Neoadjuvant PD-(L)1 blockade plus platinum-based chemotherapy for potentially resectable oncogene-positive non-small cell lung cancer.

BACKGROUND: Whether programmed cell death-1/ligand-1 (PD-1/PD-L1) blockade-based neoadjuvant treatment may benefit locally advanced oncogene-mutant non-small cell lung cancer (NSCLC) patients remains controversial. This retrospective study was designed to observe the efficacy and safety of neoadjuvant PD-1/PD-L1 blockade plus chemotherapy versus chemotherapy and corresponding tyrosine kinase inhibitors (TKIs) in patients with resectable oncogene-positive NSCLC. METHODS: Patients with potential resectable NSCLC harbouring oncogene alterations who had received neoadjuvant treatment were retrospectively recruited, and an oncogene-negative cohort of patients who received neoadjuvant PD-(L)1 blockade-based neoadjuvant treatment was reviewed for comparison during the same period. The primary aim was to observe the treatment efficacy and event-free survival (EFS) of these agents. Safety profile, molecular target, and immunologic factor data, including PD-L1 expression and tumour mutational burden (TMB), were also obtained. RESULTS: A total of 46 patients were recruited. Thirty-one of them harboured oncogene alterations, including EGFR, KRAS, ERBB2, ROS1, MET, RET, ALK, and FGFR3 alterations. Among the oncogene-positive patients, 18 patients received neoadjuvant PD-(L)1 blockade immunotherapy plus chemotherapy (oncogene-positive IO group), 13 patients were treated with neoadjuvant chemotherapy and/or corresponding TKIs or TKIs alone (oncogene-positive chemo/TKIs group), and the other 15 patients were oncogene negative and received neoadjuvant PD-(L)1 blockade plus chemotherapy (oncogene-negative IO group). The pathological complete response (pCR) and major pathological response (MPR) rates were 22.2% (4 of 18) and 44.4% (8 of 18) in the oncogene-positive IO group, 0% (P = 0.120) and 23.1% (3 of 13) (P = 0.276) in the oncogene-positive chemo/TKIs group, and 46.7% (7 of 15) (P = 0.163) and 80.0% (12 of 15) (P = 0.072) in the oncogene-negative IO group, respectively. By the last follow-up, the median EFS time had not reached in the oncogene-positive IO group, and was 29.5 months in the oncogene-positive chemo/TKIs group and 38.4 months in the oncogene-negative IO group. CONCLUSION: Compared with chemotherapy/TKIs treatment, neoadjuvant treatment with PD-(L)1 blockade plus platinum-based chemotherapy was associated with higher pCR/MPR rates in patients with partially resectable oncogene-mutant NSCLC, while the pCR/MPR rates were lower than their oncogene-negative counterparts treated with PD-(L)1 blockade-based treatment. Specifically, oncogene alteration types and other predictors of response to immunotherapy should be taken into account in clinical practice.

A new two-dimensional, spiropyran-based polymer fluorescent nanoprobe with quantitative-fluorescent and photochromic properties for multi-substance detection.

One challenge of the structural design of a fluorescent probe is how to improve the detection performance on trace target analytes in complex samples. Herein a new polymer fluorescent nanoprobe (2DSP-C28) has been synthesized, by adopting a two-dimensional (2D), spiropyran (SP)-based nanosheet structure with hydrophobic long-chain alkanes (C28). Unlike a traditional SP-based small molecule probe, the 2DSP-C28probe can exhibit quantitative-fluorescent and photochromic properties. Under the detection of metal-ions, the nanoprobe in dimethyl sulfoxide aqueous solution is selectively fluorescent-quenched-responsive for Fe-ions (∼100µM), with a characteristic stoichiometric ratio of <10, a high sensitivity (limit of detection: ∼0.2µM). When the nanoprobe is incorporated into electrospun polyethylene oxide, it can be used for gas detection, and display a color-change with acid-base gas and identify the HF gas. It is expected that this new polymer fluorescent nanoprobe can be promisingly applied for rapidly environmental monitoring on the ion or gas pollution.

