Search

Accumulating evidence suggests that atherosclerosis (AS) is the underlying cause of vascular diseases, including heart disease and stroke. Ultrasound-targeted microbubble destruction (UTMD) technology provides a tolerable, efficient and effective system for drug delivery and gene transfection, which has broad application prospects in the treatment of AS. In addition, glycogen synthase kinase (GSK)-3β has been implicated as a potentially valuable therapeutic agent for AS treatment; however, the specific molecular mechanisms remain unknown. Therefore, this study was conducted to explore the effect of downregulation of GSK-3β expression via UTMD on atherosclerotic plaque stability. We established a THP-1 macrophage-derived foam cell model in vitro and an atherosclerotic plaque model in the right common carotid artery of New Zealand rabbits. We determined levels of the relevant vulnerable plaque stability elements. The results indicate that GSK-3β was upregulated in the foam cells and in atherosclerotic rabbits. Downregulation of GSK-3β expression by UTMD suppressed vulnerable plaque factors and inflammation in vitro and in vivo, changed the cytoskeleton of the foam cells in vitro, increased Young's modulus and decreased the peak intensity of atherosclerotic plaque in vivo. Moreover, GSK-3β inhibition by UTMD did not influence the viability of the foam cells. Collectively, our results indicate that GSK-3β could be a potential target for anti-atherogenic interventions and, in particular, can improve the stability of AS plaques in combination with UTMD.

Background Calmodulin1 (CALM1) has been identified as one of the overexpression genes in a variety of cancers and EGFR inhibitor have been widely used in clinical treatment but it is unknown whether CALM1 and epidermal growth factor receptor (EGFR) have a synergistic effect in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to explore the synergistic effects of knock-out CALM1 combined with EGFR inhibitor (Afatinib) and to elucidate the role of CALM1 in sensitizing the resistance to Afatinib in ESCC. Method Immunohistochemistry (IHC) and qRT-PCR were used to examine the expression of CALM1 and EGFR in ESCC tissues. Kaplan–Meier survival analysis was used to analyze the clinical and prognostic significance of CALM1 and EGFR expression in ESCC. Furthermore, to evaluate the biological function of CALM1 in ESCC, the latest gene editing technique CRISPR/Cas9(Clustered regularly interspaced short palindromic repeats)was applied to knockout CALM1 in ESCC cell lines KYSE150, Eca109 and TE-1. MTT, flow cytometry, Transwell migration, scratch wound-healing and colony formation assays were performed to assay the combined effect of knock-out CALM1 and EGFR inhibitor on ESCC cell proliferation and migration. In addition, nude mice xenograft model was used to observe the synergistic inhibition of knock-out CALM1 and Afatinib. Results Both CALM1 and EGFR were found to be significantly over-expressed in ESCC compared with paired normal control. Over-expressed CALM1 and EGFR were significantly associated with clinical stage, T classification and poor overall prognosis, respectively. In vitro, the combined effect of knock-out CALM1 mediated by the lentivirus and EGFR inhibitor was shown to be capable of inhibiting the proliferation, inducing cell cycle arrest at G1/S stage and increasing apoptosis of KYSE-150 and Eca109 cells; invasion and migration were also suppressed. In vivo, the results of tumor weight and total fluorescence were markedly reduced compared with the sgCtrl-infected group and sgCAML1 group. Conclusion Our data demonstrated that knock-out of CALM1 could sensitize ESCC cells to EGFR inhibitor, and it may exert oncogenic role via promotion of EMT. Taken together, CALM1 may be a tempting target to overcome Afatinib resistance.

