Success Probability Assessment Based on Information Entropy

The Bayesian method is superior to the classical statistical method on condition of small sample test. However, its evaluation results are not so good if subjective prior information is intervened. The success probability assessment about the success or failure tests of weapon products focussed in this paper, and a fusing evaluation method based on information entropy is proposed. Firstly, data from equivalent surrogate tests is converted into the prior information of an equivalent source by the information entropy theory. Secondly, the prior distribution of the success probability is identified via the Bootstrap method, and the posterior distribution is provided by the Bayesian method with the information of prototype tests in succession. Lastly, an example is given, and the results show that the proposed method is effective and valuable.Defence Science Journal, 2010, 60(3), pp.271-275, DOI:http://dx.doi.org/10.14429/dsj.60.35

Efficacy and prognosis following combined cinepazaide maleate/nimodipine therapy in cerebral vasospasm patients after hemorrhage

Purpose: To investigate the efficacy and prognosis following treatment of cerebral vasospasm (CVS) patients with a combination of cinnarizide maleate and nimodipine after subarachnoid hemorrhage (SAH).Methods: Eighty-eight patients with CVS after SAH were selected and divided into control group (CG) and study group (EG), each with 44 patients (n = 44). Patients in CG were treated with intravenous infusion of cinnarizide maleate, while those in EG received intravenous infusion of cinnarizide maleate together, and their clinical efficacy and prognosis were compared.Results: Compared with CG, total treatment effectiveness (response) in EG was significantly higher, while levels of inflammatory factors were lower (p < 0.05). Serum protein levels of S100 β and ET-1, and MCA blood flow velocity in EG were notably lower (p < 0.05), but GCS scores were highercompared with CG (p < 0.05). The NIHSS scores were lower and BI indices were higher in EG than in CG (p < 0.05).Conclusion: Treatment of CVS patients after SAH using a combination of cinnarizide maleate and nimodipine effectively reduces the levels of inflammatory factors, improves quality of prognosis, and relieves symptoms of CVS, when compared with administration of cinnarizide maleate only. Therefore, the combination treatment is recommended for the management of CVS after SAH

Enhancing copper infiltration into alumina using spark plasma sintering to achieve high performance Al2O3/Cu composites

Al2O3/Cu (with 30 wt% of Cu) composites were prepared using a combined liquid infiltration and spark plasma sintering (SPS) method using pre-processed composite powders. Crystalline structures, morphology and physical/mechanical properties of the sintered composites were studied and compared with those obtained from similar composites prepared using a standard liquid infiltration process without any external pressure. Results showed that densities of the Al2O3/Cu composites prepared without applying pressure were quite low. Whereas the composites sintered using the SPS (with a high pressure during sintering in 10 minutes) showed dense structures, and Cu phases were homogenously infiltrated and dispersed with a network from inside the Al2O3 skeleton structures. Fracture toughness of Al2O3/Cu composites prepared without using external pressure (with a sintering time of 1.5 hours) was 4.2 MPa·m1/2, whereas that using the SPS process was 6.5 MPa·m1/2. These toughness readings were increased by 18% and 82%, respectively, compared with that of pure alumina. Hardness, density and electrical resistivity of the samples prepared without pressure were 693 HV, 82.5% and 0.01Ω•m, whereas those using the SPS process were 842 HV, 99.1%, 0.002Ω•m, respectively. The enhancement in these properties using the SPS process are mainly due to the efficient pressurized infiltration of Cu phases into the network of Al2O3 skeleton structures, and also due to high intensity discharge plasma which produces fully densified composites in a short time

Success Probability Assessment Based on Information Entropy

The Bayesian method is superior to the classical statistical method on condition of small sample test. However, its evaluation results are not so good if subjective prior information is intervened. The success probability assessment about the success or failure tests of weapon products focussed in this paper, and a fusing evaluation method based on information entropy is proposed. Firstly, data from equivalent surrogate tests is converted into the prior information of an equivalent source by the information entropy theory. Secondly, the prior distribution of the success probability is identified via the Bootstrap method, and the posterior distribution is provided by the Bayesian method with the information of prototype tests in succession. Lastly, an example is given, and the results show that the proposed method is effective and valuable

