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119. Multilayer electronic component systems and methods of manufacture

Author

Thompson, Dane, Wang, Guoan, Kingsley, Nickolas D, Papapolymerou, Ioannis, Tentzeris, Emmanouil M, Bairavasubramanian, Ramanan, DeJean, Gerald, and Li, RongLin

Subjects
Electronics And Electrical Engineering
Abstract

Multilayer electronic component systems and methods of manufacture are provided. In this regard, an exemplary system comprises a first layer of liquid crystal polymer (LCP), first electronic components supported by the first layer, and a second layer of LCP. The first layer is attached to the second layer by thermal bonds. Additionally, at least a portion of the first electronic components are located between the first layer and the second layer.

Published
2010

120. Relationships between leaf δ15N and leaf metallic nutrients

Author

Chen, Chongjuan, Wu, Yingjie, Wang, Shuhan, Liu, Zhaotong, and Wang, Guoan

Abstract

Metallic nutrients play a vital role in plant physiological and biochemical processes such as nitrogen uptake and assimilation, which cause isotopic fractionation against 15N. Thus, investigating the relationships between leaf nitrogen isotope ratio (δ15N) and leaf metallic nutrients could enhance our understanding of nitrogen (N) cycling. However, to our knowledge, these relationships have not been examined as yet. To fill in this research gap, we analyzed leaf δ15N and leaf potassium (K), Calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn) and zinc (Zn) contents of 624 non-N2-fixing plant samples and revealed the relationships between leaf δ15N and these metallic elements. Overall, leaf δ15N correlated positively with leaf K, Ca, Mg and Zn, and negatively with leaf Fe, whereas not with leaf Mn. The relationships of leaf δ15N with leaf K, Ca, Mg, Zn and Fe were not affected by both vegetation type and soil type, suggesting that the observed relationships could be universally valid. However, the relationship between leaf δ15N and leaf Mn depended on vegetation type and soil type, therefore, the observed relationship should not be considered to be universal. These metallic nutrients together accounted for 55.7 % of the variations in leaf δ15N; this emphasized the significance of metallic nutrients in determining leaf δ15N.

Published
2019

121. Microstrip Antenna Arrays on Multilayer LCP Substrates

Author

Thompson, Dane, Bairavasubramanian, Ramanan, Wang, Guoan, Kingsley, Nickolas D, Papapolymerou, Ioannis, Tenteris, Emmanouil M, DeJean, Gerald, and Li, RonglLin

Subjects
Technology Utilization And Surface Transportation
Abstract

A research and development effort now underway is directed toward satisfying requirements for a new type of relatively inexpensive, lightweight, microwave antenna array and associated circuitry packaged in a thin, flexible sheet that can readily be mounted on a curved or flat rigid or semi-rigid surface. A representative package of this type consists of microwave antenna circuitry embedded in and/or on a multilayer liquid- crystal polymer (LCP) substrate. The circuitry typically includes an array of printed metal microstrip patch antenna elements and their feedlines on one or more of the LCP layer(s). The circuitry can also include such components as electrostatically actuated microelectromechanical systems (MEMS) switches for connecting and disconnecting antenna elements and feedlines. In addition, the circuitry can include switchable phase shifters described below. LCPs were chosen over other flexible substrate materials because they have properties that are especially attractive for high-performance microwave applications. These properties include low permittivity, low loss tangent, low water-absorption coefficient, and low cost. By means of heat treatments, their coefficients of thermal expansion can be tailored to make them more amenable to integration into packages that include other materials. The nature of the flexibility of LCPs is such that large LCP sheets containing antenna arrays can be rolled up, then later easily unrolled and deployed. Figure 1 depicts a prototype three- LCP-layer package containing two four-element, dual-polarization microstrip-patch arrays: one for a frequency of 14 GHz, the other for a frequency of 35 GHz. The 35-GHz patches are embedded on top surface of the middle [15-mil (approx.0.13-mm)-thick] LCP layer; the 14- GHz patches are placed on the top surface of the upper [9-mil (approx. 0.23-mm)-thick] LCP layer. The particular choice of LCP layer thicknesses was made on the basis of extensive analysis of the effects of the thicknesses on cross-polarization levels, bandwidth, and efficiency at each frequency.

Published
2007

132. Relationships between leaf δ15N and leaf metallic nutrients.

Author

Chen, Chongjuan, Wu, Yingjie, Wang, Shuhan, Liu, Zhaotong, and Wang, Guoan

Subjects
NITROGEN in soils, ISOTOPIC fractionation, NUTRIENT cycles, SOIL classification, PLANT nutrients, SOIL acidity, NUTRIENT uptake, STABLE isotopes
Abstract

Rationale: Nitrogen (N) isotopic ratios (δ15N values) of plants are primarily determined by the δ15N values of their N sources. Metallic nutrients affect plant N uptake. However, there is little knowledge of the relationships between leaf δ15N values and leaf metallic nutrients. The δ15N values are often lower in soil nitrate (NO3−) than in ammonium (NH4+) due to large isotopic fractionation during nitrification. Plants acquire more NO3− than NH4+ when accumulating high potassium (K), calcium (Ca) and magnesium (Mg) to maintain charge balance. In addition, plants that absorb more NO3− than NH4+ increase the soil pH and decrease the availability of iron (Fe), manganese (Mn) and zinc (Zn). We therefore hypothesized that leaf δ15N values correlate negatively with K, Ca and Mg contents, while positively with Fe, Mn and Zn contents. Methods: Leaves of non‐N‐fixing plants were sampled across an approx. 6000 km transect in China and their δ15N values and metallic nutrient content were determined using elemental analyzer/isotope ratio mass spectrometry. Results: Inconsistent with the hypothesis, leaf δ15N values correlated positively with leaf K, Ca and Mg, indicating higher δ15N values of soil NO3− than NH4+. Higher δ15N values of soil NO3− revealed stronger denitrification than nitrification in the study regions because isotopic fractionation occurs during both processes. Leaf δ15N values correlated negatively with Fe, relating to decreases in soil Fe availability, which might be attributed to oxidation of Fe2+ to Fe3+ supplying electrons for denitrification, while greater uptake of NO3− than NH4+ of plants increases soil pH. Leaf δ15N values correlated positively with Zn and did not correlate with Mn. These observed relationships between leaf δ15N values and metallic nutrients, except Mn, were independent of vegetation or soil types. Conclusions: This study has enriched our knowledge of associations between metallic nutrients and N cycling in plant–soil systems, especially for the roles of Fe in soil N transformations and K, Ca and Mg in plant N uptake. [ABSTRACT FROM AUTHOR]

Published
2021
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144. Discrepant responses of the electron transfer capacity of soil humic substances to irrigations with wastewaters from different sources

Author

Tan, Wenbing, primary, Zhang, Yuan, additional, Xi, Beidou, additional, He, Xiaosong, additional, Gao, Rutai, additional, Huang, Caihong, additional, Zhang, Hui, additional, Li, Dan, additional, Zhao, Xinyu, additional, Li, Meng, additional, Li, Li, additional, Jiang, Jie, additional, and Wang, Guoan, additional

Published
2018
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