古镇旅游地居民旅游影响感知对支持旅游开发的影响

居民是否支持旅游开发关系到当地旅游业的长期成功和可持续发展。基于态度冲突理论和社会交换理论,本研究以浙江省乌镇 458位居民为样本,以消极旅游影响感知为中介和信任旅游开发公司为调节,实证考察了积极旅游影响感知对居民支持旅游开发的影响。研究结果表明：积极旅游影响感知和消极旅游影响感知不是无关的平行构建,前者对后者具有显著弱化作用;消极旅游影响感知部分中介积极旅游影响感知与居民支持旅游开发的关系,以直接影响为判断依据会低估积极旅游影响感知对居民支持旅游开发的影响;信任旅游开发公司正向调节消极旅游影响感知与居民支持旅游开发的负向关系。研究结论对明晰居民支持旅游开发的形成机制、获取居民对旅游开发的更大支持等具有重要意义。     

Monitoring the remediation of a near shore waste disposal site in Antarctica using the amphipod Paramoera walkeri and diffusive gradients in thin films (DGTs)

The water quality of a marine embayment (Brown Bay) was monitored during the remediation of an abandoned waste disposal site at Casey Station, East Antarctica, using a combination of biomonitoring and chemical methods. The Antarctic amphipod Paramoera walkeri, in field mesocosms suspended in the water column, was deployed adjacent to the site and at two reference sites for periods of 14 days, repeated three times during the remediation period (December to February). Diffusive gradients in thin film (DGT) samplers were deployed for the same periods to provide estimates of dissolved metals. No difference in mortality of amphipods was observed between Brown Bay and reference sites. There were significant differences, however, in accumulated metal concentrations between amphipods from Brown Bay and reference sites, with greater concentrations of antimony, copper, cadmium, lead, iron and tin at Brown Bay. The melt water/runoff treatment strategy employed for the remediation was successful in preventing acute toxic effects, but water quality was reduced at Brown Bay, where increased metal bioavailability may have been high enough to induce chronic effects in some biota. DGT samplers were less sensitive than amphipods in detecting differences in metal concentrations between sites, indicating that metals bound to suspended particulates were a potentially significant source of contamination.     

Enhanced predictions of wave impact pressure by improved incompressible SPH methods

A new criterion is proposed for a more efficient assessment of free-surface particles in a particle-based simulation. Enhanced wave impact simulations are carried out by improved Incompressible SPH (ISPH) methods. The first improvement is the same as that in the Corrected ISPH (CISPH; [Khayyer A, Gotoh, H, Shao SD. Corrected incompressible SPH method for accurate water-surface tracking in breaking waves, Coast Eng 2008; 55 (3): 236–250]) method and is proposed for the improvement of momentum conservation. The second improvement is achieved by deriving and employing a higher order source term based on a more accurate differentiation to obtain a less fluctuating and more accurate pressure field. The enhanced performance of improved ISPH methods is demonstrated through the simulation of several fluid impact simulations in comparison with the experimental data and simulation results by other numerical methods.     

Targeting the impactors: siderophile element signatures of lunar impact melts from Serenitatis

Highly siderophile element compositions of lunar impact melt breccias provide a unique record of the asteroid population responsible for large cratering events in the inner Solar System. Melt breccias associated with the 3.89 Ga Serenitatis impact basin resolve at least two separate impact events. KREEP-rich melt breccias representing the Apollo 17 poikilitic suite are enriched in highly siderophile elements (3.6-15.8 ppb Ir) with CI-normalized patterns that are elevated in Re, Ru and Pd relative to Ir and Pt. The restricted range of lithophile element compositions combined with the coherent siderophile element signatures indicate formation of these breccias in a single impact event involving an EH chondrite asteroid, probably as melt sheet deposits from the Serenitatis Basin. One exceptional sample, a split from melt breccia 77035, has a distinctive lithophile element composition and a siderophile element signature more like that of ordinary chondrites, indicating a discrete impact event. The recognition of multiple impact events, and the clear signatures of specific types of meteoritic impactors in the Apollo 17 melt breccias, shows that the lunar crust was not comprehensively reworked by prior impacts from 3.9 to 4.5 Ga, an observation more consistent with a late cataclysm than a smoothly declining accretionary flux. Late accretion of enstatite chondrites during a 3.8-4.0 Ga cataclysm may have contributed to siderophile element heterogeneity on the Earth, but would not have made a significant contribution to the volatile budget of the Earth or oxidation of the terrestrial mantle. Siderophile element patterns of Apollo 17 poikilitic breccias become more fractionated with decreasing concentrations, trending away from known meteorite compositions to higher Re/Ir and Pd/Pt ratios. The compositions of these breccias may be explained by a two-stage impact melting process involving: (1) deep penetration of the Serenitatis impactor into meteorite-free lower crust, followed by (2) incorporation of upper crustal lithologies moderately contaminated by prior meteoritic infall into the melt sheet. Trends to higher Re/Ir with decreasing siderophile element concentrations may indicate an endogenous lunar crustal component, or a non-chondritic late accretionary veneer in the pre-Serenitatis upper crust.     

