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This paper investigates an intelligent reflecting surface (IRS) aided green multiple-user downlink communication system. In contrast to the existing works that deploy the IRS in a fixed location, the location of the IRS is taken as an optimization variable to minimize the total transmit power by jointly optimizing the location of the IRS, transmit beamformers at the base station (BS), and IRS phase shifts. We point out a critical conclusion that before and after IRS deployment, the channel state information (CSI) of all the communication terminals is different, so an offline-online hybrid-CSI optimization framework is proposed to solve the problem. In the offline stage, we optimize the IRS location with only the statistical CSI (S-CSI) so the ergodic quality of service (QoS) constraints have to be considered, and universal lower bounds associated only with the location variable are derived to decouple all variables. In the online stage, all the instantaneous-CSI (I-CSI) are available. To solve this non-convex problem, an alternating optimization framework is developed. We propose a Riemannian Manifold (RM) algorithm to optimize the IRS phase shifts. Simulation results validate that the proposed algorithm is convergent and effective, and show that the location deployment of IRS is crucial for green communication.

Considering the overarching trend in mobile communication development, the extensive coverage and seamless connectivity offered by non-terrestrial networks (NTN) are becoming increasingly essential. NTN communications, characterized by extensive data volumes, hyper-connectivity, and large-scale fading, present notable challenges to traditional communication methods. This paper proposes a semantic communication-based NTN (SC-based NTN) architecture, highlighting its potential applications. However, the integration of semantic communication within NTN faces three key challenges, including multimodality, security, and resource allocation. This paper explores the opportunities presented by artificial intelligence, physical layer security, and intelligent resource management technologies, which promote multimodal, secure, and efficient communications for NTN. Finally, the paper outlines a visionary outlook for SC-based NTN, highlighting its potential impact on the future of mobile networks.

With the rapid advancement of air interface technology and the exponential growth of mobile services, mobile networks have become significantly complex. Traditional network security models, relying on regional defense strategies, are no longer sufficient to meet the current security demands. This article proposes the zero-trust architecture as a potential security mode for 6G. However, the distributed network architecture, the proliferation of connected devices, and the diverse service requirements of 6G pose sub-stantial challenges to this security model implementation. To address these issues, the article explores the opportunities presented by artificial intelligence (Al) and novel air interface technologies, which promote robust and efficient identity authentication, access control, and confidential data transmission for 6G. Finally, the article outlines a visionary outlook for the zero trust-based 6G security architecture, highlighting its potential impact on the future of mobile networks.

In this paper, physical layer security (PLS) in an intelligent reflecting surface (IRS) assisted multiple-input multiple-output multiple-antenna eavesdropper (MIMOME) system is studied. In particular, we consider a practical scenario without instantaneous channel state information (CSI) of the eavesdropper and assume that the eavesdropping channel is a Rayleigh channel. To deal with the complexity of currently available IRS-assisted PLS schemes, we propose a low-complexity deep learning (DL) based approach to design transmitter beamforming and IRS jointly, where precoding vector and phase shift matrix are used to minimize the secrecy outage probability. Simulation results demonstrate that the proposed DL-based approach can achieve a similar performance of that with conventional alternating optimization (AO) algorithms with a significantly low computational complexity.

In this paper, we propose a multi-roadside unit (RSU) assisted mobile crowd computing framework for intelligently connected vehicle (ICV) networks, where vehicles within RSUs’ coverage act as workers to provide their computation and communication resources for computing resource limited vehicle user equipments (VUEs). Physical (PHY) layer security is used to secure computation task offloading and results feedback in time-varying vehicular channels. Artificial noise (AN) assisted adaptive wiretap coding is adopted to enhance the security of offloading links. With PHY security, the intended receiver can decode secret message while eavesdropper cannot. A modified exhaustive two-dimensional (2D) search algorithm is proposed to optimize transmission rate and secrecy rate in an effective secrecy throughput maximization problem, and a multi-agent twin delayed deep deterministic policy gradient algorithm (MATD3) is utilized to assign VUEs’ tasks without a central controller, where a reward function is defined according to the computing costs, including execution time, energy consumption, and price paid for computing. Finally, simulations verify the effectiveness of the proposed framework.

