Antigravity Autonomous Superwettable Pumps for Spontaneous Separation of Oil-Water Emulsions.

Oil-water separation based on superwettable materials offers a promising way for the treatment of oil-water mixtures and emulsions. Nevertheless, such separation techniques often require complex devices and external energy input. Therefore, it remains a great challenge to separate oil-water mixtures and emulsions through an energy-efficient, economical, and sustainable way. Here, a novel approach demonstrating the successful separation of oil-water emulsions using antigravity-driven autonomous superwettable pumps is presented. By transitioning from traditional gravity-driven to antigravity-driven separation, the study showcases the unprecedented success in purifying oil/water from emulsions by capillary/siphon-driven superwettable autonomous pumps. These pumps, composed of self-organized interconnected channels formed by the packing of superhydrophobic and superhydrophilic sand particles, exhibit outstanding separation flux, efficiency, and recyclability. The findings of this study not only open up a new avenue for oil-water emulsion separation but also hold promise for profound impacts in the field.

Pollution characteristics, source apportionment and absorption spectra of size-resolved PAHs in atmospheric particles in a cold megacity of China.

Polycyclic aromatic hydrocarbons (PAHs) have the capability for solar radiation absorption related to climate forcing. Herein, pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles in a cold megacity were comprehensively investigated. The mean concentrations of Σ18PAHs in all the 11 particle size ranges were 3.95 ± 4.77 × 104 pg/m3 and 2.17 ± 1.54 × 103 pg/m3 in heating period (HP) and non-heating period (NHP), respectively. Except for most PAHs with 2 and 3 benzene rings in NHP, most other PAHs showed a unimodal distribution pattern with the peak at 0.56-1.0 µm in both periods, which was caused by PAH emission sources. The PAH-related climate forcing was mainly caused by the solar radiation absorptions at ∼325 (∼330) nm and ∼365 nm. In general, the absorption intensities were higher in HP than NHP. The absorption intensity in the particle size range of 0.56-1.0 µm was the highest, and benzo[e]pyrene was the dominant contributor. In colder periods in HP, higher PAH concentrations caused more intensive PAH-related climate forcing. This study provided new insights for pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles, which will be useful for better understanding PAH-related climate forcing.

Can energy saving and emission reduction policies promote green transformation of industrial enterprises--The Case of China.

In the context of the continued advancement of the green economy transition, the proactive pursuit of carbon emissions reduction and the early attainment of carbon neutrality goals have emerged as essential components in promoting high-quality economic development. Not only does it contribute to the creation of a community of human destiny, but it is also vital to the realization of sustainable development for human civilization. A dynamic evolutionary game model, which encompasses the interactions among government, enterprises, and the public, was constructed to examine the inherent impact mechanisms of the behavior of three players on the development of a green economy under the context of energy saving and emission reduction subsidies. The results showed that the incentive and punishment mechanisms served as effective tools for harmonizing the interests of system members. Within the mechanisms, the public demonstrated a higher sensitivity to rewards, while enterprises exhibited greater responsiveness to fines. Consequently, the government could influence the behavior of enterprises by incentivizing the public to serve as a third-party inquiry and oversight body. Simultaneously, the government could encourage enterprises to expedite green technology innovation by employing a combination of incentive and punishment mechanisms.

Point-to-Point Efficient Grafting Improved Compatibility of Boron-Based Fuel-Rich Propellants.

Due to the high mass calorific value, boron powder is widely used in energetic material systems such as solid propellants and ignition powders. Especially, boron powder has very broad application prospects in the field of fuel-rich propellants. However, due to the cross-linking reaction between the boric acid contained on the surface of boron powder and an adhesive called hydroxylated polybutadiene (HTPB), the viscosity of the propellant mixture system increases sharply, which seriously affects the preparation of the propellant. In this paper, "click chemistry" is intended to be used to graft the functional groups on the surface of boron powder to reduce the viscosity of the boron powder and HTPB in the initial mixing stage. In addition, a rheometer was used to test the viscosity of the boron powder and the HTPB system. The test results showed that compared to the viscosity of the raw boron powder system at 24.1 Pa·s, the mixing termination viscosity of the grafted sample was 17.1 Pa·s, a decrease of 29.0%.

A Gemini-Type Superwettable Separator for Consecutive Purification of Water and Oil Phases from Oil-Water Mixtures and Emulsions.

