基于l1范数相干度的量子态区分

为探究区分量子态的最优策略,以相干作为资源,利用附加辅助系统的方法来区分非正交量子态,并给出了l₁范数相干度与区分量子态的成功概率之间的数值关系,同时量化了某些特定情况下不出错的量子态区分(UQSD)的最优协议所需的l₁范数相干均值.本文的研究结果表明,通过调整生成的相干度可以提高区分量子态的成功几率.     

车联网基于信任度的RSU识别及资源分配算法

在车联网中,由于部分路侧单元（RSU）的位置比较偏远,无法得到网络管理员的及时维护,可能遭到攻击,变为不可信任的路侧单元,降低了车辆的通信质量和网络能效.为了有效地识别RSU的可靠性,提出了一种基于信任度的路侧单元识别及资源分配算法,将路侧单元识别、传输模式的选择和功率分配联合建模为网络能效的优化问题,并分成3个子优化问题,分别求解.首先,采用基于信任度的RSU识别算法,识别出可信任和不可信任的路侧单元;其次,优化车辆资源块配置和链路选择;最后,通过次梯度算法优化传输功率,最大化网络能效.理论分析和仿真结果表明,所提算法具备较低的复杂度,可以达到较高的路侧单元识别准确度,并有效地提升网络总能效.     

多孔纤维型重整微反应器的等效电阻网络建模

针对应用于重整制氢微反应器的复杂多孔金属纤维载体（PFS）的流速场高效分析难题,建立载体中随机微通道的等效电阻网络分析模型. 基于复杂随机纤维结构的统计网络模型,将纤维载体中三维联通的随机微通道结构及与之相连的进出口腔简化为规则的网络通道结构.借鉴基尔霍夫定律,建立纤维载体的等效电阻网络模型,并确定求解方法. 纤维载体流速场实例分析的结果表明,基于等效电阻网络模型求解的纤维载体流速场与计算流体力学(CFD)方法的结果之间的皮尔森相关系数约为98%,且求解效率约为CFD方法的2.9×10⁴倍. 研究成果为多孔纤维型重整制氢微反应器的设计制造提供了新的支撑方案.     

振荡翼改进运动模型的能量捕获性能分析

为了提高振荡水翼的水动力性能和能量捕获效率,基于传统简谐运动模型提出改进运动模型,通过引入俯仰运动系数k,推导改进后俯仰运动规律的一般形式,利用Fluent软件建立水翼的二维模型,综合分析半主动振荡模型下不同俯仰运动系数、折算频率和俯仰振幅等运动参数对水翼能量捕获性能的影响。结果表明:与传统简谐运动模型相比,改进运动模型能够使水翼升力系数在较长时间段内维持较大数值,提高水翼的升力系数和捕能效率;在相同的折算频率和俯仰振幅下,减小俯仰运动系数会增大俯仰角转动的角速度,进而增大俯仰运动所消耗的能量;不同俯仰振幅下对应不同的最优折算频率,折算频率越低水翼的捕能性能越不稳定,俯仰振幅越大,转动俯仰角所消耗的能量越多。在给定参数条件下,水翼的能量转化效率可超过40%。     

Future energy goals for Maryland: Greenhouse gas reductions

Legislative requirements in Maryland set very robust goals for the implementation of energy efficiency by utilities. Significant energy savings has been achieved in all customer sectors and efficiency gains have been made over time in equipment and building construction. Looking forward, utilities should implement programs to promote energy efficiency with a greater emphasis on GHG reductions. Feasibility studies need to occur, but flexibility is key given changing codes and standards and market transformation.     

不可逆量子斯特林热泵循环性能分析与优化

建立了以一维无限深势阱中极端相对论粒子为工质的不可逆量子斯特林热泵循环模型。考虑高低温热源之间的热漏,导出了循环的性能系数与无量纲泵热率的表达式。分析了循环性能与各性能参数之间的关系。研究发现,热泵的性能系数与无量纲泵热率都随粒子在状态1进处于激收态上的占有几度单调递减,性能系数与无量纲泵热率都是势阱宽度比的凸单调函数。无量纲泵热率关于性能系数的关系曲线为回原点的扭叶型,并确定了该不可逆量子斯特林热泵的最优运行区间。     

Interpretable modeling of metallurgical responses for an industrial coal column flotation circuit by XGBoost and SHAP-A “conscious-lab” development

