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The precision of machine tools heavily relies on the motorized spindle's performance. It is crucial to guarantee the thermal error prediction model's improved accuracy, as it enables enhanced machining accuracy, reduced errors, and effective control over the prediction model. The northern goshawk optimization (NGO) algorithm is used to optimize the kernel extreme learning machine (KELM) to address thermal error issues. Based on the analysis conducted, the best four temperature measurement locations are chosen. The established thermal error prediction model, combining NGO and KELM, is compared with both the basic KELM model and BA-KELM through comprehensive analysis. The results show that the determination coefficient R2 of NGO-KELM model is 0.132 and 0.026 higher than KELM and BA-KELM. The robustness, stability, and generalization ability of the NGO-KELM modeling method are verified. In order to further reduce the thermal error, this paper puts forward a method of adding a microradiator to the contact between the front and rear bearing chambers and the bearings. The findings demonstrate that it is possible to efficiently lower the temperature at the front and rear bearings and suppress the thermal deformation of the motorized spindle. [ABSTRACT FROM AUTHOR]

The halophyte Karelinia caspia has not only fodder and medical value but also can remediate saline-alkali soils. Our previous study showed that salt-secreting by salt glands is one of main adaptive strategies of K. caspia under high salinity. However, ROS scavenging, ion homeostasis, and photosynthetic characteristics responses to high salinity remain unclear in K. caspia. Here, physio-biochemical responses and gene expression associated with ROS scavenging and ions transport were tested in K. caspia subjected to 100-400mM NaCl for 7 days. Results showed that both antioxidant enzymes (SOD, APX) activities and nonenzymatic antioxidants (chlorogenic acid, α-tocopherol, flavonoids, polyamines) contents were significantly enhanced, accompanied by up-regulating the related enzyme and non-enzymatic antioxidant synthesis gene (KcCu/Zn-SOD, KcAPX6, KcHCT, KcHPT1, Kcγ-TMT, KcF3H, KcSAMS and KcSMS) expression with increasing concentrations of NaCl. These responses are beneficial for removing excess ROS to maintain a stable level of H2O2 and O2- without lipid peroxidation in the K. caspia response to high salt. Meanwhile, up-regulating expression of KcSOS1/2/3, KcNHX1, and KcAVP was linked to Na+ compartmentalization into vacuoles or excretion through salt glands in K. caspia. Notably, salt can improve the function of PSII that facilitate net photosynthetic rates, which is helpful to growing normally in high saline. Overall, the findings suggested that ROS scavenging systems and Na+/K+ transport synergistically contributed to redox equilibrium, ion homeostasis, and the enhancement of PSII function, thereby conferring high salt tolerance. [ABSTRACT FROM AUTHOR]

This paper investigates whether corporate payout policy is associated with insiders' share holdings and their tax preferences. We find that insider ownership and the implied tax liabilities are positively related to a firm's propensity to employ share repurchases. Firms with higher levels of or greater increases in insider ownership prefer stock repurchases to cash dividends. This relation is more significant in years when dividends were more tax disadvantaged relative to capital gains. Our findings are robust to the endogeneity of insider ownership and the inclusion of various control variables such as firm size, permanence of cash flows, growth opportunities, institutional ownership, and executive stock options. Overall, our results suggest that personal tax considerations from insiders affect corporate payout decisions. [ABSTRACT FROM AUTHOR]

We document strong comovement in the stock returns of firms headquartered in the same geographic area. Moreover, stocks of companies that change their headquarters location experience a decrease in their comovement with stocks from the old location and an increase in their comovement with stocks from the new location. The local comovement of stock returns is not explained by economic fundamentals and is stronger for smaller firms with more individual investors and in regions with less financially sophisticated residents. We argue that price formation in equity markets has a significant geographic component linked to the trading patterns of local residents. [ABSTRACT FROM AUTHOR]