Oil pollution results from daily activities and a variety of industries have caused not only severe environmental problems but also wastage of valuable petrochemical resources. Separation based on superwettable materials holds promise; however, practical applications of a single type of superwettable materials were often limited due to their ability in treatment of complicated oil-water systems. Herein, a Gemini-type separator was created through the cooperation of two kinds of superwettable sand particles with opposite wettability, i. e., one is superhydrophobic whereas the other is superhydrophilic. Cooperatively by the two types of superwettable sand, consecutive separation and purification of both water and oil phases from complicated oil-water systems (e. g., water mixed with a lighter or denser oil, water emulsified in oil, oil emulsified in water, and/or a combination of them in one batch) could be achieved with high flux and superior efficiency just in one single operation unit.

Size-resolved environmentally persistent free radicals in cold region atmosphere: Implications for inhalation exposure risk.

Environmental persistent free radicals (EPFRs) have attracted more attentions recently due to their potential adverse effects to human. EPFRs in full-size range particles were comprehensively investigated in this study. The average EPFRs concentration during heating season was 3.01 × 1014 spins/m3, which was much higher than that in non-heating season (4.30 × 1013 spins/m3). The highest concentration of EPFRs presented in 0.56-1.0 µm particles during heating season, while it shifted to 5.6-10 µm particles during non-heating season. Besides, the contributions of EPFRs on PM>10 to the total concentration of EPFRs cannot be neglected, especially in the non-heating season. The International Commission on Radiological Protection model and the specific factors of the Chinese population were applied to evaluate the inhalation exposure risk of EPFRs. The results indicated that the exposure levels of EPFRs to the upper respiratory tract were much higher. The daily exposure dose of EPFRs suggested the inhalation exposure risk of 3-4 years old was higher than other age groups. In summary, these finding provided new insights for the full range particle size distribution and the inhalation exposure risk of EPFRs, which improved our understanding on the environmental fate and the health risk of EPFRs in atmosphere.

Preparation and characterization of polyethyleneimine functionalized magnetic graphene oxide as high uptake and fast removal for Hg (II).

Polyethyleneimine functionalized magnetic graphene oxide adsorbent (PEI-mGO) was synthesized by introducing polyethyleneimine onto Fe3O4/graphene oxide. The structures and morphologies of PEI-mGO was identified by using Fourier-tranform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) methods. Quantities of bar-like Fe3O4 nanoparticles were observed on the surfaces of PEI-mGO. The adsorption of PEI-mGO for Cu(II), Pb(II), Hg(II), Co(II) and Cd(II) was compared. The adsorption results indicated that PEI-mGO showed higher uptake for Hg(II) than the other ions. The influence of various variables for the adsorption of Hg(II) on PEI-mGO was explored. The adsorption kinetics and isotherm could be described well by the pseudo-second-order and Langmuir models. The maximal uptake of PEI-mGO for Hg(II) from Langmuir model was 857.3 mg g-1, which was higher than that reported previously. The adsorption removal was a fast and endothermic process governed by the chemical process. The uptake increased with increasing temperature. PEI-mGO showed an excellent performance for removal of Hg(II) with 93.3% removal efficiency from simulated wastewater. Adsorption-desorption cycled experiments indicated that PEI-mGO could be recycled. PEI-mGO could be easily separated from the adsorbed solution by using a magnet. Hence, this novel adsorbent would be promising for the removal of Hg(II) from wastewater.

Sand-Based Economical Micro/Nanocomposite Materials for Diverse Applications.

Sand is one of the most fundamental construction materials that is of significant importance and widely used for making concrete, plasters, and mortars, and also for filling under floor and basements. Sand-derived functional materials, for instance superhydrophobic sand, which can be used to prepare liquid marble, separate oil-water mixtures, and transport liquids, have recently been a highly topical and promising research field. However, such materials are mainly prepared using valuable surface modification agents via complicated procedures that are difficult for mass-production, which restricted their true applications. Here, we developed a simple, low-cost, and efficient method for the development of sand-based hierarchical micro/nanostructured composite materials with diverse applications. Briefly, micro/nanostructured superhydrophobic sand was synthesized by one-step in situ growth of a network layer of silicone nanofilaments on the surface of sand microparticles, using only one cheap chemical of small molecules of silanes. The as-prepared superhydrophobic sand displays excellent performance in waterproofing, water storage, soil moisturizing, and oil-water separation. Furthermore, sand-supported micro/nanocomposite catalysts were obtained through covalent attachment of polyamines on the surface of silicone nanofilaments. Such composites, packed in a glass column, were used as a simple flow reactor for Knoevenagel condensation reactions. Quantitative amounts of pure products without further purification can be obtained in such a simple way that just allowing the reactants solution flows through the composite catalysts driven by gravity. These results pave the way toward the development of sand-based multifunctional materials with great potential for industrial use, given their versatile functions and excellent performances but easy-to-fabricate, low-cost preparation procedure.

Municipal amalgamations and the quality of public services: A study based on city-county mergers in China.

