Low Efficiency Research Articles

Evaluating and enhancing natural resource asset management efficiency in China: A data envelopment analysis study

The efficiency of China's natural resource asset management system significantly influences the sustainable utilization of resources and the promotion of an environmentally sustainable economy. In this research, we employ a Data Envelopment Analysis (DEA) model to assess and analyze the efficiency and dynamic changes within China's natural resource asset management system. Our analysis is based on panel data collected from 30 provinces spanning the years 2007–2019. Our findings reveal that only three provinces demonstrated DEA effectiveness in managing natural resource assets, highlighting substantial regional disparities in efficiency. The presence of multiple institutions operating independently has led to a situation of overlapping responsibilities, resulting in critical issues related to redundant management. Inadequate resource tax collection intensity and a low tax utilization rate have contributed to the insufficiency in resource tax utilization. Local industrial structures and government priorities have hindered the active involvement of industrial enterprises in natural resource asset management in certain regions. We categorize changes in the efficiency of system operations in non-DEA-effective regions into three types: a temporary increase followed by a continuous decline, a gradual increase with overall low efficiency, and a rapid increase with relatively high overall efficiency. Consequently, this study offers policy recommendations aimed at enhancing the efficiency of natural resource asset management: (1) Clarify the ownership of natural resource assets and establish a well-defined hierarchical proxy system along with an integrated supervision framework. (2) Allocate resource tax revenue reasonably and promote collaborative coordination between resource taxes and other policy measures. (3) Strengthen the government's commitment to natural resource asset management, draw insights from advanced regions' experiences, and tailor policy approaches to the specific conditions of different regions to effectively balance economic development and environmental protection.

Iranian Traditional Medicine (ITM) and Natural Remedies for Treatment of the Common Cold and Flu.

Traditional Iranian medicine is usually used for both prevention and relief of cold and flu symptoms in China, Iran, and many other Asian countries all over the world. There are 4 kinds of influenza viruses. Unlike type B, which may cause seasonal epidemics, type A viruses can cause pandemics, and influenza C may lead to mild human infection with little public health effects. A literature review was done by using multiple databases such as ISI Web of knowledge, PubMed, Science Direct and Google Scholar. The most notable antiviral medicinal plants for flu and cold are honeysuckle flowers, thyme leaf, green chiretta, andrographis, peppermint oil and leaf and calendula. The most important expectorant medicinal plants for cold and flu are snake root, tulsi, licorice root, slippery elm, clove, and sage leaf. Recommended immunostimulant medicinal plants for cold and flu are eucalyptus, Echinacea root, ginseng, garlic, slippery elm, marshmallow, Usnea lichen, Isatis root, ginger root, and myrrh resin. Iranian traditional medicine, which is one of the oldest schools of traditional medicine, is one of the main concepts of disease and health, and it can be considered as an important complementary and alternative medicine, as in some cases, modern medicine has many side effects, low efficiency, and high costs. Medicinal plants and herbs, which are included in many traditional systems, have significant and promising bioactive components in organic life.

Microbial Application in Heavy Metal Removal from Pharmacological Industrial Effluent

In industrial effluents, significant amounts of metallic cations such as zinc, copper, iron, manganese, lead, nickel, and cadmium are present. Long-term irrigation with these effluents increases the amount of organic carbon and heavy metals in the soil, increasing the likelihood that they will enter the food chain and, eventually, result in significant bioaccumulation. Many techniques for the treatment and disposal of metal-containing wastes, such as ion exchange, reverse osmosis, in flotation, and evaporation, have been developed in order to reduce metal pollution issues. The main disadvantages of conventional treatments are low efficiency at low concentrations of heavy metals, expensive handling, and safe disposal of toxic sludge. In light of this, an effort has been made to investigate how tannery affects the growth of green gram.

