Mesoscale Modeling of Hooked-End Steel Fiber Reinforced Concrete under Uniaxial Compression Using Cohesive Elements

Based on the cohesive zone model, the 2D mesostructures were developed for numerical studies of multi-phase hooked-end steel fiber reinforced concrete under uniaxial compression. The zero-thickness cohesive interface elements were inserted within the mortar, on interfaces of mortar and aggregates and interfaces of mortar and fibers to simulate the failure process of fiber reinforced concrete. The results showed that the numerical results matched well the experimental results in both failure modes and stress-strain behavior. Hooked-end steel fiber reinforced concrete exhibited ductile failure and maintained integrity during a whole failure process. Compared with normal concrete, HES fiber reinforced concrete was greater stiffness and compressive strength;the descending branch of the stress-strain curve was significantly flatter;the residual stress was higher.

Development of index system for inherently safer process design using an integrated approach

With a growing population, an increasing number of petrochemical facilities are built with larger capacity and more complexity, which pose a great risk to assets, community and environment. The value of inherently safer design is recognized with time by all stakeholders, and an effective tool is needed to evaluate and compare inherent safety of alternative technologies. This study developed a safety index to evaluate existing technologies for their safety levels and guide inherently safer design. The Integrated Risk-based Safety Index(IRSI) was developed based on a comprehensive review of petrochemical processes, incident cases from Sinopec and US Chemical Safety Board, and existing safety index systems. The IRSI included all major hazards, including fire, explosion,toxic release, dust explosion, physical explosion, and runaway. Also, the integrated life cycle approach considered chemical hazards, equipment failure rates and safety measures in this risk-based index. Advanced modeling techniques, PHAST simulation and Neural Network, were used in the development of three novel sub-indices in the projects, fire, explosion and toxic release. The index system could be easily incorporated into a user friendly tool for the ease of application. A case study of hydrogen dioxide was conducted using the IRSI, which showed its capability for evaluating the safety level of process facilities.

全基因组关联研究发现中国人群前列腺癌两个新易感位点9q31.2和19q13.4

0前言在全球范围内，前列腺癌的发病率和病死率存在着巨大差异。该病在西方发达国家发病率最高，在非裔美国人群病死率最高，而在亚洲人群中发病率及病死率均为全球最低，提示不同人种在前列腺癌的遗传方面存在异质性。在欧美和日本人群中，全基因组关联研究（GWAS）技术已经被用于检测前列腺癌的遗传易感性位点，但至今尚无关于GWAS检测中国人群前列腺癌易感位点的报道。

Data Integrity Checking Protocol with Data Dynamics in Cloud Computing

We introduce a model for provable data possession (PDP) which allows a client that has stored data at an untrusted server to verify that the server possesses the original data without retrieving it. In a previous work, Ateniese et al. proposed a remote data integrity checking protocol that supports data partial dynamics. In this paper, we present a new remote data possession checking protocol which allows an unlimited number of file integrity verifications and efficiently supports dynamic operations, such as data modification, deletion, insertion and append. The proposed protocol supports public verifiability. In addition, the proposed protocol does not leak any private information to third-party verifiers. Through a specific analysis, we show the correctness and security of the protocol. After that, we demonstrate the proposed protocol has a good performance.

A picture with more details is painted for prostate cancer

B y comparing all gene-coding sequences in the genome between tumors and matched normal samples from clinically localized and castration-resistant （CR） prostate cancer patients, two groups of scien- tists have recently identified more than 5000 somatic mutations.

Rhizoma Drynariae-derived nanovesicles reverse osteoporosis by potentiating osteogenic differentiation of human bone marrow mesenchymal stem cells via targeting ERα signaling

Although various anti-osteoporosis drugs are available,the limitations of these therapies,including drug resistance and collateral responses,require the development of novel anti-osteoporosis agents.Rhizoma Drynariae displays a promising anti-osteoporosis effect,while the effective component and mechanism remain unclear.Here,we revealed the therapeutic potential of Rhizoma Drynariae-derived nanovesicles(RDNVs)for postmenopausal osteoporosis and demonstrated that RDNVs potentiated osteogenic differentiation of human bone marrow mesenchymal stem cells(hBMSCs)by targeting estrogen receptor-alpha(ERα).RDNVs,a natural product isolated from fresh Rhizoma Drynariae root juice by differential ultracentrifugation,exhibited potent bone tissue-targeting activity and anti-osteoporosis efficacy in an ovariectomized mouse model.RDNVs,effectively internalized by hBMSCs,enhanced proliferation and ERαexpression levels of hBMSC,and promoted osteogenic differentiation and bone formation.Mechanistically,via the ERαsignaling pathway,RDNVs facilitated mRNA and protein expression of bone morphogenetic protein 2 and runt-related transcription factor 2 in hBMSCs,which are involved in regulating osteogenic differentiation.Further analysis revealed that naringin,existing in RDNVs,was the active component targeting ERαin the osteogenic effect.Taken together,our study identified that naringin in RDNVs displays exciting bone tissue-targeting activity to reverse osteoporosis by promoting hBMSCs proliferation and osteogenic differentiation through estrogen-like effects.

High-frequency Resonance Analysis and Impedance Reshaping Control of MMC-HVDC System Based on Frequency Coupling Impedance Model

In recent years, high-frequency resonance (HFR) events occurred in several modular multilevel converter based high-voltage direct current (MMC-HVDC) projects. The time delay of an MMC-HVDC system is the critical factor that induces HFR. The frequency coupling affects the impedance characteristics of an MMC and further deteriorates system stability. Therefore, in this paper, a multi-input multi-output admittance model of an MMC-HVDC system is developed to analyze its frequency characteristics. The effects of current loop, power loop, phase-locked loop, and operating point on the MMC frequency coupling degree are analyzed in detail. Meanwhile, to further suppress HFR in the MMC-HVDC system, an enhanced impedance reshaping control strategy based on the equivalent single-input single-output impedance model is proposed. Finally, the accuracy of the enhanced impedance model and the effectiveness of the impedance reshaping control are verified by electromagnetic transient simulations in PSCAD.

A fibrous hydroelectric generator derived from eco-friendly sodium alginate for low-grade energy harvesting

With the development of renewable energy technologies,the recovery and utilization of low-grade energy based on hydroelectric effect have drawn much attention owing to its environmental friendliness.Herein,a novel hydroelectric generator utilizing sodium alginategraphene oxide(SA-GO)fibers is proposed,which is ecofriendly and low-cost.These fibers with a length of 5 cm and a diameter of 0.15 mm can generate an open circuit voltage(Voc)of approximately 0.25 V and a short circuit current(Isc)of 4µA.By connecting SA-GO fibers in either series or parallel,this combination can power some electronic devices.Furthermore,these fibers enable the recovery of low-grade energy from the atmosphere or around the human body.Both experimental and theoretical analysis confirm that the directional flow of protons driven by water molecules is the main mechanism for power generation of SA-GO fibers.This study not only presents a simple energy transformation method that is expected to be applied to our daily life,but also provides a novel idea for the design of humidity electricity-generation devices.