节能新技术在通信基站领域内的应用研究

中国移动通信集团为实现节能减排的目的,实施了绿色行动计划,履行社会责任。在实践中,特别是在通信电源、空调领域,中国移动应用、总结了许多以节能减排为目的的新技术、新理念。本文总结了在基站电源领域最近几年应用的新技术、新产品、新理念,重点介绍了太阳能等绿色再生资源的利用,氢燃料电池替代铅酸电池及油机的尝试。     

A novel mechanical diced trench structure for warpage reduction in wafer level packaging process

The wafer warpage problem, mainly originated from coefficient of thermal expansion mismatch between the materials, becomes serious in wafer level packaging as large diameter wafer is adopted currently. The warpage poses threats to wafer handling, process qualities, and can also lead to serious reliability problems. In this paper, a novel mechanical diced trench structure was proposed to reduce the final wafer warpage. Deep patterned trenches with a depth about 100 μm were fabricated in the Si substrate by mechanical dicing method. Both experiment and simulation approaches were used to investigate the effect of the trenches on the wafer warpage and the influence of the geometry of the trenches was also studied. The results indicate that, by forming deep trenches, the stress on the individual die is decoupled and the total wafer warpage could be reduced. The final wafer warpage is closely related to the trench depth and die width. Trenched sample with a depth of 100 μm can decrease the wafer warpage by 51.4%.     

The Effect of Gradual Fluorination on the Properties of FnZnPc Thin Films and FnZnPc/C60 Bilayer Photovoltaic Cells

Motivated by the possibility of modifying energy levels of a molecule without substantially changing its band gap, the impact of gradual fluorination on the optical and structural properties of zinc phthalocyanine (F_nZnPc) thin films and the electronic characteristics of F_nZnPc/C₆₀ (n = 0, 4, 8, 16) bilayer cells is investigated. UV–vis measurements reveal similar Q‐ and B‐band absorption of F_nZnPc thin films with n = 0, 4, 8, whereas for F₁₆ZnPc a different absorption pattern is detected. A correlation between structure and electronic transport is deduced. For F₄ZnPc/C₆₀ cells, the enhanced long range order supports fill factors of 55% and an increase of the short circuit current density by 18%, compared to ZnPc/C₆₀. As a parameter being sensitive to the organic/organic interface energetics, the open circuit voltage is analyzed. An enhancement of this quantity by 27% and 50% is detected for F₄ZnPc‐ and F₈ZnPc‐based devices, respectively, and is attributed to an increase of the quasi‐Fermi level splitting at the donor/acceptor interface. In contrast, for F₁₆ZnPc/C₆₀ a decrease of the open circuit voltage is observed. Complementary photoelectron spectroscopy, external quantum efficiency, and photoluminescence measurements reveal a different working principle, which is ascribed to the particular energy level alignment at the interface of the photoactive materials.     

基于节点持续传输准则的认知传感器网络信道分配策略

在异构分级式认知传感器网络中,为提高数据分组的传输成功率,提出将节点划分为具备持续传输条件和不具备持续传输条件两类,两类节点分别以牺牲较多能耗和分配较优信道的方式提高数据分组的传输成功率,并由此得到一种集中式信道分配策略.为了降低节点在信息传输过程中每比特平均能耗,对数据分组自适应调节机制进行了优化,确保不具备持续传输条件的节点得到最优的传输数据分组大小.仿真结果证明,提出的分配策略和优化机制能够有效提高能量的使用效率,改善网络性能.     

Covalent Functionalization of Pristine and Ga-Doped Boron Phosphide Nanotubes with Imidazole

Abstract

Density functional theory (DFT) calculations at the B3LYP/6–31G* level were performed to investigate covalent functionalization of imidazole on pristine (in gas and H₂O phases) and Ga-doped BPNT models in terms of energetic, geometric, and electronic properties. The results show that imidazole, as a functional group, prefers to be adsorbed via its nitrogen atom on the pristine, Ga_B, and Ga_P nanotube models. The adsorption energy of imidazole on the (6,0) zigzag BPNT in gas and solvent phases is ?0.76 and ?1.11 eV, respectively, and about 0.38 and 0.43 electron are transferred from the imidazole to nanotube in the phases. The presence of a polar solvent increases the electron donor of imidazole molecule. The results show that Ga doping can significantly enhance the adsorption energy of imidazole on the nanotube models to about 95%.

Moreover, the imidazole adsorption on the pristine and Ga-doped BPNT models has not significant changes in the energy gap of the nanotube models and it is slightly changed after covalent functionalization process. This study may provide new insight to the development of functionalized boron phosphide nanotubes for generation of the new hybrid compounds especially in drug delivery systems for virtual applications.     

Kinetics of Alkaline Hydrolysis of Quaternary Phosphonium Salts. The Influence of Protic and Aprotic Solvents on the Hydrolysis of Alkyl Phenylphosphonium Salts

Abstract

Third order rate constants have been determined for the alkaline hydrolysis of four series of alkylphenylphosphonium salts and alkylphenylbenzylphosphonium salts at various temperatures in 50%–70% ^v/_v aqueous tetrahydrofuran and 70% ^v/_v aqueous methanol. Thermodynamic activation parameters have been calculated for the reactions of each substrate and the effects of varying the ratio of alkyl to phenyl groups have been compared, as well as the effects of changes in the nature of the alkyl group. Solvation, as revealed by trends in entropy of activation, plays a largely counter-balancing role with respect to enthalpy and energy of activation. The role of the isokinetic effect is discussed. In aqueous tetrahydrofuran, solvation effects on the hydrolyses of phosphonium salts change as the mole fraction of water changes, and for aqueous methanol the trends in the thermodynamic activation parameters actually reverse.     

Phosphorus and Energy Recovery from Manure and Digestion Residues

Abstract

Human and animal excrements, in particular manure, stand for a significant and undisputable source of plant nutrients and renewable energy. In Europe, only 36% of P-inputs to soils originate from primary resources (rock phosphate) whereas 63% come from animal and human excretions applied to cropland as manure, digestion residues and sewage sludge. Simultaneously these waste flows represent a potential hazard to human health and aquatic bodies because of pathogens and eutrophication. Management of these waste flows is far from being sustainable, in part due to the lack of efficient processing technologies. A cooperative InnoEnergy—EIT financed KIC Knowledge and Innovation Community—research project pursues development and demonstration of highly efficient technologies to overcome the constraints and to yield renewable phosphate fertilizers and energy from waste flows that may have a combined technical energy potential of 3,600 PJ/year and an annual phosphate recovery potential of 4.5–5.5 million tonnes (as P₂O₅) in Europe.     

QM/MM Studies on Cyclodextrin-Alcohol Interaction

The main objective of this study is to provide an insight into the interactions involved during adsorption of the alcohols on β-CD composite nanostructured membrane. Interactions between β-cyclodextrin (β-CD) and alcohols (methanol, ethanol and butanol) are studied using the QM/MM method. Magnitude of interaction energies show that the alcohols are adsorbed on the membrane. In addition, the thermochemical analysis suggests that the formation of these host-guest complexes is enthalpy driven.