TB-NUCA: A Temperature-Balanced 3D NUCA Based on Bayesian Optimization

Three-dimensional network-on-chip (NoC) is the primary interconnection method for 3D-stacked multicore processors due to their excellent scalability and interconnect flexibility. With the support of 3D NoC, 3D non-uniform cache architecture (NUCA) is commonly used to organize the last-level cache (LLC) due to its high capacity and fast access latency. However, owing to the layered structure that leads to longer heat dissipation paths and variable inter-layer cooling efficiency, 3D NoC experiences a severe thermal problem that has a big impact on the reliability and performance of the chip. In traditional memory-to-LLC mapping in 3D NUCA, the traffic load in each node is inconsistent with its heat dissipation capability, causing thermal hotspots. To solve the above problem, we propose a temperature-balanced NUCA mapping mechanism named TB-NUCA. First, the Bayesian optimization algorithm is used to calculate the probability distribution of cache blocks in each node in order to equalize the node temperature. Secondly, the structure of TB-NUCA is designed. Finally, comparative experiments were conducted under random, transpose-2, and shuffle traffic patterns. The experimental results reveal that, compared with the classical NUCA mapping mechanism (S-NUCA), TB-NUCA can increase the mean-time-to-failure (MTTF) of routers by up to 28.13% while reducing the maximum temperature, average temperature, and standard deviation of temperature by a maximum of 4.92%, 4.48%, and 20.46%, respectively

Interfacial bonding mechanism and annealing effect on Cu-Al joint produced by solid-liquid compound casting

Copper-aluminum (Cu-Al) based lamellar composites were prepared using a solid-liquid compound casting (SLCC) technology. Characterization results showed that the Cu-Al composites were fully-sintered at 700 °C under an argon atmosphere using the SLCC technology. Cu-Al interfacial bonding was uniform with a well-defined transitional and inter-diffusion region. Intermetallic compounds and solid solutions of CuAl2, CuAl, Cu9Al4, CuAl3 and Cu3Al2 were detected at the interfacial region. With the increase of annealing temperature, the width of the Cu-Al interfacial region was increased, and the interfacial bonding strength was also increased, whereas the types of the intermediate phases were changed. With the increase of dwelling time at a given annealing temperature, the width of Cu-Al interfacial region was increased, the interfacial bonding strength was decreased and the mesophases were changed. The bonding strength of the as-prepared composite was 30 MPa, whereas those of specimens annealed at 200 °C for 2 h, 300 °C for 2 h, 400 °C for 2 h, 300 °C for 30 min and 300 °C for 1 h were 59, 39, 74, 56, and 49 MPa, respectively. The Cu-Al interfacial bonding mechanisms were identified to be rapid inter-diffusion of copper and aluminum and formation of interfacial and graded microstructures. The formation of copper-aluminum interface is a combined result of inter-atomic diffusion and interfacial chemical reactions, the latter of which is more dominant in the diffusion process

Infiltration sintering of WCu alloys from copper-coated tungsten composite powders for superior mechanical properties and arc-ablation resistance

W70Cu30(W-30 wt.% Cu) alloys were fabricated using cold pressing and infiltration sintering methods from two types of powders, i.e., mixed copper-tungsten (M-Cu-W) powders and our newly developed copper-coated tungsten composite (Cu@W) powders. Microstructure, mechanical and arc-ablation properties of the W70Cu30 alloys were investigated, and the mechanism of enhanced physical/mechanical properties and arc-erosion resistance of the W70Cu30 alloys was discussed. For the W70Cu30 alloys prepared using the Cu@W powders, their physical properties, including hardness, electrical conductivity and relative density were much better than those prepared from the M-Cu-W powders. The W70Cu30 alloys fabricated from the Cu@W powders were free of cracks, and showed homogenous distributions of W and Cu network structures. Whereas for the alloys prepared from the M-Cu-W powders, segregation of Cu was observed and the segregation size was about 40–100 μm. Characterization of arc-erosion morphologies of the W70Cu30 alloys prepared with the Cu@W powders revealed the occurrence of evaporation of Cu phase; whereas that of W70Cu30 alloys prepared with the M-Cu-W powders revealed the occurrence of the sputtering of Cu. After arc breakdown for 200 times, mass loss of alloys made using the mixed powders was twice as much as those made using the coated composite powders. Based on the experimental results and theoretical analysis, an arc breakdown mechanism of the WCu-C alloys using the composite powders was proposed which is attributed to the formation of a homogeneous Cu-Cu network structure to uniformly disperse arc energy and dissipate the generated heat, thus prolonging the service life of the WCu alloy contacts

