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This work investigates the off-state leakage characteristics of AlN/GaN/AlGaN high electron mobility transistors (HEMTs) on Si substrate with varying mesa depths and uncovers the existence of a parasitic channel associated with the AlGaN back barrier. Significant differences in off-state leakage up to three orders of magnitude were observed between devices fabricated using different mesa depths. The electrical properties of AlN/GaN/AlGaN HEMTs were measured, and it was found that there is a N-type parasitic channel in the unintentionally doped AlGaN back-barrier. Analysis of the isolation test structure, which retains this parasitic channel, reveals a buffer leakage of 12.8 mA/mm and a sheet resistance of 7739.1 Ω/sq, as a result of the parasitic channel. The depletion electric field strength of the parasitic channel is 3.2 × 105 V/cm. Temperature-dependent I–V curves obtained from the isolation area affirm that the primary leakage mechanism is two-dimensional variable range hopping along the sidewall. As the isolation distance extends from 3 to 5 μm, the slope of the fitting line decreases from −53.14 to −126.11 due to increased resistance. [ABSTRACT FROM AUTHOR]

In0.17Al0.83N/GaN high‐electron‐mobility transistor (HEMT) using GaN‐on‐Insulator (GaNOI) technology via 200 mm wafer bonding technique is developed with good DC and RF performance and high fT/fmax. Measurements obtained from X‐Ray diffraction and micro‐Raman spectroscopy have demonstrated a 5% reduction in “a lattice strain,” which results in the improvement of the sheet resistance (Rsh) from 301 to 284 Ω □−1. A 120 nm gate‐length device achieves a peak fT up to 96 GHz which yields a fT × Lg value of 11.5 GHz μm, which compares favorably with reported GaN‐based HEMTs on Si. These results demonstrate that GaNOI HEMT on Si is an attractive candidate for future mm‐wave applications. The implementation of GaNOI technology facilitates the integration of GaN devices into a chip alongside complementary metal–oxide–semiconductor technology that opens up the potential for integrated high‐power and RF applications, enabling more compact and efficient systems. [ABSTRACT FROM AUTHOR]

Aero-space aluminum alloys, as vital materials in aerospace engineering, find extensive application in various aerospace components. However, prolonged usage often leads to the emergence of fatigue natural cracks, posing significant safety risks. Therefore, research on accurate quantitative detection techniques for the cracks in aerospace-aluminum alloys is of vital importance. Firstly, based on the three-points bending experimental model, this paper prepared the fatigue natural crack specimen, and the depth of the natural crack is calibrated. Then, given the complexity of geometric characteristics inherent in natural cracks, the pulsed eddy current signal under the different natural crack depth is acquired and analyzed using an experimental study. Finally, to better exhibit the non-linearity between PEC signal and crack depth, a GA-based BPNN algorithm is proposed. The Latin Hypercube method is considered to optimize the population distribution in the genetic algorithm. The results indicate that the characterization accuracy reaches 2.19% for the natural crack. [ABSTRACT FROM AUTHOR]

Link prediction is a concept of network theory that intends to find a link between two separate network entities. In the present world of social media, this concept has taken root, and its application is seen through numerous social networks. A typical example is 2004, 4 February “TheFeacebook,” currently known as just Facebook. It uses this concept to recommend friends by checking their links using various algorithms. The same goes for shopping and e-commerce sites. Notwithstanding all the merits link prediction presents, they are only enjoyed by large networks. For sparse networks, there is a wide disparity between the links that are likely to form and the ones that include. A barrage of literature has been written to approach this problem; however, they mostly come from the angle of unsupervised learning (UL). While it may seem appropriate based on a dataset’s nature, it does not provide accurate information for sparse networks. Supervised learning could seem reasonable in such cases. This research is aimed at finding the most appropriate link-based link prediction methods in the context of big data based on supervised learning. There is a tone of books written on the same; nonetheless, they are core issues that are not always addressed in these studies, which are critical in understanding the concept of link prediction. This research explicitly looks at the new problems and uses the supervised approach in analyzing them to devise a full-fledge holistic link-based link prediction method. Specifically, the network issues that we will be delving into the lack of specificity in the existing techniques, observational periods, variance reduction, sampling approaches, and topological causes of imbalances. In the subsequent sections of the paper, we explain the theory prediction algorithms, precisely the flow-based process. We specifically address the problems on sparse networks that are never discussed with other prediction methods. The resolutions made by addressing the above techniques place our framework above the previous literature’s unsupervised approaches.

