Study on the preparation of novel FR-245/MCM-41 suppressant and its inhibition mechanism on oil shale deflagration flame

Oil shale development is of great significance because oil and gas resources are scarce. Research on the prevention of oil shale dust explosion is particularly important for guaranteeing the safe development and utilization of oil shale resources. In this work, the flame morphology and velocity of oil shale dust with and without MCM-41 or FR-245 were compared. Furthermore, the novel green FR-245/MCM-41 inhibitor was prepared by jet mill method and used in oil shale dust explosion for the first time. The best ratio of FR-245/MCM-41 for flame inhibition was obtained, which was 9: 1. The pyrolysis oxidation behavior of oil shale before and after adding FR-245/MCM-41 was analyzed and compared by FWO and KAS methods, respectively. The results showed that the activation energy calculated by FWO and KAS methods greatly increased after adding FR-245/MCM-41, which increased by 95.36% and 115.15% than that before adding inhibitor, respectively. Significantly, the activation energy is particularly high for two methods when α between 0.2 and 0.6, due to that MCM-41 and FR-245 coexisted to limit the oxidation of oil shale. For α between 0.7 and 0.9, the activation energy is still high because of the existence of MCM-41. Combining the oil dust flame propagation behavior with the characterization results before and after explosion, the physical-chemical synergy mechanism of oil dust flame propagation inhibition was revealed.     

Incorporating fragmentation and non‐native species into distribution models to inform fluvial fish conservation

Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial‐specialist shoal bass (Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non‐native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non‐native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non‐native congeners, wherein non‐natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free‐flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats.     

介孔钛硅分子筛的表面化学特征及除铅机制研究

以表面活性剂在水溶液中形成的液晶相为模板剂，考察了钛含量对制备介孔钛硅分子筛性质的影响；应用表面络合反应关系式计算了介孔钛硅分子筛表面络合反应的基本特征参数。研究了溶液ｐＨ值、温度等对Ｐｂ＾２＋离子在介孔钛硅分子筛表面吸附的影响；并就Ｐｂ＾２＋离子在介孔钛硅分子筛表面的吸附动力学、吸附等温线和吸附机理进行了探讨。     

中孔分子筛AI-MCM-41催化裂解聚烯烃反应研究

采用水热合成法制备了不同硅铝比的中孔分子筛AI-MCM-41，将其应用于高密度聚乙烯（HDPE）和聚丙烯（PP）的催化裂解反应。通过改变硅铝比、反应温度和催化剂用量，对Al-MCM-41催化HDPE和PP裂解反应的规律进行了探讨，研究表明，HDPE裂解反应受硅铝比的影响较大；而对于PP裂解反应，硅铝比在一定范围内对催化剂活性的影响不明显。另外，与热裂解和HZSM-5小孔分子筛的催化裂解结果进行了比较，结果证明A1-MCM-41具有较高的催化活性和较高的液体产物收率，尤其适合于空间位阻较大的PP的催化裂解反应。     

Rapid synthesis of Ti-MCM-41 by microwave-assisted hydrothermal method towards photocatalytic degradation of oxytetracycline

This study employed microwave-assisted hydrothermal method to synthesize Ti-MCM-41,which are mesoporous materials with a high surface area and excellent photocatalytic ability. Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), transmission electron microscopy(TEM), and ultraviolet–visible spectroscopy(UV–Vis) were employed. The XRD findings showed that Ti-MCM-41 exhibited a peak at 2θ of 2.2°, which was attributed to the hexagonal MCM-41 structure. The BET(Brunauer–Emmett–Teller) results agreed with the TEM findings that Ti-MCM-41 has a pore size of about 3–5 nm and a high surface area of 883 m~2/g. FTIR results illustrated the existence of Si–O–Si and Si–O–Ti bonds in Ti-MCM-41. The appearance of Ti2 p peaks in the XPS results confirmed the FTIR findings that the Ti was successfully doped into the MCM-41 structure. Zeta(ζ)-potential results indicated that the iso-electric point(IEP) of Ti-MCM-41 was at about pH 3.02. In this study, the photocatalytic degradation of oxytetracycline(OTC) at different pH was investigated under Hg lamp irradiation(wavelength 365 nm). The rate constant(K′_(obs)) for OTC degradation was 0.012 min-1at pH 3. Furthermore, TOC(total organic carbon) and high resolution LC–MS(liquid chromatography–mass spectrometry) analyses were conducted to elucidate the possible intermediate products and degradation pathway for OTC. The TOC removal efficiency of OTC degradation was 87.0%, 74.4% and 50.9% at pH 3, 7 and 10, respectively. LC–MS analysis results showed that the degradation products from OTC resulted from the removal of functional groups from the OTC ring.     

