A discussion of the methods for comparing the relative effectiveness of phosphate fertilizers varying in solubility

Because various phosphate (P) fertilizers differ widely in their solubility, it is commonly observed that crop response to P fertilizers varies under the same soil and crop conditions. Furthermore, a major problem encountered in the methods for determining the relative effectiveness (RE) of water-insoluble P fertilizer (e.g., phosphate rock) with respect to water-soluble P fertilizers, e.g., single superphosphate (SSP) and triple superphosphate (TSP), is that their growth response curves are usually nonlinear and often do not share a common maximum yield. In this paper, we review and discuss the advantages and disadvantages of the three most commonly used methods for calculating the RE of phosphate rock with respect to TSP (or SSP). The three methods are vertical comparison, horizontal (substitution rate) comparison, and linear-response comparison.     

RIE gate-recessed(Al0.3Ga0.7)0.5In0.5P/InGaAsdouble doped-channel FETs using CHF3+BCl3 mixingplasma

BCl₃+CHF₃ gas mixtures for the reactive ion etching process were applied to the gate-recess for fabricating (Al_0.3Ga_0.7)_0.5In_0.5P quaternary heterostructure double doped-channel FET's (D-DCFET), where a high uniformity of Vth was achieved. With the merits of this wide bandgap (Al_0.3Ga_0.7)_0.5In_0.5P layer, microwave power performance of this heterostructure D-DCFET demonstrates a compatible performance for devices fabricated on AlGaAs/InGaAs heterostructures     

Thickness Scaling and Reliability Comparison for the Inter-Poly High- κ Dielectrics

In this letter, the inter-poly dielectric (IPD) thickness, scaling, and reliability characteristics of Al₂O₃ and HfO₂ IPDs are studied, which are then compared with conventional oxide/nitride/oxide (ONO) IPD. Regardless of deposition tools, drastic leakage current reduction and reliability improvement have been demonstrated by replacing ONO IPD with high-permittivity (high-kappa) IPDs, which is suitable for mass production applications in the future. Moreover, metal-organic chemical vapor deposition (MOCVD) can be used to further promote dielectric reliability when compared to reactive-sputtering deposition. By using the MOCVD, the charge-to-breakdown (Q_BD) can be significantly improved, in addition to enhanced breakdown voltage and effective breakdown field. Our results clearly demonstrate that high- IPD, particularly deposited by MOCVD, possesses great potential for next-generation stacked-gate Flash memories.     

Electrophosphorescent Polyfluorenes Containing Osmium Complexes in the Conjugated Backbone

Electrophosphorescent copolymers have been synthesized by covalent bonding of a red‐emitting osmium complex Os(bpftz), which contains two 3‐trifluoromethyl‐5‐(4‐tert‐butyl‐2‐pyridyl)triazolate (bpftz) cyclometalated ligands, into the backbone of a bipolar polyfluorene (PF) copolymer. Employing these copolymers, a highly efficient red polymer light‐emitting diode has been realised that has an external quantum efficiency of 18.0%, a maximum brightness of 38 000 cd m^?2, and an emission centered at 618 nm. In addition, after incorporating appropriate amounts of green‐emitting benzothiadiazole (BT) and the aforementioned Os(bpftz) into the bipolar PF, an efficient white‐light electroluminescent polymer is obtained that displays simultaneous blue, green, and red emissions.     

On delay constrained CAC scheme and scheduling policy for CBR traffic in IEEE 802.11e wireless LANs

CBR (constant bit rate) traffic is expected to be an important traffic source in wireless networks. Such sources usually have stringent jitter or delay requirements and in many cases they should be delivered exactly as they were generated. In this paper, we propose a strictly guaranteed QoS (quality‐of‐service) provisioning CAC (call admission control) scheme with a polling‐based scheduling policy for CBR traffic in IEEE 802.11e wireless LANs. Under such a scheme, the proposed transmit‐permission policy for HCCA (HCF controlled channel access) method can forecast the maximum suffered delay for each packet and derive sufficient conditions so that all the CBR sources satisfy their time constraints to provide deterministic QoS guarantees. A simple analytical model is carried out to estimate the average queueing delay of the proposed scheme. In addition to theoretical analysis, simulations are conducted to validate its promising performance. Our simulation results show that the proposed scheme maintains a high throughput with respect to the whole range of system load. Copyright © 2009 John Wiley & Sons, Ltd.     

