Experimental study of relationship between average isotopic fractionation factor and evaporation rate

Isotopic fractionation is the basis of tracing the water cycle using hydrogen and oxygen isotopes. Isotopic fractionation factors in water evaporating from free water bodies are mainly affected by temperature and relative humidity, and vary significantly with these atmospheric factors over the course of a day. The evaporation rate （E） can reveal the effects of atmospheric factors. Therefore, there should be a certain functional relationship between isotopic fractionation factors and E. An average isotopic fractionation factor （ t~＊ ） was defined to describe isotopic differences between vapor and liquid phases in evaporation with time intervals of days. The relationship between or＊ and E based on the isotopic mass balance was investigated through an evaporation pan experiment with no inflow. The experimental results showed that the isotopic compositions of residual water were more enriched with time; tr＊ was affected by air temperature, relative humidity, and other atmospheric factors, and had a strong functional relation with E. The values of 0~＊ can be easily calculated with the known values of E, the initial volume of water in the pan, and isotopic compositions of residual water.

The Factors for Transformation between the Fractions of Speciation of Trace Metals in Lake Sediments

Objective Despite the fact that the bioavailability of trace metals indicated by their speciation has been an indispensable parameter in the assessment and treatment of the environmental pollution of trace metals, many studies have suggested that the bioavailability of trace metals may change according to the conditions of the environment, and the speciation of trace metals can also transform between some fractions. These transformations are related with these factors such as the compositions, microorganism, time, and other physical-chemical conditions of the system. Our work aims to systematically investigate and probe the factors to affect the transformation aside from analysis at certain time-place. The results of these understanding and investigations can be used for reasonably determining the allocation of financial and technical resources in natural and engineered processes, with bringing about inspirations from the evolution of the speciation of the trace metals on environmental impacts.

Effect of Different Styles of Coronary Heart Disease and Its Risk Factors on Cardiac Remodeling and Dysfunction

Objectives To evaluate the effect of different styles of coronary heart disease （CHD）, different regions of acute myocardial infarction （AMI）, its risk factors and branches of coronary stenosis on left ventricular remodeling and dysfunction by applying echocardiography. Methods 251 patients with CHD and 96 patients without CHD （NoCHD） were verified by selective coronary angiography. CHD patients were divided into stable angina pectoris （SAP） 26, unstable angina pectoris（UAP） 53, acute myocardial infarction （AMI） 140 and old myocardial infarction （OMI） 30 based on clinical situation, cTnT, cardiac enzyme and ECG. AMI patients were further divided into subgroups including acute anterior myocardial infarct （Aa,n = 53）, acute inferior myocardial infarction （Ai, n=54） and Aa＋Ai （n=33） based on ECG. Cardiac parameters： end-diastolic interventricular septum thickness（IVSd）, end-diastolic left ventricular internal diameter （LVd）, left ventricular mass （LM）, end-diastolic left ventricular volume （EDV）, end-systolic left ventricular volume （ESV） and left ventricular ejection fraction（LVEF） were measured by ACUSON 128XP/10 echocardiography. Multiples linear regression analyses were performed to test statistical associations between LVEF and the involved branches of coronary stenosis, blood pressure, lipids, glucose and etc after onset of myocardial infarction. Results EDV and ESV were increased and LVEF decreased on patients with AMI,OMI and UAP （P〈0.05-0.0001）. LM was mainly increased in patients with OMI （P〈0.01） and LVd was mainly enlarged in patients with AMI. EF was significantly decreased and EDV, ESV, LM and LVd were remarkably increased in AMI patients with Aa and Aa＋Ai. With the multiple linear regression analyses by SPSS software, we found that LVEF was negatively correlated to the involved branches of coronary stenosis as well as to systolic blood pressure after onset of myocardial infarction while there was no significant correlation between LVEF and other factors. LVEF was significantly decreased, and LVd and LM increased in AMI patients with antecedent hypertension, compared to patients without hypertension （P〈0.001）. Conclusions Effects of different styles of CHD and different regions of AMI on left ventricular remodeling and cardiac function are different. Myocardial infarction, especially Aa and Aa＋Ai, is one of the most important causes of left ventricular remodeling and cardiac dysfunction. Multiple vessel stenosis and systolic blood pressure at the onset of myocardial infarction reduce LVEF in AMI patients. Antecedent hypertension may accelerate the effect of AMI on cardiac remodeling and dysfunction. Therefore primary and secondary preventions of CHD are critical for protecting heart from remodeling and dysfunction.

Lie symmetries and conserved quantities of fractional nonconservative singular systems

In this paper,according to the fractional factor derivative method,we study the Lie symmetry theory of fractional nonconservative singular Lagrange systems in a configuration space.First,fractional calculus is calculated by using the fractional factor,and the fractional equations of motion are derived by using the differential variational principle.Second,the determining equations and the limiting equations of Lie symmetry under an infinitesimal group transformation are obtained.Furthermore,the fractional conserved quantity form of singular Lagrange systems caused by Lie symmetry is obtained by constructing a gauge-generating function that fulfills the structural equation,which conforms to the Noether criterion equation.Finally,we present an example of a calculation.The results show that the Lie symmetry condition of nonconservative singular Lagrange systems is more strict than conservative singular systems,but because of increased invariance restriction,the nonconservative forces do not change the form of conserved quantity;meanwhile,the fractional factor method has high natural consistency with the integral calculus,so the theory of integer-order singular systems can be easily extended to fractional singular Lagrange systems.

Adaptive coordination control strategy of renewable energy sources,hydrogen production unit,and fuel celi for frequency regulation of a hybrid distributed power system

Owing to the significant number of hybrid generation systems(HGSs)containing various energy sources,coordina-tion between these sources plays a vital role in preserving frequency stability.In this paper,an adaptive coordination control strategy for renewable energy sources(RESs),an aqua electrolyzer(AE)for hydrogen production,and a fuel cell(FC)-based energy storage system(ESS)is proposed to enhance the frequency stability of an HGS.In the proposed system,the excess energy from RESs is used to power electrolysis via an AE for hydrogen energy storage in FCs.The proposed method is based on a proportional-integral(Pl)controller,which is optimally designed using a grey wolf optimization(GWO)algorithm to estimate the surplus energy from RESs(ie,a proportion of total power generation of RESs:Kn).The studied HGS contains various types of generation systems including a diesel generator,wind tur-bines,photovoltaic(PV)systems,AE with FCs,and ESSs(e.g.,battery and flywheel).The proposed method varies Kn with varying frequency deviation values to obtain the best benefits from RESs,while damping the frequency fluc-tuations.The proposed method is validated by considering different loading conditions and comparing with other existing studies that consider Kn as a constant value.The simulation results demonstrate that the proposed method,which changes Kn value and subsequently stores the power extracted from the RESs in hydrogen energy storage according to frequency deviation changes,performs better than those that use constant Kn.The statistical analysis for frequency deviation of HGS with the proposed method has the best values and achieves large improvements for minimum,maximum,difference between maximum and minimum,mean,and standard deviation compared to the existing method.