The main factors restricting the mining speed of the working face in Yuenan Coal Mine are the water-rich area of limestone above the coal seam and the internal geological concealed structure. The transparent detection of the working face is carried out by using transient electromagnetic method, radio wave perspective and slot wave seismic geophysical methods. In the process of detection, it is found that the induced voltage received by the secondary wave field of transient electromagnetic method is more sensitive to the area of rich water and low resistance, and the lateral situation of coal seam can be identified by observing the energy attenuation emitted and received by radio wave perspective. The integrated analysis of envelope amplitude, spectrum and dispersion curve of in-seam wave seismic imaging has good effect on identifying fault strike. Through the identification of the comprehensive response characteristics of the abnormal region by the induction factor in the multi-wave field, the plane map is superimposed according to the abnormal area delineated by the multi-source wave field, and a variety of abnormal characteristics are shown synthetically, which can effectively identify the correlation between the water-rich area of the roof of the working face and the internal structural area of the coal seam, and clearly judge the existence of the water channel. The test results show that the geophysical method can find out the internal abnormal area of the mining face and predict in advance, and the combined detection of various geophysical methods can provide a reference basis for similar geological conditions in the future. [ABSTRACT FROM AUTHOR]

Differences between the business environment in the home country and the host country are an important factor when enterprises consider their location choice with regard to outward foreign direct investment (OFDI). However, this is ignored by much existing literature. Based on the trade‐off framework of international firms between exporting and participation in OFDI under the condition of heterogeneous enterprises, this paper constructs a theoretical model of the impact of distance of doing business (DDB) on OFDI. We take China's OFDI as an example and use the World Bank Group's Ease of Doing Business Index to construct the DDB indicator, as well as test the impact of the DDB on China's OFDI by combining the macro‐location panel data of China's OFDI between 2004 and 2017. The results showed that increasing DDB significantly reduces the scale of China's OFDI. The effect is robust. The mechanism is that DDB significantly decreases the success rate of OFDI and increases the cost of OFDI, thereby decreasing the scale of OFDI. Further analysis then finds that official acts, such as building partnerships, and folk acts, such as increasing cultural identity, can significantly reduce the negative effect of DDB on OFDI. [ABSTRACT FROM AUTHOR]

Concentrated stresses and residual ones are critical for the metal structures' health, because they can cause microcracks that require emergency maintenance or can result in potential accidents. Therefore, an accurate approach to the measurement of stresses is key for ensuring the health of metal structures. The eddy current technique is an effective approach to detect the stress according to the piezoresistive effect. However, it is limited to detect the surface stress due to the skin effect. In engineering, the stress distribution is inhomogeneous; therefore, to predict the inhomogeneous stress distribution, this paper proposes a nondestructive approach which combines the eddy current technique and finite element (FE) method. The experimental data achieved through the eddy current technique determines the relationship between the applied force and the magnetic flux density, while numerical simulations through the FE method bridge the relationship between the magnetic flux density and the stress distribution in different directions. Therefore, we can predict the inhomogeneous stress nondestructively. As a case study, the applied stress in a three-point-bending simply supported beam was evaluated, and the relative error is less than 8% in the whole beam. This approach can be expected to predict the residual stress in metal structures, such as rail and vehicle structures, if the stress distribution pattern is known. [ABSTRACT FROM AUTHOR]

Currently, the business process elements in the design of organizational business architecture are becoming increasingly complex, showing trends of networking and flattening. The control of complex business processes is a key factor for business architecture design. This paper considers a complex network generation method with business process and organization structure data and analyzes complex network controllability to examine the alignment of business processes and the organization structure. The uncontrollable nodes of the complex network can be identified, which act as the input for organization structure adjustment and business architecture optimization design. [ABSTRACT FROM AUTHOR]