甲基化MCM-41吸附水中硝基苯类化合物的研究

利用三甲基氯硅烷对MCM-41进行表面修饰制得甲基化MCM-41,采用X-射线衍射分析仪（XRD）、透射电镜（TEM）、N2吸附-脱附和红外光谱（FTIR）对样品进行表征,并考察其对水中硝基苯类化合物（NACs）的吸附性能.结果表明,甲基化MCM-41对NACs的吸附速率较快,吸附为放热过程,吸附等温线可以用线性模型拟...     

Revealing life‐history traits by contrasting genetic estimations with predictions of effective population size

Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life‐history, and mating‐system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life‐history characteristics and the relative impact of different life‐history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N_ev) from genetic data () and formulated predictions for the impacts on N_ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N_ev. The comparison of effective‐size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N_ev) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N_ev). Heritability of female RS also affected N_ev; (heritability responsible for 41% decrease in N_ev). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting , namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life‐history hypotheses in light of their impact on effective population size, and contrasting predictions with genetic measurements, is a general, applicable strategy that can be used to inform conservation practice.     

MCM-41介孔分子筛的合成及其对铜离子的吸附性能

以微硅粉为硅源,CTAB和PEG-6000为模板剂,合成MCM-41介孔分子筛。采用XRD、N2吸附-脱附曲线、FT—IR以及TEM表征了其结构、比表面积、孔径分布及晶体形貌,并且以该样品为吸附剂,对含Cu2＋的溶液进行了静态吸附实验。结果表明,以微硅粉为硅源成功合成了具有典型六方排列孔道结构的MCM-41,其比表面积为869．5m。／g,孔容为0．97cm3／g,平均孔径为3．3nm;溶液pH为5—6时,MCM-41对Cu2＋的去除效果最好;MCM-41对Cu3＋的最大吸附吸附容量36．3mg／g;MCM-41对Cu2＋的吸附性能符合Langmuir吸附方程的特征。动力学研究表明,该过程符合准二级动力学模型。     

Ti-MCM-41分子筛对Cr（Ⅵ）的吸附性能

以发烟硅胶为硅源、钛酸四丁酯为钛源,采用水热合成法制备了一系列不同n（Si）∶n（Ti）的Ti-MCM-41分子筛,采用XRD、UV-Vis、BET及ICP技术对其进行了表征,考察了其对溶液中Cr（Ⅵ）的吸附性能及重复使用性能。结果表明：制备的Ti-MCM-41分子筛保持了MCM-41的介孔结构,但随着Ti含量的增加分子筛的比表面积、孔径和总孔体积均降低;在初始Cr（Ⅵ）质量浓度为100 mg/L、Ti-MCM-41分子筛（投料n（Si）∶n（Ti）为40）投加量为1 g/L、吸附时间为60 min、吸附温度为323 K、溶液pH为6的条件下,Cr（Ⅵ）吸附率可达96.3%;Ti-MCM-41分子筛对Cr（Ⅵ）的吸附符合Langmuir等温吸附模型;Ti-MCM-41分子筛的重复使用性能良好。     

Prospect theory and energy efficiency

Investments in energy efficiency entail uncertainty, and when faced with uncertainty consumers have been shown to behave according to prospect theory: preferences are reference-dependent and exhibit loss aversion, and probabilities are subjectively weighted. Using data from a choice experiment eliciting prospect theory parameters, I provide evidence that loss-averse people are less likely to invest in energy efficiency. Then, I consider policy design under prospect theory when there are also externalities from energy use. A higher degree of loss aversion implies a higher subsidy to energy efficiency. Numerical simulations suggest that the impact of prospect theory on policy may be substantial.