Improvement effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)on hydrogen storage performance of MgH_(2)

The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were successfully prepared and introduced into MgH_(2)(denoted as MgH_(2)-NiCu@C).The onset and peak temperatures of hydrogen desorption of MgH_(2)-11 wt.%NiCu@C are 175.0℃and282.2℃,respectively.The apparent activation energy of dehydrogenated reaction is 77.2±4.5 kJ/mol for MgH_(2)-11 wt.%NiCu@C,which is lower than half of that of the as-milled MgH_(2).Moreover,MgH_(2)-11 wt.%NiCu@C displays great cyclic stability.The strengthening"hydrogen pumping"effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)is proposed to explain the remarkable improvement in hydrogen absorption/desorption kinetic properties of MgH_(2).This work offers a novel perspective for the design of bimetallic nanoparticles and beyond for application in hydrogen storage and other energy related fields.

Magnesium nickel hydride monocrystalline nanoparticles for reversible hydrogen storage

Although Mg-based hydrides are extensively considered as a prospective material for solid-state hydrogen storage and clean energy carriers,their high operating temperature and slow kinetics are the main challenges for practical application.Here,a Mg-Ni based hydride,Mg_(2)NiH_(4) nanoparticles(~100 nm),with dual modification strategies of nanosizing and alloying is successfully prepared via a gas-solid preparation process.It is demonstrated that Mg_(2)NiH_(4) nanoparticles form a unique chain-like structure by oriented stacking and exhibit impressive hydrogen storage performance:it starts to release H2 at~170℃ and completes below 230℃ with a saturated capacity of 3.32 wt%and desorbs 3.14 wt% H_(2) within 1800 s at 200℃.The systematic characterizations of Mg_(2)NiH_(4) nanoparticles at different states reveal the dehydrogenation behavior and demonstrate the excellent structural and hydrogen storage stabilities during the de/hydrogenated process.This research is believed to provide new insights for optimizing the kinetic performance of metal hydrides and novel perspectives for designing highly active and stable hydrogen storage alloys.

Genetic Analysis of Superior Clones and Identification of Specific Marker of Elite Clones of Pinus kesiya

In the present study, the genetic distances between 85 superior clones from seven natural populations of Pinus kesiya var. langbianensis were analyzed by RAPD-PCR assays, and then, a UPGMA cluster diagram was established based on the genetic distances to reveal their genetic relationship. In addition, specific markers of elite clones were identified by carefully comparing the fingerprints of the 85 clones. The results showed that the 85 P. kesiya clones were divided into three groups at a genetic distance of 0.59. Two specific markers that were able to distinguish some elite clones from others were identified. The results may provide a molecular basis for the identification and selection of elite clones of Pinus kesiya var. langbianensis.

Comparative yield and efficiency of strategies based on risk assessment and fecal immunochemical test in colorectal cancer screening:A cross-sectional population-based analysis

Objective:Integration of risk stratification into fecal immunochemical test(FIT)might aid in the suboptimal detection of advanced neoplasms by FIT in colorectal cancer(CRC)screening.A comparative study was conducted to evaluate the participation and diagnostic yield of the parallel combination of questionnaire-based risk assessment(QRA)and FIT,FIT-only and QRA-only strategies in a CRC screening program in China.Methods:The study included 29,626 individuals aged 40-74 years and invited to participate in a CRC screening program in China.Participants were first invited to undertake QRA and one-time FIT(OC-sensor).Participants with positive QRA or FIT were deemed to be high-risk individuals who were recommended for subsequent colonoscopy.Participation,detection rate,and resource demand for colonoscopy were calculated and compared.Results:Of the 29,626 invitees,20,203 completed the parallel combination,8,592 completed the QRA-only,and11 completed the FIT-only strategy.For the parallel combination,FIT-only,and QRA-only strategies,the overall positivity rates were 10.2%(2,928/28,806),5.4%(1,096/20,214),and 6.8%(1,944/28,795),respectively;the yield of advanced neoplasm per 10,000 invitees were 46.9[95%confidence interval(95%CI):39.8-55.4],36.8(95%CI:30.5-44.4),and 12.2(95%CI:8.8-16.8),respectively;the positive predictive values for detecting advanced neoplasms among participants who completed colonoscopy were 4.7%(95%CI:4.0%-5.6%),9.9%(95%CI:8.3%-11.9%),and 1.9%(95%CI:1.3%-2.6%),respectively;the number of colonoscopies required to detect one advanced neoplasm was 11.4(95%CI:9.8-13.4),5.7(95%CI:4.8-6.7),and 28.4(95%CI:20.7-39.2),respectively.Conclusions:The parallel combination of QRA and FIT did not show superior efficacy for detecting advanced neoplasm compared with FIT alone in this CRC screening program.

