VP型宽频带倾斜仪的同震响应衰减关系研究∗

基于徐州台和常熟台 2 套 VP 型宽频带倾斜仪记录到的 186 次同震形变波,统计分析其振幅-震级特征,分区对比研究其衰减关系,结合观测资料计算仪器特征参数,通过岩芯试验获取场地基岩性质,综合分析仪器观测效能。结果表明：(1)相比于常熟台,徐州台的 NS 向和 EW 向拟合均较为稳定,记震能力更好;(2)不同构造分区中拟合的振幅-震级关系,随着震中距增大,最大振幅幅值呈指数上升且拟合程度显著增强;(3)仪器基墩稳定性对同震响应存在一定的影响,基墩稳定性好,观测数据年零漂小,同震记录相对稳定;不同岩性的基墩对同震记录的敏感性存在差异,同震响应振幅与基墩弹性模量成反比。     

多水源用水网络优化模型研究

为了解决含有多类供水水源的用水网络优化设计问题,研究了过程工业用水特点,将各用水单元看成水阱,各单元的排水看成潜在水源,从而将供水问题转化为水阱和水源的匹配问题,建立用于多水源用水网络优化的配水模型,并详细阐述该模型应用步骤及其特点。     

已二酸生产副产物——混合二元酸的综合利用

采用一水合硫酸氢钠作为催化剂,催化己二酸生产副产物——混合二元酸与甲醇反应合成混合二元酸二甲酯。优化工艺条件为：混合二元酸加入量0．1mol,无水甲醇加入量0．5mol,一水合硫酸氢钠加入量4．0g,环己烷加入量20mL,反应时间1．5h。合成混合二元酸二甲酯的酯化反应收率大于97％。经气相色谱检测,产物中酯的质量分数为98．91％。一水合硫酸氢钠可重复使用3次。     

莆田县土地利用特征及合理开发利用对策

土地利用作为人地关系研究的核心内容,是人地关系最直接的反映。本文对莆田县土地利用特征进行了分析,针对其存在的问题,提出了相应的解决对策     

Divergent effects of climate change on the egg-laying opportunity of species in cold and warm regions

Climate warming can substantially impact embryonic development and juvenile growth in oviparous species. Estimating the overall impacts of climate warming on oviparous reproduction is difficult because egg-laying events happen throughout the reproductive season. Successful egg laying requires the completion of embryonic development as well as hatching timing conducive to offspring survival and energy accumulation. We propose a new metric—egg-laying opportunity (EO)—to estimate the annual hours during which a clutch of freshly laid eggs yields surviving offspring that store sufficient energy for overwintering. We estimated the EO within the distribution of a model species, Sceloporus undulatus, under recent climate condition and a climate-warming scenario by combining microclimate data, developmental functions, and biophysical models. We predicted that EO will decline as the climate warms at 74.8% of 11,407 sites. Decreasing hatching success and offspring energy accounted for more lost EO hours (72.6% and 72.9%) than the occurrence of offspring heat stress (59.9%). Nesting deeper (at a depth of 12 cm) may be a more effective behavioral adjustment for retaining EO than using shadier (50% shade) nests because the former fully mitigated the decline of EO under the considered warming scenario at more sites (66.1%) than the latter (28.3%). We advocate for the use of EO in predicting the impacts of climate warming on oviparous animals because it encapsulates the integrative impacts of climate warming on all stages of reproductive life history.     

Self-healing passivation of pyrite at ambient temperature

Environmental Chemistry Letters - Acid mine drainage is highly acidic and contains heavy metals, which can be harmful to soil, water, plants, and animals. To solve this issue, surface passivation...     