To provide more insights into the responses of the soil seed bank and vegetation to human disturbance intensity, we selected four land use types, including: native grassland (no human disturbance), abandoned artificial grassland (light human disturbance), artificial grassland (moderate human disturbance), and farmland (severe human disturbance) in a semi-arid climate of northern China. The species composition and density of the soil seed bank were measured, as well as the species composition and amount of vegetation. The native grassland had a significantly higher soil seed density and species richness than the other land use types. Moreover, the common species both in the soil seed bank and vegetation between the native grassland and other land use types gradually decreased as disturbance intensity increased. The abandoned artificial grassland and artificial grassland still had abundant soil seed banks according to their seed density (≤28.2% of the native grassland) and species richness (≤70.0% of the native grassland) to restore the vegetation. Conversely, it was hard to restore the vegetation on the farmland due to its low soil seed density (10.0% of the native grassland) and species richness (40.0% of the native grassland). In conclusion, human disturbance would generate significant negative effects on the soil seed bank in desertified regions in a semi-arid climate; however, the soil seed bank in land use types with light/moderate disturbance are more adapted to vegetation restoration compared with land use types with severe disturbance in a semi-arid region. [ABSTRACT FROM AUTHOR]

For understanding the influence of initial concentrations of pesticides in the water body on removal efficiency of the contaminant by aquatic plants, one hydroponics experiment was used to investigate the influence of initial concentration (1-16 mg L-1) on toxicity and chlorpyrifos removal potential of Iris pseudacorus for 20 days under greenhouse conditions. An increased sensitivity to and reduced removal rate for chlorpyrifos were observed with increasing chlorpyrifos concentration. The relative growth rate (RGR) of I. pseudacorus was significantly inhibited in the presence of 4, 8 and 16 mg L-1 chlorpyrifos, and a negative relationship was also found between RGR and initial pesticide concentration. The half-life of chlorpyrifos was shortened in the hydroponic system with plants, indicating that I. pseudacorus accelerated chlorpyrifos removal from water. But the contribution of the plant to chlorpyrifos removal in the hydroponic phytoremediation system decreased with the increase of initial concentration of chlorpyrifos. The results also indicated that I. pseudacorus can efficiently eliminate chlorpyrifos and may ultimately serve as phytoremediation agents in the natural water body. [ABSTRACT FROM AUTHOR]

A hydroponic system was used to evaluate atrazine (ATZ) removal and uptake by three emergent hydrophytes, Iris pseudacorus, Lythrum salicaria and Acorus calamus, determining their potential as phytoremediation agents for ATZ-contaminated water. After 20 days of exposure, the relative growth rate of plants in sterile conditions was less than in natural conditions. ATZ amount in a culture solution planted with emergent plants decreased significantly compared with an unplanted solution, and the removal rate of ATZ in natural conditions was greater than in sterile conditions (p <0.05). The degradation contributions of I. pseudacorus, L. salicaria and A. calamus were 75.6, 65.5 and 61.8%, respectively. Those of the corresponding microbial population in the solution were 5.4, 11.4 and 17.4%, respectively. Emergent plants play a dominant role in reducing the ATZ level in the water body and could be used as phytoremediation agents. [ABSTRACT FROM AUTHOR]

We study the implications of market segmentation in a domestic setting, the US municipal bond market. A (state-level) segmentation of this market emerges from asymmetric tax exemption. Municipal bond investors are exempt from state and local taxes on bonds issued by their own state, but not on bonds issued by other states. We demonstrate that market segmentation imposes significant costs on both issuers and investors in the form of higher yields and higher costs of financial intermediation. Our results provide insight into some well-documented artifacts of the municipal bond market, such as high yields and the popularity of insurance. [ABSTRACT FROM AUTHOR]

This paper studies the impact of corporate headquarters location on capital structure policies. We show that firms exhibit conformity in their financing policies to those of geographically proximate firms and that the location of corporate headquarters helps explain the cross-sectional variation of capital structure in the United States. The location effect is robust to local credit market conditions and to state laws on corporate takeover and payout restrictions. The results suggest that noneconomic factors, such as local culture and social interactions among corporate executives, play a significant role in influencing corporate financial policies of firms headquartered in the same metropolitan area. [ABSTRACT FROM AUTHOR]

