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China's Going Global Strategy and Belt and Road Initiative gained great attention among scholars. Moreover, it is believed that Chinese investments abroad cause serious social and environmental externalities. Hence, in this paper, we examine how China's foreign direct investments influence the carbon emissions of 35 Belt and Road Initiative countries from 2000 to 2019. To do so, we use a panel model that accounts for heterogeneity and country cross-section dependence. Our results show that while other countries' foreign direct investments have contributed to the deterioration of the environment in these countries, Chinese investments have not. This substantiates the hypothesis of the halo effect influence of China's foreign investments as opposed to other countries' investments which may seek a haven for its carbon emissions. These results highlight the importance of source and destination regulations of foreign direct investments in terms of their environmental impact and carbon emissions in the Belt and Road Initiative countries. It also provides a fresh finding on the efficacy of China's foreign investment management policies and regulations in producing the desired environmental outcome in hosting countries.

Intravascular brachytherapy requires advances in radio-embolization technologies that combine brilliant radiostability efficacy with a facile and green synthesis route. We report a hybrid-integrated radioactive microsphere strategy using phosphorylcholine-modified lutetium-177 coordinated polymeric microspheres (177Lu-PCMs) that were fabricated via radiation-induced graft polymerization for imaging-guided locoregional intravascular brachytherapy. The underlying formation mechanism of 177Lu-PCMs is elucidated using first-principles computations and density functional theory calculations and 177Lu loading mechanisms was investigated with Near-edge and extended X-ray absorption fine structure spectroscopy. The engineered 177Lu-PCMs exhibit excellent mechanical properties, good hydrophilicity, and controlled sphere diameter. These features provide advantages of ultra-stable and ultra-selective embolic radio-theranostics, which is demonstrated in different preclinical rodent models and isolated human liver tumor tissues. During locoregional intra-arterial brachytherapy, 177Lu-PCMs can be visualized via SPECT to validate the in vivo biodistribution and retention in real time, achieving precise delivery, effective anti-cancer treatment, and a distinguished safety profile without degradation, ectopic embolization, and adverse reactions. Therefore, this study may offer a new avenue for the development of a highly innovative and translational approach for precision intravascular brachytherapy.

Effectively addressing global warming requires a rapid transformation of the ways in which energy is consumed, and nuclear power produces very low lifecycle carbon emissions. Efficient uranium extraction from unconventional uranium ore sources, such as the ocean, can provide a stable and long-term supply of nuclear fuel for nuclear power plants. Herein, we report an interconnected open-pore architecture poly(amidoxime) (PAO) fiber with PAO nanoparticles and a nano-channel structure (AO-OpNpNc) using a top-down design. A high uranium adsorption capacity of 17.57 mg-U per g-adsorbent in natural seawater and ultra-long service life of at least 30 cycles were obtained, which are the highest values among currently available adsorbents to our knowledge. Extended X-ray absorption fine structure (EXAFS) fits and density functional theory (DFT) computational studies suggest that PAO-bound uranyl is a cooperative chelating model. More importantly, uranium production costs could be reduced to $80.70–86.25 per kg of uranium with this fiber, which is similar to the uranium spot price of $86.68 per kg of uranium and lower than the costs of all currently available adsorbents. The exceptional durability of the AO-OpNpNc fibers suggests the possibility of economically producing nuclear fuel from the ocean.

Evidence on the effects of ozone on chronic lower respiratory disease (CLRD), acute respiratory infections (ARI) is still not conclusive. This study aimed to investigate the association between them in Hohhot China. Daily death counts, concentrations of PM2.5, PM10, SO2, NO2, and O3, and meteorological data were collected for Hohhot city from January 1, 2018, to December 31, 2019. We performed a time series analysis using generalized additive model (GAM). In single pollutant model, the estimated excess relative risks (EERs) for respiratory and CLRD mortality were 2.815% (95% CI: 0.075–5.630) at lag 04 and 4.409% (95% CI: 1.577–7.320) at lag 01, respectively, for each 10 µg/m3 increase in O3. No significant association was found for ARI and the other respiratory diseases mortality. Subgroup analysis showed that the respiratory diseases for men were more susceptible to O3 than women, while men had a lower association with CLRD than women. Concentrations of O3 were significantly associated with respiratory disease and CLRD for older adults. The significant positive association between O3 and respiratory mortality and CLRD mortality remained largely unchanged in the two-pollutant model and the multi-pollutant model. In conclusion, short-term exposure to O3 is significantly associated respiratory diseases and CLRD mortality, and this association is dominated by gender and age.