Full design analysis of a bridge usually has lots of load cases and leads to the analysis process, which is extremely time-consuming. To reduce the computational cost, the existing hanger pre-tensioning force optimization approaches for cable-supported bridges always consider only a few critical load cases. This study presents an efficient approach for hanger pre-tensioning force optimization of steel tied-arch bridges, which can include all the operational loads and their combinations based on the code requirements. The proposed method develops a load decoupling approach (LDA) to enhance the computational efficiency of structural analysis in optimization and utilize the particle swarm optimization algorithm to search the global optimal design. The LDA divides the structural analysis procedure into two systems: (1) iteration-varying and (2) iteration-invariant. The former evaluates the structural responses induced by different hanger forces using unit load method (ULM) and the latter solely needs a single finite element (FE) analysis before iteration to calculate the structural responses caused by the other loads. The superposition principle combines the results from the two systems to identify the minimum safety margin of the bridge under the ultimate limit state. A practical bridge is examined to compare the proposed method with three traditional hanger force determination approaches. The obtained results illustrate that the proposed method not only owns high efficiency but also leads to a safer design and has a broader application range.

Silicon-based (Si-based) junctions have been widely investigated in recent years as photoelectrochemical (PEC) water splitting photoelectrodes, including buried junctions and metal–insulator–semiconductor (MIS) Schottky junctions. However, Si-based MIS photoelectrodes suffer from low performance for the PEC oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) because of the dilemma that a thin insulator cannot provide enough interfacial passivation while a thick insulator will block the transport of charge carriers. Another trade-off is the fact that the photovoltage extracted from the band offset between the metal and semiconductor will be counteracted by the parasitic light absorption of the metal layer, sacrificing the saturation photocurrent. This paper describes the design and realization of a bifacial passivation strategy for the metal/Si interface of an MIS photoelectrode, featuring a bi-layer stack consisting of amorphous silicon (a-Si) for passivating the silicon surface and a metal oxide (TiO2) for passivating the metal surface. Upon the bifacial passivation of both a-Si and TiO2, the minority carrier lifetime of the Si MIS photoanode was significantly improved from 18 to 2360 μs. Enabled by this extremely long minority carrier lifetime, it becomes possible to place the MIS junction on the back side of a Si substrate to construct an inverted-MIS (I-MIS) structure to eliminate the parasitic light absorption of traditional Si MIS photoelectrodes. The obtained photoelectrode exhibits an excellent onset potential of 0.85 V and 0.62 V vs. reversible hydrogen electrode (RHE) for the OER and HER, respectively. Eventually, unprecedented applied bias photon-to-current efficiencies (ABPE) of 3.91% and 12.66% were obtained by Si MIS and Si I-MIS, which are the highest among MIS-based photoanodes and photocathodes, with 30 h and 108 h stable operation. When pairing the Si I-MIS photocathode with a BiVO4 photoanode to form a PEC membrane-free tandem cell, an unbiased solar-to-hydrogen conversion efficiency of 1.9% is achieved.

Background: Pyruvate kinase 2 (PKM2) is a key enzyme in glycolysis pathway and has been reported to be associated with the development of esophageal squamous cell carcinoma (ESCC). However, the prognostic value of PKM2 in ESCC remains undetermined.Materials and methods: This study aimed to investigate the clinicopathological significance of PKM2 expression in ESCC. A comprehensive and systematic literature search was conducted using PubMed, Embase, Medline and Cochrane library databases. Appraised were the quality of studies, the potential for bias, and performed meta-analysis to assess the prognostic impact of PKM2 on the overall survival (OS).Results: Five studies with 781 patients were eligible and enrolled eventually. Patients with high PKM2 expression were associated with poor prognosis in ESCC (HR=1.72, 95%CI: 1.41~2.09, P＜0.01). Furthermore, up-regulated PKM2 was significantly associated with lymph node metastasis (OR=2.38, 95%CI: 1.68~3.35, P＜0.01), clinical stage (OR=3.29, 95%CI: 2.27~4.77, P＜0.01) and T classification (OR=2.92, 95%CI: 2.05~4.16, P＜0.01).Conclusions: In conclusion, high PKM2 expression denotes worse OS in ESCC patients, and correlate with the lymph node metastasis, clinical stage and T classification. However, further studies are warranted to assess how PKM2 can be implemented as a reliable staging element in clinical practice and whether it could provide a new target for therapeutic intervention.

