Public acceptability and its determinants of unit pricing for municipal solid waste disposal: Evidence from a household survey in Beijing.

Unit pricing for domestic waste, or pay-as-you-throw (PAYT), affords a promising policy option for waste classification and reduction at source. As an emerging economy, China intends to adopt the sophisticated instrument of unit pricing. The public attitude to this policy is of high relevance for its actual implementation. For the first time in China, this paper quantitatively examined the acceptability of the policy among urban residents by randomly delivering 632 questionnaires by taking Beijing, a megacity expected to introduce the practice, as an example. Based on the ordered logit model, determinants of acceptability were empirically tested including intrinsic, external and demographic factors. The results show that the acceptability rate of PAYT in Beijing is less than half, with the proportion of firm support reaching only 42.6%. The respectively low acceptability rate indicates substantial compliance costs, due to intensive resistance to policy implementation and more resources to be invested to promote acceptability. Empirical analysis further indicates that (1) regarding demographic features, aged or less educated residents tend to accept unit pricing, (2) as for intrinsic factors, a friendly environmental attitude, deeper understanding of charging policy and better social perception can significantly improve the public acceptability of the policy, and (3) in terms of external factors, better property services and transparent funding mechanisms play significant roles in enhancing public acceptability. These findings are further confirmed by replacing the dependent variable with either the willingness to pay for household waste disposal or the acceptability of the operated sewage treatment fee. The status of residents' preference for specific pricing methods is further investigated with underlying reasons being revealed. For developing regions with an urgent demand for waste reduction, it is proposed to install unit pricing in time to avoid possible growing social acceptability costs. Specific measures are proposed including changes in intrinsic factors, paying attention to focus groups, and building social consensus for unit pricing.

Research of Online Hand-Eye Calibration Method Based on ChArUco Board.

To solve the problem of inflexibility of offline hand-eye calibration in "eye-in-hand" modes, an online hand-eye calibration method based on the ChArUco board is proposed in this paper. Firstly, a hand-eye calibration model based on the ChArUco board is established, by analyzing the mathematical model of hand-eye calibration, and the image features of the ChArUco board. According to the advantages of the ChArUco board, with both the checkerboard and the ArUco marker, an online hand-eye calibration algorithm based on the ChArUco board is designed. Then, the online hand-eye calibration algorithm, based on the ChArUco board, is used to realize the dynamic adjustment of the hand-eye position relationship. Finally, the hand-eye calibration experiment is carried out to verify the accuracy of the hand-eye calibration based on the ChArUco board. The robustness and accuracy of the proposed method are verified by online hand-eye calibration experiments. The experimental results show that the accuracy of the online hand-eye calibration method proposed in this paper is between 0.4 mm and 0.6 mm, which is almost the same as the offline hand-eye calibration accuracy. The method in this paper utilizes the advantages of the ChArUco board to realize online hand-eye calibration, which improves the flexibility and robustness of hand-eye calibration.

Design of Airborne Large Aperture Infrared Optical System Based on Monocentric Lens.

Conventional reconnaissance camera systems have been flown on manned aircraft, where the weight, size, and power requirements are not stringent. However, today, these parameters are important for unmanned aerial vehicles (UAVs). This article provides a solution to the design of airborne large aperture infrared optical systems, based on a monocentric lens that can meet the strict criteria of aerial reconnaissance UAVs for a wide field of view (FOV) and lightness of airborne electro-optical pod cameras. A monocentric lens has a curved image plane, consisting of an array of microsensors, which can provide an image with 368 megapixels over a 100° FOV. We obtained the initial structure of a five-glass (5GS) asymmetric monocentric lens with an air gap, using ray-tracing and global optimization algorithms. According to the design results, the ground sampling distance (GSD) of the system is 0.33 m at 3000 m altitude. The full-field modulation transfer function (MTF) value of the system is more than 0.4 at a Nyquist frequency of 70 lp/mm. We present a primary thermal control method, and the image quality was steady throughout the operating temperature range. This compactness and simple structure fulfill the needs of uncrewed airborne lenses. This work may facilitate the practical application of monocentric lens in UAVs.

Hybrid Fiber Optic Sensor, Based on the Fabry⁻Perot Interference, Assisted with Fluorescent Material for the Simultaneous Measurement of Temperature and Pressure.