Identifying the optimization potential for urban GI by linking supply and demand of ecosystem services under multi-scenarios a case study of Tianjin, China

Quantitative research on the supply and demand of urban green infrastructure (GI) ecosystem services (ES) can play a crucial role in supporting ecological governance, which is vital for enhancing the health and well-being of residents and promoting sustainable development. However, current supply and demand studies often fail to consider the complexity and diversity of local climates and economic status, leading to suboptimal outcomes in urban greening programs. Therefore, there is an urgent need to incorporate the diversity and variability of demand for ES in decision-making processes for urban GI planning. To address this issue, this study proposes a multi-development scenario-based supply and demand modelling framework that measures the supply and demand of ES. By using the central city of Tianjin, China, as a case study, the resulting GI construction potential zoning and optimization strategies are determined to achieve the multiple environmental-social-economic benefits of GI. The results show that the supply and demand levels of GI in the study area are significantly spatially heterogeneous, with the demand levels of GI varying considerably under different development scenarios. Furthermore, the demand for GI is highest under the ecological priority scenario. Based on the relationship between the supply and demand of ES, the study area is classified into four zones, including a GI supply deficit zone, a supply surplus zone, a low-level balance zone, and a high-level balance zone. The area of each zone decreases in turn, indicating that the study area as a whole is in a state of mismatch between the supply and demand of ES. Finally, the study area is divided into seven GI construction potential zones based on the degree of scarcity and development orientation. The proposed planning scheme helps to achieve dynamic matching goals of ES supply and demand and provides valuable insights for policymakers to coordinate urban resources and promote sustainable development

ZIF-67-Derived Flexible Sulfur Cathode with Improved Redox Kinetics for High-Performance Li-S Batteries

Lithium–sulfur (Li-S) batteries have received much attention due to their high energy density and low price. In recent years, alleviating the volume expansion and suppressing the shuttle effect during the charge and discharge processes of Li-S batteries have been widely addressed. However, the slow conversion kinetics from polysulfide (LiPSs) to Li2S2/Li2S still limits the application of Li-S batteries. Therefore, we designed a ZIF-67 grown on cellulose (named ZIF-67@CL) as an electrocatalyst to improve the interconversion kinetics from LiPSs to Li2S2/Li2S for Li-S batteries. Based on the results of adsorption experiments of LiPSs, ZIF-67@CL and CL hosts were immersed in Li2S4 solution to adsorb LiPSs, and the UV-Vis test was conducted on the supernatant after adsorption. The results showed that the ZIF-67@CL had a stronger adsorption for LiPSs compared with the cellulose (CL). Furthermore, in the Li2S nucleation tests, the fabricated cells were galvanostatically discharged to 2.06 V at 0.112 mA and then potentiostatically discharged at 2.05 V. Based on the results of Li2S nucleation tests, the catalytic effect of ZIF-67 was further verified. As a result, the sulfur cathode used a ZIF-67 catalyst (named S/ZIF-67@CL) and delivered an initial capacity of 1346 mAh g−1 at a current density of 0.2 C. Even at a high current density of 2 C, it exhibited a high-capacity performance of 1087 mAh g−1 on the first cycle and maintained a capacity output of 462 mAh g−1 after 150 cycles, with a Coulombic efficiency of over 99.82%

Analysis of Settlement Behaviour of Soft Ground Under Wide Embankment

An elastoplastic numerical model for calculating the consolidation settlement of wide embankment on soft ground is established using PLAXIS finite element software to investigate the settlement behaviour of soft ground under the wide embankment. The distribution rules are analysed and compared to narrow embankments, such as surface settlements of ground and embankment, lateral displacement of soft ground at the foot of embankment slope and excess pore pressure in soft ground. The influence rule of elastic modulus of soft ground on the settlement of soft ground under wide embankment is discussed. The results show that the settlement distributions of wide and narrow embankments on soft ground are “W” and “V” shapes, respectively. The maximum settlement of wide embankment is near the foot of the embankment slope, which is unequal to the settlement at the centreline of the embankment. The lateral displacement distribution rules of soft ground are both “belly” shaped at the foot of two types of embankments slope. However, the lateral displacement of the wide embankment is larger in each corresponding stage. During the construction period, the excess pore pressure in the soft ground under the wide embankment is much higher than that of the narrow embankment, so the post-construction consolidation time of the wide embankment is longer. Moreover, the macroscopic settlement rule of the wide embankment is still the same with the increase of elastic modulus of soft ground