Background: The aim of this invesigation was to retrospectively analyze and summarize the clinicopathological and prognostic features of patients with esophageal squamous cell carcinoma (ESCC) at the Cancer Hospital Affiliated of the Xinjiang Medical University , a Grade A tertiary hospital in Xinjiang. Methods: The clinicopathological data and follow-up data were collected from 419 ESCC patients . The overall survival (OS) and the related factors affecting survival were analyzed. Results: Among the patients , 265 (63.2%) did not receive any postoperative treatment. The 1-, 3-, and 5-year overall survival (OS) rates were 84.8%, 47.5%, and 37.3%, respectively, and the median survival time (MST) was 29.0 months . Multivariate analysis showed that sources of patients, tumor stage, lymph node metastasis and stage of the disease were the independent predictors of OS. The finding in subgroup analysis indicated that there was a positive relationship between area and overall survival.Conclusions: Postoperative treatments of these patients with ESCC were shown to be inadequent. Postadjuvant therapies of patients need to be strengthened. Targeted treatment regimes of different regions should be carried out by health department to alleviate the cancer burden.

This paper mainly discusses the current situation of the internationalization development the issues and challenges faced of enterprise standards in China in recent years, and the countermeasures and suggestions to be taken in the future. The research methods of qualitative analysis and case studies are mainly adopted. Both primary and secondary information resources are collected for an analysis and recognition of the progress of internationalization of Chinese enterprise standards. The key issues in the internationalization process of Chinese enterprise standards are put forward through analysis of the lessons learned such as lack of consistency in technology standards and real needs in the process of internationalization of Chinese enterprise standards in the last two decades, especially in the practice of participating in foreign infrastructure construction. Under China’s “One Belt and One Road (B&R) Initiative”, the high quality Chinese enterprise standards and internationalization are the prerequisite for the realization of international cooperation in science and technology. The novelty of this paper is mainly reflected in the countermeasures and suggestions how to enhance the internationalization level of Chinese enterprise standards in accordance with the initiatives of the “B&R” construction and the countries concerned actual needs. These include to further improve the technology level and quality of enterprise standards, improve the applicability of Chinese enterprise standards, strengthen international exchanges and cooperation in the field of standardization, establish and improve standard information resource sharing in big data environment, enhance the competitiveness of enterprises, and realize mutual benefit and win-win situation in “B&R” international cooperation.

Background Sepsis remains a major health issue without an effective therapy. Ferroptosis, an iron‐dependent programmed cell death, has been proposed to be related to the pathogenesis of sepsis. Irisin, a myokine released during exercise, improves mitochondrial function under various conditions. Ferroptosis is closely related to mitochondrial function. However, the role of irisin in sepsis‐induced ferroptosis and mitochondrial dysfunction in the liver remained unknown. Thus, we hypothesize that irisin treatment suppresses ferroptosis and improves mitochondrial function in sepsis. Methods To study this, we first explored the role of serum irisin levels in patients with sepsis, and then determined the effect of irisin administration on ferroptosis and mitochondrial function in the liver of septic mice. Results Serum irisin levels were decreased and negatively correlated with the APACHE II scores in patients with sepsis. In mice subjected to cecal ligation and puncture (CLP), exogenous irisin administration suppressed ferroptosis, inhibited inflammatory response, decreased reactive oxygen species (ROS) production, restored abnormal mitochondrial morphology, and increased mtDNA copy number and adenosine triphosphate (ATP) content. The effect of irisin on ferroptosis was confirmed in LPS‐treated hepatocytes and CLP‐induced septic mice. Inhibition of glutathione peroxidase 4 (GPX4), a central regulator of ferroptosis, reduced irisin's protective effects in LPS‐treated hepatocytes and CLP‐induced septic mice, while blocking the irisin receptor with RGD peptide or Echistain decreased irisin‐induced GPX4 expression. Conclusions Serum irisin levels are decreased and negatively correlated with disease severity in patients with sepsis, and irisin treatment suppresses ferroptosis and restores mitochondrial function in experimental sepsis. Irisin may offer therapeutic potential in the management of sepsis.

