能量桩工程应用研究进展及PCC能量桩技术开发

能量桩是一种由地源热泵技术与桩基埋管换热器结合组成的经济高效节能减排技术。简要介绍了基于地源热泵技术的能量桩技术原理、桩型、埋管形式以及技术经济优势,总结了近年来国内外能量桩技术的研究现状及其工程应用,包括基于灌注桩的传热管埋管形式和基于预制桩的传热管埋管形式；指出了目前工程应用中存在的一些主要问题,并提出一种新型PCC能量桩技术及其施工工艺；最后简要分析了能量桩技术在国家节能减排工程中的应用前景,并提出有待进一步研究的方向。 The energy pile is the combination of ground source heat pump technology and purposely designed pile for storing energy in the ground using buried pipes during hot climates and retrieving energy from it when it is needed. The technical principles, pile types, buried forms and economic advantages of the energy pile are introduced. The heat transfer pipes can be buried in drilled shaft, precast piles, steel piles and cement mixing piles. The current advances and research status of energy piles at home and abroad and their engineering applications (including drilled shafts and precast piles) in recent years are reviewed and summarized. Moreover, some major problems in engineering applications are revealed, leading to the development of a new PCC energy pile. The prospects of the PCC energy pile in the national energy saving projects of China are analyzed, and the further research orientation is proposed

热力耦合边界面模型在COMSOL中的开发应用

基于邊界面理論的熱力耦合模型可以模擬邊界面形狀和尺寸隨溫度的變化,能夠反映不同超固結比情況下升-降溫引起的土體體積變化和溫度對剪切特性的影響等土體重要的熱力學特性。為了在熱-流-固耦合分析中采用熱力耦合邊界面模型,基于有限元軟件COMSOL,通過修改內置材料方程、耦合滲流和固體力學控制方程以及添加計算邊界面內塑性應變偏微分方程的方法對一熱力耦合邊界面本構模型進行了二次開發。利用所開發模型,對一維固結問題、常溫等向壓縮問題、排水條件下等向升-降溫問題和不同溫度下不排水三軸壓縮問題進行了模擬,驗證了模型的可靠性和有效性。Based on bounding surface plasticity theory, both the size and shape of the bounding surface are allowed to change with temperature in the thermo-mechanical model. The thermo-bounding surface model can capture many vital aspects of thermo-mechanical behavior, including volume changes during heating and cooling, and thermal effects on shear behavior. In order to analyse thermo-fluid-solid coupling phenomena, a thermo-bounding surface model is implemented in the software COMSOL. The implementation techniques include modification of the built-in material equations of COMSOL, coupling analysis of pore fluid flow and stress, the addition of partial differential equations to compute plastic strains for any stress path within the bounding surface. The developed model was used to analyze one-dimensional consolidation, isotropic compression test at constant temperature, drained heating and cooling tests and undrained triaxial compression tests at different temperatures. By comparing with the computed and measured results, it is evident that the proposed model is capable to capture key features of the coupled soil behavior. © 2017, Science Press. All right reserved

循环温度场作用下PCC能量桩热力学特性模型试验研究

PCC能量桩是河海大学岩土所开发的一种新型能量桩技术。在常规桩基静载荷模型试验基础上,将PCC能量桩放置在南京典型砂土中,并通过导热管内水体的循环对模型桩体施加温度场,以模拟PCC能量桩在实际运行过程中的承载力特性与受力机制,PCC能量桩先加载至工作荷载(极限荷载的一半),再施加热-冷循环一次,最后加载至极限荷载,测得不同温度下PCC能量桩的荷载-位移关系曲线、桩身应力-应变关系曲线等变化规律。试验结果表明,能量桩换热过程中,热量更容易从桩体传向土体(即夏季模式的热循环);热循环及制冷循环都明显改变了桩顶位移值,且往复循环作用下产生的塑性变形不能完全恢复,其积累变形可能危害上部结构安全;桩身受温度场作用产生的热应力相对较大,且不同约束条件下其变化值有所差异;在制冷循环下,桩底部甚至可能产生较大拉应力。 PCC energy pile is based on one of new type energy pile technology methods developed by Geotechnical Engineering Institute of Hohai University. On the basis of traditional static load test of pile, PCC energy piles are embedded into Nanjing typical sand. Thermal field of model pile is simulated through water circulation in the cyclic pipe. The characteristic and mechanism of bearing capacity of PCC energy pile in operation are studied. The PCC energy pile is firstly loaded to the working load (half of the ultimate load) and then the heating and cooling cycle is applied. After that the model pile is loaded to the ultimate load. The curves of load-displacement and stress-strain of pile shaft under different temperatures are measured. The results show that the heat can easily transfer from pile to soil (summer mode). The displacement of pile top changes obviously during heating and cooling cycles. The change of temperature brings plastic deformation in the soil, which can harm the upper structure. The thermal stress in the PCC pile caused by temperature field is relatively large. The change of thermal stress is different under different constraint conditions. Under cooling cycle, tensile strain even appears on the bottom of pile. ©, 2015, Academia Sinica. All right reserved