Water-Stable High-Entropy Metal-Organic Framework Nanosheets for Photocatalytic Hydrogen Production.

Metal-organic frameworks (MOFs) have emerged as promising platforms for photocatalytic hydrogen evolution reaction (HER) due to their fascinating physiochemical properties. Rationally engineering the compositions and structures of MOFs can provide abundant opportunities for their optimization. In recent years, high-entropy materials (HEMs) have demonstrated great potential in the energy and environment fields. However, there is still no report on the development of high-entropy MOFs (HE-MOFs) for photocatalytic HER in aqueous solution. Herein, the authors report the synthesis of a novel p-type HE-MOFs single crystal (HE-MOF-SC) and the corresponding HE-MOFs nanosheets (HE-MOF-NS) capable of realizing visible-light-driven photocatalytic HER. Both HE-MOF-SC and HE-MOF-NS exhibit higher photocatalytic HER activity than all the single-metal MOFs, which are supposed to be ascribed to the interplay between the different metal nodes in the HE-MOFs that enables more efficient charge transfer. Moreover, impressively, the HE-MOF-NS demonstrates much higher photocatalytic activity than the HE-MOF-SC due to its thin thickness and enhanced surface area. At optimum conditions, the rate of H2 evolution on the HE-MOF-NS is ≈13.24 mmol h-1 g-1, which is among the highest values reported for water-stable MOF photocatalysts. This work highlights the importance of developing advanced high-entropy materials toward enhanced photocatalysis.

Design, synthesis, and evaluation of thiazolecarboxamide derivatives as stimulator of interferon gene inhibitors.

Stimulator of interferon gene (STING) plays critical roles in the cytoplasmic DNA-sensing pathway and in the induction of inflammatory response. Aberrant cytoplasmic DNA accumulation and STING activation are implicated in numerous inflammatory and autoimmune diseases. Here, we reported the discovery of a series of thiazolecarboxamide-based STING inhibitors through a molecular planarity/symmetry disruption strategy. The privileged compound 15b significantly inhibited STING signaling and suppressed immune-inflammatory cytokine levels in both human and murine cells. In vivo experiments demonstrated 15b effectively ameliorated immune-inflammatory cytokines upregulation in MSA-2-stimulated and Trex1-D18N mice. Furthermore, compound 15b exhibited enhanced efficacy in suppressing interferon-stimulated gene 15 (ISG15), a critical positive feedback regulator of STING. Overall, compound 15b deserves further development for the treatment of STING-associated inflammatory and autoimmune diseases.

A convolutional neural network prediction model for aviation nitrogen oxides emissions throughout all flight phases.

In recent years, there has been an increasing amount of research on nitrogen oxides (NOx) emissions, and the environmental impact of aviation NOx emissions at cruising altitudes has received widespread attention. NOx may play a crucial role in altering the composition of the atmosphere, particularly regarding ozone formation in the upper troposphere. At present, the ground emission database based on the landing and takeoff (LTO) cycle is more comprehensive, while high-altitude emission data is scarce due to the prohibitively high cost and the inevitable measurement uncertainty associated with in-flight sampling. Therefore, it is necessary to establish a comprehensive NOx emission database for the entire flight envelope, encompassing both ground and cruise phases. This will enable a thorough assessment of the impact of aviation NOx emissions on climate and air quality. In this study, a prediction model has been developed via convolutional neural network (CNN) technology. This model can predict the ground and cruise NOx emission index for turbofan engines and mixed turbofan engines fueled by either conventional aviation kerosene or sustainable aviation fuels (SAFs). The model utilizes data from the engine emission database (EEDB) released by the International Civil Aviation Organization (ICAO) and results obtained from several in-situ emission measurements conducted during ground and cruise phases. The model has been validated by comparing measured and predicted data, and the results demonstrate its high prediction accuracy for both the ground (R2 > 0.95) and cruise phases (R2 > 0.9). This surpasses traditional prediction models that rely on fuel flow rate, such as the Boeing Fuel Flow Method 2 (BFFM2). Furthermore, the model can predict NOx emissions from aircrafts burning SAFs with satisfactory accuracy, facilitating the development of a more complete and accurate aviation NOx emission inventory, which can serve as a basis for aviation environmental and climatic research. SYNOPSIS: The utilization of the ANOEPM-CNN offers a foundation for establishing more precise emission inventories, thereby reducing inaccuracies in assessing the impact of aviation NOx emissions on climate and air quality.

