOS Process Fluctuations in Subthreshold Current Mirrors

A novel method to characterize CMOS process fluctuations in subthreshold current mirrors （SCM） is reported. The proposed model is succinct in methodology and calculation complexity compared with previous statistical models. However,it provides favorable estimations of CMOS process fluctuations on the SCM circuit, which makes it promising for engineering applications. The model statistically abstracts physical parameters, which depend on the IC process, into random variables with certain mean values and standard deviations, while aggregating all the random impacts into a discrete martingale. The correctness of the proposed method is experimentally verified on an SCM circuit implemented in an SMIC 0.18μm CMOS 1P6M mixed signal process with a conversion factor of 100 in an input range from 100pA to lμA. The pro- posed theory successfully predicts - 10% of die-to-die fluctuation measured in the experiment, and also suggests the -lmV of threshold voltage standard deviation over a single die,which meets the process parameters suggested by the design kit from the foundry. The deviations between calculated probabilities and measured data are less than 8%. Meanwhile, pertinent suggestions concerning high fluctuation tolerance subthreshold analog circuit design are also made and discussed.

New Way to Quantize Time-Dependent RLC Electric Circuit and Quantum Fluctuations

According to the physical mechanism of the generation of the resistance or the electron phonon interaction, a new method is proposed to quantize the RLC electric circuit. Calculations show that the quantum fluctuations under this new quantization are smaller than those by the traditional effective Hamiltonian method. And squeezed states can be generated if the inductance and capacity are time dependent. Meanwhile, the shortcoming of the traditional method that the electric charge and current will vanish in the long time limit is overcome.

An Interpretation on Jig's Psychological Fluctuations in Hills like White Elephants

Hills like White Elephants is one of the masterpieces of Ernest Hemingway. The story bears an open ending. This paper attempts to analyze the heroine-Jig's psychological fluctuations, and her three emotional stages to support the author's interpretation on the end of the story—the heroine's final decision is to have the baby born.

Experimental Study of the Pressure Fluctuations in a Pump Turbine at Large Partial Flow Conditions

Frequent shifts of output and operating mode require a pump turbine with excellent stability. Current researches show that large partial flow conditions in pump mode experience positive-slope phenomena with a large head drop. The pressure fluctuation at the positive slope is crucial to the pump turbine unit safety. The operating instabilities at large partial flow conditions for a pump turbine are analyzed. The hydraulic performance of a model pump turbine is tested with the pressure fluctuations measured at unstable operating points near a positive slope in the performance curve. The hydraulic performance tests show that there are two separated positive-slope regions for the pump turbine, with the flow discharge for the first positive slope from 0.85 to 0.91 times that at the maximum efficiency point. The amplitudes of the pressure fluctuations at these unstable large partial flow conditions near the first positive slope are much larger than those at stable operating condtions. A dominant frequency is measured at 0.2 times the impeller rotational frequency in the flow passage near the impeller exit, which is believed to be induced by the rotating stall in the flow passage of the wicket gates. The test results also show hysteresis with pressure fluctuations when the pump turbine is operated near the first positive slope. The hysteresis creates different pressure fluctuations for those operation points even though their flow rates and heads are similar respectively. The pressure fluctuation characteristics at large partial flow conditions obtained by the present study will be helpful for the safe operation of pumped storage units.

Trends in Temperature Extremes in Association with Weather-Intraseasonal Fluctuations in Eastern China

Trends in the frequencies of four temperature extremes （the occurrence of warm days, cold days, warm nights and cold nights） with respect to a modulated annual cycle （MAC）, and those associated exclusively with weather-intraseasonal fluctuations （WIF） in eastern China were investigated based on an updated homogenized daily maximum and minimum temperature dataset for 1960–2008. The Ensemble Empirical Mode Decomposition （EEMD） method was used to isolate the WIF, MAC, and longer-term components from the temperature series. The annual, winter and summer occurrences of warm （cold） nights were found to have increased （decreased） significantly almost everywhere, while those of warm （cold） days have increased （decreased） in northern China （north of 40°N）. However, the four temperature extremes associated exclusively with WIF for winter have decreased almost everywhere, while those for summer have decreased in the north but increased in the south. These characteristics agree with changes in the amplitude of WIF. In particular, winter WIF of maximum temperature tended to weaken almost everywhere, especially in eastern coastal areas （by 10%–20%）; summer WIF tended to intensify in southern China by 10%–20%. It is notable that in northern China, the occurrence of warm days has increased, even where that associated with WIF has decreased significantly. This suggests that the recent increasing frequency of warm extremes is due to a considerable rise in the mean temperature level, which surpasses the effect of the weakening weather fluctuations in northern China.

