Natural self-assembled three-dimensional photonic crystals such as blue-phase liquid crystals typically assume cubic lattice structures. Nonetheless, blue-phase liquid crystals with distinct crystal ...symmetries and thus band structures will be advantageous for optical applications. Here we use repetitive electrical pulses to reconfigure blue-phase liquid crystals into stable orthorhombic and tetragonal lattices. This approach, termed repetitively applied field, allows the system to relax between each pulse, gradually transforming the initial cubic lattice into various intermediate metastable states until a stable non-cubic crystal is achieved. We show that this technique is suitable for engineering non-cubic lattices with tailored photonic bandgaps, associated dispersion and band structure across the entire visible spectrum in blue-phase liquid crystals with distinct composition and initial crystal orientation. These field-free blue-phase liquid crystals exhibit large electro-optic responses and can be polymer-stabilized to have a wide operating temperature range and submillisecond response speed, which are promising properties for information display, electro-optics, nonlinear optics, microlasers and biosensing applications.
For nonlinear time-delay systems with uncertainties, the existing approaches to robust model predictive control (MPC) are based on the min-max optimization formulation. Unfortunately, these ...approaches are generally conservative for most practical problems. For this sake, this article proposes a tube-based MPC consisting of MPC and control contraction metric (CCM) controller. The MPC is utilized as a nominal controller to generate a reference trajectory, while the CCM controller is used as a local ancillary controller to guarantee the actual trajectory to be contained within a robust invariant tube centered along the reference trajectory. Besides, we construct a variational formulation multidimensional Taylor network (MTN) as the basis function to search for the minimal geodesic. With the effective training algorithm, MTN could efficiently approximate the solution with high accuracy. The incremental exponential stability of the considered systems is proved theoretically, and the effectiveness of the proposed method is illustrated by numerical simulation.
► The Maling oilfield is typical of an oil reservoir in fluvial deposits. ► The oil origin is indicated by the biomarker characteristics. ► An oil–source correlation was made. ► The data provide a ...basis for understanding the genesis of this type of crude oil.
Maling oilfield is one of the earliest discovered oilfields in the Ordos Basin. It is also a typical representative of oil reservoirs in fluvial deposits. However, due to the deficiency of geochemical study on the crude oils and source rocks, the interpretation of the oil origin is largely based on the geological situation. Maling crude oils (21) and source rocks (14) from the basin have been systematically analyzed. The distribution of the biomarkers indicates that the crude oils mainly originated from source rocks deposited under a weakly reducing to sub-oxic, freshwater lacustrine environment. Besides algae, higher land plants have also made an important contribution to the source organic matter. Comparison of the distributions of the biomarkers suggests that there is a correlation between the Maling oilfield oils and the source rocks of the Yanchang Formation.
Although photothermal therapy (PTT) with the assistance of nanotechnology has been considered as an indispensable strategy in the biomedical field, it still encounters some severe problems that need ...to be solved. Excessive heat can induce treated cells to develop thermal resistance, and thus, the efficacy of PTT may be dramatically decreased. In the meantime, the uncontrollable diffusion of heat can pose a threat to the surrounding healthy tissues. Recently, low-temperature PTT (also known as mild PTT or mild-temperature PTT) has demonstrated its remarkable capacity of conquering these obstacles and has shown excellent performance in bacterial elimination, wound healing, and cancer treatments. Herein, we summarize the recently proposed strategies for achieving low-temperature PTT based on nanomaterials and introduce the synthesis, characteristics, and applications of these nanoplatforms. Additionally, the combination of PTT and other therapeutic modalities for defeating cancers and the synergistic cancer therapeutic effect of the combined treatments are discussed. Finally, the current limitations and future directions are proposed for inspiring more researchers to make contributions to promoting low-temperature PTT toward more successful preclinical and clinical disease treatments.
With the rapid development of engineered nanomaterials for various applications, in vivo toxicological studies for evaluating the potential hazardous effects of nanomaterials on environmental and ...human safety are in urgent need. Zebrafish has long been considered as the “gold standard” for biosafety assessments of chemicals and pollutants due to its high fecundity, cost-effectiveness, well-characterized developmental stages, optical transparency, and so forth. Thus, zebrafish holds great potential for high-throughput nanotoxicity screening. In this review, we summarize the in vivo toxicological profiles of different nanomaterials, including Ag nanoparticles (NPs), CuO NPs, silica NPs, polymeric NPs, quantum dots, nanoscale metal–organic frameworks, etc, in zebrafish and focus on how the physicochemical properties (e.g., size, surface charge, and surface chemistry) of these nanomaterials influence their biosafety. In addition, we also report the recent advances of the in vivo delivery of nanopharmaceuticals using zebrafish as the model organism for therapeutic assessment, biodistribution tracking, and the controlled release of loaded drugs. Limitations and special considerations of zebrafish model are also discussed. Overall, zebrafish is expected to serve as a high-throughput screening platform for nanotoxicity and drug delivery assessment, which may instruct the design of safe nanomaterials and more effective nanomedicines.
Display omitted
Inorganic films possess much higher thermoelectric performance than their organic counterparts, but their poor flexibilities limit their practical applications. Here, Sb2Te3/Tex hybrid thin films ...with high thermoelectric performance and flexibility, fabricated via a novel directional thermal diffusion reaction growth method are reported. The directional thermal diffusion enables rationally tuning the Te content in Sb2Te3, which optimizes the carrier density and leads to a significantly enhanced power factor of >20 µW cm–1 K–2, confirmed by both first‐principles calculations and experiments; while dense boundaries between Te and Sb2Te3 nanophases, contribute to the low thermal conductivity of ≈0.86 W m–1 K–1, both induce a high ZT of ≈1 in (Sb2Te3)(Te)1.5 at 453 K, ranking as the top value among the reported flexible films. Besides, thin films also exhibit extraordinary flexibility. A rationally designed flexible device composed of (Sb2Te3)(Te)1.5 thin films as p‐type legs and Bi2Te3 thin films as n‐type legs shows a high power density of >280 µW cm–2 at a temperature difference of 20 K, indicating a great potential for sustainably charging low‐power electronics.