Herein we design a fiber sensor able to simultaneously measure the temperature and the pressure under harsh conditions, such as strong electromagnetic interference and high pressure. It is built on the basis of the fiber-optic Fabry⁻Perot (F⁻P) interference and the temperature sensitive mechanism of fluorescent materials. Both halogen lamps and light-emitting diodes (LED) are employed as the excitation light source. The reflected light from the sensor contains the low coherent information of interference cavity and the fluorescent lifetime. This information is independent due to the separate optical path and the different demodulation device. It delivers the messages of pressure and temperature, respectively. It is demonstrated that the sensor achieved pressure measurement at the range of 120⁻400 KPa at room temperature with a sensitivity of 1.5 nm/KPa. Moreover, the linearity of pressure against the cavity length variation was over 99.9%. In the meantime, a temperature measurement in the range of 25⁻80 °C, with a sensitivity of 0.0048 ms/°C, was obtained. These experimental results evince that this kind of sensor has a simple configuration, low-cost, and easy fabrication. As such, it can be particularly applied to many fields.

Graphene-Ag Hybrids on Laser-Textured Si Surface for SERS Detection.

Surface-enhanced Raman scattering (SERS) has been extensively investigated as an effective approach for trace species detection. Silver nanostructures are high-sensitivity SERS substrates in common use, but their poor chemical stability impedes practical applications. Herein, a stable and sensitive SERS substrate based on the hybrid structures of graphene/silver film/laser-textured Si (G/Ag/LTSi) was developed, and a simple, rapid, and low-cost fabrication approach was explored. Abundant nanoparticles were directly created and deposited on the Si surface via laser ablation. These aggregated nanoparticles functioned as hotspots after a 30 nm Ag film coating. A monolayer graphene was transferred to the Ag film surface to prevent the Ag from oxidation. The SERS behavior was investigated by detecting R6G and 4-MBT molecules. The experimental results indicate that the maximum enhancement factor achieved by the G/Ag/LTSi substrate is over 107 and less than 23% SERS signals lost when the substrate was exposed to ambient conditions for 50 days. The covering graphene layer played crucial roles in both the Raman signals enhancement and the Ag nanostructure protection. The stable and sensitive SERS performance of G/Ag/LTSi substrate evince that the present strategy is a useful and convenient route to fabricate large-area graphene-silver plasmonic hybrids for SERS applications.

Hybrid micro/nano-structure formation by angular laser texturing of Si surface for surface enhanced Raman scattering.

Surface enhanced Raman spectroscopy (SERS) has drawn much research interest in the past decades as an efficient technique to detect low-concentration molecules. Among many technologies, which can be used to fabricate SERS substrates, laser ablation is a simple and high-speed method to produce large-area SERS substrates. This work investigates the angular texturing effect by dynamic laser ablation and its influence on SERS signals. By tuning the angle between the Si surface and laser irradiation, the distributions and sizes of laser induced hybrid micro/nano-structures are studied. By decorating with a silver film, plenty of hot spots can be created among these structures for SERS. It is found that when the incident laser angle is 15° at the laser fluence of 16.0 J/cm2, the SERS performance is well optimized. This work realizes antisymmetric distribution of nanoparticles deposited on Si surface, which provides a flexible tuning of the hybrid micro/nano-structures' fabrication with high controllability for practical applications.

Measurement of human body parameters for human postural assessment via single camera.

We present a camera-based human body parameters measurement approach and develop a human postural assessment system. The approach combines the conventional contact measurement method and the non-contact measurement method to overcome some shortcomings in terms of time, expense, and professionalism in early methods. The entire measurement system consists of a computer, a high-definition camera, and the sticky points that are applied to the participant's body before the measurement. The camera captures the triple view image of human body. Then, the human body outline and the joint points of the human skeleton are extracted to locate the bone feature points. Finally, measurements and extractions of the human parameters are made. Experimental results demonstrate that the global postural assessment system provides quantitative guidance for human postural evaluation, and it completely changes how human postural is evaluated. The postural assessment system is significant for early diagnosis of diseases and medical rehabilitation treatment.

Poly(lactic acid)/artificially cultured diatom frustules nanofibrous membranes with fast and controllable degradation rates for air filtration.