In this letter, we study the diffusion of water molecules inside narrow carbon nanotubes in the presence of nanotube defects, gas molecules and salt ions by using molecular dynamics simulations. Mean square displacement (MSD) with a power-law fitting parameter , and the probability distribution function (PDF) with an distribution parameter a, of water molecules are calculated. It is found that within the diffusion time scale, water molecules exhibit a superdiffusion behavior with 1$ ?> inside a perfect nanotube and the superdiffusion is weakened in the presence of gas molecules and salt ions. Meanwhile, a normal diffusion behavior with is observed inside a defective nanotube, and it is replaced by a subdiffusion behavior with when gas molecules and salt ions are involved. PDF of water molecules is found to be Gaussian-like with subject to superdiffusion and normal diffusion, while it becomes a center-peaked and long-tailed Lévy distribution with a

A primary goal of studying climate change adaptation is to identify the adaptation options that are used to improve crop productivity or reduce the negative impacts of climate change. Many of the adjustments in farm management that farmers adopt do not necessarily represent true adaptations to climate change, an issue often ignored in existing literature and resulting in a risk that policy makers are misled to think that adaptation is easier than it actually is, and thereby underestimate the challenge that climate change presents. The overall goal of this study is to identify whether farmers’ adoptions are enhancing food production and adapting to climate change. The identification uses a plot-level panel from a survey of 619 rural households in three provinces in China and county-level weather data. With the use of plot and county-by-year fixed effects as well as instrumental variable approaches, our estimates show that the autonomous adoptions are not effective in improving crop yields. This implies that farmers’ adoptions cannot be always considered adaptations to climate change. The paper provides a possible explanation for the results and concludes with policy implications.

In this paper, a novel model of a concentrating photovoltaic-photothermochemical (CPV/PTC) hybrid system is proposed. Solar spectrum is separated into several parts to enable photovoltaic (PV) and photothermochemical (PTC) conversion by utilizing the parabolic trough concentrator with a spectral beam splitter. The PV module converts a specific spectral range of solar radiation into electricity directly by the solar cells and the PTC module absorbs the rest solar energy to supply the reaction heat of methanol-steam reforming (MSR) that produces hydrogen for power generation. The energy and exergy analyses on the CPV/PTC hybrid system are carried out. The overall system efficiencies with different splitting wavebands, widths of the solar cells and heat transfer coefficients of the cooling system are investigated. Moreover, the CPV/PTC hybrid system is compared with a single PV or PTC system. The results indicate that the optimal splitting waveband, concentration ratio and heat transfer coefficient of the cooling system are 450 nm-870 nm, 7.9, and 1500 W/(m2 · K), respectively. With the optimization of the proposed CPV/PTC hybrid system, the overall power generation efficiency can reach 25.3%.

Conventional polymeric adsorbents encapsulate most of their ligand groups (such as amidoxime, AO) in dense structures, leading to problems such as low adsorption capacity for uranium extraction from seawater (UES). The uranium coordination environment of polymeric adsorbents has not been positively identified even after decades of research. Therefore, a new and functional biaxially stretched polyethylene (BSPE) membrane with poly-amidoxime (PAO) nanoparticles, mesoporous architecture, and nano-channels (PAO-BSPE) was fabricated in this study for UES, based on the interfacial self-assembly of axial grafting chains. The underlying mechanism involved in the formation of the PAO-BSPE membrane was elucidated using first-principles computations of the various reactions. The engineered PAO-BSPE membrane exhibited excellent hydrophilicity, good mechanical properties, high specific surface area, and contained mesoporous architecture and nano-channels, which facilitated advantages in terms of kinetics, capacity, and renewability in both laboratory experiments and marine field-testing. After 64 days of adsorption in natural seawater, the PAO-BSPE membrane with a low degree of grafting of 70.5% exhibited a high uranium-adsorption-capacity of 12.67 mg-U/g-ads, which was 1.77 times higher than that toward vanadium. The PAO-BSPE membrane efficiently extracted uranium in the presence of high concentrations of co-existing ions, with the distribution coefficient reaching 4.09 × 106 mL/g in natural seawater. The total amount of uranium recovered by the PAO-BSPE membrane was 15.0 g in terms of yellow cake during a total submersion time of 30 days in the ocean. The adsorbent exhibited a long service life of at least 12 cycles. Furthermore, near-edge and extended X-ray absorption fine structure spectroscopy analyses suggested that the mechanism of uranium adsorption involved the formation of a stable complex via the linkage of uranium with two amidoximes in a cooperative chelating fashion. This study presents a new adsorbent with improved efficiency for UES, which has significant implications for the development of polymer adsorbents with high selectivity.

