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Globally accurate full-dimensional ground state potential energy surface (PES) for the Cl($^2$P) + XCl $\to$ HCl + Cl($^2$P) reaction, a prototypical heavy-light-heavy abstract reaction, is developed using permutation invariant polynomial neural network (PIP-NN) method and embedded atom neural network (EANN) method, with the corresponding total root mean square error (RMSE) being only 0.043 and 0.056 kcal/mol, respectively. The saddle point of this reaction system is found to be nonlinear. A full-dimensional approximate quantum mechanical method, ring-polymer molecular dynamics (RPMD) with Cayley propagator, is employed to calculate the thermal rate coefficients and kinetic isotopic effects of title reactions Cl($^2$P) + XCl $\to$ XCl + Cl($^2$P) (X = H, D, Mu) on both new PESs. The results reproduce the experimental results at high temperatures perfectly, but with moderate accuracy at lower temperatures. The similar kinetic behavior is supported by quantum dynamics using wave packet calculations as well., Comment: 23 pages,5 figures

The force field describing the calculated interaction between atoms or molecules is the key to the accuracy of many molecular dynamics (MD) simulation results. Compared with traditional or semi-empirical force fields, machine learning force fields have the advantages of faster speed and higher precision. We have employed the method of atomic cluster expansion (ACE) combined with first-principles density functional theory (DFT) calculations for machine learning, and successfully obtained the force field of the binary Fe-Co alloy. Molecular dynamics simulations of Fe-Co alloy carried out using this ACE force field predicted the correct phase transition range of Fe-Co alloy., Comment: 17 pages, 6 figures

To investigate the shielding effects of mountains in front of a bridge on the wind field at the bridge site in an area with complex topography, a numerical simulation model of the bridge site, which is located in a deep cut V-shaped gorge, was conducted by a computational fluid dynamics method. In this study, taking the shielding effects of mountains in front of the bridge into consideration, the mean velocity, wind attack angle, wind profile, and wind direction angle under different flow cases were calculated and compared. The spatial distribution characteristics of the wind field in an area with complex topography considering shielding effects are presented. The calculation results indicate that the characteristics of the wind field near the mountain at the bridge site are affected by the mountain and the direction of the incoming flow. The shielding effects of the mountain on the eastern side of the bridge are very different under different flow directions. The wind load distribution along the girder is severely uneven in some cases due to a local cyclone existing around the girder. The conclusions of this study provide a basis for improved wind resistance designs of bridges.

Land use change and its eco-environmental responses are foci in geographical research. As a region with uneven economic development, land use change and eco-environmental responses across Jiangsu Province are relevant to China's overall development pattern. The external function of regional land use changes during different stages of economic development. In this study, we proposed a novel classification system based on the dominant function of land use according to “production-ecology-life”, and then analyzed land use change and regional eco-environmental responses from a functional perspective of regional development. The results showed that from 1985 to 2008, land use change features in Jiangsu were that productive land area decreased and ecological and living land areas increased. Land use changes in southern Jiangsu were the most dramatic. In southern and central parts of Jiangsu the agricultural production function weakened and urban life service function strengthened; in northern Jiangsu,...

The utilization of wind power is influenced by the fluctuation of the wind, to further strengthen the prediction accuracy of wind speed, two novel hybrid models uniting signal processing, deep learning and ensemble learning were proposed. Firstly, the wind speed series was disaggregated by the wavelet transform (WT). Then to enhance the forecasting precision of the subseries, the deep belief network (DBN) was applied to extract the high dimensional features. Besides, to overcome the limitation of the conventional DBN, the forecasts for each subseries processed by DBN were executed by the light gradient boosting machine (LGBM) and the random forest (RF). Some experiments have been accomplished, where the promotion of high dimensional feature extraction through DBN was explored. Meanwhile, the development of forecasting accuracy by applying tree-based models was confirmed, and the differences between these two hybrid models were discussed. It is shown that: (1) In comparison with the persistence method, the Elman neural network (ENN), DBN, LGBM, and RF, the hybrid models show a great boost in prediction accuracy. (2) The high dimensional feature extraction through DBN is in favor of improving the predicting accuracy of tree-based models, and tree-based models would facilitate the prediction. (3) Between the proposed models, the hybrid model integrated with RF slightly outperforms the other with LGBM in prediction accuracy, but the one with LGBM gets more stable predictions.