This article investigates physical layer security (PLS) in reconfigurable intelligent surface (RIS)-assisted multiple-input multiple-output multiple-antenna-eavesdropper (MIMOME) channels. Existing researches ignore the problem that secrecy rate can not be calculated if the eavesdropper’s instantaneous channel state information (CSI) is unknown. Furthermore, without the secrecy rate expression, beamforming and phase shifter optimization with the purpose of PLS enhancement is not available. To address these problems, we first give the expression of secrecy outage probability for any beamforming vector and phase shifter matrix as the RIS-assisted PLS metric, which is measured based on the eavesdropper’s statistical CSI. Then, with the aid of the expression, we formulate the minimization problem of secrecy outage probability that is solved via alternately optimizing beamforming vectors and phase shift matrices. In the case of single-antenna transmitter or single-antenna legitimate receiver, the proposed alternating optimization (AO) scheme can be simplified to reduce computational complexity. Finally, it is demonstrated that the secrecy outage probability is significantly reduced with the proposed methods compared to current RIS-assisted PLS systems.

In frequency division duplex (FDD) massive multi-input multi-output (MIMO), the two-stage beamforming (TSB) using channel covariance matrices (CCM) can significantly reduce the downlink training length (DTL) and channel feedback. However, the overhead to estimate the CCM is large. In this paper, a combinatorial multi-armed bandit (CMAB) based TSB scheme is proposed without requirement of CMM. Particularly, the problem of the pre-beamforming matrix design is transformed into a CMAB problem. We consider the pre-beamforming matrix design in each slot as the arm selection in the CMAB, and convert the problem of the arm selection into a 0-1 integer linear programming problem, which can be solved by the branch-and-bound method. During the training process, the maximum likelihood method is used to detect the power of angle spectrum, and the angle range of each user is determined adaptively. We prove that the regret grows logarithmically with time, such that the proposed scheme converges towards the optimal action. Finally, simulation results demonstrate that the proposed scheme can significantly improve the spectral efficiency.

As a promising direct measurement method of atmospheric hydroperoxyl radicals (HO2), bromide chemical ionization mass spectrometry (Br-CIMS) has been first demonstrated by Sanchez et al. (Atmos. Meas. Tech.2016, 9, 3851–3861). However, field application of this method is currently still sparse, and there is still a gap between measured HO2concentrations and calculated ones derived from the atmospheric equilibrium between HO2and peroxynitric acid (HO2NO2). In this work, we constructed an improved Br-CIMS with optimizations of custom-built front-end devices, chamber pressures, and instrumental voltages to achieve a 3σ detection limit of 0.5 ppt at an integration time of 60 s and a sensitivity of 1–3 cps ppt–1under a total reagent ion signal of 0.2 MHz for HO2detection. HO2NO2, a product from atmospheric reactions between HO2and NO2, can also be detected by Br-CIMS, whose interference on the HO2measurement was found but nearly eliminated by regulating key CIMS voltages to minimize the decomposition of (BrHO2NO2)−ions in the MS. In addition, a 2 week field campaign was carried out in urban Shanghai, demonstrating that the interference of HO2from ambient HO2NO2was less than 10% of the true HO2signal under our optimized CIMS voltage setting. Our study suggests that Br-CIMS is a reliable technique for atmospheric HO2measurements.

A series of V0.04W0.03MoxSby/TiO2catalysts was prepared by impregnating various contents of Mo and Sb. The optimum V0.04W0.03Mo0.015Sb0.018/TiO2catalyst exhibited enhanced SCR activity in a wide temperature range of 160–320 °C, together with excellent SO2and H2O resistance. The addition of an appropriate amount of Mo and Sb could strengthen the alkali metal resistance of the V0.04W0.03/TiO2catalyst. The Mo and Sb co-modified catalyst exhibited a large specific surface area. The XPS and EPR results confirmed the presence of abundant V4+and Oβon the modified catalyst. The TPR and TPD experiments revealed that the enhanced low-temperature redox ability and improved surface acidity played a key role in the superior catalytic activity and alkali metal resistance over the V0.04W0.03Mo0.015Sb0.018/TiO2catalyst. The in situDRIFTS results revealed that the reaction mechanism followed the E–R mechanism over the V0.04W0.03Mo0.015Sb0.018/TiO2catalyst at 180 °C. Additionally, the inhibitory effect of K was mainly attributed to the destruction of the redox ability and surface acidity of the catalyst.