基于GIS的重点区域地质灾害风险评价

为治理河口拦门沙,实施了通过整治及疏浚的方式打通拦门沙的射阳港双导堤工程,导堤的功能定位为“导流、挡沙、减淤”。通过对江苏盐城射阳港海岸动力地貌等环境的调查,分析研究射阳港区不同时期的水下沉积物分布特征、不同历史时期的水下地形特征,同时研究不同时期的水质、底质沉积物、生态群落等指标数据,对射阳港双导堤建设的环境影响进行后评价。研究认为：双导堤工程完工后导堤口区域出现明显冲刷,导堤两侧出现淤积,颗粒变细,但对水质环境、底质沉积物环境和生态环境的影响不大,双导堤工程建设对环境影响的风险可控。     

基于岩石性质的钻进振动响应分析

岩石在钻头破岩工作时会产生振动,为了研究岩石特性对钻进过程中岩石振动的影响,提出一种基于振动的岩石特性识别方法。通过振动学理论和弹性力学知识建立岩石振动方程,利用数值模拟软件分析不同参数对岩石振动的影响。研究表明：冲击荷载下岩石产生振动,岩石特性对振动有紧密关系;岩石的密度、刚度和抗压强度对岩石的振动都有一定影响,其中岩石强度对振动的影响最为明显;岩石刚度越小,强度越小,在冲击荷载作用下,岩石振动越大。研究冲击钻进过程岩石的振动特性,对钻进参数设置以及岩性的识别有重要意义。     

Seismic effects of the Caloris basin impact, Mercury

Striking geological features on Mercury's surface have been linked to tectonic disruption associated with the Caloris impact and have the potential to provide information on the interior structure of Mercury. The unusual disrupted terrain located directly at the antipode of the 1500-km-diameter Caloris basin could have plausibly formed as a consequence of focused seismic waves generated by the massive impact event. In this paper, we revisit the antipodal seismic focusing effects of the Caloris impact by developing physically consistent structure models for Mercury and parameterized seismic source models for the Caloris impact. If the focused seismic body waves caused the disrupted terrain, then the amplitudes of the waves and the areal extent of surface disruptions could be used for estimating the seismic energy imparted by the impact.In this study, we show that effects of direct body waves are small relative to those of focused guided waves. Two types of guided waves are produced by the Caloris impact. One is the conventional Rayleigh wave generated by the impact. The second is the mantle guided waves trapped between the core and the free surface. Mantle guided waves, not recognized in previous studies, may have played an important role in the creation of the disrupted terrain. We find that the early core state has only moderate effects on the antipodal response to the Caloris impact. The fact that the zone of predicted disruption for both fluid and solid core cases is smaller than the observed region of chaotic terrain suggests either that the antipodal response to the Caloris impact was modulated by the shallow structure of Mercury, or that the energy imparted by the impact was larger than those used in this study.     

浅谈经纬仪测风

正确、规范地使用经纬仪跟踪气球测风是提高测风质量的关键。作者根据20多年使用经纬仪测风的体会,深入浅出地论述了怎样测风以及如何提高测风质量。     

Impact Pressure of Incident Regular Waves and Irregular Waves on the Subface of Open-Piled Structures

1 .IntroductionInrecentyears,theimpactloadsactingonthesuperstructureofopen piledwharfs,shoretres tles,oildrillingplatforms ,etc .,havebecomeanimportantsafetyissueinoffshoreengineering .Owingtotheeffectofseabedsubsidenceandtheoccurrenceofextremestormconditionsthatexceedpriorpre dictions,theclearanceofthesuperstructuresofsomemarinestructuresmaybeinsufficient.So ,whenwavesoflargecrestspropagatebeneaththestructure ,itsundersidewillbesubjectedtoimpactloadsofconsiderablemagnitudeswhichmaycausethesup…     

The human impact on natural rock reserves using basalt,anorthosite, and carbonates as raw materials in insulation products

Typical crustal rocks such as basalt, limestone, and anorthosite are used in stone wool insulation products. The raw materials for stone wool production are not specific to any rare mineral source but depend upon the mixture of materials having the correct chemical composition, exemplified by 40 wt% basalt, 20 wt% anorthosite, and 40 wt% cement-bonded renewable materials. This study provides an overview of the natural cycle of these resources, including their abundances in nature, and sets the consumption by the stone wool industry and other human activities in perspective.

Basalt, anorthosite, and carbonates are widespread on all continents. Although basaltic rocks cover most of the ocean floor, these reserves are hidden below several kilometres of water and therefore are regarded as inaccessible. Instead, large igneous provinces on land constitute major basaltic reserves useful for human rock exploration. Globally, anorthositic provinces comprise smaller volumes than do limestone or basalt, but still occur in sufficient amounts to supply for the production of insulation materials indefinitely. An evaluation of the modern consumption rates and reserves shows that the crustal inventories of these rock types are so large that they could supply current human demand for millions of years.

The natural degradation of surface rocks occurs by physical and chemical weathering creating sediment that is transported along rivers and deposited in the ocean. Sediments are either obducted with continental lithosphere or subducted with oceanic crust and recycled through the mantle by plate tectonics. Insulation products have a chemical composition similar to average crustal rocks and participate in the natural rock cycle. However, these products need not accumulate in nature, inasmuch as old insulation materials serve as excellent source materials for new products. Moreover, current production lines exploit more than 30 natural and 20–30 synthetic source materials that circumvent regional depletion and contribute to the recycling of other industrial materials.