Numerical Simulation of Pressure Fluctuations in a Large Francis Turbine Runner

The pressure fluctuation caused by unsteady flow in runner is one of the main reasons of vibration for a large Francis hydraulic turbine. It directly affects the steady operation of the hydraulic turbine unit. The existing research of the pressure fluctuation in hydraulic turbine mainly focuses on the unsteady flow in draft tube. Accurate distribution of pressure fluctuations inside a runner is not very clear. In this paper, the numerical method for predicting the pressure fluctuations in runner is investigated and the numerical simulation is performed for a large Francis hydraulic turbine. It is proved that the combination of shear-stress transport（SST） k-o） turbulence model and pressure-implicit with splitting of operators（PISO） algorithm could give more reliable prediction of pressure fluctuations in runner. The frequencies of pressure fluctuations in runner are affected by the flow in guide vane and the flow in draft tube The first dominant frequency is significantly determined by the flow in draft tube, especially at part load condition. This frequency is approximately equal to one-third of the runner rotating frequency. The evident second dominant frequency is exactly equal to the guide vane passing frequency. The peak-to-peak amplitudes of pressure fluctuations in runner at small guide vane open angle are larger than that at large open angle at the same operating head. The amplitudes at points on blade pressure surface are generally greater than that on suction surface. The research results could be used to direct the hydraulic design and operation stability improvement of a large Francis hydraulic turbine.

Quantum fluctuations of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling

Based on the scheme of damped harmonic oscillator quantization and thermo-field dynamics （TFD）, the quantization of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling is proposed. The quantum fluctuations of charge and current of each loop in a squeezed vacuum state are studied in the thermal excitation case. It is shown that the fluctuations not only depend on circuit inherent parameters, but also rely on excitation quantum number and squeezing parameter. Moreover, due to the finite environmental temperature and damped resistance, the fluctuations increase with the temperature rising, and decay with time.

Model test of the influence of cyclic water level fluctuations on a landslide

Many landslides in reservoir areas continuously deform under cyclic water level fluctuations due to reservoir operations. In this paper,a landslide model, developed for a typical colluvial landslide in the Three Gorges Reservoir area, is used to study the effect of cyclic water level fluctuations on the landslide. Five cyclic water level fluctuations were implemented in the test, and the fluctuation rate in the last two fluctuations doubled over the first three fluctuations. The pore water pressure and lateral landslide profiles were obtained during the test. A measurement of the landslide soil loss was proposed to quantitatively evaluate the influence of water level fluctuations. The test results show that the first water level rising is most negative to the landslide among the five cycles. The fourth drawdown with a higher drawdown rate caused further large landslide deformation. An increase of the water level drawdown rate is much more unfavorable to the landslide than an increase of the water level rising rate. In addition, the landslide was found to have an adaptive ability to resist subsequent water level fluctuations after undergoing large deformation during a water level fluctuation. The landslide deformation and observations in the field were found to support the test results well.

Effect of water level fluctuations on temporal-spatial patterns of foraging activities by the wintering Hooded Crane(Grus monacha)

Background:The Yangtze River floodplain provides important wintering habitats for Hooded Cranes(Grus monacha) in China.Fluctuations in the water level change foraging habitat and food availability,affecting their temporal-spatial patterns of foraging activities.It is of considerable importance to investigate the effect of these fluctuations on food availability for wintering Hooded Cranes and their foraging response to these changes.Understanding their behavior patterns is beneficial in protecting the wintering crane population and restoring their wintering habitats.Methods:A field survey of the winter behavior of cranes was carried out at Shengjin Lake from November in 2013 to April in 2014.Habitat variables,as well as the spatial distribution and behavior patterns of wintering cranes at their foraging sites during five stages of water level fluctuation were collected.Based on this data we analyzed the relationship of foraging behavior relative to water level fluctuations and habitat types.Results:The foraging habitats used by Hooded Cranes varied at the different water level stages.As the water level decreased,the use of meadows and mudflats increased.When the water dropped to its lowest level,the use by the Hooded Crane in the mudflats reached a peak.There were statistically significant differences in time budget in the three types of habitats over the five stages of the water level.In the mudflats,the foraging behavior and maintenance behavior varied significantly with the water level,while the alert behavior showed little variation.Analysis of a generalized linear model showed that the five water level stages and three habitat types had a significant effect on foraging behavior,while the combined effect of these two variables was significant on the foraging time budget and the length of foraging activity of the Hooded Crane.Conclusions:With the decrease in the water level,the use of mudflats by Hooded Cranes increased correspondingly.Food availability in different habitats was affected by changes in the water level.The Hooded Crane adjusted its foraging patterns and made full use of the three available types of habitat in order to acquire enough food in response to fluctuations in the water level.

Experimental Studies of Electrostatic Fluctuations and Turbulent Transport in the Boundary of J-TEXT Tokamak Using Reciprocating Probe

As the basic of a deeper investigation on the turbulent transport, the fluctuation property in the boundary of the newly-reconstructed Joint Texas Experimental Tokamak （J- TEXT） is studied experimentally using the reciprocating Langmuir four-tip probe, which has been built and operated as the primary diagnostic tool in the boundary of J-TEXT tokamak. In this paper, spatial profiles of the plasma-edge parameters are obtained, such as electron temperature, plasma density, plasma potential, poloidal electric field and their fluctuations. The results indicate the existence of a Er ×BT shear layer at the vicinity of last closed flux surface （LCFS）, with the fluctuations suppressed in varying degrees. The turbulence-induced particle and energy fluxes can be calculated by the local plasma parameters above. Convection dominates the cross-field turbulent transport in boundary plasma. Electrostatic fluctuations properties are also studied in detail with the help of numerical analysis. Statistical analysis on density fluctuation shows that, the intermittency can affect the turbulence in the scrape-off layer （SOL）.