Discovery of hematopoietic progenitor kinase 1 inhibitors using machine learning-based screening and free energy perturbation.

Hematopoietic progenitor kinase 1 (HPK1) is a key negative regulator of T-cell receptor (TCR) signaling and a promising target for cancer immunotherapy. The development of novel HPK1 inhibitors is challenging yet promising. In this study, we used a combination of machine learning (ML)-based virtual screening and free energy perturbation (FEP) calculations to identify novel HPK1 inhibitors. ML-based screening yielded 10 potent HPK1 inhibitors (IC50 < 1 µM). The FEP-guided modification of the in-house false-positive hit, DW21302, revealed that a single key atom change could trigger activity cliffs. The resulting DW21302-A was a potent HPK1 inhibitor (IC50 = 2.1 nM) and potently inhibited cellular HPK1 signaling and enhanced T-cell function. Molecular dynamics (MD) simulations and ADME predictions confirmed DW21302-A as candidate compound. This study provides new strategies and chemical scaffolds for HPK1 inhibitor development.Communicated by Ramaswamy H. Sarma.

Discovery of a 1,6-naphthyridin-4-one-based AXL inhibitor with improved pharmacokinetics and enhanced in vivo antitumor efficacy.

The receptor tyrosine kinase AXL has emerged as an attractive target in anticancer drug discovery. Herein, we described the discovery of a new series of 1,6-naphthyridin-4-one derivatives as potent AXL inhibitors. Starting from a low in vivo potency compound 9 which was previously reported by our group, we utilized structure-based drug design and scaffold hopping strategies to discover potent AXL inhibitors. The privileged compound 13c was a highly potent and orally bioavailable AXL inhibitor with an IC50 value of 3.2 ± 0.3 nM. Compound 13c exhibited significantly improved in vivo antitumor efficacy in AXL-driven tumor xenograft mice, causing tumor regression at well-tolerated dose, and demonstrated favorable pharmacokinetic properties (MRT = 16.5 h, AUC0-∞ = 59,815 ng h/mL) in Sprague-Dawley rats. These results suggest that 13c is a promising therapeutic candidate for AXL-targeting cancer treatment.

Thiol-ene chemistry incorporates a new spiropyran-containing polyurethane ionogel with photochromic, photomechanical and photoconductive properties.

The photocuring technology based on thiol-ene click reaction can be easily applied for copolymerizing or crosslinking the acrylate monomers for ionogels. However, there is still a problem: when the acrylate monomers contain the popular spiropyran as the stimuli-responsive group, it should be concerned about the participation of the active CC bond from the ring-opened spiropyran during a thiol-ene reaction, which may in turn affect the stimuli-responsiveness of the spiropyran. Up to now, the structure and properties of spiropyran-containing ionogels in this case have still not been well investigated. Therefore, in this work we carefully study a new spiropyran-containing polyurethane ionogel by crosslinking an acrylate-terminated, spiropyran-containing polyurethane prepolymer and a polythiol in ionic liquid through thiol-ene chemistry. It is found for the first time that, during constructing an ionogel, the coexistence of a reversible thiol-ene reaction between the CC bond from the ring-opened spiropyran and the thiol group can bring about a different reverse photochromic behavior. The proposed mechanism of the abnormal photochromism is analyzed. In addition, it is also observed that the thiol-ene chemistry can incorporate photomechanical and photoconductive properties into the new spiropyran-containing ionogel.