Viral gene detection based on multifunctional microspheres and AgNPs coated substrate interface area SERS scheme

Surface-enhanced Raman spectroscopy (SERS) has emerged as an effective method for detecting viral genes in aqueous solutions. However, SERS has a low efficiency and poor reproducibility in multi-component aqueous solutions. Thus, developing a SERS scheme with stable hotspots generation, significant enhancement effects, and efficient viral gene enrichment remains a challenge. This study sought to proposes an enhanced hotspot generation scheme combining multifunctional microspheres and SERS substrates, which can achieve stable enhancement in the interface area. Multifunctional microspheres can be used to selectively enrich target biomolecules in aqueous solutions. Furthermore, simulation results show that these microspheres can synergistically form a stable enhancement area with SERS substrates. Finally, this scheme was used for immunocapture and Raman detection of hemagglutinin 7 (H7) and neuraminidase 9 (N9) specific gene in an aqueous solution containing multiple types of influenza viral genes. The relationship between the characteristic peaks and concentrations was analysed using two-dimensional correlation analysis. Spectral data analysis revealed an exceedingly high linear correlation between the selected characteristic peak intensity and concentrations. The calculation results show that the SERS enhancement factor of the proposed scheme for the H7 and N9 specific gene are 9.23×107 and 1.59×108, respectively. Notably, the detection limit of this scheme was 1 pM. Therefore, this scheme holds the promise to realize the detection of viral genes in heterogeneous, complex, and dynamic aqueous biological samples.

Development, integration, and field evaluation of an autonomous Agaricus bisporus picking robot

The disorganized and densely growing Agaricus bisporus remains challenging for robotic harvesting. Aiming at the lower efficiency, lower success rate, and higher breakage rate in the robotic harvesting process, we propose a fully integrated, autonomous, and innovative harvesting robot to overcome the challenges due to the dense growth characteristics of Agaricus bisporus. An overlapping target detection vision system based on the yolov5s deep learning network is developed to improve the detection accuracy of dense and hidden mushrooms. An intelligent picking planning strategy by fusing multiple algorithms is formulated to guide the robot to effectively pick mushroom clusters with different growth characteristics. A multi-stage telescopic flexible end-effector is designed to pick mushrooms in a narrow space and reduce the picking breakage rate. Finally, we successfully developed a fully autonomous picking robotic system and evaluated it in a mushroom cultivation factory. Experimental results show that the robot can pick Agaricus bisporus continuously with an overall success rate of 94.1 % and an average picking time of 4.23 s per mushroom. These efforts provide a solid foundation for future applications of Agaricus bisporus picking robots.

BiOCl modified TiO2 based catalyst with enhanced hydrogen generation properties under visible light via promote photogenerated electron-hole separation

Due to its wide band gap and low photogenerated carrier separation efficiency, TiO2 has an undesirable photocatalytic activity. In the present work, BiOCl was hydrothermally deposited on TiO2 and BiOCl/TiO2 composites with different ratios were obtained. The results show that 30 % BiOCl/TiO2 has the best performance of 1354.94 μmolg−1h−1, which is 18.4 times than pure TiO2 and 73.1 times than pure BiOCl. The significant increase in the photocatalytic efficiency of BiOCl/TiO2 composites is attributed to the reduction of their bandgap width and the fast separation of photogenerated electron-hole pairs. This work brings a new idea to increase the photocatalytic hydrogen production capability of TiO2.

Facile construction of gold- and BODIPY-coordinated liposomal nanocomplexes for enhanced photothermal therapy of cancer

Photothermal therapy (PTT) has attracted extensive attention in cancer treatment because of its advantages of non-invasive and few side effects. Gold nanoparticles and boron-fluorine-dipyrrole (BODIPY) dye have been used as photothermal agents (PTAs), but they have problems such as easy aggregation, poor water solubility and low photothermal conversion efficiency. In this work, we used conventional liposomes for in situ generation of small gold nanoparticles and sequentially loading BODIPY to overcome the drawbacks of the two PTAs and simultaneously realize enhanced PTT. Gold- and BODIPY-coordinated liposomal nanocomplexes LAB with small gold nanoparticles adsorbed on the surface and BODIPY entrapped inside showed uniform size of about 100 nm with good stability. LAB demonstrated laser-responsive drug release property, good cellular uptake efficiency and tumor accumulation ability. After laser irradiation, LAB can exert enhanced PTT in cancer cell lines by reducing mitochondrial membrane potential and increase intracellular reactive oxygen species level to promote cell apoptosis. In tumor-bearing mice, LAB showed fantastic tumor inhibition effect with good biosafety. This work provides a convenient method to develop PTA combinations for enhanced PTT, which could lay the foundation for the green construction of new PTAs for PTT by employing clinically used formulations and PTAs.