ABSTRACTDue to profound impact on climate and human health, air quality has attracted attention from all levels of the civil society. The key step in the provision of required tools for the society to tackle the complex air quality problem is to characterize it in a comprehensive manner with a long-term perspective. Here, we describe a continuous and comprehensive observation station and its accompanying state-of-the-art instrumentation that was established to investigate the complex urban atmospheric environment in a rapidly developing Chinese Megacity. The station, located in downtown Beijing, aims to study air quality by identifying the major atmospheric pollutants and key processes determining their formation and loss mechanisms. A few hundreds of parameters are continuously measured with the state-of-the-art instruments, including trace gas concentrations, aerosol particle size distributions, and mass concentrations, covering aerosol particle chemical composition from molecules to micrometer-sized aerosol particles. This produced long-term, comprehensive big data with around bytes per year. In this paper, we provide an overview on the facilities of the station, the instrumentation used, the workflow of continuous observations and examples of results from 2018 to 2019 and a basis for establishing a modern long-term, comprehensive atmospheric urban observation station in other megacities.

The existing investigations on artificial noise (AN) security systems assumed that only null spaces are used to send AN signals, and all eigen-subchannels should be used to transmit messages. Our previous work proposed an AN scheme that allocates some of eigen-subchannels to transmit AN signals for improving secrecy rates. Nevertheless, our previous work considered only uncorrelated MIMO Rayleigh fading channels. In fact, the correlations among antennas exist in realistic scattering channel environments. In this paper, we extend our previous AN scheme to spatially correlated Rayleigh fading channels at both legitimate receiver and eavesdropper sides and derive an exact theoretical expression for the ergodic secrecy rate of the AN scheme, along with an approximate analysis. Both numerical and simulation results show that the proposed AN scheme offers a higher ergodic secrecy rate than the existing schemes, revealing a fact that the correlation among eavesdropper’s antennas can potentially improve the secrecy rate of an MIMO system.

This paper proposes a brain-computer interface (BCI)-based teleoperation strategy for a dual-arm robot carrying a common object by multifingered hands. The BCI is based on motor imagery of the human brain, which utilizes common spatial pattern method to analyze the filtered electroencephalograph signals. Human intentions can be recognized and classified into the corresponding reference commands in task space for the robot according to phenomena of event-related synchronization/desynchronization, such that the object manipulation tasks guided by human user's mind can be achieved. Subsequently, a concise dynamics consisting of the dynamics of the robotic arms and the geometrical constraints between the end-effectors and the object is formulated for the coordinated dual arm. To achieve optimization motion in the task space, a redundancy resolution at velocity level has been implemented through neural-dynamics optimization. Extensive experiments have been made by a number of subjects, and the results were provided to demonstrate the effectiveness of the proposed control strategy.

In this paper, we deal with the existence of solutions for the fractional impulsive functional differential equations with nonlocal conditions. Then we build a new comparison theorem and obtain the existence of extremal solutions and quasi-solutions by use of the monotone iterative technique and the method of lower and upper solutions.

In this paper, we deal with multiple solutions of fractional differential equations with p-Laplacian operator and nonlinear boundary conditions. By applying the Amann theorem and the method of upper and lower solutions, we obtain some new results on the multiple solutions. An example is given to illustrate our results.

Infiltration of regioregular poly(3‐hexyl thiophene) (RR P3HT) polymer into ordered TiO2nanotube arrays is confirmed by UV–Vis absorption spectrometer measurement, time‐of‐flight secondary ion mass spectrometer (TOF‐SIMs) depth profiling and transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Ordered TiO2nanotube arrays of thickness 19 µm were formed by 2‐step anodization of titanium foil in an ethylene‐glycol‐based solution and a dip‐coating method was used to infiltrate the polymer into the TiO2nanotubes.UV–Vis absorption spectrometer measurement of P3HT/TiO2nanotubes shows a peak absorption at 500 nm due to embedded polymer within the nanotube arrays. TOF‐SIMs depth profiling up to 500 nm shows P3HT polymer is infiltrated into the TiO2nanotube arrays. Furthermore, energy‐dispersive X‐ray spectroscopy (EDX) of the TEM indicates the presence of sulfur and carbon atoms due to the P3HT polymer. Polymer nanotubes can be observed with SEM after TiO2nanotubes infiltrated with polymer are etched by dilute HF solution.