Exhaust aftertreatment device-derived ammonia emissions from conventional and hybrid light-duty gasoline vehicles over different driving cycles.

Ammonia emissions from motor vehicles have great effect on air pollution and human health in urban areas. Recently, many countries have focus on ammonia emission measurement and control technologies for light-duty gasoline vehicles (LDGVs). To analyze ammonia emission characteristics, three conventional LDGVs and one hybrid electric light-duty vehicle (HEV) were evaluated over different driving cycles. The average ammonia emission factor at 23℃ was 4.5 ± 1.6 mg/km over Worldwide harmonized light vehicles test cycle (WLTC). Most ammonia emissions mainly concentrated in low and medium speed sections at cold-start stage, which were related to rich burn conditions. The increasing ambient temperatures led to the decrease of ammonia emissions, but high load caused by extremely elevated ambient temperature led to obvious ammonia emissions. The ammonia formation is also related to three-way catalytic converter (TWC) temperatures, and underfloor TWC catalyst could eliminate ammonia partly. The ammonia emission from HEV, which are significant less than LDGV, corresponded to the engine working state. The large temperature difference in the catalysts caused by power source shifts were the main reason. Exploring the effects of various factors on the ammonia emission is beneficial for revealing the instinct formation conditions, providing theoretical support for the future regulations.

Ruthenium nanoclusters modified by zinc species towards enhanced electrochemical hydrogen evolution reaction.

Ruthenium (Ru) has been considered a promising electrocatalyst for electrochemical hydrogen evolution reaction (HER) while its performance is limited due to the problems of particle aggregation and competitive adsorption of the reaction intermediates. Herein, we reported the synthesis of a zinc (Zn) modified Ru nanocluster electrocatalyst anchored on multiwalled carbon nanotubes (Ru-Zn/MWCNTs). The Ru-Zn catalysts were found to be highly dispersed on the MWCNTs substrate. Moreover, the Ru-Zn/MWCNTs exhibited low overpotentials of 26 and 119 mV for achieving current intensities of 10 and 100 mA cm-2 under alkaline conditions, respectively, surpassing Ru/MWCNTs with the same Ru loading and the commercial 5 wt% Pt/C (47 and 270 mV). Moreover, the Ru-Zn/MWCNTs showed greatly enhanced stability compared to Ru/MWCNTs with no significant decay after 10,000 cycles of CV sweeps and long-term operation for 90 h. The incorporation of Zn species was found to modify the electronic structure of the Ru active species and thus modulate the adsorption energy of the Had and OHad intermediates, which could be the main reason for the enhanced HER performance. This study provides a strategy to develop efficient and stable electrocatalysts towards the clean energy conversion field.

Resonance-Enhanced Emission Effects toward Dual-State Emissive Bright Red and Near-Infrared Emitters.

Resonance-enhanced emission (REE) effect was discovered and lead to a novel dye family of hydrostyryl pyridinium derivatives in our recent work. Herein, the REE effect was employed to design a red and near-infrared dual-state emissive fluorophore family of SW-OH-NO2 derivatives which were easily synthesized by coupling an electron-withdrawing group (W) onto nitro(hydroxyl)styryl (S-OH-NO2 ) through a C=C double bond as π-bridge. The deprotonation of a phenolic hydroxyl group promoted by a nitro group and the electron-withdrawing group (W) on the other side of the π-bridge triggered resonance, resulting in significantly red-shifted emission. All the resultant SW-OH-NO2 compounds showed excellent dual-state emission behavior. Remarkably, hydrostyryl quinolinium (SQ-OH-NO2 ) is one of the smallest NIR emitter molecular skeleton (λem =725 nm, MW<400) and showed dual-state emission characteristics and obvious viscosity-depended fluorescent behaviors. In addition to constructing electron donor-acceptor structures and prolonging π-bridges, the REE effect promises a reliable strategy toward novel fluorophores with small size, long emissive wavelength, and dual-emission characteristics, and importantly, feasible industrial manufactures and applications due to their easy and low-cost synthesis strategy.

