Breaking the linear correlations for enhanced electrochemical nitrogen reduction by carbon-encapsulated mixed-valence Fe_(7)(PO_(4))_(6)

Electrochemical nitrogen reduction(NRR)is deemed as a consummate answer for the traditional Haber–Bosch technology.Breaking the linear correlations between adsorption and transition-state energies of intermediates is vital to improve the kinetics of ammonia synthesis and obtain a less energy-intensive process.Herein,carbon-encapsulated mixed-valence Fe_(7)(PO_(4))_(6) was prepared and applied as an electrocatalyst for high-efficiency NRR.A dramatic faradaic efficiency(FE)of 36.93%and an NH_(3) production rate of 13.1μg h^(-1) mg_(cat)^(-1) were obtained at-0.3 V versus RHE,superior to nearly all Fe-based catalysts.Experiments and DFT calculations revealed that the superior performance was ascribed to the synergistic effect of mixed-valence iron pair,which braked the linear correlations to improve the kinetics of ammonia from collaborative hydrogenation and*NH_(3) separation.This work proves the feasibility of mixedvalence catalysts for nitrogen reduction and thus opening a new avenue towards artificial nitrogenfixation catalysts.

THE LINEAR CORRELATIONS BETWEEN ELECTRONIC TRANSITION ENERGY AND HAMMETT CONSTANTS FOR THE SUBSTITUTED PORPHYRIN-LIKE MACROCYCLE

The properties of absorption spectra are presented and the linear correlations of Hammett constants with the 0-0 transition energy(E_(o,o))of S_←S_o, and the ratios of oscillator strength(f/f)are used to probe the interactions betwee π-electron of aromatic maerocycles or metal ion of complexes with the sub- stituents on β-position of benzene ring for porphyrin-like maerocyclic compounds.

Unraveling and tuning the linear correlation between CH_(4) and C_(2) production rates in CO_(2) electroreduction

Although many catalysts have been reported for the CO_(2)electroreduction to C_(1)or C_(2)chemicals,the insufficient understanding of fundamental correlations among different products still hinders the development of universal catalyst design strategies.Herein,we first discover that the surface*CO coverage is stable over a wide potential range and reveal a linear correlation between the partial current densities of CH_(4)and C_(2)products in this potential range,also supported by the theoretical kinetic analysis.Based on the mechanism that*CHO is the common intermediate in the formation of both CH_(4)(*CHO→CH4)and C_(1)(*CHO+*CO→C_(2)),we then unravel that this linear correlation is universal and the slope can be varied by tuning the surface*H or*CO coverage to promote the selectivity of CH_(4)or C_(2)products,respectively.As proofs-of-concept,using carbon-coated Cu particles,the surface*H coverage can be increased to enhance CH_(4)production,presenting a high CO_(2)-to-CH_(4)Faradaic efficiency(FE_(CH_(4))~52%)and an outstanding CH_(4)partial current density of-337 m A cm;.On the other hand,using an Agdoped Cu catalyst,the CO_(2)RR selectivity is switched to the C_(2)pathway,with a substantially promoted FE;of 79%and a high partial current density of-421 m A cm;.Our discovery of tuning intermediate coverages suggests a powerful catalyst design strategy for different CO_(2)electroreduction pathways.

Correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma

Objective:To evaluate the correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma(SBA).Methods:46 patients with solitary bronchogenic adenocarcinomas (SBA)(diameter≤4 cm)underwent multi-location dynamic contrast material-enhanced(nonionic contrast material was administrated via the antecubital vein at a rate of 4 mL/s by using an autoinjector 90 mL,4×5 mm or 4×2.5 mm scanning mode with stable table were performed)serial CT.Precontrast and postcontrast attenuation on every scan was recorded.Perfusion (PBA),peak height(PHBA),ratio of peak height of the SPN to that of the aorta(BA-to-A ratio)and mean transit time(MTT)were calculated.The correlation between peak height of the aorta(PHA)and parameters of the SBA(PHBA,BA-to-A ratio,PBA,and MTT)and those among parameters of the SBA were assessed by means of linear regression analysis.Regression equation among parameters of the SBA were obtain by means of stepwise regression.Results:The correlation between the SBA peak height(PHBA,36.78 HU±12.02)and the aortic peak height(PHA)was significant(r=0.506,P<0.0001).No significant cor- relation was found between the BA-to-Apeak height ratio(15.33%±4.55)and the aortic peak height(r=0.130,P=0.388> 0.05)as it was between the SBA perfusion(PBA,31.86 mL/min/100 g±9.74)and the aortic peak height(r=0.049,P=0.749 >0.05).The SBA perfusion correlated with the PHBA and the BA-to-A peak height ratio(r=0.394,P=0.007<0.05;r=0.407, P=0.005<0.05).The PHBA correlated positively with the BA-to-A peak height ratio(r=0.781,P<0.0001).Mean transit time was 14.84 s±5.52.PBA=18.500+0.872×BA-to-A ratio.BA-to-A ratio=4.467+0.295×PHBA.Conclusion:The linear correlation between the SBA perfusion and BA-to-Aratio and that between BA-to-Aratio and PHBA can be expressed by equation. It is possible to design a simpler scanning procedure of investigation of bronchogenic adenocarcinoma angiogenesis.

Research on the Model of Linear Data Fitting Method

By using the method of least square linear fitting to analyze data do not exist errors under certain conditions, in order to make the linear data fitting method that can more accurately solve the relationship expression between the volume and quantity in scientific experiments and engineering practice, this article analyzed data error by commonly linear data fitting method, and proposed improved process of the least distance squ^re method based on least squares method. Finally, the paper discussed the advantages and disadvantages through the example analysis of two kinds of linear data fitting method, and given reasonable control conditions for its application.

Fast speedometer identification in dynamic scene based on phase correlation

Speedometer identification has been researched for many years.The common approaches to that problem are usually based on image subtraction,which does not adapt to image offsets caused by camera vibration.To cope with the rapidity,robust and accurate requirements of this kind of work in dynamic scene,a fast speedometer identification algorithm is proposed,it utilizes phase correlation method based on regional entire template translation to estimate the offset between images.In order to effectively reduce unnecessary computation and false detection rate,an improved linear Hough transform method with two optimization strategies is presented for pointer line detection.Based on VC＋＋ 6.0 software platform with OpenCV library,the algorithm performance under experiments has shown that it celerity and precision.

Structural-visual functional relationships detected by optical coherence tomography in varying age-cohorts' patients with optic neuritis

AIM: To assess the relationships of final best-corrected visual acuity(BCVA) and the optic nerve structural loss in varying age-cohorts of optic neuritis(ON) patients.METHODS: This is a retrospective, cross-sectional study.Totally 130 ON subjects(200 eyes) without ON onset within 6mo were included, who underwent BCVA assessment,peripapillary retinal nerve fibre layer(pRNFL) and macular segmented layers evaluation by optical coherence tomography(OCT).RESULTS: For the 0-18y cohort, the final BCVA(logMAR)was significantly better and less frequent recurrences than adult cohorts(P=0.000). The final BCVA(logMAR) in all age-cohorts of the ON patients had negative and linear correlations to the pRNFL thicknesses and macular retinal ganglion cell layer(mRGCL) volumes, when the pRNFL thicknesses were reduced to the thresholds of 57.2-67.5 μm or 0.691-0.737 mm;in mRGCL volumes, respectively, with the strongest interdependence in the 19-40y cohort. The ON patients from varying age cohorts would be threatened by blindness when their pRNFL thicknesses dropped 36.7-48.3 μm or the mRGCL volumes dropped to 0.495-0.613 mm;.CONCLUSION: The paediatric ON has best prognosis and young adult ON exhibits perfectly linear correlations of final vision and structural loss. The pRNFL and the mRGCL could be potential structural markers to predict the vision prognosis for varying-age ON patients.