Synuclein γ (SNCG), previously identified as a breast cancer-specific gene, is highly expressed in malignant cancer cells but not in normal epithelium. The molecular targets of SNCG during breast cancer progression have not been fully identified. Here we analyzed the effect of SNCG on stimulation of membrane-initiated estrogen signaling. While SNCG expression enhanced estrogen-induced activation of ERK1/2 and mammalian target of rapamycin, knockdown of endogenous SNCG decreased membrane-initiated estrogen signaling. SNCG functions as a molecular chaperone protein for estrogen receptor (ER)-α36, a membrane-based variant of ER-α. SNCG bound to ER-α36 in the presence and absence of functional molecular chaperone heat shock protein 90. Disruption of heat shock protein 90 with 17-AAG significantly reduced ER-α36 expression and membrane-initiated estrogen signaling. However, expression of SNCG prevented ER-α36 degradation and completely recovered 17-AAG-mediated down-regulation of estrogen signaling. The function of SNCG in ER-α36-mediated estrogen signaling is consistent with its ability to stimulate cell growth in response to estrogen. Expression of SNCG also renders tamoxifen resistance, which is consistent with the clinical observation on the association of ER-α36 expression and tamoxifen resistance. The present study indicates that ER-α36 is a new member of the ER-α family that mediates membrane-initiated estrogen signaling and that SNCG can replace the function of heat shock protein 90, chaperone ER-α36 activity, stimulate ligand-dependent cell growth, and render tamoxifen resistance.

Previously, we have shown that synuclein γ (SNCG), a member of the brain protein synuclein family, is highly expressed in human infiltrating breast carcinomas but not expressed in normal or benign breast tissues. The SNCG mRNA was also detected in several human breast cancer cell lines with the highest expression found in H3922, a cell line derived from an infiltrating ductal carcinoma. In this study, we show that expression of SNCG mRNA in H3922 cells is significantly decreased by treating cells with the cytokine oncostatin M (OM) who has a growth-inhibitory effect on these cells. A decrease in SNCG mRNA level can be detected as early as 30 min after OM addition. By 4 h OM treatment, the level of SNCG mRNA was decreased to 70% of control, and by 24 h the mRNA was below detectable level. Western blot analysis further demonstrated the suppression of SNCG protein expression by OM. The level of SNCG protein in H3922 cells was reduced more than 90% by OM after 2 days. Since OM- induced growth inhibition occurs after 3–4 days, the down-regulation of SNCG expression appears to proceed the effect of OM on cell growth. Additional experiments to measure the transcriptional rates of SNCG indicate that the observed OM-induced down-regulation of SNCG mRNA occurs mainly at the transcriptional level. In an attempt to examine the role of SNCG gene in the proliferation of breast cancer cells, SNCG cDNA was stably transfected into MCF-7 cells that do not express endogenous SNCGgene. Examination of cell growth under anchorage-dependent and anchorage-independent conditions demonstrates that over expression of SNCGgene significantly stimulated the growth of MCF-7 cells both in monolayer culture and in soft agar. These data together suggest that SNCG may play a role in cell proliferation.

Intense and frequent new particle formation (NPF) events have been observed in polluted urban environments, yet the dominant mechanisms are still under debate. To understand the key species and governing processes of NPF in polluted urban environments, we conducted comprehensive measurements in downtown Beijing during January–March, 2018. We performed detailed analyses on sulfuric acid cluster composition and budget, as well as the chemical and physical properties of oxidized organic molecules (OOMs). Our results demonstrate that the fast clustering of sulfuric acid (H2SO4) and base molecules triggered the NPF events, and OOMs further helped grow the newly formed particles toward climate‐ and health‐relevant sizes. This synergistic role of H2SO4, base species, and OOMs in NPF is likely representative of polluted urban environments where abundant H2SO4and base species usually co‐exist, and OOMs are with moderately low volatility when produced under high NOxconcentrations. Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine particles worldwide. Those particles profoundly influence climate and human health. NPF includes two consecutive processes, that is, the formation of new particles (∼2 nm in diameter) and their subsequent growth to larger sizes. Extensive studies conducted in the laboratory and in forested areas have shown that many gaseous species can participate in NPF, such as sulfuric acid, ammonia, amines, and oxidize organic molecules. However, the actual roles of these vapors may vary significantly from location to location and are largely unclear in urban environments. Here, based on measurements of sulfuric acid, sulfuric acid clusters, and oxidize organic molecules, we demonstrate that sulfuric acid and base molecules were responsible for the initial formation of new particles during a wintertime field campaign in Beijing. The majority of oxidized organic molecules had a minor contribution to the formation of new particles but were crucial for particle growth above 2–3 nm to climate‐ and health‐relevant sizes. Process‐level understanding of new particle formation (NPF) in wintertime Beijing was obtained based on measurement state‐of‐the‐art instrumentsThe analysis of sulfuric acid cluster composition and budget showed that sulfuric acid‐base clustering initiated NPFCondensable organic vapors were characterized and demonstrated to have a crucial influence on the growth of newly formed particles Process‐level understanding of new particle formation (NPF) in wintertime Beijing was obtained based on measurement state‐of‐the‐art instruments The analysis of sulfuric acid cluster composition and budget showed that sulfuric acid‐base clustering initiated NPF Condensable organic vapors were characterized and demonstrated to have a crucial influence on the growth of newly formed particles