Recent advances and perspectives towards emission inventories of mobile sources: Compilation approaches, data acquisition methods, and case studies.

In recent years, great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source populations. Compilation of a mobile source emission inventory is conducive to the analysis of pollution emission characteristics and the formulation of emission reduction policies. This study summarizes the latest compilation approaches and data acquisition methods for mobile source emission inventories. For motor vehicles, a high-resolution emission inventory can be developed based on a bottom-up approach with a refined traffic flow model and real-world speed-coupled emission factors. The top-down approach has advantages when dealing with macroscale vehicle emission estimation without substantial traffic flow infrastructure. For nonroad mobile sources, nonroad machinery, inland river ships, locomotives, and civil aviation aircraft, a top-down approach based on fuel consumption or power is adopted. For ocean-going ships, a bottom-up approach based on automatic identification system (AIS) data is adopted. Three typical cases are studied, including emission reduction potential, a cost-benefit model, and marine shipping emission control. Outlooks and suggestions are given on future research directions for emission inventories for mobile sources: building localized emission models and factor databases, improving the dynamic updating capability of emission inventories, establishing a database of emission factors of unconventional pollutants and greenhouse gas from mobile sources, and establishing an urban high temporal-spatial resolution volatile organic compound (VOC) evaporation emission inventory.

Effectiveness of inactivated COVID-19 vaccines against mild disease, pneumonia, and severe disease among persons infected with SARS-CoV-2 Omicron variant: real-world study in Jilin Province, China.

It is critical to determine the real-world performance of vaccines against coronavirus disease 2019 (COVID-19) so that appropriate treatments and policies can be implemented. There was a rapid wave of infections by the Omicron variant in Jilin Province (China) during spring 2022. We examined the effectiveness of inactivated vaccines against Omicron using real-world data from this epidemic. This retrospective case-case study of vaccine effectiveness (VE) examined infected patients who were quarantined and treated from April 16 to June 8, 2022 and responded to an electronic questionnaire. Data were analyzed by univariable and multivariable analyses. A total of 2968 cases with SARS-CoV-2 infections (asymptomatic: 1061, mild disease: 1763, pneumonia: 126, severe disease: 18) were enrolled in the study. Multivariable regression indicated that the risk for pneumonia or severe disease was greater in those who were older or had underlying diseases, but was less in those who received COVID-19 vaccines. Relative to no vaccination, VE against the composite of pneumonia and severe disease was significant for those who received 2 doses (60.1%, 95%CI: 40.0%, 73.5%) or 3 doses (68.1%, 95%CI: 44.6%, 81.7%), and VE was similar in the subgroups of males and females. However, VE against the composite of all three classes of symptomatic diseases was not significant overall, nor after stratification by sex. There was no statistical difference in the VE of vaccines from different manufacturers. The inactivated COVID-19 vaccines protected patients against pneumonia and severe disease from Omicron infection, and booster vaccination enhanced this effect.

Emission Characteristics and Health Risks of Volatile Organic Compounds (VOCs) Measured in a Typical Recycled Rubber Plant in China.

The continued development of the automotive industry has led to a rapid increase in the amount of waste rubber tires, the problem of "black pollution" has become more serious but is often ignored. In this study, the emission characteristics, health risks, and environmental effects of volatile organic compounds (VOCs) from a typical, recycled rubber plant were studied. A total of 15 samples were collected by summa canisters, and 100 VOC species were detected by the GC/MS-FID system. In this study, the total VOCs (TVOCs) concentration ranged from 1000 ± 99 to 19,700 ± 19,000 µg/m3, aromatics and alkanes were the predominant components, and m/p-xylene (14.63 ± 4.07%-48.87 ± 3.20%) could be possibly regarded as a VOCs emission marker. We also found that specific similarities and differences in VOCs emission characteristics in each process were affected by raw materials, production conditions, and process equipment. The assessment of health risks showed that devulcanizing and cooling had both non-carcinogenic and carcinogenic risks, yarding had carcinogenic risks, and open training and refining had potential carcinogenic risks. Moreover, m/p-xylene and benzene were the main non-carcinogenic species, while benzene, ethylbenzene, and carbon tetrachloride were the dominant risk compounds. In the evaluation results of LOH, m/p-xylene (25.26-67.87%) was identified as the most key individual species and should be prioritized for control. In conclusion, the research results will provide the necessary reference to standardize the measurement method of the VOCs source component spectrum and build a localized source component spectrum.

