Facile Synthesis of Ultralight and Porous Melamine-Formaldehyde (MF) Resin-Derived Magnetic Graphite-Like C3N4/Carbon Foam with Electromagnetic Wave Absorption Behavior

Society demands effective electromagnetic wave (EMW) absorbers that are lightweight, with a broad absorption band and strong absorption, to solve excessive electromagnetic radiation. Herein, ultralight magnetic graphite-like C3N4/carbon foam (MCMF) was fabricated via impregnating polymerized melamine formaldehyde (MF) foams in Fe3O4 nanoparticle solution, followed by in situ pyrolysis at 1000 °C. MCMF possesses porous architectures consisting of graphitic C3N4/carbon and CFe15.1. The magnetic particles (α-Fe, Fe3O4 and Fe3C) were formed and modified on the internal skeleton surface. The EMW absorption capacity of MCMF is better than the that of carbonized MF foam without Fe3O4 (CMF), possessing excellent absorption behavior, with a minimum RL value of −47.38 dB and a matching thickness as thin as 3.90 mm. The corresponding effective absorbing bandwidth is as broad as 13.32 GHz. Maxwell–Wagner–Sillars (MWS) polarization and the residual loss are proved to be beneficial for such superior absorption behavior. Besides, graphitic C3N4 enriches the interface polarization effect and the electromagnetic matching effect. The microporous structures are beneficial for increasing EMW propagation, resulting in internal multiple reflections and scatterings, which are also beneficial for EMW attenuation.

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In Situ Coating of Needle-like NiCo2O4 Magnetic Nanoparticles on Lightweight Reticulated Vitreous Carbon Foam toward Achieving Improved Electromagnetic Wave Absorption

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.1c02636 ◽

2021 ◽

Author(s):

Kaumudi Yadav ◽

Rohit Bagal ◽

Saurabh Parmar ◽

T. Umasankar Patro ◽

Ashutosh C. Abhyankar

Keyword(s):

Electromagnetic Wave ◽

Magnetic Nanoparticles ◽

Carbon Foam ◽

Vitreous Carbon ◽

Reticulated Vitreous Carbon ◽

Electromagnetic Wave Absorption ◽

Wave Absorption ◽

In Situ Coating

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A High Angle, Double Tilting Cold Stage for the AEI EM7

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052262 ◽

1974 ◽

Vol 32 ◽

pp. 450-451

Author(s):

P.R. Swann ◽

A.E. Lloyd

Keyword(s):

Habit Plane ◽

Temperature Control ◽

Tilt Angle ◽

Cooling System ◽

Thermal Drift ◽

High Angle ◽

Cold Stage ◽

High Degree ◽

Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

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STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN

Acta Endocrinologica ◽

10.1530/acta.0.0450535 ◽

1964 ◽

Vol 45 (4) ◽

pp. 535-559 ◽

Cited By ~ 88

Author(s):

E. Bolté ◽

S. Mancuso ◽

G. Eriksson ◽

N. Wiqvist ◽

E. Diczfalusy

Keyword(s):

Pregnant Women ◽

Comparative Studies ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Radioactive Material ◽

Placental Barrier ◽

Therapeutic Abortion ◽

Limited Ability ◽

Better Than

ABSTRACT In 15 cases of therapeutic abortion by laparotomy the placenta was disconnected from the foetus and perfused in situ with tracer amounts of radioactive dehydroepiandrosterone (DHA), dehydroepiandrosterone sulphate (DHAS), androst-4-ene-3,17-dione (A), testosterone (T) and 17β-oestradiol (OE2). Analysis of the placentas, perfusates and urine samples revealed an extensive aromatisation of DHA, A and T; more than 70% of the radioactive material recovered was phenolic, and at least 80 % of this phenolic material was identified as oestrone (OE1), 17β-oestradiol (OE2) and oestriol (OE3), the latter being detected only in the urine. Comparative studies indicated that A and T were aromatised somewhat better than DHA and that all three unconjugated steroids were aromatised to a much greater extent than DHAS. Radioactive OE1 and OE2 were isolated and identified in the placentas and perfusates, but no OE3, epimeric oestriols, or ring D ketols could be detected in these sources, not even when human chorionic gonadotrophin (HCG) was added to the blood prior to perfusion. Lack of placental 16-hydroxylation was also apparent when OE2 was perfused. Regardless of the precursor perfused, there was three times more OE2 than OE1 in the placenta and three times more OE1 than OE2 in the perfusate. This was also the case following perfusion with OE2. The results are interpreted as suggesting the existence in the pregnant human of a placental »barrier« limiting the passage of circulating androgen. The barrier consists of a) limited ability to transfer directly DHAS and b) an enzymic mechanism resulting in the rapid and extensive aromatisation of the important androgens DHA, A and T.

