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With unconventional oil and gas booming commercial development, its inevitable damage to the environment arouses the vigilance of the public. It is of great necessity both for practitioners and governors, to learn from the history, find the pattern of violations then build a sound production warning system. In this respect, we utilized the “Oil and Gas Compliance Report” from the Pennsylvania Department of Environmental Protection from 2000 to 2019. After the preprocessing, a total of 5737 violation records were obtained. Through LDA (Latent Dirichlet Allocation) analysis combined with the decision tree model, our research attained the following conclusions: first, we find that the LDA themes of violations as "Erosion and sediment" and "Water pollution" are key factors for “Failed” enforcement results. Therefore, policymakers and practitioners should pay more attention to these two types of accidents. Second, it is noted that counties are also one of the important features that matter the enforcement results. Third, we need to consider the role of economic punishment dialectically, while it is not a significant feature for successful enforcement results. That is to say, monetary punishment may not necessarily improve the effectiveness of the company’s handling of violations.

With unconventional oil and gas booming in commercial development, its inevitable environmental damage has aroused the public's vigilance. To support the regulation improvement and early-warning system building, it is of great need to learn the regular patterns in recurrent violations both for practitioners and governments. In this respect, we utilized the "Oil and Gas Compliance Report" from the Pennsylvania Department of Environmental Protection from 2000 to 2019, a total of 5737 violation records, to dig out the historical violation patterns. Through LDA (Latent Dirichlet Allocation) analysis combined with the decision tree model, our research attained the following conclusions: first, we find that the LDA themes of violations as "Erosion and sediment" and "Water pollution" are critical factors for "Failed" enforcement results. Therefore, policymakers and practitioners should pay more attention to those two types of accidents. Second, it is noted that counties are also one of the essential features that matter the enforcement results. Third, we need to consider the role of economic punishment dialectically, while it is not a significant feature for successful enforcement results. That is to say, a monetary penalty may not necessarily improve the effectiveness of the company's measurements.