A high ZT of ≈1 at 453 K is achieved in an inorganic Sb2Te3/Te hybrid thin film via a novel directional thermal diffusion reaction growth method with extraordinary flexibility, and the rationally designed flexible device shows a high power density by a low‐temperature difference.
The electrocatalytic transformation of carbon dioxide (CO2) to formate is a promising route for highly efficient conversion and utilization of CO2 gas, due to the low production cost and the ease of ...storage of formate. In this work, porous poly(ionic liquid) (PPIL)‐based tin‐silver (Sn‐Ag) bimetallic hybrids (PPILm‐SnxAg10‐x) are prepared for high‐performance formate electrolytic generation. Under optimal conditions, an excellent formate Faradaic efficiency of 95.5% with a high partial current density of 214.9 mA cm−2 is obtained at −1.03 V (vs reversible hydrogen electrode). Meanwhile, the high selectivity of formate (>≈83%) is maintained in a wide potential range (>630 mV). Mechanistic studies demonstrate that the presence of Ag‐species is vital for the formation, maintenance, and high dispersion of tetravalent Sn(IV)‐species, which accounts for the active sites for CO2‐to‐formate conversion. Further, the introduction of Ag‐species significantly enhances the activity by increasing the electron density near the Fermi energy level.
Porous poly(ionic liquid) (PPIL)‐based tin‐silver (Sn‐Ag) bimetallic hybrids (PPILm‐SnxAg10‐x) are synthesized for high‐efficient electrocatalytic carbon dioxide (CO2)‐to‐formate conversion. An excellent formate selectivity of 95.5% with a high partial current density of 214.9 mA cm−2 is achieved at −1.03 V (vs. reversible hydrogen electrode). Besides, the formate selectivity of > ≈83% is maintained in a wide potential range (>630 mV).
The use of indirect calorimetry (IC) is increasing due to its precision in resting energy expenditure (REE) measurement in critically ill patients. Thus, we aimed to evaluate the clinical outcomes of ...an IC-guided nutrition therapy compared to predictive equations strategy in such a patient population.
We searched PubMed, EMBASE, and Cochrane library databases up to October 25, 2020. Randomized controlled trials (RCTs) were included if they focused on energy delivery guided by either IC or predictive equations in critically ill adults. We used the Cochrane risk-of-bias tool to assess the quality of the included studies. Short-term mortality was the primary outcome. The meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.
Eight RCTs with 991 adults met the inclusion criteria. The overall quality of the included studies was moderate. Significantly higher mean energy delivered per day was observed in the IC group, as well as percent delivered energy over REE targets, than the control group. IC-guided energy delivery significantly reduced short-term mortality compared with the control group (risk ratio = 0.77; 95% CI 0.60 to 0.98; I
= 3%, P = 0.03). IC-guided strategy did not significantly prolong the duration of mechanical ventilation (mean difference MD = 0.61 days; 95% CI - 1.08 to 2.29; P = 0.48), length of stay in ICU (MD = 0.32 days; 95% CI - 2.51 to 3.16; P = 0.82) and hospital (MD = 0.30 days; 95% CI - 3.23 to 3.83; P = 0.87). Additionally, adverse events were similar between the two groups.
This meta-analysis indicates that IC-guided energy delivery significantly reduces short-term mortality in critically ill patients. This finding encourages the use of IC-guided energy delivery during critical nutrition support. But more high-quality studies are still needed to confirm these findings.
The “One Belt and One Road” strategy provides a new opportunity for deepening oil and gas energy cooperation between China and Central-North Asian countries. This paper systematically studies the ...supply and demand characteristics, interdependence and cooperation prospects of oil and gas between them using relevant oil and gas energy data of these countries from 2016 to 2021. The objective of this research is to provide a basis for the overall planning of oil and gas energy cooperation between China and Central-North Asian countries in the future. The results show that the proven reserves of oil and gas in Central-North Asian countries are high; particularly, the proven reserves of natural gas account for 30% of the world. These countries also have high oil and gas self-sufficiency rates. These have laid a material foundation for China to strive for the sustained and stable import of oil and gas energy from Central-North Asian countries. At the same time, there are great imbalances in oil and gas reserves, production, consumption, available exports and their growth rates among Central-North Asian countries, which provide a basis for China and Central-North Asian countries to make strategic decisions on oil and gas energy differential cooperation. China imports 80 × 106 tons of oil and 490 × 108 cubic meters of gas from Central-North Asian countries every year and Chinese dependence on oil and gas imports in this region is 16% and 37%, respectively. The study believes that China has certain potential to increase the import of oil and gas from Central-North Asian countries and has good prospects for oil and gas cooperation. It is proposed that China should give priority to increasing oil and gas exploration and development cooperation with Central-North Asian countries with high oil and gas reserve–production ratios, and should strengthen oil and gas resource trade cooperation with Central-North Asian countries with high oil and gas self-sufficiency rates. At the same time, China should increase investment and cooperation in the midstream and downstream business of the oil industry in major Central-North Asian countries through various financing channels. China should uphold the principle of win–win cooperation to promote the in-depth and steady development of oil and gas energy cooperation between China and Central-North Asian countries.
PDF