Study on Lightning Protection Design of DCS in a Nuclear Power Plant

DCS （distributed control system） plays a decisive role in the overall operation of a nuclear power plant. If DCS fails, it will seriously affect the normal production of nuclear power plant, causing great losses. So it is very important to take perfect lightning protection measures on DCS of the nuclear power plant. In this paper, according to the actual situation of DCS in a nuclear power plant, by controlling lightning point, securely booting lightning into the ground network, improving low-resistance ground network, eliminating ground loops, determining the safety space, surge protection of power and signal, a set of complete lightning protection design scheme was systematically put forward. Some specific lightning protection measures were highlighted, such as the DCS grounding, equipotential bonds and shields, and some specific considerations were put forward. All of these could offer reference in the practical application.

Facet-dependent catalytic activity of two-dimensional Ti_(3)C_(2)T_(x) MXene on hydrogen storage performance of MgH_(2)

Two-dimensional Ti_(3)C_(2)T_(x) MXenes exposing different active facets are introduced into MgH_(2), and their catalytic effects are systematically investigated in depth through experimental and theoretical approaches. Excluding factors such as interlayer space, surface functional groups and experimental contingency, the exposed facets is considered to be the dominant factor for catalytic activity of Ti_(3)C_(2)T_(x) towards MgH_(2).More exposed edge facets of Ti_(3)C_(2)T_(x) displays higher catalytic activity than that with more exposed basal facets, which also leads to different rate-controlling steps of MgH_(2) in the de/hydrogenation process. The low work function, strong hydrogen affinity and high content of in situ metallic Ti for the edge facet contribute the high catalytic activity. This work will give insights into the structural design of two-dimensional Ti_(3)C_(2)T_(x) MXene used for enhancing the catalytic activity in various fields.

The ethanol response gene Cab45 can modulate the impairment elicited by ethanol and ultraviolet in PC12 cells

High consumption of ethanolic beverages facilitates neurodegeneration, but the mechanism of this process still remained elusive. Suppression subtractive hybridization （SSH） is a technique for detection of rare transcripts. With SSH approach, we identified one ethanol response gene Cab45, which was down-regulated by ethanol with time-dependent manner in B104 cells. The full-length sequence of Cab45 gene was obtained by 5＇-RACE （5＇Rapid Amplification of cDNA Ends） for the first time in rat. Based on the sequence of deduced amino acid of rat Cab45, the alignment was conducted with its counterparts in different species and displayed a high conservation. Using different tissues in rat and cell lines, Cab45 was characterized by a ubiquitous expression and differentiation dependent down-regulation. Given that ethanol facilitates some cell differentiation, we hypothesize that Cab45 is involved in ethanol-mediated differentiation. With transient transfection, the function of Cab45 was investigated by up-regulation and down-regulation in PC12 cells. Ethanol treatment and UV exposure were conducted subsequently and cell proliferations were detected by MTT （Methyl Thiazolyl Tetrazolium） approach. It revealed that the up-regulation of Cab45 modulated the impairment elicited by ethanol and UV in transfected cells. As a member of new calcium binding protein family, the exact role of Cab45 still remains unclear.

Effects of highly dispersed Ni nanoparticles on the hydrogen storage performance of MgH_(2)

MgH_(2)with a large hydrogen capacity is regarded as a promising hydrogen storage material.However,it still suffers from high thermal stability and sluggish kinetics.In this paper,highly dispersed nano-Ni has been successfully prepared by using the polyol reduction method with an average size of 2.14 nm,which significantly improves the de/rehydrogenation properties of MgH_(2).The MgH_(2)–10wt%nano-Ni sample starts releasing H_(2)at 497 K,and roughly 6.2wt%H_(2)has been liberated at 583 K.The rehydrogenation kinetics of the sample are also greatly improved,and the adsorption capacity reaches 5.3wt%H_(2)in 1000 s at 482 K and under 3 MPa hydrogen pressure.Moreover,the activation energies of de/rehydrogenation of the MgH_(2)–10wt%nano-Ni sample are reduced to(88±2)and(87±1)kJ·mol−1,respectively.In addition,the thermal stability of the MgH_(2)–10wt%nano-Ni system is reduced by 5.5 kJ per mol H_(2)from that of pristine MgH_(2).This finding indicates that nano-Ni significantly improves both the thermodynamic and kinetic performances of the de/rehydrogenation of MgH_(2),serving as a bi-functional additive of both reagent and catalyst.

