A High Precision and Multifunctional Electro‐Optical Conversion Efficiency Measurement System for Metamaterial‐Based Thermal Emitters

In this study, a multifunctional high-vacuum system was established to measure the electro-optical conversion efficiency of metamaterial-based thermal emitters with built-in heaters. The system is composed of an environmental control module, an electro-optical conversion measurement module, and a system control module. The system can provide air, argon, high vacuum, and other conventional testing environments, combined with humidity control. The test chamber and sample holder are carefully designed to minimize heat transfer through thermal conduction and convection. The optical power measurements are realized using the combination of a water-cooled KBr flange, an integrating sphere, and thermopile detectors. This structure is very stable and can detect light emission at the μW level. The system can synchronously detect the heating voltage, heating current, optical power, sample temperatures (both top and bottom), ambient pressure, humidity, and other environmental parameters. The comprehensive parameter detection capability enables the system to monitor subtle sample changes and perform failure mechanism analysis with the aid of offline material analysis using scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. Furthermore, the system can be used for fatigue and high-low temperature impact tests

Isolation and characterization of centromeric repetitive DNA sequences in Saccharum spontaneum

Sugarcane (Saccharum hybrids spp.) is the most important sugar crop that accounts for ~75% of the world’s sugar production. Recently, a whole-genome sequencing project was launched on the wild species S. spontaneum. To obtain information on the DNA composition of the repeat-enriched region of the centromere, we conducted a genome-wide analysis of the DNA sequences associated with CenH3 (a mutant of histone H3 located in eukaryote centromeres) using chromatin immunoprecipitation followed by sequencing (ChIP-seq) method. We demonstrate that the centromeres contain mainly SCEN-like single satellite repeat (Ss1) and several Ty3/gypsy retrotransposon-related repeats (Ss166, Ss51, and Ss68). Ss1 dominates in the centromeric regions and spans up to 500 kb. In contrast, the Ty3/gypsy retrotransposon-related repeats are either clustered spanning over a short range, or dispersed in the centromere regions. Interestingly, Ss1 exhibits a chromosome-specific enrichment in the wild species S. spontaneum and S. robustum, but not in the domesticated species S. officinarum and modern sugarcane cultivars. This finding suggests an autopolyploid genome identity of S. spontaneum with a high level of homology among its eight sub-genomes. We also conducted a genome-wide survey of the repetitive DNAs in S. spontaneum following a similarity-based sequence clustering strategy. These results provide insight into the composition of sugarcane genome as well as the genome assembly of S. spontaneum

Strong electronic coupling between single Ru atoms and cobalt-vanadium layered double hydroxide harness efficient water splitting

Atomic coordination modulation and electronic structure engineering are appealing routes to develop versatile electrocatalysts targeting high-performance water electrolysis. Herein, atomically dispersed Ru sites are successfully anchored on the surface of CoV layered double hydroxide (LDH), affording a vertically aligned and interconnected nanosheet array architecture. Benefitting from the strong electronic coupling, fast charge transfer capability and well-defined morphology of as-prepared catalyst, ultralow overpotentials for hydrogen evolution reaction (HER, eta 10 = 28 mV) and oxygen evolution reaction (OER, eta 25 = 263 mV) are required. The two-electrode configuration cell only requires a cell voltage of 1.52 V to reach 10 mA cm-2, which is lower than that of commercialized Pt/C||RuO2 couple. Synchrotron X-ray absorption spectroscopy studies in combination with density functional theory calculations reveal that the strong electronic coupling between monatomic Ru with CoV LDH induces spatial charge redistribution and a distorted coordination environment around V atoms, thereby accelerating the hydrogen release for HER and reducing the rate-determining step (O* -> OOH*) free energy for OER.Web of Science452art. no. 13915

High risks of HIV transmission for men who have sex with men--a comparison of risk factors of HIV infection among MSM associated with recruitment channels in 15 cities of China.

While the HIV epidemic varies greatly by region and population group throughout China, the HIV incidence among men who have sex with men (MSM) continues to rise at an alarmingly fast pace. We seek to analyze the risk factors associated with HIV infection among MSM recruited from different channels in large urban centers across China, in an attempt to shed light on the design of future targeted intervention strategies.A total of 33,684 MSM from 14 cities and one province were recruited from July to December 2011. Demographic (e.g. age, marital status, education) and behavioral (e.g. condom use, HIV testing history) data were collected using information collection cards. Blood samples were also collected to test for HIV and Syphilis.Participants were recruited from five different channels, and all demonstrated distinct characteristics. The overall rate of positive HIV screening was 6.27% and the rate of syphilis infection was 6.50%. Participants recruited from bathhouses had the highest HIV (11.80%) and syphilis infection rates (11.20%). Participants who were infected with syphilis had the highest HIV-positive screening rate (13.75%; 95% CI OR, 2.33-3.06). living in the southwest region of the country (11.64%; OR=2.76, 95%CI OR 2.19-3.47), Being >20 years of age (P<0.001), living in the southwest region of the country (OR=2.76, 95%CI 2.19-3.47), not having sex with female over the previous 3 months (OR=1.27, 95%CI 1.09-1.48), no condom use during the last anal intercourse (OR=1.54, 95%CI 1.39-1.70) and other factors were all associated with a higher probability of having an HIV-positive test result.Depending on the way they are recruited, more targeted interventions are required to prevent the spread of HIV/AIDS among MSM with different characteristics and behaviors. Results from this study could provide evidence for researchers to conduct further studies and policy-makers to establish more effective and strategic interventions for MSM in China

Tuning the electronic structure of W18O49 via dual doping for efficient oxygen evolution reaction

Doping is an effective approach to tune the structure of materials at an atomic level, optimizing their performance toward various energy conversion applications. Herein, we show that nickel (Ni) and iron (Fe) dual doping activates the electrochemical inert W18O49 into a highly active electrocatalyst toward the oxygen evolution reaction (OER). Compared to monodoping, dual doping of Ni and Fe in the lattice of W18O49 results in the synergistic modulation of the electronic structure and physicochemical properties of tungsten oxides. The Ni and Fe dual-doped W18O49 (NiFe-W18O49) achieves a low overpotential of 325 mV at a current density of 10 mA cm(-2). and a Tafel slope of 42 mV deC(-1) for the OER in 0.1 M potassium hydroxide (KOH) solution, comparable with those of state-of-the-art IrO2. The Zn-air battery based on a NiFe-W18O49 cathode displays a long-term cycling durability of over 180 h, superior to the battery with a commercial Pt/C-IrO2 cathode. Combined experimental analysis and density functional theory calculations unveil that the distorted geometric structure and regulated electronic structure of W18O49 contribute crucially to the activation of its inert catalytic activity.Web of Science533216320

HIV screening and syphilis testing procedures.

<p>HIV screening and syphilis testing procedures.</p