Toda chain from the kink-antikink lattice

In this paper, we have studied the kink and antikink solutions in several neutral scalar models in 1+1 dimension. We follow the standard approach to write down the leading order and the second order force between long distance separated kink and antikink. The leading order force is proportional to exponential decay with respect to the distance between the two nearest kinks or antikinks. The second order force have a similar behavior with the larger decay factor, namely $3\over 2$. We make use of these properties to construct the kink lattice. The dynamics of the kink lattice with leading order force can be identified as ordinary nonperiodic Toda lattice. Also the periodic Toda lattice can be obtained when the number of kink lattice is even. The system of kink lattice with force up to the next order corresponds to a new specific deformation of Toda lattice system. There is no well study on this deformation in the integrable literatures.We found that the deformed Toda system are near integrable system, since the integrability are hindered by high order correction terms. Our work provides a effective theory for kink interactions and a new near or quasi integrable model.Comment: 20 pages no figure

Near integrability of kink lattice with higher order interactions

In the paper, we make use of Manton's analytical method to investigate the force between kink and the anti-kink with large distance in $1+1$ dimensional field theory. The related potential has infinite order corrections of exponential pattern, and coefficients for each order are determined. These coefficients can also be obtained by solving the equation of the fluctuation around the vacuum. At the lowest order, the kink lattice represents the Toda lattice. With higher order correction terms, the kink lattice can represent one kind of the generic Toda lattice. With only two sites, the kink lattice is classically integrable. If the number of sites of the lattice is larger than two, the kink lattice is not integrable but a near integrable system. We take use of the Flaschka's variables to study the Lax pair of the kink lattice. These Flaschka's variables have interesting algebraic relations and the non-integrability can be manifested. We also discussed the higher Hamiltonians for the deformed open Toda lattice, which has a similar result as the ordinary deformed Toda

Biochar to improve soil fertility. A review

International audienceAbstractSoil mineral depletion is a major issue due mainly to soil erosion and nutrient leaching. The addition of biochar is a solution because biochar has been shown to improve soil fertility, to promote plant growth, to increase crop yield, and to reduce contaminations. We review here biochar potential to improve soil fertility. The main properties of biochar are the following: high surface area with many functional groups, high nutrient content, and slow-release fertilizer. We discuss the influence of feedstock, pyrolysis temperature, pH, application rates, and soil types. We review the mechanisms ruling the adsorption of nutrients by biochar

Analysis of Aroma Components of Red Jujube from Different Origins Based on HS-SPME-GC-MS and Chemometrics

To compare the volatile flavor characteristics of red jujube from different origins, volatile aroma components of jujube fruit from five origins (Xinzheng, Lingbao, Yulin, Hotan and Dezhou) were analyzed by headspace solid-phase microextraction combined with gas chromatography mass spectrometry. The results showed that a total of 51 compounds were identified, among which the most volatile compounds were contained in Xinjiang Hotan jujube. Combined with multivariate statistical analysis, the differences in the overall volatile flavor substances of red jujube from different origins could be well distinguished. Under the conditions of satisfying the variable importance in projection>1 and P<0.05, 13 differential characteristic aroma substances, including methyl caproate, methyl decanoate, hexanal, and benzaldehyde, were screened out from red jujube samples, which imparted unique almond, sweet, and fruity flavors to red jujube. The results of this study clarify the chemical substance basis of the aroma quality of red jujube from different origins, provide a new idea for the origin tracing study of red jujube, and further provide a scientific basis for the rational processing and utilization of jujube fruit resources