BiSbTe has been realized as an ideal p-type thermoelectric material near room temperature; however, its commercial applications are largely restricted by its n-type counterpart that exhibits relatively inferior thermoelectric performance. In this work, n-type BiTeSe based composites Bi2Te2.7Se0.3–f InSb (0 ≤ f ≤ 2.5 vol%) are prepared by a ball milling and spark plasma sintering method. A record-high ZT value of ∼1.22 is achieved at 323 K for Bi2Te2.7Se0.3–1.5 vol% InSb composites. This significant enhancement in thermoelectric performance is attributed to the incorporation of nanostructured InSb into the Bi2Te2.7Se0.3 matrix, which can simultaneously modulate the electrical and thermal transport. InSb with high carrier mobility precipitated in the matrix can strengthen interface scattering at the phase boundaries, which can effectively scatter the heat-carrying phonons and thus yield an extremely low lattice thermal conductivity, while the high power factor is maintained. As a result, a maximum ZT of 1.22 is obtained. The average ZT in the temperature range of 300–425 K for Bi2Te2.7Se0.3–1.5 vol% InSb is 1.14, which is at least 15% larger than that of previously reported values. Our results demonstrate that for n-type bismuth-telluride-based alloys, imbedding nanostructured phases with a high carrier mobility is an effective strategy for enhancing the performance of the state-of-the-art thermoelectric systems.

Rice, China's most important food crop, is highly dependent on irrigation, but an increasing number of extreme drought events have challenged rice production in many regions. This paper investigates the role of local irrigation infrastructure in improving farmers' ability to respond to drought and its effectiveness in mitigating the drought risk in rice production in China. The analysis relies on a moment-based specification of the stochastic production function, capturing mean, variance and skewness effects. Using household survey data from 86 villages in five provinces, we jointly estimate farmers' adaptive irrigation decisions and their effects on rice yield and production risk. Our econometric analyses show that irrigation infrastructure in villages contributes to enhancing farmers' irrigation capacity in adapting to drought, and increased irrigation leads to a significant increase in mean yield and a reduction in exposure to risk as well as downside risk in rice production. The paper concludes with policy implications.

As an arid and semiarid region in that is frequently hit by drought, Northwest China is ecologically vulnerable. Faced with drought and other extreme events, policy makers have given top priority to the formulation and implementation of adaptation policies. This paper investigates the roles of community assets, including community social capital and access to public services, in mitigating the impact of drought in Northwest China. Based on a micro-level dataset of individual households and villages from two provinces, we find a major effect of community assets on grain yields, after controlling for other influences. Our econometric analyses show that the severity of drought in the study areas significantly reduces grain yields. The negative impact of drought, however, can be significantly mitigated in villages with better community assets. Several policies, including enhancing investments in communities’ infrastructure and providing public services related to drought, are recommended to both improve local adaptive capacity to drought and reduce poverty in the drought-prone areas.

This paper presents the coupling-degree-based heuristic prioritized planning method (CDH-PP) to improve the efficiency and robustness of swarm path planning. The proposed method decouples the swarm path generation problem into a series of single-UAV path planning problems. And the couplingdegree-based priority heuristic generation criterion is tailored to determine the planning order of UAV swarms. The swarm coupling degree matrix is established to determine the coupling relations among UAV swarms based on the collision-detection algorithm. Anytime repairing sparse A*algorithm (AR-SAS) is adopted to plan path for single-UAV considering obstacles and inter-UAV collisions. Simulation results show the proposed CDH-PP method can generate collision-free paths for UAV swarms. And the comparative studies with the random prioritized planning and distance-based heuristic prioritized planning method demonstrate higher computational efficiency and robustness of CDH-PP.