Unraveling the influence of Sb dopant to reversible capacity and initial Coulombic efficiency of SnO2-graphene as anodes for sodium storage

Sodium storage materials based on conversion and alloying reactions often suffer from low initial Coulombic efficiency (ICE). Most of literature shows that the SnO2-based anode commonly reveals an ICE below 50 %, and the reasons could be attributed to the partial reversibility in conversion reaction by forming an intermediate phase. This work focuses on using an element doping strategy to suppress the formation of an inert intermediate phase and improve the ICE for SnO2-based anodes in sodium storage applications. Mechanisms of performance enhancement are also carefully investigated. The 3 % Sb doped sample is demonstrated with enhanced electrochemical performance. Specifically, it delivers an initial discharge capacity of 847 mAh/g at 50 mA g−1, combining an average enhanced ICE of 57.1 % (37.8 % for the undoped comparison), and it also presents a good rate performance of 206 mAh/g at a high current density of 1600 mA g−1. It is found that the Sb dopant reduces the specific capacity of active materials, but it enhances reaction reversibility; improves the overall conductivity of active materials, but does not directly enhance the Na+ diffusion coefficient; helps to restrain the formation of inert phase (the SnO phase) in sodium storage reactions to improve reversibility and initial Coulombic efficiency. Therefore, reversible capacities and initial Coulombic efficiencies can be effectively enhanced after introducing the Sb dopant at an optimized percentage. This work could provide valuable inspiration for designing conversion and alloying-type anodes for sodium storage applications via ion doping methods.

High-Efficiency WPT Systems for Potable Electronics Based on DC-Bias-Voltage- Controlled Variable Capacitor

The power density of wireless power transfer (WPT) systems employed in portable electronics can be enhanced by increasing the operating frequency, but at the expense of lower efficiency due to increased switching and parasitic losses. This paper proposes a method, based on the DC-bias-voltage-controlled variable capacitor (VC) and variable frequency (VF) regulation, to improve the overall efficiency of the WPT system for portable electronics. The method uses VC on the primary side to detune the resonant tank and dynamically regulate the output power, while VF is employed to improve the system efficiency using a look-up table based on a power loss model. A DC bias voltage control module with self-supply ability is employed to control the equivalent capacitance of the VC. A control strategy is proposed to regulate both VC and VF. Experimental results of a 150W prototype are presented to demonstrate that constant output voltage can be maintained despite a wide load range, with an overall efficiency range of 82.1% (@25W) and 92.2% (@150W).

Methods, Mechanisms, and Application Prospects for Enhancing Extracellular Vesicle Uptake.

Extracellular vesicles (EVs) are considered to be a new generation of bioinspired nanoscale drug delivery systems due to their low immunogenicity, natural functionality, and excellent biocompatibility. However, limitations such as low uptake efficiency, insufficient production, and inhomogeneous performance undermine their potential. To address these issues, numerous researchers have put forward various methods and applications for enhancing EV uptake in recent decades. In this review, we introduce various methods for the cellular uptake of EVs and summarize recent advances on the methods and mechanisms for enhancing EV uptake. In addition, we provide further understanding regarding enhancing EV uptake and put forward prospects and challenges for the development of EV-based therapy in the future.

Application of enhanced combustion strategies and optimized ignition timing for achieving high thermal efficiency and low N2O emissions of marine ammonia engine at full-load condition

To meet the requirement of reducing greenhouse gas (GHG) emissions, the application of carbon-free fuel ammonia in marine engines has gained importance. However, the use of ammonia as fuel leads to low thermal efficiency and high emissions of pollutants in engines. Increasing the rate of combustion of the fuel mixture in the engine helps to solve this problem. Therefore, the influence of hydrogen volume fraction (XH2) and oxygen volume fraction (XO2) in the main chamber, via numerical simulations, on the combustion and emission characteristics of a marine ammonia engine featuring a pre-chamber. Further analysis was conducted via adjustments in the start of ignition (SOI) to optimize both engine performance and emissions. The results showed that the increase of both XH2 and XO2 contributed to the improvement of indicated thermal efficiency (ITE) and the reduction of N2O emissions. However, this is usually accompanied by higher NOx emissions, especially in the case of high XO2. In addition, adjusting the SOI resulted in the engine ITE is greater than 47.6% in each case and reduces GHG emissions by about 80% (<40 ppm N2O). Finally, chemical kinetic analysis showed that oxygen-enriched or hydrogen-enriched conditions did not change the main reaction pathway.