Improvement of color temperature using independent control of red, green, blue luminance in AC plasma display panel

This paper presents a new driving scheme for the improvement and flexibility of a color temperature without sacrificing a peak white luminance using an independent control of the red (R), green (G), and blue (B) luminance in an alternating current plasma display panel (AC-PDP). The independent control for the R, G, and B emissions can be achieved by selective application of the various narrow auxiliary pulses to the R, G, and B address electrodes during a sustain-period. The auxiliary pulses can control the luminance levels independently from the R, G, and B cells by forming the fast and efficient plasma or by slight disturbing of the wall charge accumulation. By the application of various auxiliary pulses leading to the simultaneous control of each color's luminance, it is observed that the new driving scheme can improve the color temperature from 5396 K to 10 980 K in a 4-in test panel with almost the same peak white luminance as that of the conventional driving scheme.     

Plasma-induced charging damage in ultrathin (3-nm) gate oxides

Plasma-induced damage in various 3-nm-thick gate oxides (i.e., pure oxides and N₂O-nitrided oxides) was investigated by subjecting both nMOS and pMOS antenna devices to a photoresist ashing step after metal pad definition. Both charge-to-breakdown and gate leakage current measurements indicated that large leakage current occurs at the wafer center as well as the wafer edge for pMOS devices, while only at the wafer center for nMOS devices. These interesting observations could be explained by the strong polarity dependence of ultra thin oxides in charge-to-breakdown measurements of nMOS devices. In addition, pMOS devices were found to be more susceptible to charging damage, which can be attributed to the intrinsic polarity dependence in tunneling current between nand p-MOSFETs. More importantly, our experimental results demonstrated that stress-induced leakage current (SILC) caused by plasma damage can be significantly suppressed in N₂O-nitrided oxides, compared to pure oxides, especially for pMOS devices. Finally, nitrided oxides were also found to be more robust when subjected to high temperature stressing. Therefore, nitrided oxides appear to be very promising for reducing plasma charging damage in future ULSI technologies employing ultrathin gate oxides     

Artificial convolution neural network techniques and applications for lung nodule detection

We have developed a double-matching method and an artificial visual neural network technique for lung nodule detection. This neural network technique is generally applicable to the recognition of medical image pattern in gray scale imaging. The structure of the artificial neural net is a simplified network structure of human vision. The fundamental operation of the artificial neural network is local two-dimensional convolution rather than full connection with weighted multiplication. Weighting coefficients of the convolution kernels are formed by the neural network through backpropagated training. In addition, we modeled radiologists' reading procedures in order to instruct the artificial neural network to recognize the image patterns predefined and those of interest to experts in radiology. We have tested this method for lung nodule detection. The performance studies have shown the potential use of this technique in a clinical setting. This program first performed an initial nodule search with high sensitivity in detecting round objects using a sphere template double-matching technique. The artificial convolution neural network acted as a final classifier to determine whether the suspected image block contains a lung nodule. The total processing time for the automatic detection of lung nodules using both prescan and convolution neural network evaluation was about 15 seconds in a DEC Alpha workstation.     

Five channel WDM soliton pulse generation using sinusoidally drivenelectroabsorption modulators in 16×1 laser/modulator array

Five wavelength multiplexed pulse streams are generated in an integrated 16×1 laser modulator array by sinusoidally driving five of the potential 16 electroabsorption modulators. At a repetition rate of 2.5 GHz, near transform-limited pulses spaced in wavelength over 7.6 nm are observed. Pseudorandom coding of one channel is achieved by applying an electrical RZ data signal to the modulator     

斜坡电流测试应用与比较方法研究

讨论了斜坡电流测试的相关参数如电流斜坡速率、步长及电流倍增速率对测试结果击穿电荷具有的严重影响。指出斜坡电流测试中各个参数的设定、影响及其相关性,使斜坡电流测试的结果具有可比较性。同时,讨论了由于斜坡电流测试本身的特性,击穿电荷具有非连续性,针对击穿电荷的非连续性,提供了一种统计上的数据处理方法,并且根据工程上不同的定性比较结果提供了不同的统计比较方法,可以对非连续的斜坡电流测试结果进行定量的统计比较。在产品验证或生产线出现异常时,能够进行统计上的比较,给出定量的结果。据此能对生产线的稳定性或异常事件对产品的影响给出明确的结论,为受影响的产品的处置提供定量的数据支持。这是首次对斜坡电流测试数据的统计定量分析。