We analyze the US equity holdings of more than 3000 non-US-based mutual funds from 22 countries and find robust evidence that fund managers strongly prefer to invest in stocks of US firms that have presence in their home country. This "home bias" is independent of the degree of global involvement and visibility of these US firms. While these firms have significantly greater exposure to local equity markets, their local presence offers little information advantage to local fund managers. Our findings suggest that the lack of international diversification is more serious than currently documented in the literature. [ABSTRACT FROM AUTHOR]

Rhyolites with high Nb-Ta contents were recently discovered in the north Daxingan Mountains, China. We determined the geochemical characteristics and zircon U-Pb ages of these rhyolites to elucidate their tectonic setting of formation and petrogenesis. Zircons from the high Nb-Ta rhyolites are idiomorphic or hypidiomorphic, short prismatic crystals with oscillatory zoning; the zircon trace element has a higher Th/U ratio (> 0.4); zircon rare earth element (REE) content is high (average is 1729 × 10−6) and indicates heavy REE (HREE) enrichment (average is 1561 × 10−6) and shows positive Ce (Ce/Ce* = 2.1-103.4) and negative Eu (Eu/Eu* = 0.18-0.64) anomalies typical of crustal magmatic zircons. Their weighted-mean LA-ICP-MS U-Pb age of 155 ± 1 Ma indicates that they formed in the Upper Jurassic. The rhyolites are characterized by high SiO2 and alkali contents and low Fe, Ca, Mg, and Mn contents, and are weakly peraluminous, indicating that they are high-K calc-alkaline rocks. Trace element compositions are characterized by enrichments in Nb, Ta, Zr, Hf, Ce, and Rb and depletions in Sr, Eu, Ba, P, Ti, Co, and Ni, with significant positive Ce (Ce/Ce* = 2.4-2.7) and negative Eu (Eu/Eu* = 0.06) anomalies. Niobium and Ta are hosted in the zircons. In (Na2O+K2O+FeOT+MgO+TiO2) vs (Na2O+K2O)/(FeOT+MgO+TiO2) and (Al2O3+FeOT+MgO+TiO2) vs Al2O3/(FeOT+MgO+TiO2) mineral characterization diagrams, data for the samples plot in the metamorphic greywacke or basic argillaceous rock fields, indicating that the magma originated from partial melting of crustal material. εSr(t) values cover a wide range (− 18.2 to + 102.9), whereas εNd(t) values have a narrow range (1.9-2.0) with T2DM model ages of 789-785 Ma, indicating that the source was the Neoproterozoic Xinghua Ferry Group crustal basement. This crustal rock suite comprises a volcanic-sedimentary formation of metamorphosed mafic volcanic and terrigenous clastic rocks derived from a mixture of mantle and crustal materials. Residual phases in the source region include Ca-rich plagioclase, amphibole, orthopyroxene, and zircon + garnet. Together with the positive Ce anomalies and low-Sr/high-Yb characteristics of the rhyolites, this indicates that the source rocks melted at relatively shallow depths (< 30 km), low pressures (< 0.8 GPa), and high O2 fugacity. Ga × 104/Al > 2.6, Ta vs Yb, and (Rb/30) vs Hf vs (3Ta) discrimination diagrams, data for the samples plot in the A-type rhyolite and intraplate granite fields, whereas in the Nb vs Y vs Ce diagram, the data plot in the A1-type field. It is concluded that an extensional tectonic setting, resulting from closure of the Mongolia-Okhotsk Ocean at the end-Triassic, or northward subduction of oceanic lithosphere under the Siberian Plate, caused underplating of mantle-derived basaltic magma and partial melting of metamorphic crustal rocks. [ABSTRACT FROM AUTHOR]