Hepatocarcinoma‐intestine‐pancreas/pancreatitis‐associated protein (HIP/PAP), a C‐type lectin, exerts anti‐oxidative, anti‐inflammatory, bactericidal, anti‐apoptotic, and mitogenic functions in several cell types and tissues. In this study, we explored the role of HIP/PAP in pulmonary fibrosis (PF). Expression of HIP/PAP and its murine counterpart, Reg3B, was markedly increased in fibrotic human and mouse lung tissues. Adenovirus‐mediated HIP/PAP expression markedly alleviated bleomycin (BLM)‐induced lung injury, inflammation, and fibrosis in mice. Adenovirus‐mediated HIP/PAP expression alleviated oxidative injury and lessened the decrease in pulmonary superoxide dismutase (SOD) activity in BLM‐treated mice, increased pulmonary SOD expression in normal mice, and HIP/PAP upregulated SOD expression in cultured human alveolar epithelial cells (A549) and human lung fibroblasts (HLF‐1). Moreover, in vitro experiments showed that HIP/PAP suppressed the growth of HLF‐1 and ameliorated the H2O2‐induced apoptosis of human alveolar epithelial cells (A549 and HPAEpiC) and human pulmonary microvascular endothelial cells (HPMVEC). In HLF‐1, A549, HPAEpiC, and HPMVEC cells, HIP/PAP did not affect the basal levels, but alleviated the TGF‐β1‐induced down‐regulation of the epithelial/endothelial markers E‐cadherin and vE‐cadherin and the over‐expression of mesenchymal markers, such as α‐SMA and vimentin. In conclusion, HIP/PAP was found to serve as a potent protective factor in lung injury, inflammation, and fibrosis by attenuating oxidative injury, promoting the regeneration of alveolar epithelial cells, and antagonizing the pro‐fibrotic actions of the TGF‐β1/Smad signaling pathway. [ABSTRACT FROM AUTHOR]

To figure out the temperature drift problem in a dual coil eddy current displacement sensor (DC-ECDS) which is widely applied in food industry, the structure and working principle of DC-ECDS was descripted first. Then, the influence of the working temperature of the DC-ECDS on the difference signal from the dual coils was deeply investigated by the numerical simulation and experimental study. By the investigation, the temperature-invariant phenomenon (TIP) was found in the embedded DC-ECDS and non-embedded DC-ECDS. The interesting thing was that in the temperature invariant region (TIR), the impact of the working temperature on the difference signal could be neglected. Next, we found that the location of TIR was dependent of the excitation frequency and the geometric size of the electromagnetic shielding ring of the DC-ECDS. Finally, the TIP was applied in designing a novel eddy current limit switch, which exhibited the stable output regardless of working temperature change. [ABSTRACT FROM AUTHOR]

Non-destructive testing (NDT) plays a crucial role in large scale industrial production such as in the nuclear industry and bridge structures where even a small crack can lead to severe accidents. The pulsed eddy current infrared thermography testing method, as a classic non-destructive testing technology, is proposed to detect cracks in the presence of excitation sources that cause temperature changes in the vicinity of defects, which is higher than normal area. However, in the vicinity of the excitation sources, the temperature is higher than normal even if there is no defect. Traditional infrared image enhancing algorithms do not work efficiently when processing infrared images because the colors in the images represent the temperature. To address this, a novel algorithm is proposed in this paper. A weighted estimation algorithm is proposed because each pixel value has a strong relationship with its neighboring pixels. The value of each pixel is determined by calculating the values of its neighboring pixels with a specific step-size and the correlation coefficients between them. These coefficients are obtained by calculating the differences between the pixels. The experimental results indicated that the outline of the welding defect became significantly clearer after being processed using the proposed algorithm, which can eliminate the errors caused by the excitation source. [ABSTRACT FROM AUTHOR]

Abstract: Background: The present study aimed to clarify the effects of thymosin β4 (Tβ4) on CCl4‐induced hepatic fibrosis in mice and to further explore the underlying mechanisms. Methods: Expression of Tβ4 in fibrotic liver tissues was assessed by a quantitative real time‐reverse transcriptase polymerase chain reaction and immunohistochemistry. The effects of intraperitoneal adeno‐associated virus‐Tβ4 (AAV‐Tβ4) on CCl4‐induced hepatic fibrosis were observed by the evaluation of collagen deposition, hepatic stellate cell (HSC) activation and pro‐fibrotic cytokine expression. In vitro tests with HSCs and hepatocytes were performed to confirm the effects of Tβ4. Results: The expression of Tβ4 was down‐regulated in fibrotic mouse livers but was rapidly up‐regulated by CCl4‐induced acute injury. AAV‐Tβ4 pre‐treatment significantly attenuated liver injury, collagen deposition, HSC activation and pro‐fibrotic cytokine over‐expression, such as transforming growth factor β1 (TGF‐β1), platelet‐derived growth factor B (PDGF‐B), connective tissue growth factor (CTGF) and plasminogen activator inhibitor‐1 (PAI‐1) in CCl4‐intoxicated mouse livers. In vitro experiments showed that Tβ4 suppressed HSC proliferation, blunted TGF‐β1‐induced HSC activation and reduced TGF‐β1‐induced TGF‐β1, PDGF‐B, CTGF and PAI‐1 expression in both HSCs and hepatocytes. Ectopic Tβ4 ameliorated the over‐expression of TGF‐β receptor‐II (TGF‐βRII) in the fibrotic mouse livers. Exogenous Tβ4 down‐regulated TGF‐βRII expression, whereas neutralizing endogenous extracellular Tβ4 with a specific antibody up‐regulated TGF‐βRII expression in cultured HSCs and hepatocytes. Conclusions: Tβ4 possesses anti‐fibrotic activity in the liver, which is attributable, at least partly, to down‐regulating TGF‐βRII and thereby blunting TGF‐β1‐mediated fibrogenetic signaling in both HSCs and hepatocytes. [ABSTRACT FROM AUTHOR]

