Proportional Fairness-Based Energy-Efficient Power Allocation in Downlink MIMO-NOMA Systems with Statistical CSI

In this paper, proportional fairness(PF)-based energy-efficient power allocation is studied for multiple-input multiple-output(MIMO) non-orthogonal multiple access(NOMA) systems. In our schemes, statistical channel state information(CSI) is utilized for perfect CSI is impossible to achieve in practice. PF is used to balance the transmission efficiency and user fairness. Energy efficiency(EE) is formulated under basic data rate requirements and maximum transmitting power constraints. Due to the non-convex nature of EE, a two-step algorithm is proposed to obtain sub-optimal solution with a low complexity. Firstly, power allocation is determined by golden section search for fixed power. Secondly total transmitting power is determined by fractional programming method in the feasible regions. Compared to the performance of MIMO-NOMA without PF constraint, fairness is obtained at expense of decreasing of EE.

Geological and geochemical characteristics of the Baogudi Carlintype gold district(Southwest Guizhou, China) and their geological implications

The newly discovered Baogudi gold district is located in the southwestern Guizhou Province,China,where there are numerous Carlin-type gold deposits.To better understand the geological and geochemical characteristics of the Baogudi gold district,we carried out petrographic observations,elemental analyses,and fluid inclusion and isotopic composition studies.We also compared the results with those of typical Carlin-type gold deposits in southwestern Guizhou.Three mineralization stages,namely,the sedimentation diagenesis,hydrothermal(main-ore and late-ore substages),and supergene stages,were identified based on field and petrographic observations.The main-ore and late-ore stages correspond to Au and Sb mineralization,respectively,which are similar to typical Carlin-type mineralization.The mass transfer associated with alteration and mineralization shows that a significant amount of Au,As,Sb,Hg,Tl,Mo,and S were added to mineralized rocks during the main-ore stage.Remarkably,arsenic,Sb,and S were added to the mineralized rocks during the late-ore stage.Element migration indicates that the sulfidation process was responsible for ore formation.Four types of fluid inclusions were identified in ore-related quartz and fluorite.The main-ore stage fluids are characterized by an H2O–NaCl–CO2–CH4±N2system,with medium to low temperatures(180–260℃)and low salinity(0–9.08%NaCl equivalent).The late-ore stage fluids featured H2O–NaCl±CO2±CH4,with low temperature(120–200℃)and low salinity(0–7.48%Na Cl equivalent).The temperature,salinity,and CO2and CH4concentrations of ore-forming fluids decreased from the main-ore stage to the late-ore stage.The calculated δ^13C,d D,and δ^18O values of the ore-forming fluids range from-14.3 to-7.0%,-76 to-55.7%,and 4.5–15.0%,respectively.Late-ore-stage stibnite had δ^34S values ranging from-0.6 to 1.9%.These stable isotopic compositions indicate that the ore-forming fluids originated mainly from deep magmatic hydrothermal fluids,with minor contributions from strata.Collectively,the Baogudi metallogenic district has geological and geochemical characteristics that are typical of Carlin-type gold deposits in southwest Guizhou.It is likely that the Baogudi gold district,together with other Carlin-type gold deposits in southwestern Guizhou,was formed in response to a single widespread metallogenic event.

餐厨废弃油脂磺酸盐二元复合驱油效果评价

经磺化反应制备了餐厨废弃油脂磺酸盐(KWOS),通过降低油水间界面张力性能、热稳定性能、抗钙镁离子性能和吸附损耗性能实验评价了KWOS溶液与原油间界面张力的适应性能。配制KWOS和聚丙烯酰胺的二元复合体系开展驱油实验,分析岩心渗透率和KWOS质量分数对该体系驱油效果的影响。结果表明:随着KWOS质量分数增加,油水间的界面张力逐渐降低,当质量分数达到0.175%时,油水界面张力即可降至10^(-3) mN/m数量级。KWOS溶液与原油间的界面张力随热稳定时间增长、钙镁离子总质量浓度增大和吸附损耗有所增加,但仍能够维持在10^(-3) mN/m数量级。随着岩心渗透率降低和KWOS质量分数增加,二元复合体系提高原油采收率均呈现先增加后降低的变化趋势,当岩心渗透率为0.421μm^(2)、KWOS质量分数为0.3%时,二元复合体系提高的原油采收率最高。

A Method for Rapid Determination of Polymer Dissolution Time

In view of the limited space of offshore platform and the large amount of polymer injection, the dissolution time method, solution viscosity method, conductivity method, undissolved filtration method and falling ball method are used as the rapid detection methods of polymer dissolution. The results show that the error of conductivity method is the largest, and that of dissolution time method is the second, and both methods are time-consuming. Solution viscosity method and insolubles filtration method have small error, but they are time-consuming, especially for offshore platforms, which makes detection inconvenient. The drop ball method is simple in operation and has a small error, so it is a promising method for rapid determination of polymer dissolution time.