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TRACERS DERIVED IN SITU REPLICATE AND MIX BETTER THAN FALLOUT TRACERS INCORPORATED INTO GRAIN COATINGS

10.1130/abs/2017am-299479 ◽

2017 ◽

Author(s):

Amanda H. Schmidt ◽

◽

Paul R. Bierman ◽

Veronica Sosa-Gonzalez ◽

Thomas B. Neilson ◽

...

Keyword(s):

Better Than

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Nanoferric tetroxide decorated N-doped residual carbon from entrained-flow coal gasification fine slag for enhancing the electromagnetic wave absorption capacity

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2021.159878 ◽

2021 ◽

Vol 874 ◽

pp. 159878

Author(s):

Jun He ◽

Shengtao Gao ◽

Yuanchun Zhang ◽

Hanxu Li

Keyword(s):

Electromagnetic Wave ◽

Coal Gasification ◽

Absorption Capacity ◽

Residual Carbon ◽

Electromagnetic Wave Absorption ◽

Wave Absorption ◽

Entrained Flow

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In situ construction of CNWs/SiC-NWs hybrid network reinforced SiCN with excellent electromagnetic wave absorption properties in X band

Carbon ◽

10.1016/j.carbon.2020.06.081 ◽

2020 ◽

Vol 168 ◽

pp. 278-289 ◽

Cited By ~ 1

Author(s):

Fangyuan Ren ◽

Jimei Xue ◽

Xiaoling Liu ◽

Laifei Cheng

Keyword(s):

Electromagnetic Wave ◽

Hybrid Network ◽

Absorption Properties ◽

Electromagnetic Wave Absorption ◽

Wave Absorption ◽

X Band

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Performance of the SoLid reactor neutrino detector

EPJ Web of Conferences ◽

10.1051/epjconf/201921908003 ◽

2019 ◽

Vol 219 ◽

pp. 08003

Author(s):

Maja Verstraeten

Keyword(s):

Quality Control ◽

Energy Resolution ◽

Neutrino Detector ◽

Channel Response ◽

In Situ Calibration ◽

Reactor Neutrino ◽

Li Isotope ◽

Better Than

The SoLid Collaboration is currently operating a 1.6 ton neutrino detector near the Belgian BR2 reactor. Its main goal is the observation of the oscillation of electron antineutrinos to previously undetected flavour states. The highly segmented SoLid detector employs a compound scintillation technology based on PVT scintillator in combination with LiF-ZnS(Ag) screens containing the 6Li isotope. The experiment has demonstrated a channel-to-channel response that can be controlled to the level of a few percent, an energy resolution of better than 14% at 1 MeV, and a determination of the interaction vertex with a precision of 5 cm. This contribution highlights the major outcomes of the R&D program, the quality control during component manufacture and integration, the current performance and stability of the full-scale system, as well as the in-situ calibration of the detector with various radioactive sources.

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Ti3C2MXenes modified with in situ grown carbon nanotubes for enhanced electromagnetic wave absorption properties

Journal of Materials Chemistry C ◽

10.1039/c6tc05226f ◽

2017 ◽

Vol 5 (16) ◽

pp. 4068-4074 ◽

Cited By ~ 129

Author(s):

Xinliang Li ◽

Xiaowei Yin ◽

Meikang Han ◽

Changqing Song ◽

Hailong Xu ◽

...

Keyword(s):

Carbon Nanotubes ◽

Electromagnetic Wave ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Chemical Vapor ◽

Absorption Properties ◽

Electromagnetic Wave Absorption ◽

Catalytic Chemical Vapor Deposition ◽

Wave Absorption

Ti3C2TxMXenes modified within situgrown carbon nanotubes (CNTs) are fabricatedviaa simple catalytic chemical vapor deposition (CVD) process.

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Test Methods for Mechanical Properties of Structural Adhesives

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.814 ◽

2010 ◽

Vol 97-101 ◽

pp. 814-817 ◽

Cited By ~ 1

Author(s):

Jun Deng

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Shear Strength ◽

Elastic Modulus ◽

Butt Joint ◽

Test Methods ◽

Joint Specimen ◽

Lap Shear ◽

Better Than

One of the greatest drawbacks to predicting the behaviour of bonded joints has been the lack of reliable data on the mechanical properties of adhesives. In this study, methods for determining mechanical properties of structural adhesive were discussed. The Young’s modulus, Poisson’s ratio and tensile strength of the adhesive were tested by dogbone specimens (bulk form) and butt joint specimens (in situ form). The shear modulus and shear strength were test by V-notched specimens (bulk form) and thick adherend lap-shear (TALS) joint specimens (in situ form). The test results show that the elastic modulus provided by the manufacturer is too low, the dogbone specimen is better than the butt joint specimen to test the tensile strength and elastic modulus and the TALS joint specimen is better than the V-notched specimen to test the shear strength.

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