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An essential part of today's power plants are flanges, for example, as connection between turbine housings and pipes. They allow for revisions, inspections, and maintenance measures. Ongoing changes toward higher amounts of renewable energy sources leading to higher demands in flexibility to counterbalance weather-related fluctuations. This flexibility leads to changing load types with more frequent warm and hot starts, causing uncertainties for the design and the determination of maintenance intervals of bolted flange connections. In this context, results of a recently finished research project and ongoing numerical investigations are presented. Tests were conducted on a model of an IP turbine flange under near-to-service loads, such as internal pressure and temperature, using a test rig allowing heating on the flange's inner surface. Concerning different influences on the stress relaxation behavior, results are shown for tests with martensitic and nickel-based bolted joints. The total test time of 5000 h for each bolted joint consist of 2000 h under steady-state conditions and 3000 h under transient conditions. Comparisons of the results with the martensitic and nickel-based bolted joint show an opposite creep strain distribution in the bolt and flange. In addition, a significant influence of the already existing creep deformation from previous load periods can be observed. Comparative simulations with a modified Graham–Walles creep model are carried out. The results confirm the differences in creep behavior with both bolted joints and reproduce the observed influence of the previous creep deformation.

During the 13thFive-Year Plan, China's natural gas industry developed rapidly, and a diversified supply and marketing pattern was formed, including domestic conventional gas, unconventional gas (shale gas, tight sandstone gas, coalbed methane, etc.), coal-based synthetic natural gas, imported LNG and imported pipeline gas. The gross calorific value of gas sources ranged from 34 MJ/m3to 43 MJ/m3, and the maximum difference of calorific value between different gas sources exceeded 20%. On May 24th, 2019, the National Development and Reform Commission and other three ministries/commissions jointly issued the Supervision Regulation on the Fair Access of Oil and Gas Pipeline Network Facilities and required that a natural gas energy measuring and pricing system shall be established within 24 months from the implementation date of this Regulation. In order to speed up the construction of China's natural gas energy measuring system, this paper summarizes domestic achievements in the construction of natural gas energy measuring system from the aspects of value traceability and energy measurement standard, and analyzes natural gas flowrate measurement technology, calorific value determination technology, value traceability, localization, intelligentization and application technology of key energy measurement equipment, natural gas pipeline network energy balancing technology based on big data analysis, multi-source quality tracking and monitoring technology, and energy measurement standard system, the need of new energy detection and measurement technology, and put forward strategy for the development of natural gas measuring in China. And the following research results are obtained. First, China's natural gas energy measuring system can basically meet the requirements of implementing natural gas energy measurement, but it still falls behind the international leading level in terms of calibration and application of high-level flowmeter (such as 0.5 class), high-accuracy gas reference material, level of calorific value reference equipment, and measurement standard system, and needs to be further improved. Second, it is necessary for China to speed up the research and application of the localization and intelligentization technologies of key energy measurement equipment. Third, natural gas pipeline network shall be equipped with measurement check method, energy balancing system based on big data analysis, and multi-source quality tracking and monitoring system, so that the energy transmission loss index of natural gas pipeline network can be superior to the international leading level (0.10%). Fourth, to realize the large-scale application of hydrogen energy and bio-energy and the mixed transportation of hydrogen, bio-methane and natural gas, it is necessary to carry out research on new technology and standardization of hydrogen/bio-methane blended natural gas detection and measurement.

Here we present results from FarGen Phase I exomes. This dataset is based on the FarGen cohort, which consists of 1,541 individuals from the isolated population of the Faroe Islands. The purpose of this cohort is to serve as a reference catalog of coding variants, and to conduct population genetic studies to better understand the genetic contribution to various diseases in the Faroese population. The first whole-exome data set comprise 465 individuals and a total of 148,267 genetic variants were discovered. Principle Component Analysis indicates that the population is isolated and weakly structured. The distribution of variants in various functional classes was compared with populations in the gnomAD dataset; the results indicated that the proportions were consistent across the cohorts, but probably due to a small sample size, the FarGen dataset contained relatively few rare variants. We identified 19 variants that are classified as pathogenic or likely pathogenic in ClinVar; several of these variants are associated with monogenetic diseases with increased prevalence in the Faroe Islands. The results support previous studies, which indicate that the Faroe Islands is an isolated and weakly structured population. Future studies may elucidate the significance of the 19 pathogenic variants that were identified. The FarGen Phase I dataset is an important step for genetic research in the Faroese population, and the next phase of FarGen will increase the sample size and broaden the scope.