Surprisingly, no investigation has been explored relationships between operating variables and metallurgical responses of coal column flotation (CF) circuits based on industrial databases for under operation plants. As a novel approach, this study implemented a conscious-lab “CL” for filling this gap. In this approach, for developing the CL dedicated to an industrial CF circuit, SHapley Additive exPlanations (SHAP) and extreme gradient boosting (XGBoost) were powerful unique machine learning systems for the first time considered. These explainable artificial intelligence models could effectively convert the dataset to a basis that improves human capabilities for better understanding, reasoning, and planning the unit. SHAP could provide precise multivariable correlation assessments between the CF dataset by using the Tabas Parvadeh coal plant (Kerman, Iran), and showed the importance of solid percentage and washing water on the metallurgical responses of the coal CF circuit. XGBoost could predict metallurgical responses (R-square > 0.88) based on operating variables that showed quite higher accuracy than typical modeling methods (Random Forest and support vector regression).     

Formation of Proto-Kranz in C3 Rice Induced by Spike-Stalk Injection Method

Introduction of C4 photosynthetic traits into C3 crops is an important strategy for improving photosynthetic capacity and productivity. Here, we report the research results of a variant line of sorghum–rice (SR) plant with big panicle and high spikelet density by introducing sorghum genome DNA into rice by spike-stalk injection. The whole-genome resequencing showed that a few sorghum genes could be integrated into the rice genome. Gene expression was confirmed for two C4 photosynthetic enzymes containing pyruvate, orthophosphate dikinase and phosphoenolpyruvate carboxykinase. Exogenous sorghum DNA integration induced a series of key traits associated with the C4 pathway called “proto-Kranz” anatomy, including leaf thickness, bundle sheath number and size, and chloroplast size in bundle sheath cells. Significantly, transgenic plants exhibited enhanced photosynthetic capacity resulting from both photosynthetic CO₂-concentrating effect and improved energy balance, which led to an increase in carbohydrate levels and productivity. Furthermore, such rice plant exhibited delayed leaf senescence. In summary, this study provides a proof for the feasibility of inducing the transition from C3 leaf anatomy to proto-Kranz by spike-stalk injection to achieve efficient photosynthesis and increase productivity.     

Nanocomposites of CsPbBr3 perovskite quantum dots embedded in Gd2O3:Eu3+ hollow spheres for LEDs application

Gd₂O₃:Eu³⁺@CsPbBr₃ quantum dots (QDs) mesoporous hollow nanocomposites with good luminescent properties and high stability were built. Among which, the hollow Gd₂O₃:Eu³⁺ spheres and CsPbBr₃ QDs were prepared by urea homogeneous precipitation and hot-injection method, respectively. Finally, the Gd₂O₃:Eu³⁺@CsPbBr₃ QDs shell–core compounds were constructed through mechanical stirring. The structure, morphology, stability and luminescent properties were studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry/thermogravity (DSC/TG), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence excitation/photoluminescence (PLE/PL) and life decay tools. Compared to the original CsPbBr₃ QDs, Gd₂O₃:Eu³⁺@CsPbBr₃ QDs display better photostability, thermal stability and current stability. The resulting Gd₂O₃:Eu³⁺@CsPbBr₃ QDs composite exhibits good yellow emission. The Gd₂O₃:Eu³⁺@CsPbBr₃ QDs mixed silicone resin was directly coated on the blue LED chip, then the w-LED device with the color coordinate of (0.31, 0.32) was successfully assembled. The Gd₂O₃:Eu³⁺@CsPbBr₃ QDs compounds with excellent luminescent properties and stability are expected to be widely used in lighting and display areas.     

An electrochemical method for the preparation of Mg–Li alloys at low temperature molten salt system

Mg–Li alloys have been prepared by electrolysis in a molten salt electrolyte of 50% LiCl–50% KCl (mass%) at low temperature of 420–510 °C. The effects of electrolytic temperature and cathodic current density on alloy formation rate and current efficiency were studied. For the deposition of metallic lithium on the cathode consisting of solid Mg and liquid Mg–Li, both electrolytic temperature and cathodic current density have no obvious influence on current efficiency; while for the deposition of metallic lithium on the solid magnesium cathode, both electrolytic temperature and cathodic current density greatly affect alloy formation rate and current efficiency. The optimum electrolysis condition is—molten salt mixture, LiCl:KCl = 1:1 (mass%), electrolytic temperature: 480 °C, cathode current density: 1.13 A cm⁻². Mg–Li alloys with low lithium content (about 25 wt% Li) were prepared via electrolysis at low temperature following by thermal treatment at higher temperature.