Anti-tumour effects of a macrolide analog F806 in oesophageal squamous cell carcinoma cells by targeting and promoting GLUT1 autolysosomal degradation.

Cancer cells are characterized by altered energetic metabolism with increasing glucose uptake. F806, a 16-membered macrodiolide analogue, has anti-tumour effects on oesophageal squamous cell carcinoma (ESCC) cells. However, its precise anti-tumour mechanism remains unclear. Here, metascape analysis of our previous quantitative proteomics data showed that F806 induced glucose starvation response and inhibited energy production in ESCC cells. The reduced glucose uptake and ATP production were further validated by the fluorescent methods, using glucose-conjugated bioprobe Glu-1-O-DCSN, and the bioluminescent methods, respectively. Consistently, under F806 treatment the AMP-activated protein kinase signalling was activated, and autophagy flux was promoted and more autophagosomes were formed. Moreover, live-cell imaging and immunofluorescence analysis showed that F806 induced GLUT1 plasma membrane dissociation and promoted its internalization and autolysosome accumulation and lysosome degradation. Furthermore, molecular docking studies demonstrated that F806 bound to GLUT1 with a comparable binding energy to that of GLUT1's direct interacting inhibitor cytochalasin B. Amino acid mutation was used to test which residues of GLUT1 may participate in F806 mediated-GLUT1 internalization and degradation, and results showed that Thr137, Asn411 and Trp388 were required for GLUT1 internalization and degradation, respectively. Taken together, these findings shed light on a novel anti-tumour mechanism of F806 by targeting and promoting GLUT1 internalization and further autolysosomal degradation.

Evaluation of real-world emissions of China V heavy-duty vehicles fueled by diesel, CNG and LNG on various road types.

Natural gas has been widely considered as an alternative fuel to diesel on heavy-duty vehicles (HDVs). To evaluate the real-world emissions, 19 diesel HDVs, 3 CNG HDVs and 9 LNG HDVs were tested using portable emission measurement system on urban, suburban and freeway roads . The results show that average emission rates of CO, HC and NOx from diesel, CNG and LNG HDVs tend to rise with the increasing of VSP. Due to different emission control strategies and complicated driving cycle, NOx reduction rates of real-world emission factors are lower than those of the corresponding limits from China II to China V diesel HDVs. CO and NOx emission factors from all tested HDVs on urban road are generally higher than those on suburban road in the same velocity intervals, which means driving behaviors on different road types have great influence on emission factors in the same velocity intervals. NOx emission factors from LNG HDVs are higher than those from diesel HDVs, indicating that using China V LNG HDVs instead of China V diesel HDVs could not be an ideal alternative for freeway transportation. As CO and NOx comprehensive emission factors from China V CNG HDVs are higher than those from China V diesel, even higher than China IV diesel HDVs, China V CNG HDVs are unable to be considered as cleaner vehicles when compared to China V diesel HDVs in the study. It is noticeable that HC emission factors from CNG and LNG HDVs are extremely higher compare with diesel HDVS. NO2 emission factors from LNG HDVs are 2.14-9.19 and 4.74-8.53 times than those from diesel and CNG HDVs with various road types. Our study can provide development road map for different fuel types of HDVs and the reference for new emission legislation of HDVs.

Study on real-world power-based emission factors from typical construction machinery.