Adaptive bitrate (ABR) algorithms are employed for delivering media content across wireless networks. Current ABR schemes only focus on video bitrate adaptation, considering that audio content encoding has negligible impact on streaming quality, due to its smaller size. However, many commercial platforms use high-quality audio which is significant in size. Improper audio bitrate selection thus leads to imbalanced audio/video buffer levels and adversely affects video bitrate selection. To tackle this issue, we propose VAMP, an approach that drives Video and Audio adaptation using Multi-step Predictions. Experimental results demonstrate VAMP’s vast superiority over SOTA solutions.

Despite a large body of literature on peer feedback and writing motivation, relatively few rigorously designed, experimental studies have been conducted to explore whether or not peer feedback affects students’ writing motivation and which dimensions of writing motivation may consequently change. Using an experimental design, this study explored the impact of peer feedback on students’ writing motivation among 76 university students for whom English was their second language (L2). In this study, the 76 university students were randomly divided into two groups. For one semester, the experimental group of 38 students participated in peer feedback sessions, whereas the control group of 38 students received traditional teacher assessments. At the beginning and end of the semester, both groups were given a questionnaire on L2 writing motivation as a pretest and a posttest; after the semester, individual interviews with the writing teacher and five university students from the experimental group were conducted. The results of a series of ANCOVAs demonstrated that peer feedback had significant effects on students’ attitudes toward L2 writing courses and significantly improved their self-confidence in L2 writing, whereas peer feedback had little effect on students’ anxiety about L2 writing. The results of the interviews corroborated the quantitative results. Such evidence can inform writing pedagogy, especially in light of a recent call for the integration of formative assessment into L2 writing instruction.

As a universal workplace phenomenon, the impact of work-related rumination on job performance is attracting scholars’ attention. In the current study, the relationship between two types of work-related rumination, counterproductive behavior, and creativity at work were examined, as well as the mechanism of this association. Participants were 1109 employees from a variety of jobs in mainland China. The results showed that affective rumination was negatively associated with employees’ work creativity and positively associated with counterproductive behavior. On the contrary, problem-solving pondering was positively related to creativity and negatively related to counterproductive behavior. The loss of self-control resource partially mediated the link between affective rumination and counterproductive behavior. Problem-solving pondering had no significant impact on self-control resource. Results suggest the significant effects of problem-solving pondering may be positive in the workplace and clarify the self-control resource is the internal mechanism linking rumination and job performance.

Umbilical cord blood from 1 023 consecutive births in the Faroe Islands showed a median blood-mercury concentration of 121 nmol/l (24.2 [mu]g/l); 250 of those samples (25.1%) had blood-mercury concentrations that exceeded 200 nmol/l (40 [mu]g/l). Maternal hair mercury concentrations showed a median of 22.5 nmol/g (4.5 [mu]g/g), and 130 samples (12.7%) contained concentrations that exceeded 50 nmol/g (10 [mu]g/g). Frequent ingestion of whale meat dinners during pregnancy and, to a much lesser degree, frequent consumption of fish, and increased parity or age were associated with high mercury concentrations in cord blood and hair. Blood-mercury levels were slightly lower if the mother had occasionally ingested alcoholic beverages. Mercury in blood correlated moderately with blood selenium (median, 1.40 [mu]mol/l). Increased selenium concentrations were associated with intake of whale meat, alcohol abstention, delivery after term, and high parity. Lead in cord blood was low (median, 82 nmol/l), particularly if the mothers had frequently had fish for dinner and had abstained from smoking., ACCUMULATION of mercury in fish, shellfish, and cetaceans results in increased human exposures to this metal in populations whose diets include a high intake of marine food.[1] An area with [...]