Phylogenetic Analysis of Brine Shrimp (Artemia) in China Using DNA Barcoding

DNA barcoding is a powerful approach for characterizing species of organisms, especially those with almost identical morphological features, thereby helping to to establish phylogenetic relationships and reveal evolutionary histories. In this study, we chose a 648-bp segment of the mitochondrial gene, cytochrome c oxidase subunit 1 （COI）, as a standard barcode region to establish phylogenetic relationships among brine shrimp （Artemia） species from major habitats around the world and further focused on the biodiversity of Artemia species in China, especially in the Tibetan Plateau. Samples from five major salt lakes of the Tibetan Plateau located at altitudes over 4,000 m showed clear differences from other Artemia populations in China. We also observed two consistent amino acid changes, 153A/V and 183L/F, in the COI gene between the high and low altitude species in China. Moreover, indels in the COI sequence were identified in cyst and adult samples unique to the Co Qen population from the Tibetan Plateau, demonstrating the need for additional investigations of the mitochondrial genome among Tibetan Artemia populations.

A pentapeptide enabled AL3810 liposome-based glioma-targeted therapy with immune opsonic effect attenuated

AL3810,a molecular dual inhibitor of the vascular endothelial growth factor receptor(VEGFR)and fibroblast growth factor receptor(FGFR),has earned the permission of phase II clinical trial for tumor treatment by China FDA.As a reversible ATP-competitive inhibitor,AL3810 targets ATP-binding site on intracellular region of VEGFR and FGFR,whereas,AL3810 lacking interplay with extracellular region of receptors rendered deficient bloodebrain tumor barrier(BBTB)recognition,poor brain penetration and unsatisfactory anti-glioma efficacy.Integrin avb3 overexpressed on capillary endothelial cells of BBTB as well as glioma cells illuminated ligand-modified liposomes for pinpoint spatial delivery into glioma.The widely accepted peptide c(RGDyK)-modified liposome loading AL3810 of multiple dosing caused hypothermia,activated anti-c(RGDyK)-liposome IgG and IgM antibody and pertinent complements C3 b and C5 b-9,and experienced complement-dependent opsonization.We newly proposed a pentapeptide mn with superb avb3-binding affinity and tailored AL3810-loaded mn-modified liposome that afforded impervious blood circulation,targeting ability,and glioma therapeutic expertise as vastly alleviated immune opsonization on the underpinning of the finite antibodies and complements assembly.Stemming from attenuated immunogenicity,peptide mn strengthened liposome functions as a promising nanocarrier platform for molecular targeting agents.

Soil macrofaunal communities develop a habitat-specific trophic structure dependent on the degree of degradation of alpine wetlands

The alpine wetlands in the Qinghai-Tibetan Plateau have degraded in recent decades.However,the response of the soil food web to the degradation is still unclear.Four habitats including a wet meadow(WM),a grassland meadow(GM),a moderately degraded meadow(MDM)and a severely degraded meadow(SDM)(sandy meadows)were selected along the degrees of degradation.The soil macrofaunal biomass and the environmental factors of vegetation and soil were investigated.The soil macrofaunal community biomass increased significantly from WMto MDM and decreasedto a very small amount in SDM,with most taxa disappearing.The biomass of the trophic groups of detritivores,herbivores and predators exhibited similar responses to soil macrofaunal communities.The relative biomass of detritivores increased from WM to MDM,but herbivores responded in an opposite manner,resulting in the dominant trophic group and trophic structure varying progressively from WM to GM to MDM.Soil properties but not vegetation determined the changes in trophic groups and trophic structure.The results implied that the higher trophic levels(carnivores or omnivores)responded more sensitively than the lower trophic levels(herbivores)to alpine wetland degradation.Our results also suggested that soil macrofauna have a habitat-specific characteristic trophic structure and can be used as indicators of soil health conditions.