This paper presents a receding path planning method using priority-based artificial potential field (PAPF) for UAV swarms considering moving obstacle and inter-UAV collision avoidance constraint. To enhance computational efficiency, PAPF is proposed to decouple the UAV swarm cooperative path planning problem into a series of single-UAV path planning problems. The receding planning mechanism is used to reduce the horizon of the path planning to further reduce the computational burden. In each planning horizon, when sequentially generating the paths of multiple UAVs, lower priority UAVs treat the path points of higher priority ones as obstacles for collision avoidance. Simulation studies show that PAPF can generally generate swarm paths in around Is on the scenario involving 16 UAVs, which verifies the efficiency merit of PAPF in solving dynamic path planning problems for UAV swarms.

Capillary imbibition of water plays a significant role in various applications at both the macroscopic and microscopic scales. However, it is still unclear whether capillary imbibition could be manipulated by the geometry structure of the nanotubes. In this paper, we adjust the concentric tube length difference ∆L of the double-walled nanotubes (DWNTs) to manipulate the capillary imbibition by molecular dynamics simulations. Three configurations are considered, i.e. ∆L = 0 (the common DWNT structure, labeled as configuration I), ∆L < 0 (configuration II, the inner tube is shorter than the outer tube), and ∆L > 0 (configuration III, the inner tube is longer than the outer tube). By comparing with the single-walled nanotube, it is found that the imbibition velocities of the water molecules in the DWNT are weakened 9.1% in configuration I and enhanced 30%–46.5% in configuration II and 10% in configuration III. By analyzing the microscopic structure of the water molecules, it is found that the imbibition velocity adjustment originates from the potential energy difference of the water molecules in the water reservoir and at the entrance of the nanotube at the nanotube cylindrical pore. An exponential relation between the imbibition velocity v L and the potential energy difference ΔE is obtained as v L ( t ) ∼ e − Δ E k B T . Furthermore, it is found that imbibition velocity is independent from the radius differences in all three configurations. Our results suggest a possible way to manipulate the capillary imbibition behavior and it has significant implications for water treatment, nano-switches, catalysis engines and biological sensors.

To combat pollution, the Chinese government has taken a series of environmental regulations, including requiring cities to report their daily air quality information. This has affected not only the environmental performance of governments and enterprises but also individual happiness. This paper attempts to explore whether and how mandatory air quality information disclosure affects happiness in China, using a difference-in-differences (DID) approach across cities for the waves 2007, 2008 and 2013. Empirical results show that in Chinese cities, people feel less happy over time although there is an increase in GDP per capita. Moreover, it is found that mandatory air pollution index (API) disclosure exerts a significantly positive impact on happiness, mainly by reducing air pollution. Our analysis has policy implications that for developing countries, air quality information disclosure should be encouraged since it is effective in combating air pollution resulting from high economic development and meanwhile it adds to individual happiness.

This study investigates the impact of market-based environmental regulations on firm innovation by examining one of the first large-scale market-based regulatory attempts in a developing country, China’s sulfur dioxide emissions trading program. Based on the difference-in-differences method, triple differences, and a rich set of robustness checks, we find robust evidence that the emissions trading program has led to a significant increase in patents and environmental friendly production practices among regulated firms. Furthermore, our analysis shows that private firms are more responsive to the regulation than state-owned firms. Our findings suggest that market-based environmental regulations could incentivize regulated firms to innovate even in a weak institutional environment.