Highly Efficient Photodynamic Hydrogel with AIE-Active Photosensitizers toward Methicillin-Resistant Staphylococcus aureus Ultrafast Imaging and Killing.

Methicillin-resistant Staphylococcus aureus (MRSA) causes great health hazards to society because most antibiotics are ineffective. Photodynamic treatment (PDT) has been proposed to combat MRSA due to the advantage of imaging-guided no-drug resistance therapy. However, the traditional photosensitizers for PDT are limited by aggregation-caused quenching for imaging and low photodynamic antibacterial efficiency. In this work, we synthesize a new aggregation-induced emission (AIE) photosensitizer (APNO), which can ultrafast distinguish between Gram-positive and Gram-negative bacteria within 3 s by AIE-active photosensitizer imaging. Meanwhile, APNO can generate antibacterial reactive oxygen species under light irradiation, which holds potential for antibacterial PDT. Then, APNO is loaded by PHEAA hydrogel to obtain a highly efficient photodynamic hydrogel (APNO@gel). In vitro results show complete inhibition of MRSA by APNO@gel under lower-power light irradiation. Transcriptome analysis is performed to investigate antibacterial mechanism of APNO@gel. Most importantly, APNO@gel also exhibits significant inhibition and killing ability of MRSA in the MRSA wound infection model, which will further promote rapid wound healing. Therefore, the photodynamic hydrogel provides a promising strategy toward MRSA ultrafast imaging and killing.

Improvement of Efficiency of Inverters in Hydro Photovoltaic Power Station with Particle Swarm Optimization

In the sparsely populated areas without electricity, the hydro photovoltaic power station is a feasible solution for electricity supply. The strategy of distributing the power among the inverters is critical to the efficiency of them. The conventional distributing strategies result in low efficiency of the inverters. In order to improve the efficiency, this paper analysed the loss and efficiency characteristics of the inverter and expressed the power distributing problem as an optimal control problem minimizing the total loss for the inverters. The optimal control problem was solved with particle swarm optimization and the efficiency optimum power distribution strategies in three operation scenarios were obtained. The quantitative analysis method was adopted to evaluate the effect of the efficiency optimum power distribution strategies. The total efficiency of the inverters with the optimal strategies and the conventional strategies were calculated respectively.  The optimal distribution strategies were compared quantitatively with conventional power distribution strategies on the basis of the efficiency. The results demonstrated the validity of the strategies obtained in this paper in improving the total efficiency of the inverters.

Comparative analysis of Benchmark and Aeon Blue Technologies for sustainable eFuel production: Integrating Direct Air Capture and Green Hydrogen approaches

