深港数字化工程合作的BIM应用平台建设

香港的工程项目建设与内地相比,有着鲜明的特色。本文根据深港两地合作的工程项目经验,阐述了项目中BIM数据信息管理要求,特别突出了香港项目建模要求的关键点,总结了香港模式的优点和可借鉴之处。根据香港的项目实践经验,基于严格的建模需求,可以实现一致地用于竣工交付的模型。未来深港两地的合作应当以此为基础,通过平台进一步挖掘工程数据的潜力。文中指出,依靠现有的信息化技术,可以建立一套结合多种类数据的架构体系。通过将模型数据提取到独立的平台中,可以逐步实现工程项目全过程BIM应用的目标。这一平台基于香港的标准化BIM体系,结合深圳方面的工程数字化技术能力,在粤港澳大湾区建设的政策推动下,具备广阔的发展前景。     

Structural evolution of low-dimensional metal oxide semiconductors under external stress

Metal oxide semiconductors (MOSs) are attractive candidates as functional parts and connections in nanodevices. Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in structural instability and thus degrade the performance of MOS. Hence, the basic insight into the structural evolutions of low-dimensional MOS is a prerequisite for extensive applications, which unfortunately remains largely unexplored. Herein, we review the recent progress regarding the mechanical deformation mechanisms in MOSs, such as CuO and ZnO nanowires (NWs). We report the phase transformation of CuO NWs resulting from oxygen vacancy migration under compressive stress and the tensile strain-induced phase transition in ZnO NWs. Moreover, the influence of electron beam irradiation on interpreting the mechanical behaviors is discussed.     

A 26-Gb/s CMOS optical receiver with a reference-less CDR in 65-nm CMOS

This paper presents a 26-Gb/s CMOS optical receiver that is fabricated in 65-nm technology. It consists of a triple-inductive transimpedance amplifier (TIA), direct current (DC) offset cancellation circuits, 3-stage gm-TIA variable-gain amplifiers (VGA), and a reference-less clock and data recovery (CDR) circuit with built-in equalization technique. The TIA/VGA front-end measurement results demonstrate 72-dBΩ transimpedance gain, 20.4-GHz −3-dB bandwidth, and 12-dB DC gain tuning range. The measurements of the VGA’s resistive networks also demonstrate its efficient capability of overcoming the voltage and temperature variations. The CDR adopts a full-rate topology with 12-dB imbedded equalization tuning range. Optical measurements of this chipset achieve a 10⁻¹² BER at 26 Gb/s for a 2¹⁵−1 PRBS input with a −7.3-dBm input sensitivity. The measurement results with a 10-dB @ 13 GHz attenuator also demonstrate the effectiveness of the gain tuning capability and the built-in equalization. The entire system consumes 140 mW from a 1/1.2-V supply.     

TSJ6/660水源钻机的升级改造与配套

TSJ6/660水源钻机是国内1000m级别水井钻机的主要钻机型号之一,为适应北京浅层地热井及深水井施工的需要,将其改造成2000m级别的钻机有着很好的市场潜力.本文分析了这种钻机的结构和配套情况,提出了改造的方案,改造后的钻机成功施工了2000m级别的水井,取得较好的经济效益.     

四川乐山几个李子品种的品质特征研究

为了解不同品种李子的品质特性,本文选取12个品种李子作为研究对象,分别从外观、理化及糖酸组成等方面对果实品质进行了对比分析,同时采用主成分分析和聚类分析对李子品质性状进行综合评价。结果表明,不同品种李子外观、理化和糖酸组成等指标均表现出丰富的多样性。糖酸组成、色泽、单果重、果实密度和果形指数等是评价李子综合品质的关键性指标。12个品种中‘紫皇’（ZH）‘圣雪珀’（SXP）‘爱丽丝’（ALS）‘香李’（XL）‘香甜李’（XTL）5个品种综合评分为正值,品质较好。其中,ZH和SXP品质特征为出汁率、可溶性固形物、总糖含量及色泽品质高;ALS品质特征为总糖、总甜度、甜酸比和糖酸比最高;XL和XTL品质特征为可溶性固形物含量、糖酸比、甜酸比高,但出汁率低。该研究结果可作为不同用途李子品种筛选的重要参考依据。

     

Dual-Schottky-junctions coupling device based on ultra-long β-Ga2O3 single-crystal nanobelt and its photoelectric properties