Background: Calmodulin1 (CALM1) has been identified as one of the overexpression genes in a variety of cancers and EGFR inhibitor have been widely used in clinical treatment but it is unknown whether CALM1 and epidermal growth factor receptor (EGFR) have a synergistic effect in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to explore the synergistic effects of knock-out CALM1 combined with EGFR inhibitor (Afatinib) and to elucidate the role of CALM1 in sensitizing the resistance to Afatinib in ESCC. Method: Immunohistochemistry (IHC) and qRT-PCR were used to examine the expression of CALM1 and EGFR in ESCC tissues. Kaplan–Meier survival analysis was used to analyze the clinical and prognostic significance of CALM1 and EGFR expression in ESCC. Furthermore, to evaluate the biological function of CALM1 in ESCC, the latest gene editing technique CRISPR/Cas9（Clustered regularly interspaced short palindromic repeats）was applied to knockout CALM1 in ESCC cell lines KYSE150, Eca109 and TE-1. MTT, flow cytometry, Transwell migration, scratch wound-healing and colony formation assays were performed to assay the combined effect of knock-out CALM1 and EGFR inhibitor on ESCC cell proliferation and migration.. In addition, nude mice xenograft model was used to observe the synergistic inhibition of knock-out CALM1 and Afatinib.Results: Both CALM1 and EGFR were found to be significantly over-expressed in ESCC compared with paired normal control. Over- expressed CALM1 and EGFR were significantly associated with clinical stage, T classification and poor overall prognosis, respectively. In vitro, the combined effect of knock-out of CALM1 mediated by the lentivirus and EGFR inhibitor was shown to be capable of inhibiting the proliferation, inducing cell cycle arrest at G1/S stage and increasing apoptosis of KYSE-150 and Eca109 cells; invasion and migration were also suppressed. In vivo, the results of tumor weight and total fluorescence were markedly reduced compared with the sgCtrl-infected group and sgCAML1 group.Conclusion: Our data demonstrated that knock-out of CALM1 could sensitize ESCC cells to EGFR inhibitor, and it may exert oncogenic role via promotion of EMT. Taken together, CALM1 may be a tempting target to overcome Afatinib resistance.

Facing the COVID-19 global healthcare crisis, scientists worldwide are collaborating to develop prophylactic and therapeutic interventions against the disease. Antibody therapeutics hold enormous promise for the treatment of COVID-19. In March 2020, the Chinese Antibody Society, in collaboration with The Antibody Society, initiated the “COVID-19 Antibody Therapeutics Tracker” (“Tracker”) (https://chineseantibody.org/covid-19-track/) program to track the antibody-based COVID-19 interventions in preclinical and clinical development globally. The data are collected from the public domain and verified by volunteers on an ongoing basis. Here, we present exploratory data analyses and visualization to demonstrate the latest trends of COVID-19 antibody development, based on data for over 150 research and development programs and molecules included in the “Tracker” as of 8 August 2020. We categorized the data mainly by their targets, formats, development status, developers and country of origin. Although details are limited in some cases, all of the anti-SARS-CoV-2 antibody candidates appear to target the viral spike protein (S protein), and most are full-length monoclonal antibodies. Most of the current COVID-19 antibody therapeutic candidates in clinical trials are repurposed drugs aimed at targets other than virus-specific proteins, while most of these virus-specific therapeutic antibodies are in discovery or preclinical studies. As of 8 August 2020, eight antibody candidates targeting the SARS-CoV-2 S protein have entered clinical studies, including LY-CoV555, REGN-COV2, JS016, TY027, CT-P59, BRII-196, BRII-198 and SCTA01. Ongoing clinical trials of SARS-CoV-2 neutralizing antibodies will help define the utility of these antibodies as a new class of therapeutics for treating COVID-19 and future coronavirus infections.