Two experiments were conducted to investigate the effects of slow-release urea (SRU) on in vitro rumen fermentation parameters, growth performances, nutrient digestibility, and serum metabolites of beef cattle. The single factor design was applied in both experiments. Three diets with different nitrogen sources including soybean meal (Control group), slow-release urea (SRU group), and common urea (Urea group) was designed (concentrate to forage ratio was 4:6). The diets were formulated to be isoenergetic and isonitrogenous, 75% of the soybean meal in the control diet was replaced by 1.41% SRU and 1.15% urea in SRU group and Urea group, respectively. In experiment 1, five healthy Jinjiang cattle (average body weight (BW) was 380 ± 17.1 kg) with permanent rumen fistulas were used in in vitro ruminal fermentation experiment. The results showed that supplementing SRU increased the dry matter degradation rate (DMD), digestible organic matter (DOM) and propionic acid concentration in cultivated fluid, and SRU supplementation decreased pH, NH3-N, total volatile fatty acid (TVFA), acetic acid, butyric acid concentration and microbial growth efficiency (MOEFF) in cultivated fluid. In experiment 2, eighteen Simmental crossbred cattle BW= 315 ± 5.2 kg) were stratified by BW and then assigned to the three groups to have equal BW among groups. The results showed that supplementing SRU reduced the average dry matter intake (ADMI), apparent digestibility of ether extract (EE), the activity of glutathione peroxidase (GSH-Px), the levels of IgG and IgA, and the production of thiiodothronine (T3) in serum, SRU supplementation increased the apparent digestibility of dry matter and organic matter (OM) and alanine aminotransferase (ALT) concentration in serum. These results indicated that some soybean meal could be replaced by SRU and urea in the production of beef cattle. In addition, compared with urea, SRU had a good sustained-release effect. The replacement of some soybean meal by SRU in the diet had no adverse impact on rumen fermentation, growth performance, and serum metabolites of beef cattle. Os dois experimentos foram conduzidos para investigar os efeitos da uréia de liberação lenta nos parâmetros de fermentaçãono do rúmen em vitro, desempenho de crescimento, digestibilidade dos nutrientes e metabolitos séricos de gado de corte. O design de fator único foi aplicado em ambos os experimentos. As três dietas com diferentes fontes de nitrogênio, incluindo farelo de soja (Grupo de controle), uréia de liberação lenta (Grupo de uréia de liberação lenta) e uréia comum (Grupo de uréia) foi designado (concentre-se em relação forrageira foi de 4: 6). As dietas foram formuladas para serem isoenergéticas e isonitrógenas, 75% da farinha de soja na dieta controle foi substituída por 1,41% de uréia de liberação lenta e 1,15% de uréia no Grupo uréia de liberação lenta e Grupo uréia, respectivamente. No experimento 1, cinco gados Jinjiang saudáveis (peso corporal médio (PC) de 380 ± 17,1 kg) com fístulas ruminais permanentes foram utilizadas no experimento de fermentação do rúmen em vitro. Os resultados mostraram que a suplementação de uréia de liberação lenta aumentou a taxa de degradação da substância seca, substância orgânica digestível e concentração de ácido propiônico no líquido cultivado, e a suplementação de SRU diminuiu o pH, NH3-N, ácido graxo volátil total, ácido acético, concentração de ácido butírico e eficiência de crescimento microbiano no fluido cultivado. No experimento 2, dezoito gados mestiços Simmental (PC = 315 ± 5,2 kg) foram estratificados por PC e, em seguida, atribuído aos três grupos para ter PC igual entre os grupos. Os resultados mostraram que a suplementação de uréia de liberação lenta reduziu a ingestão média da substância seca, digestibilidade aparente do extrato etéreo, a atividade da glutationa peroxidase, os níveis de IgG e IgA, e a produção de tiiodotronina (T3) no soro, a suplementação de uréia de liberação lenta aumentou a digestibilidade aparente da concentração de substância seca e substância orgânica e concentração de alanina aminotransferase no soro. Esses resultados indicaram que algum farelo de soja pode ser substituída por uréia de liberação lenta e uréia na produção de gado de corte. Além disso, comparado com a uréia, uréia de liberação lenta teve um bom efeito de liberação sustentada. A substituição de algum farelo de soja por uréia de liberação lenta na dieta não teve impacto adverso na fermentação ruminal, desempenho de crescimento e metabolitos séricos de gados de corte.

This paper explores the crucial factors driving the changes in household energy consumption (HEC) in China during 2005–2017. We propose a decomposition framework based on the Kaya identity and the logarithmic mean Divisia index (LMDI) method to decompose the change in HEC into energy structure effect, energy intensity effect, regional structure effect, per capita consumption effect and population scale effect. We use the model to shed light on the differences of these five factors affecting HEC between urban and rural and among regions while retaining their energy-use characteristics respectively. The results suggest that: (1) Energy intensity and regional structure reduced HEC, whereas population scales, per capita consumption, and energy structure stimulated HEC growth. (2) Rural energy structure contributed larger shares of the increment in HEC. Rural per capita consumption increased generally much more energy consumption than urban counterpart in coastal developed economic regions. Rural population scale curbed the growth of HEC, while urban population scale drove the growth of HEC. (3) Although energy intensity decreased energy consumption at regional level, the differences were found between regions. Moreover, the impacts of regional structure differed significantly between regions, but insignificantly at provincial level. Finally, some policy recommendations will be made based on these suggestive conclusions.