Online social networks (OSNs) have become more and more popular and have attracted a great many users. Friend recommendation, which is one of the important services in OSN, can help users discover their interested friends and alleviate the problem of information overload. However, most of existing recommendation methods only consider either user link or content information and hence are not effective enough to provide high quality recommendations. In this paper, we propose a topic community-based method via Nonnegative Matrix Factorization (NMF). This method first applies joint NMF model to mine topic communities existing in OSN by combing link and content information. Then it computes user pairwise similarities and makes friends recommendation based on topic communities. Furthermore, this method can be implemented using the MapReduce distributed computing framework. Extensive experiments show that our proposed method not only has better recommendation performance than state-of-the-art methods but also has good scalability to deal with the problem of friend recommendation in large-sale OSNs. Moreover, the application case demonstrates that it can significantly improve friend recommendation service in the real world OSN. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• Effect of cooling rate on a-C-to-graphene transformation in RTP process was studied. • There were no C atoms precipitated from C-Ni intermixing layer during cooling process. • RTP method exhibited different mechanism from traditional Ni-catalyzed CVD technique. • The transformation was dominated by C diffusion and Ni-induced crystallization. • Regular arrangement of as-grown RTP graphene highly depended on the cooling rate. Amorphous carbon with Ni as catalyst can be transformed into graphene on the dielectric substrate directly without the subsequent transfer process during rapid thermal processing (RTP). However, the effect of cooling rate on this transformation process is still not fully understood yet, leading to the controversy of underlying mechanism. Here, by the combined reactive molecular dynamics simulation with experimental approach, we investigated the evolution of RTP graphene structure and diffusion behavior of C atoms with cooling rates. Results demonstrated that for each case, there were no C atoms precipitated from C-Ni intermixing layer during the cooling process, which was different from the behavior observed in the Ni-catalyzed CVD growth process of graphene. This confirmed that the a-C-to-graphene transformation mechanism during the RTP process was dominated by the C diffusion and Ni-induced crystallization rather than the traditional dissolution/precipitation mechanism for graphene growth. Most importantly, it was also found that tailoring the cooling rate could achieve the regular arrangement of distorted structure in as-grown RTP graphene and thus promote the high-quality synthesis of graphene, which was confirmed by the experimental result. [ABSTRACT FROM AUTHOR]

As a new coagulant, the efficiency and performance of Moringa oleifera seed presscake extract for the coagulation removal of direct black 19 was investigated under different operation conditions in contrast with polyaluminum chloride (PAC). The results indicated that the removal efficiencies decreased with rising pH for both of the two coagulants in the pH range of 5-9, and Moringa oleifera seed presscake extract was more efficient than PAC at pH 5-8 ( P < 0.05). The optimal temperature for the two coagulants was 25 °C, and Moringa oleifera seed presscake extract was also better than PAC at every temperature ( P < 0.05). The removal of direct black 19 increased with the increase of dosages of Moringa oleifera seed presscake extract and PAC. Both of NaCl and Na 2 SO 4 increased the coagulation efficiency of Moringa oleifera seed presscake extract. In contrast, NaCl increased the removal percentage of PAC, but Na 2 SO 4 decreased the performance. The suspended solid simulated by kaolin improved the direct black 19 removal. Overall, The Moringa oleifera seed presscake extract is better for direct black 19 removal than PAC ( P < 0.05). [ABSTRACT FROM AUTHOR]