Partial Correlation Analysis Based Identification of Distribution Network Topology

Accurately identifying distribution network topol-ogy,which tends to be a mesh configuration with increasing penetration rate of distributed energy resources(DERs),is critical for reliable operation of a smart distribution network.Multicollinearity among node voltages makes existing topology identification methods unstable and inaccurate.Considering partial correlation analysis can reveal the intrinsic correlation of two variables by eliminating the influence of other variables,this paper develops a novel data-driven method based on partial correlation analysis to identify distribution network topology(radial,mesh,or including DERs)using only historical voltage amplitude data.First,maximum spanning tree of network is generated through Prim algorithm.Then,the loops of network are identified by taking tree neighbors as controlling variables in partial correlation analysis.Finally,a new topology verification mechanism based on partial correlation analysis is developed to correct wrong connections caused by multicollinearity.Test results on IEEE 33-node system,IEEE 123-node system and practical distribution network demonstrate that our method outperforms common data-driven methods,and can robustly identify both radial and mesh distribution network with DERs.IndexTerms-Data-driven,linear correlation,partial correlation,smart meter,topology identification.

Multi-band Image Registration Method Based on Fourier Transform

This paper presented a registration method based on Fourier transform for multi-band images which is involved in translation and small rotation. Although different band images differ a lot in the intensity and features, they contain certain common information which we can exploit. A model was given that the multi-band images have linear correlations under the least-square sense. It is proved that the coefficients have no effect on the registration progress if two images have linear correlations. Finally, the steps of the registration method were proposed. The experiments show that the model is reasonable and the results are satisfying.

Theoretical Studies on the Intermonomer Interaction of F^(-)·(H_(2)O)_(n)(n=1,2)

Five optimized geometries of F-?(H2O)n (n = 1, 2) were obtained with ab initio calculation at the B3LYP/6-311++G** level. The accurate intermonomer interaction energy was calculated using the MP2 electron correlation correction as well as the basis set superposition error correction by the Boys-Bernardi “counterpoise” protocol. Natural bond orbital (NBO) theory was applied to quantify the relative strength of these interactions and account for their effects on the stability, structural and vibrational parameters of Fˉ?(H2O)n (n = 1, 2). It is shown that the charge transferring from the lone pair of F-1 to the σ?OH(…F) antibonding orbital is important. The results indicate the occupancy of σ?OH(…F) is increased (denoted ?σ?OH(…F)) and the σOH(…F) bond is leng- thened (denoted ?ROH(…F)), leading to the red-shift and the red-shift values have linear correlation with both ?σ?OH(…F) and ?ROH(…F).

A Cross-Sectional Study According to Risk Factors Associated with Erectile Dysfunction in Men

Background: Erectile dysfunction (ED) is a common condition in general population. It has a negative impact on the couple’s quality of life. In 1995, it was estimated that it affected 152 million people worldwide, and that it would affect more than 322 million people in 2025 with a large increase in developing countries. Several studies have suggested a causal link between ED and cardiovascular disease. In the Democratic Republic of Congo, no studies exist on this subject. Nonetheless, we are seeing increased promotion on the management of sexual disorders in our media, which could testify to the extent of this problem. Objective: To assess the extent of cardiovascular risk factors for ED in Kinshasa. Material and Methods: This is a cross-sectional study for analytical purposes. It collected several categories of individuals from May 1 to October 31, 2018. The severity of ED was assessed by the IIEF-5 score and the associated risk factors sought via logistic regression. Results: The mean age of the respondents was 59.9 ± 19.2 years, more than half of the respondents were over the age of 60 years old (60%). The ED proportion was 78.8%, and 75% of respondents had at least moderate ED. This anomaly was significantly elevated among respondents aged over 60 years (94.8%), diabetics (87.5%), hypertensive patients (92.3%) and stroke victims (86%). The independently associated risk factors were: age > 60 years [ORa: 9.87;95% CI: 6.42 - 10.48, p < 0.001], diabetes mellitus [ORa: 2.99;95% CI: 1.80 - 4.95, p = 0.013] and the stroke [ORa: 2.1;95% CI: 1.36 - 3.39;p = 0.012%]. The age threshold predicting ED was 67 years. Conclusion: ED is a frequent disorder in our environment and likely to affect the quality of life of men who suffer from it. There is an ED and cardiovascular risk factors correlation. A proactive attitude of the caregiver in current practice would allow early detection of ED with a view to early and optimal management.

