Pollution Haven hypothesis and Porter hypothesis provide two different behavioral strategies for pollution industries under stringent environmental regulations, which make a clear line between the ...two hypotheses in the previous literature. This paper studies the pollution industry transfer in China from the perspective of industry mobility, and proves that the transfer of pollution industries under environmental regulations is the comprehensive effect of “Pollution Haven” and “Innovation Compensation” by using Chinese provincial-level data from 2000 to 2015. The empirical results find that strongly mobile pollution industries have tended to transfer directly to the areas with loose regulations, but “Innovation Compensation” effect is not significant, leading to the pollution industries transferring out; the weakly mobile pollution industries have not shown the “Pollution Heaven” effect, environmental regulations will stimulate innovation and increase industry output through the mechanism of “Innovation Compensation”, which increases the regional proportion of pollution industries output. In short, we believe this study can provide a new perspective for explaining the current pollution industry transfer in China and help for more precise and reasonable environmental policies.
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•Based on the industry mobility, this paper studies the pollution industry transfer in China.•We break the line between PHH and PH by providing an analytical framework and an empirical test.•Pollution industries with different mobility have different strategies respond to regulations.•Pollution industry transfer is a result of the comprehensive effect of PHH and PH.
Autophagy is a highly conserved catabolic process and participates in a variety of cellular biological activities. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of ...rapamycin (mTOR) pathway, as a critical regulator of autophagy, is involved in the initiation and promotion of a series of pathological disorders including various tumors. Autophagy also participates in regulating the balance between the tumor and the tumor microenvironment. Natural products have been considered a treasure of new drug discoveries and are of great value to medicine. Mounting evidence has suggested that numerous natural products are targeting PI3K/AKT/mTOR-mediated autophagy, thereby suppressing tumor growth. Furthermore, autophagy plays a “double-edged sword” role in different tumors. Targeting PI3K/AKT/mTOR-mediated autophagy is an important therapeutic strategy for a variety of tumors, and plays important roles in enhancing the chemosensitivity of tumor cells and avoiding drug resistance. Therefore, we summarized the roles of PI3K/AKT/mTOR-mediated autophagy in tumorigenesis, progression, and drug resistance of tumors, which may be utilized to design preferably therapeutic strategies for various tumors.
To suppress the shuttle effect of lithium polysulfides and promote fast kinetics of the charge-discharge process in Li-S batteries, it is essential to search for promising catalysts with sufficient ...stability and high activity. Here, we employ density functional theory to explore the performance of 3d, 4d and 5d transition metals embedded in nitrogen-doped defective graphene (M@N/G, including M@N3/G and M@N4/G) as single atom catalysts toward fast kinetics in Li-S batteries. Four evaluation criteria of M@N/G are established to guide the screening of catalysts. Electronic structure analysis shows that the nitrogen coordination environment can largely tune the valence orbital splitting of the metal center and further affect the intrinsic activity of catalysts; M@N4/G exhibits superior catalytic performance to M@N3/G. We also found that sulfur-metal interactions play a critical role in the adsorption and activation of sulfur species on M@N/G. We therefore propose to use the sulfur atom adsorption free energy as a descriptor of catalytic activity combined with the knowledge of M
3d
@N/G to effectively predict the activity of M
4d,5d
@N/G. As a result, we expect that the Sc, Cr, Mn, Ru, Os, and Ir single metal atom catalysts supported on N4/G have better than or at least comparable catalytic performance to the ever-reported V, Fe, and Co@N4/G for Li-S batteries. In particular, because of the low cost, Cr@N4/G and Mn@N4/G are preferentially recommended with a small free energy change of the rate-determining step (0.62 eV and 0.54 eV) during discharge and a low decomposition barrier of *Li
2
S (1.42 eV and 1.29 eV) during charge simultaneously. Our study builds a novel screening strategy and can guide future theoretical study on catalysts toward Li-S batteries with fast kinetics.
We built a novel strategy to systematically screen 3d to 5d transition metal single atom catalysts supported on N-doped defective graphene, M@N3/G and M@N4/G, toward fast kinetics in Li−S batteries. Cr@N4/G and Mn@N4/G are preferentially recommended.