Ac-erbB-2 expression vector was transfected into the estrogen receptor positive (ER+) MCF-7 human breast cancer cell line to determine if overexpression of this transmembrane tyrosine kinase could increase the malignant phenotype of this cell line. Loss of transfectedc-erbB-2 expression was observed when cells were carried in medium containing estrogen. Homogeneous populations stably overexpressing levels of the 185 kDac-erbB-2 observed in the SKBR-3 a breast cancer cell line which overexpressesc-erbB-2 as a result of gene amplification could be obtained by continually maintaining the transfected cell lines in estrogen-free conditions. Levels of constitutively activatedc-erbB-2 varied among clonal isolates. Whereas some over-expressing lines did acquire the ability to form transient tumor nodules in ovariectomized nude mice without estrogen supplementation, as well as in mice that received the antiestrogen tamoxifen, one cell line that exhibited the highest levels of constitutively activatedc-erbB-2 was able to form static tumors of a larger size under both conditions. This same cell line formed progressively growing tumors in estrogen-supplemented mice that were much larger than observed in mice injected with control cell lines, and also showed reduced sensitivity to antiestrogensin vitro, but it continued to have a low metastatic phenotype. These results suggest that signal transduction mediated by thec-erbB-2 tyrosine kinase can partially overcome the estrogen dependence of ER+ breast cancer cells for growth and thatc-erbB-2 overexpression confers a selective advantage to such cells in the absence of estrogen.

The tissue inhibitors of metalloproteinases (TIMPs) constitute a family of proteins, of which three members have so far been described. Using the expressed sequence tag sequencing approach, we have identified a novel TIMP-related cDNA fragment and subsequently cloned a fourth human TIMP (TIMP-4) from a human heart cDNA library. The open reading frame encodes a 224-amino acid precursor including a 29-residue secretion signal. The predicted structure of the new protein shares 37% sequence identity with TIMP-1 and 51% identity with TIMP-2 and −3. The protein has a predicted isoelectric point of 7.34. The open reading frame-directed expression of TIMP-4 protein in MDA-MB-435 human breast cancer cells showed metalloproteinase inhibitory activity on reverse zymography. By Northern analysis, only the adult heart showed abundant TIMP-4 transcripts with a 1.4-kilobase predominant transcript band; very low levels of the transcripts were detected in the kidney, placenta, colon, and testes, and no transcripts were detected in the liver, brain, lung, thymus, and spleen. This unique expression pattern suggests that TIMP-4 may function in a tissue-specific fashion in extracellular matrix homeostasis.

The binding properties of the newly described tissue inhibitor of metalloproteinases-4 (TIMP-4) to progelatinase A and to the COOH-terminal hemopexin-like domain (C domain) of the enzyme were examined. We present evidence for the first time of a specific, high affinity interaction between TIMP-4 and the C domain of human gelatinase A and show that TIMP-4 binds both progelatinase A and the C domain in a similar manner to that of TIMP-2. Saturable binding of recombinant C domain to TIMP-4 and to TIMP-2 but not to TIMP-1 was demonstrated using a microwell protein binding assay. The recombinant collagen binding domain of gelatinase A, comprised of the three fibronectin type II-like repeats, did not bind to TIMP-4, indicating that binding is mediated selectively by the C domain. Binding to TIMP-4 was of high affinity with an apparent Kdof 1.7 × 10−7mbut slightly weaker than that to TIMP-2 (apparent Kdof 0.66 × 10−7m). Affinity chromatography confirmed the TIMP-4-C domain interaction and also showed that the complex could not be disrupted by 1 mNaCl or 10% dimethyl sulfoxide, thereby further demonstrating the tight binding. To verify the biological significance of this interaction, binding of full-length progelatinase A to TIMP-4 was investigated. TIMP-4 and TIMP-2 but not TIMP-1 bound specifically to purified TIMP-2-free human recombinant full-length progelatinase A and to full-length rat proenzyme from the conditioned culture medium of ROS 17/2.8 cells. Preincubation of the C domain with TIMP-2 was found to reduce subsequent binding to TIMP-4 in a concentration-dependent manner. Competition between TIMP-2 and TIMP-4 for a common or overlapping binding sites on the gelatinase A C domain may occur; alternatively TIMP-2 may prevent the binding of TIMP-4 by steric hindrance or induction of a conformational change in the C domain. We propose that the binding of progelatinase A to TIMP-4 represents a third TIMP-progelatinase interaction in addition to that of progelatinase A with TIMP-2 and progelatinase B with TIMP-1 described previously. This new phenomenon may be of important physiological significance in modulating the cell surface activation of progelatinase A.