Absract The influence of oxygen-related thermal donors (TDs) on the performance of silicon heterojunction (SHJ) solar cells was explored experimentally in this paper. It is found that a certain number of thermal donors could do much harm to the performance of SHJ solar cells. The efficiency of SHJ solar cells is usually reduced by a value of ~ 1% absolute in the case of thermal donors with a concentration of nearly 1015 cm−3. The microwave photoconductance decay and Hall Effect studies have proved that the TDs can significantly reduce the carrier lifetime of n-type silicon substrate, but have no influence on the carrier mobility. Deep level transient spectroscopy (DLTS) measurements have further demonstrated that the TDs cause an energy level at Ec-0.13 eV with carrier capture cross-section of 10−15 cm2, which is responsible for the reduction of carrier lifetime and solar cell efficiency.

Graphene/silicon (Gr/Si) Schottky junction solar cells have attracted widespread attention for the fabrication of high-efficiency and low-cost solar cells. However, their performance is still limited by the working principles of Schottky junctions. Modulating the working mechanism of the solar cells into a quasi p–n junction has advantages, including higher open-circuit voltage (VOC) and less carrier recombination. In this study, Gr/Si quasi p–n junction solar cells were formed by inserting a tunneling Al2O3 interlayer in-between graphene and silicon, which led to obtain the PCE up to 8.48% without antireflection or chemical doping techniques. Our findings could pave a new way for the development of Gr/Si solar cells.

Background: Increased microvascular leakage is a cardinal feature of many critical diseases. Regular exercise is associated with improved endothelial function and reduced risk of cardiorespiratory disease. Irisin, secreted during exercise, contributes to many health benefits of exercise. However, the effects of irisin on endothelial function in the context of lung injury remain unknown. Methods: The direct effect of irisin on endothelial barrier function was studied in human microvascular endothelial cells (HMVECs) and human umbilical vein endothelial cells (HUVECs). The therapeutic effect of irisin was evaluated in 4 preclinical models of acute lung injuey (ALI). Serum irisin levels were measured and associated with disease severity in 60 ARDS patients. Findings: In this study, we found that irisin remarkably strengthened endothelial junctions and barrier function via binding to integrin αVβ5 receptor in LPS-treated endothelial cells. The beneficial effect of irisin was associated with suppression of the Src-MLCK-β-catenin pathway, activation of the AMPK-Cdc42/Rac1 pathway and improvement of mitochondrial function. In preclinical models of ALI, exogenous irisin improved pulmonary function, decreased lung edema and injury, suppressed inflammation, and increased survival. In ARDS patients, serum irisin levels were decreased and inversely correlated with disease severity and mortality. Interpretation: Irisin enhances endothelial barrier function and mitigates microvascular leakage related lung injury. Irisin may assist with the urgent medical need for preventing or minimizing ARDS and other microvascular leakage related diseases. Funding Statement: National Nature Science Foundation of China (No. 81770491) and the Ministry of Education Innovation Team Development Program of China (No. IRT16R57). Declaration of Interests: The authors declare no competing financial interests. Ethics Approval Statement: The study was approved by the Ethics Committee of the First Affiliated Hospital of Xi’an Jiaotong University. All study participants provided informed consent in accordance with the Declaration of Helsinki.

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep learning curve. The introduction of the cuff technique for anastomosis of the portal vein (PV) and infrahepatic vena cava (IHVC) has significantly simplified the transplant procedure in rats. However, due to the short anterior wall of the recipients' suprahepatic vena cava (SHVC), the cuff technique is very difficult to use for the reconstruction of the SHVC. Most researchers in this field still use the hand-suture technique for SHVC reconstruction, which makes it the bottleneck step in rat orthotopic liver transplantation. The magnetic anastomosis technique (i.e., magnamosis) is a method of connecting two vessels using the attractive force between two magnets. Our recent study has shown that the magnetic anastomosis technique is superior to the hand-suture technique for SHVC reconstruction in rats. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using the novel magnetic anastomosis technique. In this model, the reconstruction of the PV and IHVC was performed by the standard cuff technique, while the reconstruction of the bile duct (BD) was performed by a stent technique. The hepatic re-arterialization was not performed. The magnetic anastomosis technique made SHVC reconstruction much easier and significantly shortened the anphepatic phase. After a reasonable learning curve, even researchers without advanced microsurgical skills can produce reliable and reproducible results using this rat model of OLT.