Frost tolerance is an important breeding goal of cereal breeding in the temperate climate zone. Main emphasis of this study was to identify and characterize allelic diversity for frost tolerance in rye. Genetic variation of frost tolerance was investigated in 201 winter rye genotypes from different populations using a candidate gene-based association analysis based on three different phenotyping platforms. Significant associations between frost tolerance and DNA polymorphisms were identified in nine out of twelve candidate genes. The results of this study will help to elucidate the genetic mechanisms of frost tolerance in rye and will be instrumental in marker-assisted selection of frost tolerance. Frosttoleranz ist ein bedeutendes Zuchtziel der Getreidezüchtung. Hauptziel dieser Arbeit war die Charakterisierung allelischer Diversität für Frosttoleranz bei Roggen. In einer Kandidatengen-basierten Assoziationsstudie wurde die genetische Variation für Frosttoleranz an 201 Winterroggen-Genotypen aus unterschiedlichen Populationen und in drei verschiedenen Phänotypisierungsplattformen untersucht. Signifikante Assoziationen zwischen Frosttoleranz und DNA-Polymorphismen wurden in neun von zwölf Kandidatengenen gefunden. Die erzielten Ergebnisse tragen zur Aufklärung der genetischen Mechanismen der Frosttoleranz in Roggen bei und können in der marker-gestützten Selektion eingesetzt werden.

Land grant premiums and land tax revenues have become two major sources of fiscal revenue for city governments in China. This type of fiscal revenue strategy for city governments is generally referred to as “land finance”, and it has drawn increasing research attention in recent years. This paper explores the institutional causes of the “land finance” strategy of city governments in China. We first analyze the institutional foundation of “land finance” (including China's urban land use system and land expropriation system). We then propose two hypotheses about the institutional causes of “land finance”. The first hypothesis is that the current system of fiscal decentralization is a major reason city governments choose the “land finance” fiscal strategy. The second hypothesis is that under the current personnel control system, which uses local economic performance as the most important indicator for evaluating local government officials, the competition between city governments to promote local economic growth is another major reason city governments choose the “land finance” fiscal strategy. We test the hypotheses by estimating econometric models using data for 31 provincial-level regions for the period 1999–2008. The empirical results suggest that fiscal decentralization and competition between city governments to promote economic growth are two major causes of “land finance”.

Rationale: Coronary artery ectasia (CAE) is characterized by an abnormal dilatation of the coronary arteries. CAE is often associated with the presence of slow coronary flow and may lead to acute myocardial infarction (AMI), even without total occlusion. Patient concerns and diagnosis: We report a case of a 24-year-old male patient with CAE suffering from AMI. Interventions: Percutaneous coronary intervention with aspiration thrombectomy failed to restore adequate blood flow. Heparin and antiplatelet treatment were provided for pharmacological management, but follow-up angiography 15 days later still revealed a poor result. This patient was ultimately treated with antiplatelet therapy in combination with warfarin treatment. Outcomes: Follow-up coronary angiography 15 months later showed a restored normal Thrombolysis In Myocardial Infarction grade (TIMI) 3 flow. Lessons: CAE-related infarct is often associated with high-burden thrombus formation. Long-term warfarin in combination with antiplatelet therapy may be a good alternative intervention to decrease thrombus burden and enhance blood flow.

Background. Postpartum depression (PPD) does great harm to women following childbirth. The aim of this study was to conduct a systematic review of the literature to assess the efficacy and safety of CHM for the treatment of PPD. Methods. Published or ongoing registered trials were searched for from the inception of the various databases to December 31, 2015. Data extraction and methodology assessment were conducted independently by two researchers. RevMan 5.3 software was used to analyze the data. Results. Forty-seven registered clinical trials (RCTs) were identified and reviewed. The results showed CHM alone or in combination with routine treatments could reduce HAMD score, EPDS score, incidence of adverse events, TESS, and SERS. CHM combined with routine treatment was more effective in increasing serum estradiol levels and reducing progesterone levels than routine treatment alone. Meanwhile, pooled data revealed that MRLQS combined with routine treatments or MRLQS plus MSHS combined with routine treatments were more effective than other therapeutic methods in TCM. MRLQS plus MSHS alone was found to be an effective alternative when compared to routine treatments. Conclusions. This review suggested that CHM was safe and effective in the treatment of PPD. However, this could not be proven conclusively. To ensure evidence-based clinical practice, more rigorously designed trials are warranted.