Local fiscal distress and investment efficiency of local SOEs

In this paper, we use A-share listed firms between 2002 and 2010 to investigate the relationship between local fiscal distress and the investment efficiency of local SOEs, along with the effect of corporate tax payments on this relationship. We find a positive relationship between the extent of local SOEs’ overinvestment and the fiscal distress of the corresponding local government where the enterprise and this relationship become stronger for firms that pay fewer taxes. The pattern of underinvestment among local SOEs was in contrast, and these relationships do not exist for non-SOEs or central SOEs. Moreover, we find that expanding a firm’s investment scale leads to an increase in total taxes paid, including income and turnover taxes, which further result in more local fiscal revenue. Overall, we conclude that local governments have an incentive to increase fiscal revenue when faced with fiscal distress by raising the investment scale of local SOEs and that the incentives and effects of such interventions appear to be stronger among firms that contribute less to local fiscal revenue

Is the quality of female auditors really better? Evidence based on the Chinese A-share market

Unlike previous studies in which a single index was used to measure audit quality, this study establishes a new comprehensive index to measure audit quality via Discretionary Accrual, as estimated by Jones’ basic model (1991) and Audit Opinions. The former is used to measure the quality of financial statements, and the latter is used to measure the auditors’ independence in the mainstream international literature. We examine whether and how an auditor’s gender affects the quality of his or her audits under the framework of empathy theory and gender role socialization theory. Using a large sample of 9861 auditor-firm-year observations from Chinese A-share–listed companies from 2011 to 2015, we find that the audit quality of signed auditors shows significant gender differences: these significant gender differences differ from the findings of previous studies that female auditors could provide a higher-quality audit than male auditors; that is, in our study the audit quality of the male auditors exceeds that of the female auditors. After distinguishing the positive and negative directions of the Discretionary Accrual, we find no significant gender differences in audit quality between male and female auditors when the earnings had been adjusted upward by the client; that is, female and male auditors had the same audit risk perception. However, when the client adjusted earnings downward, which indicates a lower audit risk for the auditor, the audit quality of female auditors was significantly lower than that of the male auditors. After controlling for the age and position of the auditors, we also find that the gender differences in the auditors’ audit quality decreased significantly or even disappeared when the auditor’s age exceeded 45 years and/or their position was manager or above. These results are consistent with the empathy theory and gender role socialization theory. Keywords: Auditor characteristics, Sex difference, Gender difference, Audit quality, Personal characteristic

Troubled by unequal pay rather than low pay: The incentive effects of a top management team pay gap

We examine the relationships with firm performance of the internal pay gap among individual members of the top management team (TMT) and the compensation level of TMT members relative to their industry peers. We find that pay gap is positively related to firm performance and that this positive relation is stronger when the TMT pay level is higher than the industry median. However, we do not observe such effects in Chinese state-owned enterprises (SOEs), in which both the executive managerial market and compensation are government-regulated. We also document that cutting central SOE managers’ pay level can increase firm value, whereas doing so for local SOE managers has the opposite effect. Our findings have important implications for research on TMT compensation as well as for policy makers considering SOE compensation reform

Microbiota Succession and Chemical Composition Involved in Lactic Acid Bacteria-Fermented Pickles

Pickles are a type of traditional fermented vegetables in China. To ascertain the effect of different lactic acid bacteria on pickles, the chemical composition characteristics, flavor substances, and bacterial diversity of the pickles fermented by natural bacteria, Lactobacillus plantarum R5, Lactobacillus pentosus R8, and L. plantarum R5 plus L. pentosus R8 were investigated in this study. The results showed that Lactobacillus enhanced the decrease in pH, increase in total acid content, degradation of nitrite, and production of organic acid (lactic acid and malic acid) of fermented pickles. A total of 80 flavors were detected in the pickles fermented for 14 days, and esters in pickles fermented by Lactobacillus were more plentiful. Firmicutes emerged as the predominant microbial phyla. Amongst these, the commonly encountered microorganisms were Lactobacillus, unclassified Enterobacteriaceae, Pantoea, and Weissella. The multivariate statistical analysis further showed that Lactobacillus had a strong negative correlation with pH and a strong positive correlation with malic acid and lactic acid, and the microorganisms in pickles could acclimate to the changing fermentation environment. The insights gained from this study may be of assistance to us in obtaining new insights into the microbiota succession and chemical compounds involved in the pickles fermented by Lactobacillus