Renewable Fuels of Non-Biological Origin (RFNBOs, a.ka. “eFuels”) are drop-in replacements for fossil fuels in the “hard-to-abate” sectors, and utilise existing distribution and storage infrastructure, but suffer from low synthetic efficiency. In particular, the low efficiency and high energy consumption of hydrogen synthesis by freshwater electrolysis remains a problem to be addressed. In the current study, we explore the potential of saltwater electrolysis (chloralkali) for the synthesis of eFuels generally, and specifically eMethanol. The study explores the use of chlorinated water in carbonate-loop pH-swing “cold capture” of carbon dioxide, and the resulting synergetic integration of the chloralkali process in eFuel syntheses. Doing so eliminates the high energy consumption of the calciner and the slaker of the benchmarked carbonate-loop thermal-swing method. It is replaced with a spontaneous chemical process in which chlorine is neutralized in the presence of carbonates. This allows the simultaneous solution of “The Chlorine Problem” of saltwater electrolysis, and a lower overall energy consumption of direct air capture when combined with green hydrogen synthesis. The only limitation on the comparison is that a large amount of carbon dioxide is over-captured when using chloralkali. That is, the ratio of hydrogen generated to carbon dioxide captured is fixed by the stoichiometry of chloralkali and not that of the eFuel. This results in an excess of carbon captured and thus a carbon-negative eFuel. We examine one configuration of secondary revenue and use it to inform the marginal cost of CO2 capture. In the system proposed by Aeon Blue Technologies (ABT), carbon dioxide is absorbed into caustic according to the standard method. Hydrogen gas is produced in a standard chloralkali electrolyzer, along with caustic for the contactor, and chlorine. Water oxidation by chlorine gives the strong acid, hydrochloric acid, and the weak acid, hypochlorous acid, which react directly with wet carbonate to release CO2. H2 and CO2 react in a methanol reactor to produce eFuel. H2 is the limiting reagent for eFuel synthesis, giving an excess of cold captured CO2. Thus, the current study underscores significant advancements in renewable fuel synthesis, particularly eMethanol, and evaluates the carbon capture and energy efficiency of a novel method. The simulation indicates that the marginal energy cost for a tonne of CO2 is ∼ 184kWh. This gives ∼ 76 % theoretical carbon capture efficiency and an overall process efficiency of 79.5 % (approximately a threefold improvement over the benchmark). The authors are unaware of a comparable method. The overall system yields a tonne of carbon-neutral e-methanol (eMeOH) while capturing an additional 3 tonnes of carbon dioxide, which means the modelled process captures over 300 % more carbon dioxide than is released upon combustion of the eFuel. In summary, this research contributes valuable insights into carbon-negative eFuel production, representing a significant scientific step in sustainable fuel production.

Tunable on-chip optical traps for levitating particles based on single-layer metasurface

Abstract Optically levitated multiple nanoparticles have emerged as a platform for studying complex fundamental physics such as non-equilibrium phenomena, quantum entanglement, and light–matter interaction, which could be applied for sensing weak forces and torques with high sensitivity and accuracy. An optical trapping landscape of increased complexity is needed to engineer the interaction between levitated particles beyond the single harmonic trap. However, existing platforms based on spatial light modulators for studying interactions between levitated particles suffered from low efficiency, instability at focal points, the complexity of optical systems, and the scalability for sensing applications. Here, we experimentally demonstrated that a metasurface which forms two diffraction-limited focal points with a high numerical aperture (∼0.9) and high efficiency (31 %) can generate tunable optical potential wells without any intensity fluctuations. A bistable potential and double potential wells were observed in the experiment by varying the focal points’ distance, and two nanoparticles were levitated in double potential wells for hours, which could be used for investigating the levitated particles’ nonlinear dynamics, thermal dynamics and optical binding. This would pave the way for scaling the number of levitated optomechanical devices or realizing paralleled levitated sensors.

Strongly-Confined CsPbBr3 Perovskite Quantum Dots with Ultralow Trap Density and Narrow Size Distribution for Efficient Pure-Blue Light-Emitting Diodes.

The development of pure-blue perovskite light-emitting diodes (PeLEDs) faces challenges of spectral stability and low external quantum efficiency (EQE) due to phase separation in mixed halide compositions. Perovskite quantum dots (QDs) with strong confinement effects are promising alternatives to achieve high-quality pure-blue PeLEDs, yet their performance is often hindered by the poor size distribution and high trap density. A strategy combining thermodynamic control with a polishing-driven ligand exchange process to produce high-quality QDs is developed. The strongly-confined pure-blue (≈470nm) CsPbBr3 QDs exhibit narrow size distribution (12% dispersion) and are achieved in Br-rich ion environment based on growth thermodynamic control. Subsequent polishing-driven ligand exchange process removes imperfect surface sites and replaces initial long-chain organic ligands with short-chain benzene ligands. The resulting QDs exhibit high photoluminescence quantum yield (PLQY) to near-unity. The resulting PeLEDs exhibit a pure-blue electroluminescence (EL) emission at 472nm with narrow full-width at half-maximum (FWHM) of 25nm, achieving a maximum EQE of 10.7% and a bright maximum luminance of 7697cdm-2. The pure-blue PeLEDs show ultrahigh spectral stability under high voltage, a low roll-off of EQE, and an operational half-lifetime (T50) of 127min at an initial luminance of 103cdm-2 under continuous operation.