Will Political Stability Factors Influence FDI Inflow？

In this paper, the authors discuss whether political stability would influence Foreign Direct Investment （FDI） inflow. There is an increasing interest among scholars about FDI since it has been considered as a way to offer abundant foreign capital, high skills, and new jobs throughout developing countries. Foreign companies pay more attention to the institutional properties and time horizon of the government leader. From historical experience, autocratic countries attract more FDI because of their flexibility and powerfulness. Hence, the research assumes that political stability as well as other factors like GDP, OMI, and interest rate probably would increase FDI inflow. Stata and Eviews have been used for regressing the independent variables and dependent variable. Correlation between each individual variable was calculated, and Least Squares method was used for investigating whether the linear correlation is significant. Finally, carefully analysing each indicator and ploting the graphs, things were found that there is no significant correlation between political stability factors of a country and FDI inflow. There are several explanations about the failure of hypothesis. First, the 10-year span is not long enough to prove the relationship. Then, the countries picked are most on the transition from autocracies to democracies. All the factors might influence the result of the correlation. Specific external factors such as economic conditions of investors need to be explored to see if it would probably determine the strong or weak of FDI.

Correlation functions of gauged linear σ-model

This is the second paper in a series following Tian and Xu(2015), on the construction of a mathematical theory of the gauged linear σ-model(GLSM). In this paper, assuming the existence of virtual moduli cycles and their certain properties, we define the correlation function of GLSM for a fixed smooth rigidified r-spin curve.

Potential Energy of Crops

This work consists of estimating the energy achieved from all land and water-based vegetations. This real potential is determined by identifying 10 biomass samples taken from vegetable resources which are favored by their aptitude of adaptation to the conditions of Iran. The net energy values of the 10 biomass samples change in the range of 13.65-18.00 MJ/kg using bomb calorimeter. By means of least squarere regression method all correlations were found. The results of 10 different biomass materials have been used to develop a linear equation correlation.

Calculating Auroral Oval Pattern by AE Index

The relationship between the auroral oval pattern, i.e., location, size, shape, and intensity, and the auroral electrojet activity index （AE index） is studied. It is found that the maximal auroral intensity is elliptically distributed, and the lengths of semimajor and semiminor axes are positively correlated to AE. The intensity along the normal of the auroral oval can be satisfyingly described by a Gaussian distribution, and the maximum and the full width at half maximum of the Gaussian distribution ave both positively correlated to AE. Based on these statistical results, a series of experimental formulas as a function of AE are developed to calculate the location, size, shape, and intensity of the auroral oval. These formulas are validated by the auroral images released by SWPC/NOAA.

Causality Analysis of Futures Sugar Prices in Zhengzhou Based on Graphical Models for Multivariate Time Series

This paper presents a method of constructing a mixed graph which can be used to analyze the causality for multivariate time series.We construct a partial correlation graph at first which is an undirected graph.For every undirected edge in the partial correlation graph,the measures of linear feedback between two time series can help us decide its direction,then we obtain the mixed graph.Using this method,we construct a mixed graph for futures sugar prices in Zhengzhou（ZF）,spot sugar prices in Zhengzhou（ZS） and futures sugar prices in New York（NF）.The result shows that there is a bi-directional causality between ZF and ZS,an unidirectional causality from NF to ZF,but no causality between NF and ZS.