A general procedure of 1,2-dibromination of vicinal sp3C–H bonds of arylethanes using N-bromosuccinimide as the bromide reagent without an external initiator has been established. The modulation of the strength of the intermolecular noncovalent interactions between the solvent and arylethane ethanes, quantitatively evaluated via quantum chemical calculations, allows us to circumvent the fact that arylethane ethane cannot be dibrominated through traditional methods. The mechanism was explored by both experiments and quantum chemical calculations, revealing a radical chain with HAA process.

Reactive oxygen species (ROS) are not only used as a therapeutic reagent in chemodynamic therapy (CDT), to stimulate the release of antineoplastic drugs, they can also be used to achieve a combined effect of CDT and chemotherapy to enhance anticancer effects. Herein, we synthesized a pH-responsive prodrug (PEG2k-NH-N-DOX), ROS-responsive prodrug (PEG2k-S-S-CPT-ROS), organic CDT agents (TPP-PEG2k-LND, TPP-PEG2k-TOS), and T1-enhanced magnetic resonance imaging contrast agents (Gd-DTPA-N16-16), and used them to encapsulate combrestatinA4 (CA4) to prepare traceable pH/ROS dual-responsive multifunctional nanoparticles (TLDCAGNPs) with endogenous ROS burst and spatiotemporally controlled multiple drug release ability. Firstly, TLDCAGNPs were accumulated in the tumor cell microenvironment viaan enhanced permeability and retention (EPR) effect. Secondly, CA4 was released and specifically destroyed angiogenesis to facilitate the interaction between the tumor and the remaining TLDCGNPs. After accumulating in tumor cells, the TLDCGNPs could be destroyed under acidic conditions to quickly release doxorubicin (DOX), TPP-PEG2k-LND, and TPP-PEG2k-TOS. Thirdly, TPP-PEG2k-LNDand TPP-PEG2k-TOSquickly targeted mitochondria, induced endogenous ROS bursts, reduced the mitochondrial membrane potential, and induced tumor cell apoptosis. Endogenous ROS can not only be used as a therapeutic reagent for CDT, but also can cut off the thioketal bond in PEG2k-S-S-CPT-ROSand release camptothecin (CPT). Finally, TLDCAGNPs were traced by magnetic resonance imaging (MRI). Furthermore, in vitroand vivoresults indicate that the TLDCAGNPs have vigorous antitumor activity and negligible systemic toxicity. Therefore, the TLDCAGNPs provide an efficient strategy for enhancing antitumor efficacy.

The X-ray fluorescence (XRF) core-scanned Rb/Sr ratios of lake sediments have been widely used as a proxy for chemical weathering intensity and past climate change. However, some factors could affect Rb/Sr ratios, causing misinterpretation and limiting its application. In this study, we present a high-resolution XRF core-scanned Rb/Sr record of core ZB13-C1 from the Zoige Basin in the eastern Tibetan Plateau. To validate its application, we correlated this record with the chemical index of alteration (CIA) and other paleoclimatic proxies. Our results showed that (1) the core-scanned Rb/Sr ratios and CIA were reliable proxies of chemical weathering intensity in fine-grained sedimentary sequences; (2) the low values of core-scanned Rb/Sr ratios and CIA were significantly correlated with high total organic carbon content, arboreal pollen content, carbonate content, and C/N ratios, confirming its reliability as a proxy for the Asian summer monsoon intensity; (3) the core-scanned Rb/Sr ratios at core depths of 25–0.3 and 56–17 m were unable to reliably reflect chemical weathering intensity due to both the grain-size effect and the low test accuracy. Our study highlights the need for mutual verification of multiple indicators before accurately applying Rb/Sr as a paleoclimatic proxy in other similar study areas.