• GAD of ta-C was realized by adjusting the filtered incident carbon ions. • GAD benefited a notable reduction of residual stress without distinct hardness loss. • The superior corrosion resistance of ta-C was obtained at glancing angle of 45°. • High sp3 content and enhanced hydrophobicity contributed to anti-corrosion. Tetrahedral amorphous carbon (ta-C) films were obliquely deposited on silicon substrate using a custom-made 45 degree double-bent filtered cathodic vacuum arc (FCVA) system. The effect of glancing angle in a range of 0° to 75° on the growth characteristics, mechanical and electrochemical corrosion behavior of the films were focused. Results showed that increasing the incident angle of carbon ions resulted in a rough surface with agglomerated particles. As the glancing angle changed from 0° to 75°, the residual stress of ta-C film decreased by 28.8%, while the high hardness exceeding 30 GPa were maintained in the films due to the small reduction (13.6%) of sp3 hybridized carbon content. The electrochemical corrosion tests in 3.5 wt% NaCl solution revealed that the superior corrosion resistances were obtained at glancing angle of 45°, which could be discussed in terms of the relatively high sp3 bonded carbon content and the enhanced hydrophobicity properties of the films. [ABSTRACT FROM AUTHOR]

Background: In dental clinical practice, self-perception of orofacial appearance is highly correlated with treatment satisfaction. Therefore, it is important to explore factors correlated with self-perception of orofacial appearance. Perfectionism may be one such factor. This study investigated the role of perfectionism in self-perception of orofacial appearance., Methods: Participants completed an online questionnaire that included demographic data, a measure of perfectionism, a measure of self-perception of orofacial appearance (including body image, smile appearance concern, and self-esteem), and a measure of anxiety and depression., Results: High perfectionism scores significantly predicted greater age, body image, smile appearance concern, and mental health scores and lower self-esteem scores ( p  < 0.005). After adjusting for possible confounding variables, smile appearance concern largely disappeared. Mental health acted as a mediator in the relationships between perfectionism and three orofacial appearance characteristics., Conclusion: High perfectionism predicted higher self-perception of body image, and lower mental health and self-esteem in college students. Mental health could mediate the relationships between perfectionism and self-perception of orofacial appearance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Gao, Zhong, Li, Pei, Li, Zhang, Yue and Xiong.)

Objective: To examine the kinetics of B cell subsets and activation markers in the early stage of belimumab treatment and their correction with treatment response. Methods: We enrolled 27 systemic lupus erythematosus (SLE) patients receiving 6 months belimumab treatment. Flow cytometry was used to test their B cell subsets and activation markers (including CD40, CD80, CD95, CD21 low , CD22, p-SYK and p-AKT). Results: During belimumab treatment, SLEDAI-2K declined, the proportions of CD19 + B cells and naïve B cells decreased, whereas the switched memory B cells and non-switched B cells increased. The larger variations of the B cell subsets and the activation markers were in the first 1 month than the other later time frames. The ratio of p-SYK/p-AKT on non-switched B cell at 1 month was associated with the SLEDAI-2K decline rate in the 6 months of belimumab treatment. Conclusion: B cell hyperactivity was rapidly inhibited in the early stage of belimumab treatment, and the ratio of p-SYK/p-AKT may predict SLEDAI-2K decline. Clinical Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT04893161?term=NCT04893161&draw=2&rank=1; identifier: NCT04893161., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Ju, Zhu, Li, Luo, Zhang, Hu, Mo, Wang, Pan, Huang, Lv, Pu, Hao, He and Li.)

Background: The spider family Leptonetidae Simon, 1890 includes 20 genera and 366 species from North America, the Mediterranean Region and Asia. Currently, 132 species belonging to six genera have been recorded in China., New Information: A new genus and species of leptonetid spiders, Yueleptonetadongxing gen. et sp. n., is described from Guangdong Province, China. Yueleptoneta gen. n. is distinct from the other genera in the chelicerae having the stridulatory file on the lateral margin and the male palp having a tarsal spur, lacking strong spines or apophyses on the femur and tibia., (Kuiwen Yang, Hanchao Li, Yanfeng Tong, Dongju Bian.)