The quantitative change in cultivated land resources is affected by many factors, which include population increase and fixed asset investments. The system of finance and taxation, which is the deep cause affecting the quantitative change in cultivated land resources in China is discussed in this article. From the quantitative and mechanism analysis, the quantitative change in cultivated land resources is affected by the current system of finance and taxation in both a positive and passive manner. As a whole, it is negative as far as protection of cultivated land resources is concerned. The result of the quantitative analysis verifies that the current finance and taxation system has an effect on the quantitative change in cultivated land resources. The article presents some suggestions: add financial budget revenue of the local government, distribute the land transfer rent reasonably, and make use of the land transfer rent to improve people's standard of living

In this study, representative samples from thermal wells and springs were chemically analyzed and geothermometers were used to calculate the deep temperatures of geothermal reservoirs on the basis of water–mineral equilibrium. In some cases, however, the chemical components are not in equilibrium with the minerals in the reservoir. Therefore, log( Q / K ) diagrams are used to study the chemical equilibrium for the minerals that are likely to participate. The Na–K–Mg triangular diagram is also applied to evaluate the equilibrium of water with reservoir rocks. Standard curves at the reference temperatures are prepared to reveal which type of silica geothermometer is appropriate for the specified condition. This study shows that water samples from geothermal wells W9 and W12 are in equilibrium with the selective minerals, and chalcedony may control the fluid–silica equilibrium. It is estimated that there is an exploitable low-temperature reservoir with possible temperatures of 80–90°C in the Guanzhong basin.

The kinetic isotope effect (KIE) of the seven-atom reactions OH + CH[subscript 4] → CH[subscript 3] + H[subscript 2]O and OH + CD[subscript 4] → CD[subscript 3] + HDO over the temperature range 200–1000 K is investigated using ring polymer molecular dynamics (RPMD) on a full-dimensional potential energy surface. A comparison of RPMD with previous theoretical results obtained using transition state theory shows that RPMD is a more reliable theoretical approach for systems with more than 6 atoms, which provides a predictable level of accuracy. We show that the success of RPMD is a direct result of its independence of the choice of transition state dividing surface, a feature that is not shared by any of the transition state theory-based methods. Our results demonstrate that RPMD is a prospective method for studies of KIEs for polyatomic reactions for which rigorous quantum mechanical calculations are currently impossible., United States. Dept. of Energy. Office of Basic Energy Sciences (Combustion Energy Research Fellowship Award DE-SC0001198), United States. Dept. of Energy (Grant DE-SC0001198)

The thermal rate coefficients and kinetic isotope effects have been calculated using ring polymer molecular dynamics (RPMD) for the prototypical reactions between methane and several hydrogen isotopes (H, D, and Mu). The excellent agreement with the theoretical rate coefficients of the H + CH[subscript 4] reaction obtained previously from a multi-configuration time-dependent Hartree calculation on the same potential energy surface provides strong evidence for the accuracy of the RPMD approach. These quantum mechanical rate coefficients are also in good agreement with the results obtained previously using the transition-state theory with semi-classical tunneling corrections for the H/D + CH[subscript 4] reactions. However, it is shown that the RPMD rate coefficients for the ultralight Mu reaction with CH[subscript 4] are significantly smaller than the experimental data, presumably suggesting inaccuracies in the potential energy surface and/or experimental errors. Significant discrepancies between the RPMD and transition-state theory results have also been found for this challenging system., United States. Dept. of Energy (Grant DE-FG02-98ER14914), United States. Dept. of Energy. Office of Basic Energy Sciences (Combustion Energy Research Fellowship Award DE-SC0001198)