高光敏性高稳定性氢化非晶硅薄膜的研制

采用“不间断生长/退火”技术,并配之以微量硼补偿,制备了高性能的氢化非晶硅薄膜(a-Si:H),其光敏性(σ_(ph)σ_d)达到10~6)量级,并且稳定性得以显著提高,在100mW/cm~2的白光长时间照射后没有观察到衰退现象。分析指

System Toxicology Research of Tripterygium wilfordii Hook. f. on Female Rat Using LC-MS Based Urinary Metabolomics

Tripterygium wilfordii Hook. f. has a long history of use in traditional Chinese herbal medicine. It is used for the treatment of arthritis, muscle injury, skin diseases, and other diseases. However, it is thought to be toxic or even fatal if taken to excess. Here, a metabolomics- based toxicology approach was used to elucidate the toxicity in SD female rats induced by tripterygiumon. Overnight 12 h urine samples were collected from rats exposed to three different doses and healthy controls at predose and at the 3rd, 5th, 9th, 14th, 19th and 26th day postdose. Urinary metabolic profiling was analyzed by principal component analysis (PCA) to find the differential metabolites and altered biological pathways which are in response of herbal toxin. The results showed that tripterygiumon caused a dose-dependent and time-dependent toxic and it perturbed metabolic regulatory network to disorder amino acid, purine and choline metabolism pathways. Metabolomics can be a systems approach to provide comprehensive information of drug induced toxicity. With metabolomics, the systemic toxic effects can be detected at an earlier stage compared to the histopathological assessment.Tripterygium wilfordii Hook. f. has a long history of use in traditional Chinese herbal medicine. It is used for the treatment of arthritis, muscle injury, skin diseases, and other diseases. However, it is thought to be toxic or even fatal if taken to excess. Here, a metabolomics- based toxicology approach was used to elucidate the toxicity in SD female rats induced by tripterygiumon. Overnight 12 h urine samples were collected from rats exposed to three different doses and healthy controls at predose and at the 3rd, 5th, 9th, 14th, 19th and 26th day postdose. Urinary metabolic profiling was analyzed by principal component analysis (PCA) to find the differential metabolites and altered biological pathways which are in response of herbal toxin. The results showed that tripterygiumon caused a dose-dependent and time-dependent toxic and it perturbed metabolic regulatory network to disorder amino acid, purine and choline metabolism pathways. Metabolomics can be a systems approach to provide comprehensive information of drug induced toxicity. With metabolomics, the systemic toxic effects can be detected at an earlier stage compared to the histopathological assessment

一种气体痕量组分在色谱毛细管柱分析中的富集捕获方法

本发明涉及气相色谱分析，是一种气体中的痕量组分在毛细管柱分析中采用CO2区域致冷的富集捕获方法；利用液体CO2区域致冷源，通过喷口对预柱或毛细管柱的柱头进行局部致冷，以实现对气体样品中痕量组分的富集。本发明方法对痕量组分的色谱分析定量精度高、分析速度快、富集比大、冷量使用合理、设备投资小、操作方便、可以和毛细管柱直接联用、同时对气相色谱仪也没有特殊要求，因此推广容易、应用前景广阔。带填