Municipal amalgamation is one of the core policy tools for Chinese government intervention in urbanization. The city-county merger policy provides a valuable research object for examining whether government-led urban expansion improves the quality of public services. By using city panel data from 2003 to 2019, this paper examines the policy effects of city-county mergers on the quality of public services using the Propensity Score Matching-Difference-in-Differences (PSM-DID) model. The results indicate that, after controlling for other factors, city-county mergers have increased the quality of public services by 1.2%. A placebo test has validated the robustness of this positive effect. Through further tests, the paper finds that the policy has positively affected all three aspects of the quality of public services in China: education, health care, and transport infrastructure, with the greatest impact being on education. Using a case study of a city-county merger in the Fenghua District of Ningbo, this paper depicts the transmission mechanism and argues that the policy affects the quality of public services by providing institutional security (financial and administrative power) and promoting regional integration in the new city area.

Cardiac cephalalgia closely associated with acute myocardial infarction.

Cardiac cephalalgia is an uncommon symptom occurring in coronary artery disease. It is difficult to identify cardiac cephalalgia and link it to coronary artery disease because these patients present with only a headache and no typical symptoms of angina, such as chest pain, radiating pain, or chest tightness. Currently, the diagnostic value of cardiac cephalalgia in acute myocardial infarction is still under debate. We here report a case of cardiac cephalalgia. An 83-year-old woman with a severe headache lasting 6 h was diagnosed with acute myocardial infarction. ST elevation and severe stenosis of the right coronary artery were observed. Passage of the guide wire and radiocontrast agent increased the intensity of the headache, which disappeared once the right coronary artery was opened. As of one month into follow-up, the headache had not recurred. These observations strongly indicate a close association between cardiac cephalalgia and acute myocardial infarction, and they could help diagnose acute myocardial infarction related to headaches.

Preparation of ROS-responsive core crosslinked polycarbonate micelles with thioketal linkage.

Herein, we prepared novel reactive oxygen species (ROS) responsive core crosslinked (CCL/TK) polycarbonate micelles conveniently by click reaction between amphiphilic diblock copolymer poly(ethylene glycol)-poly(5-methyl-5-propargylxycar-bonyl-1,3-dioxane-2-one) (PEG-PMPC) with pendant alkynyl group and thioketal containing azide derivative bis (2-azidoethyl) 3, 3'- (propane-2, 2-diylbis (sulfanediyl)) dipropanoate (TK-N3). The CCL/TK micelles were obtained with small size of 146.4 nm, showing excellent stability against dilution and high doxorubicin (DOX) loading. In vitro toxicity tests demonstrated that the obtained CCL/TK micelles have good biocompatibility and low toxicity with cell viability above 95 %. Furthermore, DOX-loaded CCL/TK micelles showed significantly superior toxicity with IC50 values for HeLa and MCF-7 cells about 3.74 µg/mL and 3.91 µg/mL, respectively. Confocal laser scanning microscope (CLSM) and flow cytometry showed excellent internalization efficiency and intracellular drug release of DOX-loaded CCL/TK micelles. The obtained ROS-responsive CCL/TK micelles showed great potential for anticancer drug delivery.

Thermally Activated Delayed Fluorescence Carbonyl Derivatives for Organic Light-Emitting Diodes with Extremely Narrow Full Width at Half-Maximum.

Two novel thermally activated delayed fluorescence (TADF) emitters, 3-phenylquinolino[3,2,1- de]acridine-5,9-dione (3-PhQAD) and 7-phenylquinolino[3,2,1- de]acridine-5,9-dione (7-PhQAD), were designed and synthesized based on a rigid quinolino[3,2,1- de]acridine-5,9-dione (QAD) framework. With the effective superimposed resonance effect from electron-deficient carbonyls and electron-rich nitrogen atom, both emitters realize significant TADF characteristics with small Δ ESTs of 0.18 and 0.19 eV, respectively. And, molecular relaxations were dramatically suppressed for both emitters because of their conjugated structure. In the devices, 3-PhQAD realizes superior performance with a maximum external quantum efficiency (EQE) of 19.1% and a narrow full width at half-maximum (FWHM) of 44 nm, whereas a maximum EQE of 18.7% and an extremely narrow FWHM of 34 nm are realized for 7-PhQAD. These superior results reveal that apart from nitrogen and boron-aromatic systems, QAD framework can also act as a TADF matrix with effective resonance effect, and QAD derivatives are ideal candidates to develop TADF emitters with narrow FWHMs for practical applications.

Development of Red Exciplex for Efficient OLEDs by Employing a Phosphor as a Component.