Nano Fertilizers: New Vistas towards Sustainable Agriculture and Climate Change Mitigation: A Review

To ensure the food and nutritional security of the burgeoning global population, food production needs to be doubled in developing countries by 2050. Currently, 30-40% of agriculture production predominantly relies on chemical fertilizers. Precise crop nutrition, low nutrient efficiency, maintaining soil fertility, less damage to soil flora and minimal environmental footprint are the major challenges in modern agriculture. Recent developments in the application of nanotechnology to produce agriculture inputs emerged as a sustainable solution for addressing the challenges in modern intensive agriculture by replacing synthetic bulk fertilizers with their nanoparticle size ( less than 100 nm), superior properties and smart delivery system. Nano fertilizers had the potential to fulfill the requirements of plant nutrition along with imparting sustainability in crop production without compromising the yield of the crops. Some of the current research studies have been reviewed in this paper with citation and these results showed that nano fertilizers have a substantial effect on plant growth, development and physiological parameters including chlorophyll content and photosynthetic activity, it depends on their composition, method and time of application. Their enhanced nutrient use efficiency, correlated with mitigating greenhouse gas emissions. Hence evolving as a cutting-edge approach for sustainable agriculture in climate change is enlightened in this review.

Electrochemical Oxidation of Organic Compounds and the Creation of Metal Oxide Nanocomposites

Electrochemical regeneration suffers from low regeneration efficiency due to side reactions like oxygen evolution, as well as oxidation of the adsorbent. Utilizing the solution cast method, we three alternative strategies for producing Cr2O3 nanoparticle-laden polyvinyl alcohol (PVA) solid polymer films. The peaks in the FTIR spectrum at molecular vibration and chemical bonding frequencies indicate that Cr2O3 is present in the PVA polymer structure.

High‐Temperature Semiconductor CuO/SiC‐Based Catalyst for Artificial Photosynthesis

AbstractArtificial photosynthesis can convert CO2 and H2O into hydrocarbons via solar energy. However, the extremely low process efficiency is a major obstacle to this application. The photocatalyst is considered to be the key factor to raise the overall solar energy conversion efficiency. Much research focused on co‐catalysts, but less attention has been paid on the high‐temperature semiconductor. Herein, a strategy is proposed involving high‐temperature semiconductor to design target photocatalyst dealing with the artificial photosynthesis at high temperature. Based upon this strategy, a CuO/SiC catalyst with single atom characteristic was designed, prepared and the activity of CO2 photoreduction with H2O was tested in a high temperature environment. Above 150 °C, the catalyst activity was boosted and unprecedented performance values were attained. Under the irradiation condition delivered by a 1000 W Xe light and at 350 °C, the obtained yields of CH4, C2H4, and C2H6 were 2041.4 μmol ⋅ g−1, 15.2 μmol ⋅ g−1, and 63.6 μmol ⋅ g−1, respectively. The overall CO2 conversion reached 24.6 % and the maximum solar energy conversion efficiency was 2.3 % without any sacrificed agents. This strategy will be helpful to overcome the current limitations for the industrialization of artificial photosynthesis and accelerate the related research on photothermal catalysis.

Toward “super-scintillation” with nanomaterials and nanophotonics

Abstract Following the discovery of X-rays, scintillators are commonly used as high-energy radiation sensors in diagnostic medical imaging, high-energy physics, astrophysics, environmental radiation monitoring, and security inspections. Conventional scintillators face intrinsic limitations including a low extraction efficiency of scintillated light and a low emission rate, leading to efficiencies that are less than 10 % for commercial scintillators. Overcoming these limitations will require new materials including scintillating nanomaterials (“nanoscintillators”), as well as new photonic approaches that increase the efficiency of the scintillation process, increase the emission rate of materials, and control the directivity of the scintillated light. In this perspective, we describe emerging nanoscintillating materials and three nanophotonic platforms: (i) plasmonic nanoresonators, (ii) photonic crystals, and (iii) high-Q metasurfaces that could enable high performance scintillators. We further discuss how a combination of nanoscintillators and photonic structures can yield a “super scintillator” enabling ultimate spatio-temporal resolution while enabling a significant boost in the extracted scintillation emission.