Abstract
Highly magnified stars residing in caustic crossing lensed galaxies at
z
≃ 0.7–1.5 in galaxy cluster lensing fields inevitably exhibit recurrent brightening events as they traverse a ...microcaustic network cast down by foreground intracluster stars. The detectable ones belong to nature’s most massive and luminous class of stars, with evolved blue supergiants being the brightest ones at optical wavelengths. Considering single stars in this work, we study to what extent intrinsic stellar parameters are measurable from multifilter light curves, which can be obtained with optical/near-IR space telescopes during one or multiple caustic crossing events. We adopt a realistic model for the axisymmetric surface brightness profiles of rotating O/B stars and develop a numerical lensing code that treats finite source size effects. With a single microcaustic crossing, the ratio of the surface rotation velocity to the breakup value is measurable to a precision of ∼0.1–0.2 for feasible observation parameters with current space telescopes, with all unknown intrinsic and extrinsic parameters marginalized over and without a degeneracy with inclination. Equatorial radius and bolometric luminosity can be measured to 1/3 and 2/3 of the fractional uncertainty in the microcaustic strength, for which the value is not known at each crossing but an informative prior can be obtained from theory. Parameter inference precision may be further improved if multiple caustic crossing events for the same lensed star are jointly analyzed. Our results imply new opportunities to survey individual massive stars in star formation sites at
z
≃ 0.7–1.5 or beyond.
This article develops an adaptive group lasso estimator for factor models with both global and group-specific factors. The global factors can affect all variables, whereas the group-specific factors ...are only allowed to affect the variables within a certain group. We propose a new method to separately identify the spaces spanned by global and group-specific factors, and we develop a new shrinkage estimator that can consistently estimate the factor loadings and determine the number of factors simultaneously. The asymptotic result shows that the proposed estimator can select the true model specification with a probability approaching one. An information criterion is developed to select the optimal tuning parameters in the shrinkage estimation. Monte Carlo simulations confirm our asymptotic theory, and the proposed estimator performs well in finite samples. In an empirical application, we implement the proposed method to a dataset consisting of Eurozone, United States, and United Kingdom macroeconomic variables, and we detect one global factor, one U.S.-specific factor, and one Eurozone-specific factor.
Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. ...Herein, a semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA‐TN‐AO with a high anti‐biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA‐TN‐AO to uranium in seawater reaches 6.07 mg g−1, which is 1.33 times of that in dark. The NDA‐TN‐AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.
Photoelectric and photocatalytic effects endow the covalent organic framework NDA‐TN‐AO with good anti‐biofouling activity. This occurs by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby improving the uranium adsorption capacity.
With proliferation of smart phones and an increasing number of services provisioned by clouds, it is commonplace for users to request cloud services from their mobile devices. Accessing services ...directly from the Internet data centers inherently incurs high latency due to long RTTs and possible congestions in WAN. To lower the latency, some researchers propose to `cache' the services at edge clouds or smart routers in the access network which are closer to end users than the Internet cloud. Although `caching' is a promising technique, placing the services and dispatching users' requests in a way that can minimize the users' access delay and service providers' cost has not been addressed so far. In this paper, we study the joint optimization of service placement and load dispatching in the mobile cloud systems. We show this problem is unique to both the traditional caching problem in mobile networks and the content distribution problem in content distribution networks. We develop a set of efficient algorithms for service providers to achieve various trade-offs among the average latency of mobile users' requests, and the cost of service providers. Our solution utilizes user's mobility pattern and services access pattern to predict the distribution of user's future requests, and then adapt the service placement and load dispatching online based on the prediction. We conduct extensive trace driven simulations. Results show our solution not only achieves much lower latency than directly accessing service from remote clouds, but also outperforms other classical benchmark algorithms in term of the latency, cost and algorithm running time.
Photocatalytic CO2 reduction attracts substantial interests for the production of chemical fuels via solar energy conversion, but the activity, stability, and selectivity of products were severely ...determined by the efficiencies of light harvesting, charge migration, and surface reactions. Structural engineering is a promising tactic to address the aforementioned crucial factors for boosting CO2 photoreduction. Herein, a timely and comprehensive review focusing on the recent advances in photocatalytic CO2 conversion based on the design strategies over nano‐/microstructure, crystalline and band structure, surface structure and interface structure is provided, which covers both the thermodynamic and kinetic challenges in CO2 photoreduction process. The key parameters essential for tailoring the size, morphology, porosity, bandgap, surface, or interfacial properties of photocatalysts are emphasized toward the efficient and selective conversion of CO2 into valuable chemicals. New trends and strategies in the structural design to meet the demands for prominent CO2 photoreduction activity are also introduced. It is expected to furnish a comprehensive guideline for inside‐and‐out design of state‐of‐the‐art photocatalysts with well‐defined structures for CO2 conversion.
The advance on CO2 photoreduction based on the design strategies over nano‐/microstructure, crystalline and band structure, surface structure and interface structure for promoting three crucial factors, including light harvesting, charge migration and surface reactions, are systematically summarized. It is expected to furnish a guideline for inside‐and‐out design of photocatalysts with well‐defined structures for CO2 conversion.
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