标准型、缺口型和螺旋缺口型圆盘耙性能比较（摘选）

对标准型、缺口型和螺旋缺口型圆盘耙性能分别在室内3个装有沙壤土的土槽测试耕作圆盘的性能。实验室测试设置包括土槽系统和数据采集系统。双扩展八角形环（DEOR）传感器和滑环扭矩传感器,用于三维应力和扭矩测量。圆盘角和旋转速度是研究对象。对于所有型式的圆盘耙而言,使用外源动力驱动都可以减少土壤作用在耕作圆盘耙上的合力。形态各异的切割边缘显著影响耕作圆盘耙的受力和对土壤的切削作用。螺旋缺口圆盘耙表现出比缺口和标准圆盘耙低的土壤作用。螺旋切削刃提供剪切割行动,消除冲击载荷,提供流畅的操作。由于其能对作物残留物进行有效切割,因此,螺旋缺口圆盘耙是适合保护性耕作作业最具潜力的机具。      

打孔型宽频带夹心式换能器

超声波换能器是将电信号转换为超声波的装置。分析单一振动模态单一谐振频率的换能器拓宽频带的机理,提出以在前盖板上打孔的方式来减小换能器的等效质量,从而降低其品质因数,进而达到拓宽频带的目的;研制打孔型宽频带换能器,设计大辐射面来增强拓宽频带的效果;对加工完成的换能器进行测试实验,对比有无负载条件下的性能指标。实验结果显示：换能器拓宽频带的效果及其它性能指标均满足设计要求。     

Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure

Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-κB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 × 10⁴ hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-α from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-κB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF.     

In situ measurement of the vertical linear shrinkage curve of soils

In situ studies on soil shrinkage has been limited so far to highly swelling soils due to the limited precision of the in situ measurements. We present a new experimental set-up for the in situ measurement of the vertical linear shrinkage curve (LSC) of soils that uses electronic linear displacement transducers to measure soil layer thickness variations. We used block kriging, instead of arithmetic averaging as done by former authors, to estimate locally the water content of the soil layers at the same spot where the thickness measurements are done. We tested this in situ LSC measurement method in the borderline case of two weakly swelling soils from Senegal. The precision of the soil layer thickness measurements are better than or equal to ±10 μm. With block kriging, the gravimetric water content of the soil could be estimated with a precision less than ±0.02 kg kg⁻¹, in average, from only 3 samples. The global in situ shrinkage of the two weakly swelling soils ranged from 0.02%–0.36% in relative values, which is two orders of magnitude less than that measured on highly swelling soils. Owing to the precision of the measurements, LSCs of both soils could be drawn. They had a shape similar to that of highly swelling soils, with a structural shrinkage phase followed by an uncompleted basic shrinkage phase. Residual shrinkage was never observed, except for the sandy top layer of the ferrallitic soil.     

ZDH60型智能电子地衡

针对我国林区现用机械式地衡进行木材检尺存在的缺点,论述研制电子地衡的必要性和先进性,介绍了该型电子地衡的主要技术性能、结构和工作原理、主要部件的选择计算、提高电子地衡精度的措施、经济效益和社会效益分析。     

Study on the Difference Phase Degree Division Displacement Transducer

Pointing out the shortages of the traditional bar thread displacement transducer, brings forward new thought of designing difference phase degree division displacement transducer, which transforms the problem of measuring displacement directly in angle into the problem of measuring the difference between the phases of two signals which have the same frequency and then gets the displacement in angle indirectly. The theories on designing the phase difference calculation displacement transducer and correlation displacement transducer is suggested. Because the difference phase degree division displacement transducer, supported by the computer technology and the signal processing technology, adapts to the development of instrument's fictionzing and intelligentizings, it is an advanced technology.     

少免耕播种机牵引阻力远程监测系统

针对少免耕播种机牵引阻力的监测,该文提出了一种能够实时采集信号、无线传输数据、现场移动监测、远程同步监测的少免耕播种机牵引阻力监测系统。该系统通过在3点悬挂杆铰接处安装2维轴销测力传感器实现对其受力情况的实时检测。采用无线传感网络技术(wireless sensor network,WSN)实现传感器信号采集和数据短距离无线传输。采用嵌入式技术开发无线数据监测移动终端,实现牵引阻力的现场监测以及数据转发。利用Visual C++开发的远程监测软件,在远程计算机上实现牵引阻力的动态监测、实时显示、在线分析和批量存储。经计量,该系统模拟量检测最大误差为4 mV,线性度为0.04%。田间试验表明:系统实现了少免耕播种机牵引阻力的现场移动监测以及远程同步监测,系统使用方便并降低了田间测试的复杂程度。