The worldwide pandemic, coronavirus COVID-19, has been posing a serious threat to the global economy and security in last 2 years. The monthly consumption and subsequent discarding of 129 billion masks (equivalent to 645,000 tons) pose a serious detrimental impact on environmental sustainability. In this study, we report a novel type of nanofibrous membranes (NFMs) with supreme filtration performance and controllable degradation rates, which are mainly composed of polylactic acid (PLA) and artificially cultured diatom frustules (DFs). In this way, the filtration efficiency of particular matter (PM) and the pressure drop were significantly improved in the prepared PLA/DFs NFMs as compared with the neat PLA NFM. In specific, with incorporation of 5% DFs into fibers, PM0.3 removal with a filtration efficiency of over 99% and a pressure drop of 109 Pa were achieved with a membrane thickness of only 0.1 mm. Moreover, the yield strength and crystallinity degree of the PLA/DFs5 NFMs were sharply increased from 1.88 Mpa and 26.37% to 2.72 Mpa and 30.02%. Besides those unique characters, the PLA/DFs5 presented excellent degradability, accompanied by the degradation of 38% in 0.01 M sodium hydroxide solution after 7 days and approximately 100% in natural condition after 42 days, respectively. Meanwhile, the environmentally friendly raw materials of the composite polylactic acid and artificially cultured diatom frustules could be extracted from corn-derived biomass and artificially cultivated diatoms, ensuring the conformance to carbon neutrality and promising applications in personal protection. Supplementary information: The online version contains supplementary material available at 10.1007/s42114-022-00474-7.

Fast Self-Healing Superhydrophobic Thermal Energy Storage Coatings Fabricated by Bio-Based Beeswax and Artificially Cultivated Diatom Frustules.

Diatom frustules (DFs) with delicate hierarchical pores and a large specific surface area are extracted from artificially cultured diatoms, showing their utilization potential as shape-stabilized phase change materials (ss-PCMs). Herein, we successfully prepared a fully biomass-based ss-PCM, superhydrophobic thermal energy storage (STES) coating by employing beeswax (BW) as phase change materials (PCMs) and DFs as supporting materials via a facile spraying method. DFs can adsorb as much as 65 wt % BW without leakage, accompanied with a high heat storage capacity of 112.57 J/g. The thermal stability test demonstrates that the DF/BW coating can undergo 500 heating-freezing cycles with the reduction of the phase change enthalpy being less than 5%. Simultaneously, the DF also endows BW with a higher thermal degradation temperature (from ∼200 to ∼250 °C). In addition, the DF/BW coating shows superhydrophobicity due to the incorporation of the low surface energy of BW and the micro/nanostructures of DFs. This superhydrophobic surface can quickly and repeatedly recover its excellent water repellency through a simple heat treatment (80 °C, 20 min) after being damaged by a water impact or strong acid and alkali corrosion. This self-healing ability can effectively overcome the poor durability of traditional superhydrophobic materials. Our research can expand the application of DFs in the field of ss-PCMs and guide the preparation of durable superhydrophobic surfaces with rapid self-healing performance.

Laser-assisted chemical vapor deposition setup for fast synthesis of graphene patterns.

An automatic setup based on the laser-assisted chemical vapor deposition method has been developed for the rapid synthesis of graphene patterns. The key components of this setup include a laser beam control and focusing unit, a laser spot monitoring unit, and a vacuum and flow control unit. A laser beam with precision control of laser power is focused on the surface of a nickel foil substrate by the laser beam control and focusing unit for localized heating. A rapid heating and cooling process at the localized region is induced by the relative movement between the focalized laser spot and the nickel foil substrate, which causes the decomposing of gaseous hydrocarbon and the out-diffusing of excess carbon atoms to form graphene patterns on the laser scanning path. All the fabrication parameters that affect the quality and number of graphene layers, such as laser power, laser spot size, laser scanning speed, pressure of vacuum chamber, and flow rates of gases, can be precisely controlled and monitored during the preparation of graphene patterns. A simulation of temperature distribution was carried out via the finite element method, providing a scientific guidance for the regulation of temperature distribution during experiments. A multi-layer graphene ribbon with few defects was synthesized to verify its performance of the rapid growth of high-quality graphene patterns. Furthermore, this setup has potential applications in other laser-based graphene synthesis and processing.

Laser-Induced-Plasma-Assisted Ablation and Metallization on C-Plane Single Crystal Sapphire (c-Al2O3).