High quality β-Ga₂O₃ single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132 μm were synthesized by carbothermal reduction method. Based on the grown nanobelt with the length of 600 μm, the dual-Schottky-junctions coupling device (DSCD) was fabricated. Due to the electrically floating Ga₂O₃ nanobelt region coupling with the double Schottky-junctions, the current I_S2 increases firstly and rapidly reaches into saturation as increase the voltage V_S2. The saturation current is about 10 pA, which is two orders of magnitude lower than that of a single Schottky-junction. In the case of solar-blind ultraviolet (UV) light irradiation, the photogenerated electrons further aggravate the coupling physical mechanism in device. I_S2 increases as the intensity of UV light increases. Under the UV light of 1820 μW/cm², I_S2 quickly enters the saturation state. At V_S2 = 10 V, photo-to-dark current ratio (PDCR) of the device reaches more than 10⁴, the external quantum efficiency (EQE) is 1.6 × 10³%, and the detectivity (D^*) is 7.5 × 10¹² Jones. In addition, the device has a very short rise and decay times of 25−54 ms under different positive and negative bias. DSCD shows unique electrical and optical control characteristics, which will open a new way for the application of nanobelt-based devices.     

Distributed Nash Equilibrium Seeking Strategies Under Quantized Communication

This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achieve the optimization o players’ objective functions while restricting their actions within required non-empty, convex and compact domains. In addition, a leader-following consensus protocol, in which quantized informa tion flows are utilized, is employed for information sharing amon...     

龟甲胶对环磷酰胺引起的贫血大鼠的改善作用研究

目的：研究鱼鳔、驴皮化学成分及对环磷酰胺所致贫血小鼠的改善作用。方法：测定总蛋白含量、氨基酸组成及分子量范围;胃蛋白酶辅助提取获得胶原蛋白,并分析其含量、组成及结构;腹腔注射环磷酰胺（80 mg/kg）建立小鼠贫血模型,灌胃给予受试物（鱼鳔胶1.52 g/（kg·d）、驴皮胶1.39 g/（kg·d））,观察对脏器系数和血液学指标的影响。结果：鱼鳔、驴皮总蛋白含量均大于97%,鱼鳔胶、驴皮胶分子量在50 Da~328 kDa之间;鱼鳔、驴皮胶原蛋白均为Ⅰ型胶原蛋白,鱼鳔胶原蛋白含量约为驴皮的6.51倍,但胶原蛋白三螺旋结构不同,鱼鳔胶原蛋白以α-螺旋结构为主,驴皮胶原蛋白以反平行为主。功效评价结果表明,给药28 d,鱼鳔胶与驴皮胶均可促进环磷酰胺贫血小鼠造血机能的恢复,以鱼鳔胶效果更佳。与模型组相比,鱼鳔胶给药组红细胞、血红蛋白、血小板、网织红细胞、脾脏及胸腺系数均得到显著改善（P<0.05）;驴皮胶给药组红细胞、血红蛋白及胸腺系数显著改善（P<0.05）。结论：对鱼鳔、驴皮化学成分进行系统研究,确定了化学成分间的差异;发现鱼鳔胶、驴皮胶均可促进环磷酰胺贫血小鼠造血机能的恢复,且鱼鳔胶效果更佳,推测二者补血活性可能与氨基酸、胶原蛋白等成分有关。本研究为鱼鳔资源精深加工奠定理论基础。

     

我国红茶产业现状及可持续发展对策

为探明祁门红茶、GABA红茶、滇红等三种红茶特征挥发性成分差异,采用顶空固相微萃取（HS-SPME）与气相色谱-质谱联用（GC-MS）方法,结合多元统计分析进行研究。气-质联用结果表明,共定性鉴定出78种已知挥发性成分,包括碳氢化合物、萜烯类、醇类、酯类、酮类、醛类、杂环化合物、酚类。三种红茶总挥发性物质种类数量相近,但其含量差异较大,其共有挥发性成分主要包括芳樟醇、香叶醇、壬醛、水杨酸甲酯、氧化芳樟醇等。多元统计分析结果表明,根据挥发性成分可以区分GABA红茶、滇红、祁门红茶。经偏最小二乘判别分析筛选出12种差异挥发性成分,包括醋酸橙花酯、水杨酸甲酯、异龙脑、芳樟醇、柠檬醛等,其中醋酸橙花酯、柠檬醛在祁门红茶中含量最高,有助于形成祁门红茶的花果香型;异龙脑、芳樟醇在滇红中含量最高;芳樟醇、水杨酸甲酯在GABA红茶中含量较高,有利于形成GABA红茶鲜嫩花果香。本研究结果可为科学客观地评价GABA红茶香气特征,阐明祁门红茶、GABA红茶、滇红香气品质差异及构建不同种类红茶风味品质鉴别图谱奠定理论基础。