Radiation-induced enteritis is a major side effect in cancer patients undergoing abdominopelvic radiotherapy. The Nrf2/HO-1 pathway is a critical endogenous antioxidant stress pathway, but its precise role in radiation-induced enteritis remains to be clarified. Polysaccharides extracted from Rheum tanguticum (RTP) can protect the intestinal cells from radiation-induced damage, but the underlying mechanism is unknown. SD rats and IEC-6 cells were exposed to 12 or 10 Gy X-ray radiation. Rat survival, and histopathological and immunohistochemical profiles were analyzed at different time points. Indicators of oxidative stress and inflammatory response were also assessed. Cell viability, apoptosis and Nrf2/HO-1 expression were evaluated at multiple time points. Significant changes were observed in the physiological and biochemical indexes of rats after radiation, accompanied by significant oxidative stress response. The mRNA and protein expression of Nrf2 peaked at 12 h after irradiation, and HO-1 expression peaked at 48 h after irradiation. RTP administration reduced radiation-induced intestinal damage, upregulated Nrf2/HO-1, improved physiological indexes, significantly decreased apoptosis and inflammatory factors, and upregulated HO-1, particularly at 48 h after irradiation. In conclusion, Nrf2 is activated in the early stage of radiation-induced intestinal injury and plays a protective role. RTP significantly ameliorates radiation-induced intestinal injury via the regulation of Nrf2 and its downstream protein HO-1.

Modern welded structures often contain weld ends due to increasing component complexity and economic motives. Under cyclic loading, crack initiation mainly occurs at those weld ends which makes them the failure critical location. So far, no detailed approach for the assessment of the fatigue life of weld ends has been added to known international or national guidelines. A new specimen type was developed at the Materials Testing Institute University of Stuttgart with which the fatigue resistance of weld ends of different welding procedures can be evaluated and compared. Tensile tests and fatigue tests on those new specimens show that the loading capacity is dependent on the welding procedure and the weld end point considered, i. e. weld start or weld end. In a sketched assessment approach, those results can be transferred to components in order to carry out a fatigue strength assessment or to enable the selection of a welding procedure. The assessment with the notch stress concept is preferred for the further development of the assessment approach.

Self-piercing riveting (SPR) is one of the advanced mechanical joining techniques used intensively in modern automobiles. SPR is a cold forming process involving a semi-tubular rivet as fastener to join two or three similar or dissimilar materials. The present study deals with the development of a five-step simulation process chain capable of numerically predicting the SPR joint geometry and the joint strength under different loading conditions such as Shear, Cross-tension and Peel loading. The complete process chain considers a 2D axisymmetric model for the process simulation and a 3D simulation model with solid-shell interaction for the joint failure simulation. The calibration of damage models and their application in the joint strength analysis are integral parts of the present study. The comparison of joint strength analysis results with experiments under the criteria: mode of joint failure, maximum force (indicating joint failure) and displacement at maximum force provides basis for validation of the simulation process chain. Additionally, a comparison of joint geometry with joint cross-section images and force-displacement curves from experiments provides an opportunity for an intermediate verification of the numerical process flow. The study also presents an accuracy comparison of different damage models and the impact of rivet setting depth on the joint strength and mode of joint failure.

Drought represents a significant stress to microorganisms and is known to reduce microbial activity and organic matter decomposition in Mediterranean ecosystems. However, we lack a detailed understanding of the drought stress response of microbial decomposers. Here we present metatranscriptomic and metabolomic data on the physiological response of in situ microbial communities on plant litter to long-term drought in Californian grass and shrub ecosystems. We hypothesised that drought causes greater microbial allocation to stress tolerance relative to growth pathways. In grass litter, communities from the decade-long ambient and reduced precipitation treatments had distinct taxonomic and functional profiles. The most discernable physiological signatures of drought were production or uptake of compatible solutes to maintain cellular osmotic balance, and synthesis of capsular and extracellular polymeric substances as a mechanism to retain water. The results show a clear functional response to drought in grass litter communities with greater allocation to survival relative to growth that could affect decomposition under drought. In contrast, communities on chemically more diverse and complex shrub litter had smaller physiological differences in response to long-term drought but higher investment in resource acquisition traits across precipitation treatments, suggesting that the functional response to drought is constrained by substrate quality. Our findings suggest, for the first time in a field setting, a trade off between microbial drought stress tolerance, resource acquisition and growth traits in plant litter microbial communities.