Enhancement of extracellular Cr(VI) reduction for anammox recovery using hydrazine: performance,pathways, and mechanism

● N₂H₄ addition enhanced and recovered anammox performance under Cr(VI) stress. ● N₂H₄ accelerated electron transfer of Cr(VI) reduction for detoxification. ● N₂H₄ enhanced anammox metabolism for activity recovery from Cr(VI) inhibition. ● Extracellular Cr(VI) reduction to less toxic Cr(III) was the dominant mechanism. The hexavalent chromium (Cr(VI)) would frequently impose inhibition to anaerobic ammonium oxidation (anammox) process, hindering the efficiency of nitrogen removal in wastewater treatment. Hydrazine (N₂H₄), which is an intermediate product of anammox, participates in intracellular metabolism and extracellular Cr(VI) reduction. However, the roles of N₂H₄-induced intracellular metabolism and extracellular reduction in nitrogen removal under Cr(VI) stress remain unclear. The addition of 3.67 mg/L of N₂H₄ increased the anammox activity by 17%. As an intermediate, N₂H₄ enhanced anammox metabolism by increasing the heme c content and electron transfer system activity. As a reductant, N₂H₄ accelerated the reduction of c-Cyts-mediated extracellular Cr(VI) to the less toxic Cr(III). Extracellular Cr(III) accounts for 74% of the total Cr in a Cr(VI)-stressed anammox consortia. These findings highlight that N₂H₄-induced extracellular Cr(VI) reduction is the dominant mechanism for the survival of anammox consortia. We also found that N₂H₄ increased the production of extracellular polymeric substances to sequester excessive Cr(VI) and produced Cr(III). Taken together, the study findings suggest a potential strategy for enhancing nitrogen removal from ammonium-rich wastewater contaminated with Cr(VI).     

矿业废弃地对环境的扰动及其有效化解的对策选择

作为矿产资源开发活动的直接结果之一,矿业废弃地对环境的压力与污染在相当程度上与矿产资源开发利用的方式及环境直接相关。依据矿业废弃地污染环境的性质与特点,具体治理过程中,将基于生态恢复与生物技术利用以及正式与非正式的制度约束方面的对策措施结合起来,具有相当的必要性与合理性。     

BDE -47对脑发育期大鼠甲状腺激素内稳态及谷胱甘肽抗氧化系统的影响

以处于脑发育期的新生3d大鼠为试验对象,研究不同剂量2,2',4,4'-四溴联苯醚(BDE - 47)对大鼠暴露21 d后,大鼠体内甲状腺激素内稳态、脑中谷胱甘肽及相关酶的变化.结果显示,与对照组相比,大鼠血清中总甲状腺激素(TT4)、游离甲状腺激素(FT4)、总三碘甲状腺原氨酸(TT3)无显著改变,但高暴露剂量组大鼠血清中游离三碘甲状腺原氨酸(FT3)含量显著降低(p＜ 0.01).氧化损伤试验结果表明,与对照组相比,各暴露组大鼠脑中氧化型谷胱甘肽(GSSG)含量显著上升(中、低剂量组p＜ 0.01,高剂量组p＜0.05);暴露组大鼠脑中谷胱甘肽过氧化物酶(GSH - px)活力变化与剂量相关,呈现低、中剂量升高,高剂量暴露下降的趋势;暴露大鼠脑中谷氨酸半胱氨酸合成酶(GCL)活性、还原型谷胱甘肽(GSH)含量无显著变化,但GCL呈明显的下降趋势.脑发育期BDE - 47暴露将造成大鼠甲状腺激素,尤其是FT3的内稳态失衡,并造成机体GSH抗氧化系统相关指标的紊乱,出现氧化应激效应.     

室外大气颗粒物中痕量砷和锑测定的研究

采用微波消解-氢化物发生-原子荧光光谱法，用L-半胱氮酸预还原法对室外大气颗粒物中砷和锑进行了分析。讨论并确定了实验的最佳测定条件，结果表明，砷和锑的检出限分别为0．058ng／mL和0．075ng／mL，回收率为101．8％和98．4％，相对标准偏差分别为0．6％和0．9％。该法准确、快速、简便，应用于室外大气颗粒物中砷和锑的测定，结果满意。