Weather Typing and Dissipation Forecast of Fog in Haizhou Bay

[ Objective] The research aimed to study weather typing and dissipation forecast of the fog in Haizhou Bay. [ Method] Based on the me- teorological observation data of three representative stations in Lianyungang, we analyzed weather situation before fog occurrence as well as the meteorological elements of coastal fog in Haizhou Bay, and established dissipation rating forecast equation of the fog. [ Result] From the surface weather chart, the fog in Haizhou Bay was divided into four types： low-pressure inverted trough type, prefrontal warm-zone type, high-pressure rear type and high-pressure bottom type. FOg formation was closely related to stratification stability, temperature, relative humidity, wind direction and wind velocity. By using multiple linear regression method, dissipation rating prediction equation of the fog was established. Via test, prediction was correct basically, and it reached 77% that forecast rating error was below level 0.5.[Conclusion] The research could provide favorable reference for forecast and warninq of the fo_q in Haizhou Bay.

Comparative Analysis on Physical Quantity Diagnosis and Wind Profile Radar Data of Two Heavy Rainfalls

[ Objective] The research aimed to contrast physical quantity diagnosis and wind profile radar data of two heavy rainfalls. [ Method ] From circulation background, physical quantity field and wind profile radar data, we analyzed two big rainstorm weather processes （8 -9 July and August 10） in Lianyungang City in 2012. [ Result] Rainstorm generation was related to favorable large-scale circulation situation. The first-stage precipitation during 8 -9 July was warm-zone precipitation, and the precipitation at the second stage was triggered by shear line. Precipitation on August 10 was generated by typhoon low-pressure inverted trough and cold air. Sufficient water vapor content and strong water vapor transportation were favorable for generation of the heavy precipitation. Suction effect by divergence at high layer and convergence at middle and low layers was favorable for maintenance of the strong ascending motion. Occurrence of the heavy precipitation must have ascending motion condition. But it was not that the stronger the ascending motion, the stronger the rainfall intensity. Kindex and θse500 -θse 850 were closely related to rainstorm occurrence. Horizontal wind data of the wind profile radar provided fine structure of the atmospheric horizontal motion at vertical direction, could clearly display vertical structure of the wind field in rainstorm process, and directly reflected change characteristics of the wind field in precipitation process. [ Conclusion] The research could provide reference for future forecast work.

Air-stable magnesium nickel hydride with autocatalytic and self-protective effect for reversible hydrogen storage

Among the factors which restrict the large-scale utilization of magnesium-based hydride as a hydrogen storage medium,the high operating temperature,slow kinetics,and air stability in particular are key obstacles.In this work,a novel method,namely hydriding combustion synthesis plus short-term mechanical milling followed by air exposure,was proposed to synthesize air stable and autocatalytic magnesium nickel hydride(Mg2NiH4),which shows excellent hydrogen absorption/desorption kinetics,capacity retention and oxidation resistance.The short-term-milled Mg2NiH4 can desorb 2.97 wt.%hydrogen within 500 s at 230℃.Even after exposure under air atmosphere for 67 days,it can still desorb 2.88 wt.%hydrogen within 500 s at 230℃.The experimental and theoretical results both indicated that the surface of as-milled Mg2NiH4 was easy to be oxidized under air atmosphere.However,the in-situ formed Ni during air exposure of Mg2NiH4 improved the hydrogen desorption kinetics,and the formed surface passivation layer maintained the hydrogen storage capacity and avoided further poisoning,which we called autocatalytic and self-protective effect.Such a novel dual effect modified the reaction activity and oxidation resistance of the air-exposed Mg2NiH4.Our findings provide useful insights into the design and preparation of air stable metal-based hydride for large-scale utilization and long-term storage.

Assisting Ni catalysis by CeO_(2) with oxygen vacancy to optimize the hydrogen storage properties of MgH_(2)

Although MgH_(2) has been widely regarded as a promising material for solid-state hydrogen storage,its high operating temperature and slow kinetics pose a major bottleneck to its practical application.Here,a nanocomposite catalyst with interfacial coupling and oxygen defects,Ni/CeO_(2),is fabricated to promote H_(2) desorption and absorption properties of MgH_(2).The interface of Ni/CeO_(2) contributes to both strong mechanical coupling towards stabilizing partial Ni and electronic coupling towards inducing a high con-centration of oxygen vacancies in CeO_(2).Theoretical calculations evidence that CeO_(2) with oxygen vacancy assist Ni in weakening the energy of Mg-H bond as well as enhancing the adsorption energy of Ni upon hydrogen atoms,and the extent of this assistance surprisingly increases with increasing oxygen vacancies concentration.As a result,an impressive performance is achieved by MgH_(2)-5 wt.%Ni/CeO_(2) with onset desorption temperature of only 165°C,and it absorbs approximately 80%hydrogen in just 800 s at 125°C.The generation mechanism of intermediate active species concerning Ni/CeO_(2) in different states has been analyzed for the first time,and the relationship between interfacial coupling and phase evolution has been elucidated.Therefore,a mechanism of the catalysis-assisting effect regarding oxygen defects is proposed.It is believed that this work provides a unique perspective on the mechanism of interfacial coupling and the generation of defects in composite catalysts.