Exciplexes are ideal candidates as effective thermally activated delayed fluorescence (TADF) emitters. However, efficient orange and red TADF exciplexes have been reported seldomly, because their significant non-radiative (NR) decay of excited states lead to unavoidable energy loss. Herein, we propose a novel strategy to construct efficient red TADF exciplexes by introducing phosphor as one component. Due to the strong spin-orbit coupling of heavy metal (e.g., Ir, Pt, et al.) ion cores, the NR decays will be evidently decreased for both singlet and triplet excitons, reducing the undesired exciton waste. Moreover, compared with the conventional exciplexes, phosphorescence plays an important role for such novel exciplexes, further improving the exciton utilization. Based on this strategy, we fabricated a red exciplex containing 1,3,5-triazine-2,4,6-triyl)tris(benzene-3,1-diyl)tris(diphenylphosphine oxide) (PO-T2T) and tris(2-phenylpyridine) iridium(III) (Ir(ppy)3) as components and realize a red emission with a peak at 604 nm, a CIE coordinate of (0.55, 0.44), and a high maximum external quantum efficiency of 5% in organic light-emitting device. This efficiency is 2.6 times higher than that of the device based on the conventional red exciplex emitter, proving the superiority of our novel strategy to construct TADF exciplexes with phosphors.

Rural settlements transition (RST) in a suburban area of metropolis: Internal structure perspectives.

Rural settlements transition (RST) is one of the most significant indices for understanding the phenomena of rural reconstruction and urban-rural transformation in China. However, a systematic overview of RST is missing, and there is a lack of evidence regarding its characteristics from the internal structure perspectives. In this paper, we systematically explore the RST regarding spatio-temporal change characteristics of internal structure, patterns and impacts on rural environment and development by using practical survey internal land-use data from 2005 to 2015. The results show that the temporal change characteristics of the internal structure of rural settlements demonstrate a tendency for housing land to decrease and other land-use types to increase. The spatial change characteristics reveal that the structure inclines to more complexity and diversity from an exurban area to an urban-rural fringe area. Based on this finding, we identify that rapid development of rural industrialization, more agglomerate and effective industrial land-use, and improved public infrastructure construction are the general RST patterns. Spatially, there exists a physical decay pattern in the exurban area, thereby resulting in the hollowing-out of rural industries and of the population. In addition, the extensive and disorderly pattern in the suburban area causes low efficiency output and serious environmental pollution. The RST pattern in the urban hinterland promoted the "men-environment" compatible development. The study concludes that regional differentiation in patterns and impacts are significant in the process of RST. Future adaptive strategies for rural settlements adjustment should be conducted according to regional characteristics, including socio-economic status, physical geography condition and economic location to improve the rural environmental sustainability.

Spin relaxation in single-layer graphene with tunable mobility.

Graphene is an attractive material for spintronics due to theoretical predictions of long spin lifetimes arising from low spin-orbit and hyperfine couplings. In experiments, however, spin lifetimes in single-layer graphene (SLG) measured via Hanle effects are much shorter than expected theoretically. Thus, the origin of spin relaxation in SLG is a major issue for graphene spintronics. Despite extensive theoretical and experimental work addressing this question, there is still little clarity on the microscopic origin of spin relaxation. By using organic ligand-bound nanoparticles as charge reservoirs to tune the mobility between 2700 and 12 000 cm(2)/(V s), we successfully isolate the effect of charged impurity scattering on spin relaxation in SLG. Our results demonstrate that, while charged impurities can greatly affect mobility, the spin lifetimes are not affected by charged impurity scattering.

Manipulating graphene mobility and charge neutral point with ligand-bound nanoparticles as charge reservoir.

The high carrier mobility of graphene makes it an attractive candidate for future electronic device applications.(1) In SiO2/Si-supported graphene devices, the mobility typically varies from 2000 to ∼2,0000 cm(2) V(-1) s(-1).(2) By removing SiO2,(3,4) much higher mobility (2 × 10(5) cm(2) V(-1) s(-1) in the latter) has been obtained, suggesting the importance of the Coulomb scattering in graphene transport. Although such elaborate device fabrication is clearly effective, the mobility of finished devices is fixed thereafter and can vary from device to device. In this work, we first demonstrate a significant enhancement in carrier mobility in SiO2-supported graphene decorated with a layer of ligand-bound nanoparticles (NPs) such as iron oxide, titanium dioxide, or cadmium selenide acting as a charge reservoir. By transferring charges between graphene and the NP reservoir through the molecules, we show a remarkable reversible tunability in mobility (4000-19000 cm(2) V(-1) s(-1)) in the same device, which unambiguously proves that the charged impurity scattering is the prevailing mechanism for graphene mobility. In addition, the charge neutral point or the Dirac point can also be independently tuned over a wide gate voltage range. The reversible tuning is useful for fabricating large-area graphene devices such as nonvolatile memory with enhanced sensitivity.