The aims of this study were to evaluate the effects of biweekly bevacizumab administration on a tumor microenvironment and to investigate the mechanisms of radiosensitization that were induced by it. Briefly, bevacizumab was administered intravenously to Balb/c nude mice bearing non-small cell lung cancer (NSCLC) H1975 xenografts; in addition, bevacizumab was added to NSCLC or endothelial cells (ECs) in vitro, followed by irradiation (IR). The anti-tumor efficacy, anti-angiogenic efficacy and repair of DNA double-strand breaks (DSBs) were evaluated. The activation of signaling pathways was determined using immunoprecipitation (IP) and WB analyses. Finally, biweekly bevacizumab administration inhibited the growth of H1975 xenografts and induced vascular normalization periodically. Bevacizumab more significantly increased cellular DSB and EC apoptosis when administered 1 h prior to 12 Gy/1f IR than when administered 5 days prior to IR, thereby inhibiting tumor angiogenesis and growth. In vitro, bevacizumab more effectively increased DSBs and apoptosis prior to IR and inhibited the clonogenic survival of ECs but not NSCLC cells. Using IP and WB analyses, we confirmed that bevacizumab can directly inhibit the phosphorylation of components of the VEGR2/PI3K/Akt/DNA-PKcs signaling pathway that are induced by IR in ECs. In conclusion, bevacizumab radiosensitizes NSCLC xenografts mainly by inhibiting DSB repair in ECs rather than by inducing vascular normalization.

The graphene-silicon (Gr-Si) Schottky junction solar cell has been recognized as one of the most low-cost candidates in photovoltaics due to its simple fabrication process. However, the low Gr-Si Schottky barrier height largely limits the power conversion efficiency of Gr-Si solar cells. Here, we demonstrate that electric field doping can be used to tune the work function of a Gr film and therefore improve the photovoltaic performance of the Gr-Si solar cell effectively. The electric field doping effects can be achieved either by connecting the Gr-Si solar cell to an external power supply or by polarizing a ferroelectric polymer layer integrated in the Gr-Si solar cell. Exploration of both of the device architecture designs showed that the power conversion efficiency of Gr-Si solar cells is more than twice of the control Gr-Si solar cells. Our study opens a new avenue for improving the performance of Gr-Si solar cells.

Graphene-on-silicon (Gr–Si) heterojunction solar cells have recently attracted significant attention as promising candidates for low-cost photovoltaic applications. However, the power conversion efficiency of Gr–Si solar cells is generally smaller than 4% without chemical doping treatments. It is mainly limited by the low work function of Gr and high density defect states at the Gr–Si interface. Here, we have reported a new structure of Gr–Si solar cells by introducing a graphene oxide (GO) interlayer to engineer the Gr–Si interface for improving device performance. It is found that the GO interlayer can effectively increase open circuit voltage and meanwhile suppress the interface recombination of solar cells. As a result, a maximum efficiency of 6.18% can be achieved for the Gr/GO/Si solar cells, which is a new record for the pristine monolayer Gr–Si solar cell reported to date. Further, it is clarified that the Gr/GO/Si solar cell is significantly more stable than the Gr–Si solar cell with chemical doping. These results show a new route for fabricating efficient and stable chemical-doping-free Gr–Si solar cells.

We have demonstrated that the edge recombination effect exists in full area industrial silicon heterojunction (SHJ) solar cells, which can cause significant short-circuit current density (JSC) loss. The mechanism behind this observation was studied using different SHJ cell structures. We demonstrated further that this JSC loss effect can be suppressed effectively by simply controlling the gap between the edge of the transparent conductive oxide layer and that of the cell. Using this strategy, the average JSC of our state-of-art SHJ solar cells was enhanced by 0.36 mA/cm2, resulting in an average efficiency gain of 0.28% absolute.