Although the importance of forests in climate change mitigation has been widely recognized, there has been a lack of empirical research regarding the role of forests in agricultural adaptation to climate change. This paper uses a careful designed household survey in South China that considers an exogenous shock of drought, to determine whether the presence of natural and planted forests near rice-producing villages can reduce the adverse effects of drought on rice yield. After controlling for local climate and water infrastructure, we find robust evidence that natural forests and not planted forests have significant positive effects on rice yield, due to their influence on the availability of water for irrigation. Although drought hinders farmers access to irrigation, which negatively affects rice yield, forests near villages provide protection for rice against drought. These findings support the adoption of forest ecosystem-based adaptation (EBA) to cope with climate change and enhance food security. Acknowledgement

In this chapter Jikun Huang and Yangjie Wang provide an overview and case studies of the connection between agriculture, foreign aid and climate change, and argue the extent to which agriculture is heavily underfunded and that foreign aid needs to be scaled up significantly to tackle the great challenge of food security in a climate change context. They also point at how to make climate finance through foreign aid more effective to tackle mitigation and adaptation in agriculture across different types of mitigation and adaptation measures.

Whether the emission trading scheme (ETS) can achieve energy conservation and emission reduction in developing countries is crucial for these countries to achieve sustainable economic and environmental development. This study investigates the energy conservation and emission reduction effects of China's carbon dioxide (CO2) ETS pilot policy implemented in 2011. Based on panel data of the two-digit industry at province level from 2005 to 2015, we adopt the difference-in-differences (DID) model to examine the effects of the CO2 ETS on energy conservation and emission reduction. The results show that the CO2 ETS decreases the energy consumption of the regulated industries in pilot areas by 22.8% and the CO2 emissions by 15.5% compared to those in nonpilot areas. Further analysis indicates that the policy effects are mainly driven by improving technical efficiency and adjusting industrial structure. In addition, we find that the CO2 ETS performs better in areas with high levels of environmental enforcement and marketization. Overall, our findings suggest that the CO2 ETS has achieved energy conservation and emission reduction effects in developing countries.

We use “China's sulfur dioxide (SO2) emissions trading program” as a quasi-natural experiment to identify the causal effect of this market-based environmental regulation on firm's labor demand. Based on the difference-in-differences (DID) method and a series of robustness tests, we observe robust evidence that the emissions trading program significantly increases the labor demand of regulated firms, and that this positive employment effect is driven by the expansion of firm's production scale. The observable evidence leads us to cautiously conclude that the market-based environmental regulations in even developing countries could achieve the double dividend of coexistence of environmental protection and employment growth.

In this paper, a novel solar thermochemical volumetric receiver/reactor with nanofluid is proposed. Thermal and chemical performance analyses of the volumetric receiver/reactor are numerically investigated and compared with those of the conventional surface receiver/reactor. A two-dimensional axisymmetric heat and mass transfer model coupled with reaction kinetics is developed to predict the temperature distribution and reactant conversion ratio. The effects of particle characteristics including size and volume fraction and solar irradiation intensity are discussed. The results indicate that for the nanofluid with a volume fraction greater than 0.005, an optical path depth of 0.015 m is sufficient to absorb almost 100% of the incident solar energy. The volume weighted average temperature of the volumetric receiver/reactor with a volume fraction of 0.05 and particle diameter of 10 nm can reach 506.0 K which is about 8.8 K higher than that of the surface receiver/reactor leading to a 5.2% increase of the outlet methanol conversion ratio from 56.9% to 62.1% under a typical operating condition. The methanol conversion ratio increases with the reduction of nanoparticle size and the increment of the volume fraction and solar irradiation intensity. The thermochemical efficiency has a maximum value of 48.9% when solar irradiation intensity is 600 W/m2.

Maternal mortality in China decreased 59 percent during 2000–2014, while clean energy consumption nearly doubled. This paper examines how the widespread adoption of natural gas as a source of clean energy improves the health of pregnant women, an environment-sensitive group often ignored in previous pollution studies. Using variation across provinces and over time in the density of natural gas infrastructure in China, we identify a significant and negative clean energy adoption – maternal mortality relationship in China. Specifically, we find that a one-unit increase in natural gas density – measured by the length of natural gas pipelines per 10,000 persons – would cause the maternal mortality rate to decrease by 4 percent, which would translate into an annual gain of approximately 648 pregnant women’s lives. We also present several additional specification checks and find that the results are insensitive to these considerations. This finding suggests that natural gas adoption has substantial health externalities and should be an important part of policy discussions surrounding clean energy production. To our knowledge, this is the first study to draw a causal link between clean energy use and maternal mortality.