Laser-induced-plasma-assisted ablation (LIPAA) is a promising micro-machining method that can fabricate microstructure on hard and transparent double-polished single crystal sapphire (SCS). While ablating, a nanosecond pulse 1064 nm wavelength laser beam travels through the SCS substrate and bombards the copper target lined up behind the substrate, which excites the ablating plasma. When laser fluence rises and is above the machining threshold of copper but below that of SCS, the kinetic energy of the copper plasma generated from the bombardment is mainly determined by the laser fluence, the repetition rate, and the substrate-to-target distance. With a lower repetition rate, SCS becomes metallized and gains conductivity. When micro-machining SCS with a pulsed laser are controlled by properly controlling laser machining parameters, such as laser fluence, repetition rate, and substrate-to-target distance, LIPAA can ablate certain line widths and depths of the microstructure as well as the resistance of SCS. On the contrary, conductivity resistance of metalized sapphire depends on laser parameters and distance in addition to lower repetition rate.

[The effects of mechanical ventilation with different tidal volumes on the expression of caveolin-1 in lung tissue and its related downstream signaling in rats].

OBJECTIVE: To investigate the expression of caveolin-1 (cav-1) and its downstream signal under mechanical ventilation with different tidal volumes (VT) in lung tissue of rats. METHODS: Forty healthy male Sprague-Dawley (SD) rats were randomly assigned into five groups (each n=8). The rats in control group (group A) remained to have spontaneous breathing but underwent tracheostomy only. The rats in protective ventilation group underwent protective ventilation for 1 hour or 2 hours (group B1, B2), with VT set at 6 ml/kg. The rats in high VT ventilation group were given mechanical ventilation for 1 hour or 2 hours (group C1, C2), with VT set at 30 ml/kg. After incision of trachea in group A, and mechanical ventilation was given for 1 hour or 2 hours in ventilation groups. Rats of group A were sacrificed immediately. Rats of other groups were sacrificed 1 hour or 2 hours after mechanical ventilation. Specimens of lung tissues and bronchoalveolar lavage fluid (BALF) were harvested. Lung pathological changes were observed with optical microscope. The expression levels of cav-1 mRNA and eNOS mRNA in lung tissue were measured by reverse transcription-polymerase chain reaction (RT-PCR). The protein levels of cav-1, endothelial nitric oxide synthase (eNOS), interleukin-1 receptor-associated kinase 4 (IRAK4) and nuclear factor-ΚB (NF-ΚB) p65 in lung tissues were assayed with immunohistochemistry staining. Lung myeloperoxidase (MPO) activity was measured by colorimetric analysis, and wet/dry weight ratio (W/D) was calculated. The levels of tumor necrosis factor-α (TNF-α) in BALF was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: No statistical significance in the mRNA expression of cav-1 and eNOS, the protein expression of cav-1, eNOS, IRAK4, NF-ΚBp65, as well as W/D ratio, MPO and TNF-α in BALF was found among group A, group B1 and group B2. The expression of cav-1 mRNA (A value ratio) and cav-1, IRAK4, NF-ΚBp65 protein (A value) were significantly up-regulated (cav-1 mRNA: 0.833±0.085 vs. 0.384±0.011, 1.162±0.166 vs. 0.388±0.014; cav-1 protein: 0.188±0.011 vs. 0.140±0.052, 0.210±0.013 vs. 0.125±0.014; IRAK4 protein: 0.181±0.009 vs. 0.150±0.008, 0.205±0.085 vs. 0.155±0.012;NF-ΚBp65 protein: 0.294±0.011 vs. 0.236±0.015, 0.304±0.012 vs. 0.239±0.005), the expression of eNOS mRNA (A value ratio) and protein (A value) was significantly down-regulated (eNOS mRNA: 0.174±0.016 vs. 0.278±0.021, 0.107±0.014 vs. 0.262±0.045; eNOS protein: 0.180±0.017 vs. 0.211±0.010, 0.161±0.016 vs. 0.216±0.013), while W/D ratio, MPO and TNF-α in BALF were significantly increased (W/D: 5.64±0.42 vs. 4.63±0.12, 6.73±0.83 vs. 4.70±0.15; MPO: 1.86±0.26 U/g vs. 0.85±0.11 U/g, 2.14±0.24 U/g vs. 0.88±0.18 U/g; TNF-α: 386.53±29.12 ng/L vs. 50.57±10.98 ng/L, 455.77±37.78 ng/L vs. 52.11±9.92 ng/L) in group C1 and group C2 compared with those in group B1 and group B2 (all P<0.05). With prolongation of time of mechanical ventilation, changes in those parameters were more obvious in group C2 as compared with group C1 (all P<0.05). CONCLUSION: Cav-1 and the activation of downstream signals in lung tissue participate in the development of the ventilator-induced lung injury.