Reliability of Blood Pressure Measurements: An Analysis of the White Coat Effect and Its Fluctuations

In this paper, we evaluate the difference between the first and second measurements of blood pressure (BP) when BP is measured twice using the results of 17,775 medical checkups. The two measurements for both systolic BP (SBP) and the diastolic BP (DBP) fluctuated a large amount even though they were measured at a short interval. The first measurements were 6.7 and 2.4 mmHg higher than the second ones for SBP and DBP, suggesting a white coat effect. Then, the factors that might affect the differences between the two measurements were analyzed by the regression models. For both SBP and DBP, the difference increased as the first measurement increased. Age, gender, BMI and alcohol consumption were other important factors affecting the difference. In the case of a typical male individual, the typical criteria for hypertension of 140/90, 160/100 and 180/110 mmHg criteria in the first measurement would correspond to 135/86, 150/94 and 165/102 mmHg in the second measurement. The necessity of developing accurate and cost-efficient BP measurement methods is strongly suggested.

Angle-of-arrival fluctuations in moderate to strong turbulence

Based on the modified spectrum, the analytic expressions for the variance and normalized covariance of angleof-arrival （AOA） fluctuations are presented, which are applicable to the weak and strong regimes. The experimental data of AOA fluctuations validate the new derived expressions in weak and strong regimes. The results show that the receiving aperture D, outer scale and cell scale larger than the scattering disc S contribute significantly to the AOA fluctuations, and contributions from the small-scale turbulence are negligible. For the case of 4S/D 〈〈 1, the receiving aperture dominates low-pass filtering effects and the new displacement variances are in good agreement with the results from the old weak-fluctuation theory. For the case of 4S/D 〉〉 1, the scattering disc dominates the low-pass filtering effects and the new displacement variances depart from the results from the old weak-fluctuation theory.

Fluctuations of Single-Mode Laser Driven by Two Different Kinds of Colored Noise

A single-mode laser with coupling between additive and multiplicative noise terms is investigated when the multiplicative noise and the coupling between two noise terms are colored fluctuations with finite correlation times T1 and T2. Combining the unified colored noise approximation （UCNA） and the functional analysis, the stationary probability distribution （SPD） and the variance of the laser intensity is derived. It is found that the colored nature of multiplicative noise and the coupling strength between two noise terms can affect both the structure and the height of the SPD, while the colored nature of the coupling between two noise terms can only affect the height of the SPD. The multiplicative noise can enhance the intensity fluctuations while the additive noise can reduce the fluctuations in a laser system. Numerical simulations are presented and consistent to the analytical results.

Functional Integrals and Quantum Fluctuations on Two-Dimensional Noncommutative Space-Time

The generalized Thirring model with impurity coupling is defined on two-dimensional noncommutativespace-time,a modified propagator and free energy are derived by means of functional integrals method.Moreover,quantum fluctuations and excitation energies are calculated on two-dimensional black hole and soliton background.

High-Order Statistics of Temperature Fluctuations in an Unstable Atmospheric Surface Layer over Grassland

Skewness(S) and kurtosis(K) of temperature in the surface layer over a grassland are investigated under unstable thermal stratifications. We find that both skewness and kurtosis generally obey Monin–Obukhov similarity theory and tend to be constant values(1.5 and 5.3, respectively) when the stability parameter z/L <-2. Quantitative formulas of the similarity functions are proposed. The temperature probability density function(PDF) is close to Gaussian in near neutral stratification and non-Gaussian in unstable stratification. The influence of coherent motions on the PDF behavior is analyzed using the quadrant analysis technique. It shows that PDF behaviors are controlled by ejections and sweeps. The results also indicate that the PDF type of the ejections always follows a Gaussian distribution, while the PDF of the sweeps changes with stability.

Large eddy simulation of hot and cold fluids mixing in a T-junction for predicting thermal fluctuations

Temperature fluctuations in a mixing T-junction have been simulated on the FLUENT platform using the large eddy simulation （LES） turbulent flow model and a sub-grid scale Smagorinsky-Lilly model. The normalized mean and root mean square temperatures for describing time-averaged temperature and temperature fluctuation intensity, and the velocity are obtained. The power spectrum densities of temperature fluctuations, which are key parameters for thermal fatigue analysis and lifetime evaluation, are analyzed. Simulation results are consistent with experimental data published in the literature, showing that the LES is reliable. Several mixing processes under different conditions are simulated in order to analyze the effects of varying Reynolds number and Richardson number on the mixing course and thermal fluctuations.