A nanocomposite was prepared from graphene-like two-dimensional black phosphorene (BP, an allotrope of phosphorus) and nafion (Nf) treated with isopropanol (IP). A glassy carbon electrode (GCE) modified with this nanocomposite was found to be a viable sensor for voltammetric determination of clenbuterol (CLB). Unlike previously reported pure BP, the BP nanocomposite was stable towards water and oxygen. Its morphology, structure, electrochemically active surface area and electrochemical stability were investigated. The BP-Nf (IP) modified GCE displayed good electrochemical stability and electrocatalytic capacity with a low working potential of 0.94 V (vs. SCE), excellent peak current response for CLB in a linear concentration range of 0.06-24 μM with a detection limit of 3.7 nM (3σ/m) and a sensitivity of 0.14 μA·μM-1·cm-2 under optimal conditions. A sensing mechanism for the electro-oxidation of CLB was suggested and verified by density functional theory calculations under imitation of aqueous solution conditions. The sensor was successfully applied to the determination of CLB in bovine meat and bovine serum samples. Graphical abstract Highly-stable black phosphorene (BP) nanocomposite based on Nafion (Nf) was used to modify a glassy carbon electrode (GCE). It is shonw to be a viable electrochemical platform for sensitive voltammetric determination of trace clenbuterol (CLB) in bovine beef and bovine serum.

Mulching is critical for increasing water availability and hence winter wheat production in dryland farming systems. A two-year study was conducted to assess the effects of mulches on soil water storage (SWS), temperature, water use efficiency (WUE) and yields of winter wheat on the Loess Plateau. Four treatments were examined: conventional flat planting (CK), straw mulch (FPS), transparent plastic film mulch (FPP) and ridge-furrow with plastic film-mulched ridge and straw-mulched furrow (RFPS). Compared with CK, RFPS greatly increased SWS from 0–60 cm, FPP increased SWS from 0–40 cm, and FPS slightly increased SWS from 0–60 cm; however, FPP significantly (P P

The synthesis and component of red phosphor, Sr4Al14O25: Mn, were optimized for application in white light-emitting diodes. The microstructure and morphology were investigated by the X-ray diffraction and scanning electron microscopy. Different valences of Mn ions in Sr4Al14O25 were discriminated using the electron paramagnetic resonance and X-ray absorption near-edge structure spectroscopy techniques. The bond-valence theory was used to analyze the effective valences of Sr2+ and Al3+ in Sr4Al14O25. As a result, the strong covalence of Al3+ in the AlO4 tetrahedron other than in the AlO6 octahedron is disclosed. The deep red emission is attributed to Mn4+ occupying the center of AlO6 octahedron. The mechanism of energy transfer is mainly through dipole–dipole interaction, revealed by the analyses of critical distance and concentration quench. A high color rendering white LED prototype with color-rendering index up to Ra 93.23 packaged by using the red phosphor demonstrates its applicability.

In this work, the crystal field stabilization energy ( D q ) and the Racah B and C parameters were calculated quantitatively to evaluate the nephelauxetic effect of Mn 4+ suffering from the Sr 4 Al 14 O 25 host, aiming for developing novel highly efficient red phosphor for white light-emitting diodes. The phosphor of Mn 4+ activated Sr 4 Al 14 O 25 was synthesized via a high temperature solid reaction in air ambient. The crystallinity was investigated using the X-ray diffraction; and the photoluminescence properties were characterized with the spectrometer. The red emission was attributed to the Mn 4+ which occupies the center of AlO 6 octahedron. Meanwhile, the Mn 2+ and Mn 3+ were detected by using the X-ray absorption near-edge structure spectroscopy (XANES) assisted with Electron Paramagnetic Resonance (EPR) techniques. The energy levels of 4 A 2 , 4 T 2g and 4 T 1g were determined according to excitation spectra, corresponding to the 4 A 2 (t 2 3 ) → 4 T 1 ( 4 F) and the 4 A 2 (t 2 3 ) → 4 T 2g (t 2 2 e) transitions at 330 and 450 nm respectively, whereby the calculation was carried out according to the Tanabe–Sugano diagram for octahedral complex with the d 3 electron configuration. The nephelauxetic ratio β about 0.32 suggests a strong cloud expansion of Mn 4+ in the Sr 4 Al 14 O 25 crystal lattice with D q ∼ 2222 cm −1 , B ∼ 794 cm −1 , C ∼ 3232 cm −1 and C / B ∼ 4.07. In the perspective of physics, these parameters are helpful to perceive the inter-repulsion of the outer electrons in 3 d orbit of Mn 4+ and the effect of local circumstance, in essential to understand the variant spectral configurations of Mn 4+ luminescence observed in different hosts.