Water environmental capacity(WEC) of Jiaozuo section of Manghe River(JSMR) were calculated by using one-dimensional water quality model. And the projects of total content control of pollutants were determined. The results showed that WEC of CODcr and NH 3 -N are 3403.93 tons/yr and 88.70 tons/yr respectively, and are much smaller than the amount of CODcr and NH 3 -N discharged into the river, which are 18396.36 tons/yr and 1189.99 tons/yr respectively. In order to attain the water environmental quality objective of JSMR, the total control and reduced quantity of CODcr should be 396.60 tons/yr and 17999.76 tons/yr respectively, and NH 3 -N 17.75 tons/yr and1172.24 tons/yr. This study can provide basic materials and scientific basis for the protection and management of JSMR.

Objective To evaluate the influence of the metabolic syndrome (MS) on artery intima-media thickness (IMT) and/or plaque in patients with essential hypertension (EH). Methods A total of 1505 EH patients were chosen, including 659 male patients and 846 female patients, with age from 20 to 90 years old. These patients were divided into MS group (EH with MS) and non-MS group (EH without MS), MS group was then divided into glucose abnormal subgroup, fat abnormal subgroup and glucose and fat both abnormal subgroup. Carotid IMT and plaque were detected and measured by B-ultrasound. Results The age, abdominal circumference, body mass index (BMI), fasting blood glucose (FBG), total cholesterol (TC), total triglycerides (TG), low density lipoprotein cholesterol (LDL-C), uric acid (UA) and hypersensitive C reactive protein (hsCRP) in MS group were significantly higher than non-MS group, while high density lipoprotein-cholesterol (HDL-C) in MS group was significantly lower than non-MS group. The IMT in fat abnormal subgroup, glucose abnormal subgroup, glucose and fat both abnormal subgroup and non-MS group, were (0.86±0.18) mm, (0.90±0.20) mm, (0.89±0.18) mm and (0.84±0.17) mm, respectively (p=0.001). In MS group with abnormal blood glucose, the incidence of IMT and plaque was the highest. Logistic regression analysis showed that males, age, smoking, MS, FBG, LDL-C were the independent risk factors for carotid atherosclerosis. IMT was strongly related with FBG. Conclusion MS has significant effects on carotid athersclerosis in patients with EH. Glucose may play more important part in carotid athersclerosis than other compositions.

Objective To investigate the epidemiological characteristics and risk factors of stroke among adult residents in the urban areas of Tianjin, and provide references for directive population intervention. Methods A total of 28 515 residents aged above 18 years (including 18 years) in the urban areas of Tianjin were investigated through questionnaires. Eight hundred and twenty six patients of stroke were detected, consisting 691 patients with only cerebral arterial thrombosis, 117 patients with only haemorrhagic apoplexy and 18 patients with both conditions. Physical examination included measurement of blood pressure, height, weight, waist circumference and hip circumference. Logistic regression analysis was used for multivariate analysis. Results (1) The prevalence rates of stroke, cerebral arterial thrombosis and hemorrhagic apoplexy were 2.897%, 2.486% and 0.473%, while the age adjusted prevalence rates were 1.290%, 1.073% and 0.250%, respectively. (2) Stroke prevalence rate increased with age, with the rates being higher among males than females (p=0.000). (3) Stroke prevalence rate decreased as the educational level and per capita income increased (p=0.036 and 0.001, respectively). (4) Han people made up 96.44% of the population investigated, and the remaining 3.56% being non-Han origin. There was no statistical difference of stroke prevalence rates between Han and those of non-Han origin (p=0.246). (5) The stroke prevalence rates were 1.27 times higher in population with abdominal obesity than those without abdominal obesity (p=0.021), 5.94 times higher in population with hypertension than those without hypertension (p=0.000), 3.19 times higher in population with dyslipidemia than those without dyslipidemia (p=0.000), and 2.33 times higher in population with diabetes mellitus than those without diabetes mellitus (p=0.000). (6) Logistic regression analysis showed that higher educational levels and per capita income were protective factors, but male gender, age, hypertension, dyslipidemia and diabetes mellitus were risk factors, especially for hypertension, which had the highest OR value (OR=4.225, p=0.000). Conclusions There is a high prevalence rate of stroke in the urban adult population of Tianjin, and the risk factors should be well controlled, especially for hypertension.