Background: The present study aimed to clarify the effects of thymosin β4 (Tβ4) on CCl 4 -induced hepatic fibrosis in mice and to further explore the underlying mechanisms., Methods: Expression of Tβ4 in fibrotic liver tissues was assessed by a quantitative real time-reverse transcriptase polymerase chain reaction and immunohistochemistry. The effects of intraperitoneal adeno-associated virus-Tβ4 (AAV-Tβ4) on CCl 4 -induced hepatic fibrosis were observed by the evaluation of collagen deposition, hepatic stellate cell (HSC) activation and pro-fibrotic cytokine expression. In vitro tests with HSCs and hepatocytes were performed to confirm the effects of Tβ4., Results: The expression of Tβ4 was down-regulated in fibrotic mouse livers but was rapidly up-regulated by CCl 4 -induced acute injury. AAV-Tβ4 pre-treatment significantly attenuated liver injury, collagen deposition, HSC activation and pro-fibrotic cytokine over-expression, such as transforming growth factor β1 (TGF-β1), platelet-derived growth factor B (PDGF-B), connective tissue growth factor (CTGF) and plasminogen activator inhibitor-1 (PAI-1) in CCl 4 -intoxicated mouse livers. In vitro experiments showed that Tβ4 suppressed HSC proliferation, blunted TGF-β1-induced HSC activation and reduced TGF-β1-induced TGF-β1, PDGF-B, CTGF and PAI-1 expression in both HSCs and hepatocytes. Ectopic Tβ4 ameliorated the over-expression of TGF-β receptor-II (TGF-βRII) in the fibrotic mouse livers. Exogenous Tβ4 down-regulated TGF-βRII expression, whereas neutralizing endogenous extracellular Tβ4 with a specific antibody up-regulated TGF-βRII expression in cultured HSCs and hepatocytes., Conclusions: Tβ4 possesses anti-fibrotic activity in the liver, which is attributable, at least partly, to down-regulating TGF-βRII and thereby blunting TGF-β1-mediated fibrogenetic signaling in both HSCs and hepatocytes., (© 2018 John Wiley & Sons, Ltd.)

To observe the immunogenicity of hPDGF-B immunogens that were synthesized with the fusional expression vector pET28-Trx and to test the suppressive effect of these specific antibodies induced by both of immunogens on proliferation of human HepG2 hepatoma cells. First, we chose 2 antigenic epitopes hPDGF-BΔ103-118aa and hPDGF-BΔ152-167aa from human PDGF-B and inserted these 2 coding regions into the empty vector plasmid pET28-Trx, separately. Second, mice were immunized with purified recombinant proteins to generate polyclonal antibody. Then we intraperitoneally injected mice bearing hepatoma 22 (H22) tumor cells to prepare antibody ascites. ELISA and Western blot were used to detect the titer and the utility of the antibody, respectively. Finally, HepG2 cells were exposed to PDGF-BB protein or anti-PDGF-B ascite antibody in different dilution concentrations groups and the proliferation of HepG2 cells was quantified by CCK8 assay. As the results, we identified mice that could produce high drop of neutralizing antibodies against hPDGF-B induced by both two recombinant proteins. Two anti-PDGF-B ascite antibodies could markedly inhibit the proliferation of HepG2 cells by blocking the stimulating effect of PDGF-BB protein. Our results suggest that Trx-PDGF-B recombinant protein as immunogen provides a new method for the preparation of PDGF-B vaccine, and also a new idea for the treatment of hepatocellular carcinoma in clinical practice.

Inland lakes play important roles in water and greenhouse gas cycling in the environment. This study aims to test the performance of a flux-gradient system for simultaneous measurement of the fluxes of water vapor, CO2, and CH4 at a lake-air interface. The concentration gradients over the water surface were measured with an analyzer based on the wavelength-scanned cavity ring-down spectroscopy technology, and the eddy diffusivity was measured with a sonic anemometer. Results of a zero-gradient test indicate a flux measurement precision of 4.8 W m(-2) for water vapor, 0.010 mg m(-2) s(-1) for CO2, and 0.029 μg m(-2) s(-1) for CH4. During the 620 day measurement period, 97%, 69%, and 67% of H2O, CO2, and CH4 hourly fluxes were higher in magnitude than the measurement precision, which confirms that the flux-gradient system had adequate precision for the measurement of the lake-air exchanges. This study illustrates four strengths of the flux-gradient method: (1) the ability to simultaneously measure the flux of H2O, CO2, and CH4; (2) negligibly small density corrections; (3) the ability to resolve small CH4 gradient and flux; and (4) continuous and noninvasive operation. The annual mean CH4 flux (1.8 g CH4 m(-2) year(-1)) at this hypereutrophic lake was close to the median value for inland lakes in the world (1.6 g CH4 m(-2) year(-1)). The system has adequate precision for CH4 flux for broad applications but requires further improvement to resolve small CO2 flux in many lakes.