The energy band diagram of the HIT solar cell obtained using AFORS-HET simulations reveals that a p-type inversion layer is induced in the n-type c-Si near the front hetero-interface. The HIT solar cell actually behaves like a "pseudo" p-n homojunction solar cell, in which the p-type inversion layer acts as the cell emitter and controls the performance of the solar cell. The formation of the inversion layer is controlled by the Fermi level of the p-Si:H layer, which is adjustable by varying its doping level. The study also suggests that the work function of the front TCO layer should be keep as high as possible for achieving high conversion efficiency.

We present industrialized bifacial solar cells on large area (149 cm2) 2 cm CZ monocrystalline silicon wafers processed with industrially relevant techniques such as liquid source BBr3 and POCl3 open-tube furnace diffusions, plasma enhanced chemical vapor deposition (PECVD) SiNx deposition, and screen printed contacts. The fundamental analysis of the paste using at boron-diffused surface and the bifacial solar cell firing cycle has been investigated. The resulting solar cells have front and rear efficiencies of 16.6 and 12.8%, respectively. The ratio of the rear JSC to front JSC is 76.8%. It increases the bifacial power by 15.4% over a conventional solar cell at 20% of 1-sun rear illumination, which equals to the power of a conventional solar cell with 19.2% efficiency. We also present a bifacial glass–glass photovoltaic (PV) module with 30 bifacial cells with the electrical characteristics. Copyright © 2010 John Wiley & Sons, Ltd.

The purpose of this work is to improve the precision of the elemental analysis of coal using laser-induced breakdown spectroscopy (LIBS). The LIBS technique has the ability to allow simultaneous elemental analysis and on-line determination, so it could be used in the elemental analysis of coal. Organic components such as C, H, O, N and inorganic components such as Ca, Mg, Fe, Al, Si, Ti, Na, and K of coal have been identified. The precision of the LIBS technique depends strongly on the experimental conditions, and the choice of experimental parameters should be aimed at optimizing the repeatability of the measurements. The dependences of the relative standard deviation (RSD) of the LIBS measurements on the experimental parameters including the sample preparation parameters, lens-to-sample distance, sample operation mode, and ambient gas have been investigated. The results indicate that the precision of LIBS measurements for the coal sample can be improved by using the optimum experimental parameters.

The Na-doped p-type ZnO thin films were prepared by DC reactive magnetron sputtering. Two types of substrates were used for separate testing purposes: silicon wafers for crystallinity measurements and glass slides for electrical and optical transmittance measurements. The lowest room-temperature resistivity under the optimal condition was 59.9 Ω cm, with a Hall mobility of 0.406 cm2 V−1s−1 and a carrier concentration of 2.57 × 1017 cm−3. The Na-doped ZnO thin films possessed a good crystallinity with c-axis orientation and a high transmittance (∼85%) in the visible region. The effects of the substrate temperature on the crystallinity and the electrical properties were discussed.

Organic/silicon nanowires (SiNWs) hybrid solar cells have recently been recognized as one of potentially low-cost candidates for photovoltaic application. Here, we have controllably prepared a series of uniform silicon nanowires (SiNWs) with various diameters on silicon substrate by metal-assisted chemical etching followed by thermal oxidization and then fabricated the organic/SiNWs hybrid solar cells with poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). It is found that the reflective index of SiNWs layer for sunlight depends on the filling ratio of SiNWs. Compared to the SiNWs with the lowest reflectivity (LR-SiNWs), the solar cell based on the SiNWs with low filling ratio (LF-SiNWs) has a higher open-circuit voltage and fill factor. The capacitance-voltage measurements have clarified that the built-in potential barrier at the LF-SiNWs/PEDOT:PSS interface is much larger than that at the LR-SiNWs/PEDOT one, which yields a strong inversion layer generating near the silicon surface. The formation of inversion layer can effectively suppress the carrier recombination, reducing the leakage current of solar cell and meanwhile transfer the LF-SiNWs/PEDOT:PSS device into a p-n junction. As a result, a highest efficiency of 13.11% is achieved for the LF-SiNWs/PEDOT:PSS solar cell. These results pave a way to the fabrication of high efficiency organic/SiNWs hybrid solar cells.