The phosphors of Sb3+ and Eu3+ activated YBO3 were synthesized via solid-state reaction. The crystal structure was investigated using X-ray diffraction analysis. The luminescence and energy transfer were investigated on the synchrotron radiation instrument, by exciting with different wavelengths at room temperature or as low temperature as 14 K. The electron-lattice interaction between the activator Sb3+ and the host of YBO3 combined with the spin-orbit interaction of Sb3+ result in a large Stokes shift in Sb3+ emission, giving rise to no matchable energy levels for the energy transfer from Sb3+ to Eu3+. Nevertheless, the excitation energy could transfer from Bi3+ to Eu3+, which has the same ns(2) electronic configuration as Sb3+. Taking advantage of the simultaneous isolated luminescence of Sb3+ and Eu3+, finally, the white luminescence from a single phosphor was tuned up by tailoring Sb3+ and Eu3+ concentrations in the YBO3 host, which shows potential application in deep ultraviolet light-emitting diodes (LEDs). (C) 2014 Elsevier B.V. All rights reserved.

This study provides an explanation for the mechanism of carbothermal reduction contributing to the synthesis of a Sr2Si5N8 : Eu2+ nitride phosphor, in terms of the heat released and propagated within the local region, which makes the actual temperature far higher than that determined in the reaction. Two pathways of carbon mixing were designed for synthesizing SrSi2O2N2 : Eu2+ at relatively lower temperatures than that required for synthesis of Sr2Si5N8: Eu2+. However, formation of the nitride, Sr2Si5N8 : Eu2+, was observed by mixing carbon with the raw materials, rather than placing a layer of carbon underneath for heat conduction, indicating that close contact of carbon with the raw materials was a precondition of nitride formation. In addition, the presence of an amorphous layer on the surface of the phosphor particles, identified using a high-resolution transmission electron microscope, provided a clue to understanding the mechanism of the nitridation reaction at relatively low temperatures.

To enhance the luminescence of (Sr,Ba) 3 SiO 5 :Eu 2+ for white light-emitting diodes, a new method for the synthesis of phosphor was developed. In the proposed method, the mixture of large and nano SiO 2 particles as a silica source was employed to control the nucleation and crystal growth of the material. The impurity phase (Sr,Ba) 2 SiO 4 , which easily coexisted with (Sr,Ba) 3 SiO 5 was suppressed. Accordingly, the luminescence was enhanced significantly by the partial substitution of conventional SiO 2 with nano SiO 2 . The improvement in crystallinity and morphology was examined with XRD and SEM. Moreover, the sintering temperature and the concentration of nano SiO 2 was optimized. The results show that appropriate amount of nano SiO 2 has pronounced effects on the nucleus formation and crystal growth, while excessive crystal seeds formed may hinder the growth of particles. A mechanism for this improvement was proposed.

The deficiency of Y3Al5O12:Ce (YAG:Ce) luminescence in red component can be compensated by doping Gd3+, thus lead to it being widely used for packaging warm white light-emitting diode devices. This article presents a systematic study on the photoluminescence properties, crystal structures and electronic band structures of (Y1−xGdx)3Al5O12: Ce3+ using powerful experimental techniques of thermally stimulated luminescence, X-ray diffraction, X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) and ultraviolet photoelectron spectra (UPS) of the valence band, assisted with theoretical calculations on the band structure, density of states (DOS) and charge deformation density (CDD). A new interpretation from the viewpoint of compression deformation of electron cloud in a rigid structure by combining orbital hybridization with solid-state energy band theory together is put forward to illustrate the intrinsic mechanisms that cause the emission spectral shift, thermal quenching and luminescence intensity decrease of YAG: Ce upon substitution of Y3+ by Gd3+, which are out of the explanation of the classic configuration coordinate model. The results indicate that in a rigid structure, the charge deformation provides an efficient way to tune chromaticity, but the band gaps and crystal defects must be controlled by comprehensively accounting for luminescence thermal stability and efficiency.