Construction machinery accounts for a large share of the non-road machinery market and is an important pollutant source. In this study, real-world emission tests were undertaken on 16 excavators and 19 wheel loaders by using a portable emission measurement system (PEMS) to obtain their real-world engine performance and emission factors. The typical operating modes were categorized as idling, moving and working modes. The results show that in the working mode, the engine continuously operated at a high speed, high torque and high load factor, which led to sharp up and down CO, HC, NOx and particle number (PN) emissions. As the emission standards were strengthened, the CO, HC and NOx emissions clearly decreased, and the excavators and wheel loaders showed a higher emission level in the moving mode. A comparison of the excavator and wheel loader in China III displayed that the CO, HC, and NOx total emission factors of the wheel loader were 10.20, 2.70 and 1.79 times higher than those of the excavator, respectively, so the wheel loader contributed more seriously to environmental pollution. The CO and HC measured emission factors of the excavators and wheel loaders were 0.05-1.38 times and 0.13-0.58 times higher than the corresponding Limitation and the recommended values from the national emission inventory Guideline. However, the NOx emission factors were 1.20-3.25 times higher than the corresponding Limitation and the recommended value from the Guideline, which means that the recommended values overestimate CO and HC, and underestimate NOx. A comparison of the emission factors of the excavators and wheel loaders in this study with others demonstrate that the CO and HC power-based emission factors were generally lower, but the NOx emission factor was higher.

Modeling the emissions of rural vehicles based on real-world driving cycles.

Characterized by a high frequency of use, harsh working environments, poor maintenance, and low levels of emission controls, rural vehicles (RVs) are becoming an important source of air pollution. Our study used a portable emission measurement system (PEMS) to test the real-world emissions of 35 RVs on provincial, rural, and farm roads. The results show that high emission rates of carbon monoxide (CO) and hydrocarbons (HC) mainly occurred when accelerating at low speeds. However, high levels of nitrogen oxides (NOx) were emitted during high-speed acceleration. The particulate number (PN) of emissions was higher when the RVs were accelerating. According to the overall test results, the vehicle specific power (VSP) on the provincial road mostly ranged within (0, 3], accounting for 68.80% of the total. The VSP on rural and farm roads was concentrated within (0, 2] kW·ton-1, accounting for 67.09% and 76.64% of the total, respectively. We defined 14 bins based on the distribution of the VSP values and calculated the average emission rate of each bin. By comparing the average emission rate among the bins, we found that within Bins 1-7 (VSP < 0 kW·ton-1), CO, HC, and NOx emissions slowly increased as the VSP increased. In Bins 8-13 (VSP ≥ 0 kW·ton-1), the average emission rates of four pollutants increased as the VSP increased. However, all pollutants decreased in Bin 14 (VSP ≥ 6 kW·ton-1). We built a microscopic emission model according to the VSP distribution characteristics of RVs on different road types. We compared the measured and simulated emission factors and found that our emission model can greatly simulate the HC, NOx and PN emission factors of RVs.

Shallow Oxygen Substitution Defect to Deeper Defect Transformation Mechanism in Ta3N5 under Light Irradiation.

Defects are ubiquitous in semiconductors and critical to photo(electro)chemical performance, but the change of defect properties under light irradiation remains poorly understood. Herein, we studied defect change properties of Ta3N5 with transient absorption (TA) spectroscopy. A broad transient absorption (>650 nm) was observed and attributed to trapped electrons in oxygen impurities (substitution oxygen at nitrogen sites, ON), and two bleach signals at 510 and 580 nm were obtained and ascribed to free holes of Ta3N5. The charge recombination between the trapped electrons and the free holes is sensitively related to ON defects. The trap-detrapping recombination is retarded by increase of excitation intensity, which is contrary to the normal dependence of charge dynamics on excitation intensity. This abnormal dependence indicates that shallow ON• (singly positive charge states) defects of Ta3N5 transform to deeper ON× (neutral charge states) defects under strong light irradiation. The defect transformation results in long-lived free holes in Ta3N5 for photo(electro)catalysis.