TIMP-4, a novel human tissue inhibitor of metalloproteinase, was identified and cloned (Greene, J., Wang, M., Raymond, L. A., Liu, Y. E., Rosen, C., and Shi, Y. E. (1996) J. Biol. Chem.271, 30375–30380). In this report, the production and characterization of recombinant TIMP-4 (rTIMP4p) are described. rTIMP4p, expressed in baculovirus-infected insect cells, was purified to homogeneity by a combination of cation exchange, hydrophobic, and size-exclusion chromatographies. The purified protein migrated as a single 23-kDa band in SDS-polyacrylamide gel electrophoresis and in Western blot using a specific anti-TIMP-4 antibody. Inhibition of matrix metalloproteinase (MMP) activities by rTIMP4p was demonstrated in five MMPs. Enzymatic kinetic studies revealed IC50values (concentration at 50% inhibition) of 19, 3, 45, 8, and 83 nmfor MMP-1, MMP-2, MMP-3, MMP-7, and MMP-9, respectively. Purified rTIMP4p demonstrated a strong inhibitory effect on the invasion of human breast cancer cells across reconstituted basement membranes. Thus, TIMP-4 is a new enzymatic inhibitor in MMP-mediated extracellular matrix degradation and may have therapeutic potential in treating cancer malignant progression.

Sulfuric acid (SA)‐dimethylamine (DMA)‐H2O cluster formation has been proven to be responsible for a significant part of new particle formation (NPF) in a Chinese megacity. However, the possible involvement of common atmospheric acids in the subsequent growth of SA‐DMA clusters remains elusive. We simulated formation and growth of clusters using atmospheric relevant concentrations of SA, DMA, and trifluoroacetic acid (TFA), a commonly observed atmospheric perfluorocarboxylic acid, using Density Functional Theory combined with Atmospheric Cluster Dynamics Code. The presence of TFA leads to complex cluster formation routes and an enhancement of NPF rates by up to 2.3 ([TFA] = 5.0 × 106molecules cm−3, [SA] = 1.0 × 106molecules cm−3, and [DMA] = 1.5 × 109molecules cm−3). The agreement of (SA)1·(DMA)1‐2·(TFA)1concentrations between simulations and ambient measurements during NPF events validates model predictions and implies that perfluorocarboxylic acids could potentially boost atmospheric SA‐DMA NPF rates. Atmospheric nucleation is the earliest step to form new aerosol particles, which includes a complex transformation from gaseous molecules to small clusters, then to critical clusters, and finally to freshly nucleated nanoparticles. Sulfuric acid and dimethylamine have been proved to explain atmospheric nucleation events in urban China. However, whether other atmospheric acidic species could participate in this nucleation process remains elusive. Herein, we report a sulfuric acid‐dimethylamine based nucleation mechanism with the participation of trifluoroacetic acid, a commonly observed strong acid in the atmosphere, using theoretical calculation methods. The model predictions are then validated by ambient measurements in urban Shanghai. Our results suggest that perfluorocarboxylic acids could potentially boost the formation of nanoparticles. Theoretical simulations indicate complex atmospheric new particle formation mechanisms involving sulfuric acid, dimethylamine, and trifluoroacetic acidGood agreement of key cluster concentrations between simulations and ambient measurements during new particle formation events is obtainedTrifluoroacetic acid can participate in the growth of sulfuric acid‐dimethylamine clusters and enhance the nucleation rates

Orbital image mapping is a key technology to achieve scientific and engineering goals in deep space exploration missions. It provides topographic and morphological information for various scientific researches and also supports follow-up landing missions. This paper presents rigorous photogrammetric models for Chang'E-1 and MRO HiRISE images based on the pushbroom imaging principle. A multi-level stereo image matching method is developed in order to generate high precision DEMs of lunar and Mars surfaces.