Graphene-silicon (Gr-Si) heterojunction solar cells have been recognized as one of the most low-cost candidates in photovoltaics due to its simple fabrication process. However, the high sheet resistance of chemical vapor deposited (CVD) Gr films is still the most important limiting factor for the improvement of the power conversion efficiency of Gr-Si solar cells, especially in the case of large device-active area. In this work, we have fabricated a novel transparent conductive film by hybriding a monolayer Gr film with silver nanowires (AgNWs) network soldered by the graphene oxide (GO) flakes. This Gr-AgNWs hybrid film exhibits low sheet resistance and larger direct-current to optical conductivity ratio, quite suitable for solar cell fabrication. An efficiency of 8.68% has been achieved for the Gr-AgNWs-Si solar cell, in which the AgNWs network acts as buried contacts. Meanwhile, the Gr-AgNWs-Si solar cells have much better stability than the chemically doped Gr-Si solar cells. These results show a new route for the fabrication of high efficient and stable Gr-Si solar cells.

Graphene-silicon (Gr-Si) Schottky solar cell has attracted much attention recently as promising candidate for low-cost photovoltaic application. For the fabrication of Gr-Si solar cell, the Gr film is usually transferred onto the Si substrate by wet transfer process. However, the impurities induced by this process at the graphene/silicon (Gr/Si) interface, such as H2O and O2, degrade the photovoltaic performance of the Gr-Si solar cell. We found that the thermal annealing process can effectively improve the photovoltaic performance of the Gr-Si solar cell by removing these impurities at the Gr/Si interface. More interestingly, the photovoltaic performance of the Gr-Si solar cell can be improved, furthermore, when exposed to air environment after the thermal annealing process. Through investigating the characteristics of the Gr-Si solar cell and the properties of the Gr film (carrier density and sheet resistance), we point out that this phenomenon is caused by the natural doping effect of the Gr film.

With the development of stage lighting technology, people have increasing demands for the lighting control, such as real-time and portable, However, existing LED dimming control equipments usually have large size and complicated functions, so they are not easy to move and operate. In order to improve these problems, this paper proposes a portable LED stage lighting control system and designed its software and hardware. Its hardware is composed of three parts: stage lighting manipulator, the communication lines based on DMX512 protocol and LED dimming control circuit. ATmega16 is the core of the control system. Data transmission follows the DMX512 protocol. The test results showed this system had stable performance and high reliability, which can completely met the requirement of stage lighting control. Its simple structure and convenient operation made it easy to carry and use. Meanwhile, using LED lamps instead of traditional ones can effectively save energy.

With the rapid development of stage equipment in recent years, the traditional SCR Dimming control technology is difficult to complete the performance requirements of stage lighting. In this paper, we proposed and researched the stage lighting dimming control technology based on sine wave, which used Atmega16 microcontroller, IXDP610 chip and IGBT as the main hardware. We could receive the DMX512 data sent from lighting console, and control IXDP610 chip to generate PWM signal with adjustable duty cycle and dead time by the microcontroller. This PWM signal can control the IGBT through driving circuit to achieve the purpose of dimming. According to the simulation and experimental results, this technology has a good dimming performance and it can effectively avoid the generation of harmonics. The research has theoretical significance and practical value to the development of stage lighting dimming control technology.

It is well-known that RCM is an advanced and effective maintenance strategy in practice. With the development of the automation and mechanization in modern industry, RCM method turns to be complex and consumes more resources in real production. However, the development and application of the Streamline RCM (SRCM) has injected new vitality for the new situation, especially in the nuclear power plants. This paper firstly introduces the background, the characteristics of the SRCM and the differences from RCM, and then shows the process in detail as well as the application status of the SRCM in country and abroad. It is proved that SRCM is a unique available method which saves the time and resource consumed, ensuring the integrity and correctness of the classical RCM. Finally, the weak points and the prospect are reviewed and prospected.Copyright © 2010 by ASME