宁夏红寺堡盆地隐伏古隆起成因机制及其对区域沙漠化的影响

目前对于青藏高原东北缘活动构造研究多集中于活动断裂带的活动性,而对夹持于其间的沉积盆地构造格架及活动性研究甚少。以夹持于烟筒山断裂与牛首山—罗山断裂之间的宁夏红寺堡盆地为研究对象,采用重力资料重处理解译、音频大地电磁测深(AMT)和地震勘探相结合,揭示红寺堡盆地隐伏构造特征,并进一步采用盆山一体化思路分析隐伏构造的成因机制及其对区域沙漠化的控制作用。结果表明:青藏高原在中新世末发生强烈的NE向推挤、扩展和隆升,红寺堡盆地由坳陷盆地转变为挠曲盆地; 在青藏高原NE向扩展的影响下,烟筒山断裂发生强烈的逆冲作用,古生代—中生代基底逆冲于古近系—新近系之上,受构造变形影响的最新地层为中新统彰恩堡组; 红寺堡盆地内的隐伏古隆起呈NW—SE向,与烟筒山构造带具有相同的构造动力学背景,受青藏高原NE向扩展影响形成于中新世末,并且至今仍具有活动性; 隐伏古隆起周缘断裂的活动破坏了地表稳定性、蓄水能力和地表植被,导致区域沙漠化呈现有规律的NW—SE向带状展布。该研究成果对于宁夏红寺堡盆地区域稳定性评价及沙漠化的综合治理具有现实指导意义。     

Retention of Eucalyptol,a Natural Volatile Insecticide,in Delivery Systems Based on Hydroxypropyl‐β‐Cyclodextrin and Liposomes

Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release.     

聚乙烯醇/牛I型胶原支架材料的制备及评价

研究了一种聚乙烯醇(PVA)和胶原(COL)复合支架材料的制备方法。采用氨基硅烷对PVA海绵表面进行了氨基化修饰后，通过戊二醛溶液交联牛Ⅰ型胶原(COL)，最后通过赖氨酸溶液封闭，获得一种PVA/COL复合支架材料。采用扫描电镜(SEM)、X光电子能谱仪(XPS)、傅里叶红外光谱(FT-IR)等手段对支架材料的理化性能进行表征，并通过细胞实验对支架材料的生物学性能进行评价。结果表明，经过COL修饰的PVA孔隙率为21.33%，平均孔径为168.68 ?m且均匀分布，支架材料接触角为20.03°。对支架材料的生物学评价结果表明C3A细胞在复合材料上黏附良好，优于PVA组；CCK-8增殖检测结果表明细胞在复合材料上呈增殖生长趋势，与对照组PVA相比差异显著(P?0.01)。将PVA和COL复合制备得到的支架材料具有良好的理化及生物学特性，具有广阔的应用前景。     

Mn在2297铝锂合金中的微合金化作用

利用金相显微镜、拉伸测试、SEM、TEM、STEM-HAADF等手段研究了微量Mn的添加对2297铝锂合金微观组织与力学性能的影响。结果表明,Mn在2297铝锂合金中主要以AlCuMn棒状弥散粒子和Al(CuMnFe)粗大相形式存在,并且相比Mn-free合金,2297合金中粗大相尺寸较小、分布均匀,因而合金的抗拉强度得到提高。研究表明,Mn的添加没有影响Al_3Zr粒子的析出行为,尽管析出了AlCuMn棒状弥散相,但整体上没有改变2297合金的再结晶程度。     

Investigation on the anti-reduction mechanism of Ti4+ in high dielectric constant system Ca0.9La0.067TiO3 by doping with Al2O3

Ca_0.9La_0.067TiO₃ (abbreviated as CLT) ceramics doped with different amount of Al₂O₃ were prepared via the solid state reaction method. The anti-reduction mechanism of Ti⁴⁺ in CLT ceramics was carefully investigated. X-ray diffraction (XRD) was used to analyze the phase composition and lattice structure. Meanwhile, the Rietveld method was taken to calculate the lattice parameters. X-ray photoelectron spectroscopy (XPS) was employed to study the valence variation of Ti ions in CLT ceramics without and with Al₂O₃. The results showed that Al³⁺ substituted for Ti⁴⁺ to form solid solution and the solid solubility limit of Al³⁺ is near 1.11 mol%. Furthermore, the reduction of Ti⁴⁺ in CLT ceramics was restrained by acceptor doping process and the Q × f values of CLT ceramics were improved significantly. The CLT ceramic doped with 1.11 mol% Al₂O₃ exhibited good microwave dielectric properties: ε_r = 141, Q × f = 6848 GHz, τ_f = 576 ppm/°C.     

The impact of the ICT4D project on sustainable rural development using a capability approach: Evidence from Bangladesh

Information and Communication Technology for Development (ICT4D) projects have shown a great promises in recent years. However, simply materializing of ICT4D projects is not enough for minimizing the prevalent digital divide in rural areas in developing countries. For the success of an Information and Communication Technology (ICT) intervention, it is important to consider the capabilities of users, who are responsible for converting ICT resources into outcome. While most of the ICT-related studies are focused on the adoption of actual technologies and influences of different internal and external factors on intervention outcomes, very few studies are focused on evaluating intervention outcomes and redesigning intervention strategies. In this study, I opted for using a conceptual framework following the Capability Approach that simultaneously identifies the influence factors for intervention outcome as well as evaluates the outcome based on Noble Laureate Amartya Sen’s five freedoms concept. A qualitative technique has been chosen to conduct the study. As part of the impact evaluation of an ICT4D intervention, a project known as Union Digital Centres (UDCs) in Bangladesh was selected. A total of ten themes are identified indicating that the outcome of the intervention is contributing to socio-economic and human development. However, the study has revealed that lack of capabilities of users (e.g. prior knowledge and financial inability) bar the UDC programs to fulfill their goals at highest level. This study would practically help the UDC policy makers to adjust the UDC intervention design by addressing the shortcomings of the users to yield higher UDC program outcome. Additionally, this study theoretically contributes in ICT adoption literature by showing that there is a mutual influence between users’ capabilities and ICT-related project outcomes. Finally, using specific case study (ICT4D project in Bangladesh), this study contextualizes Amartya Sen’s five freedoms concept in the ICT-specific context.     

An easy and scalable approach to synthesize three-dimensional sandwich-like Si/Polyaniline/Graphene nanoarchitecture anode for lithium ion batteries

A new three-dimensional (3D) sandwich-like Si/Polyaniline/Graphene nanoarchitecture anode for lithium ion batteries (LIBs) is successfully fabricated through an easy approach. In this nanoarchitecture, the in-situ polymerized electronic conductive polyaniline (PAni) hydrogel, acting as “glue”, agglutinates tightly to both the silicon nanoparticles (SiNPs) and graphene sheets, forming efficient conductive networks with high elastic modulus and high tensile strength. This mechanically robust nanoarchitecture can endure the great volume change of silicon and retain structural stability during Li-ion insertion/extraction. The electrodes consisting of this 3D sandwich-like Si/Polyaniline/Graphene nanoarchitecture reveal excellent electrochemical performance. The progress made in this work provides an easy and scalable route for preparing Si-based anode materials with high performance for advanced LIBs.