Objective To investigate the influence of the metabolic syndrome (MS) on essential hypertention-related target organ damage (TOD), and assess the value of a systematic search for cardiac and extra-cardiac TOD in MS. Methods A total of 1487 untreated and treated essential hypertensives were considered for this analysis. All patients underwent extensive investigation for left ventricular hypertrophy (LVH, cardiac TOD), carotid plaques and/or intima-media thickening (IMT, vascular TOD) and microalbuminuria (MAU) and/or increased serum creatinine (renal TOD). Subjects were classified as: positive for none (group 0), one (group 1), two (group 2) or three markers (group 3) of TOD. Results In whole population, the most common phenotype of TOD was alterations in LV structure and geometry (LVH or LV concentric remodelling: 63.3%), followed by carotid thickening (carotid plaque and/or carotid thickening: 51.1%), MAU (32.9%) and increased serum creatinine (0.7%). MS prevalence rates progressively rose across the groups stratified according to the TOD score. The distribution of subjects with and without the MS across the groups was 13.2% vs 20.0% (group 0), 30.9% vs 32.6% (group 1), 39.2% vs 36.1% (group 2) and 16.7% vs 11.3% (group 3), respectively. Thus, subjects having two or three markers of TOD were 55.9% among those with MS and 47.4% (p=0.000) among those without MS. Age, waist, systolic blood pressure (SBP), duration of hypertension, triglycerides, serum creatinine, prevalence of type 2 diabetes all showed a progressive increase from group 0 to group 3. There was a significant difference in duration of hypertention, waist, fasting blood glucose, high density lipoprotein cholestorol, triglycerides, total cholesterol, low density lipoprotein cholesterol (LDL-C), body mass index and prevalence of type 2 diabetes. The prevalence of concentric LVH showed a stepwise increase from group 1 to group 3, and was higher in all MS groups than in their counterparts. In whole population, left ventricular mass index (LVMI) and IMT showed significant and positive correlation with clinic SBP (LVMI: r=0.125, p=0.000; IMT: r=0.078, p=0.003). Significant correlations were found between TOD variables and age, creatinine, uric acid, LDL-C and duration of hypertention. Significant associations were also observed between LVMI and IMT (r=0.146, p=0.000) or UACR (urinary albumin-creatinine ratio, r=0.075, p=0.004). Conclusion MS may substantially enhance the risk of multiple TOD and concentric LVH, independently of blood pressure and age. This finding calls for a systematic search for cardiac and extracardiac TOD in all hypertensives with MS.

© 2017 American Chemical Society. ABX3 (A = organic cation; B = Sn, Pb; and X = halogen) organohalide perovskites have recently attracted much attention for their photovoltaic applications. Such hybrid compounds are derived from the replacement of the inorganic monovalent metal element by an organic cation, for example, methylammonium ion (MA = CH3NH3+) and formamidinium ion (FA= +HC(NH2)2). In particular, since the organic cations are polar, it is interesting to investigate their possible long-range ordering and the corresponding Rashba spin-split bands. In this work, by using density functional theory calculations, we estimate the ferroelectric polarization corresponding to a complete ordering of dipole moments for the optimized structures of 12 perovskite halides, with A = MA, FA; B = Pb, Sn; X = Cl, Br, I. The adiabatic path and functional mode analysis have been discussed for all cases. The calculated values of the polarization may be as high as a conventional inorganic ferroelectric compound, such as BaTiO3. The concomitant inversion symmetry breaking, coupled to the sizable spin-orbit coupling of Pb and Sn, results in a fairly large Rashba spin-splitting effect for both valence and conduction bands. We highlight a rather anisotropic dispersion of spin-orbit split bands which gives rise to different Rashba parameters in different directions perpendicular to the polar axis in k-space. Furthermore, we found a weak and positive correlation between the magnitude of polarization and relevant spin-split band parameters. Since the mechanism for enhanced carrier lifetime in 3D Rashba materials is connected to the reduced recombination rate due to the spin-forbidden transition, our study could aid in the understanding of the fundamental physics of organometal halide perovskites and the optimization and design of materials for better performance.