where A represents the magnetic vector potential, is an integral of the hydromagnetic equations. This -integral made it possible to formulate a variational principle for the force-free magnetic fields. The integral expresses the fact that motions cannot transform a given field in an entirely arbitrary different field, if the conductivity of the medium isconsidered infinite. In this paper we shall show that the full set of hydromagnetic equations admit five more integrals, besides the energy integral, if dissipative processes are absent. These integrals, as we shall presently verify, are I2 =fbHvdV, (2)

Proceedings of the National Academy of Sciences

'Blogging' - a contraction of the term 'web logging' - is perhaps best described as a form of micro-publishing. Easy to use, from any Internet connection point, blogging has become firmly established as a web based communications tool. The blogging phenomenon has evolved from its early origin as a medium for the publication of simple, online personal diaries, to the latest disruptive technology, the 'killer app' that has the capacity to engage people in collaborative activity, knowledge sharing, reflection and debate (Hiler, 2003). Many blogs have large and dedicated readerships, and blog clusters have formed linking fellow bloggers in accordance with their common interests. 
This paper explores the potential of blogs as learning spaces for students in the higher education sector. It refers to the nascent literature on the subject, explores methods for using blogs for educational purposes in university courses (eg. Harvard Law School), and records the experience of the Brisbane Graduate School of Business at Queensland University of Technology, with its 'MBA blog'. The paper concludes that blogging has the potential to be a transformational technology for teaching and learning.

Exploring the use of blogs as learning spaces in the higher education sector

Neuromorphic computers comprised of artificial neurons and synapses could provide a more efficient approach to implementing neural network algorithms than traditional hardware. Recently, artificial neurons based on memristors have been developed, but with limited bio-realistic dynamics and no direct interaction with the artificial synapses in an integrated network. Here we show that a diffusive memristor based on silver nanoparticles in a dielectric film can be used to create an artificial neuron with stochastic leaky integrate-and-fire dynamics and tunable integration time, which is determined by silver migration alone or its interaction with circuit capacitance. We integrate these neurons with nonvolatile memristive synapses to build fully memristive artificial neural networks. With these integrated networks, we experimentally demonstrate unsupervised synaptic weight updating and pattern classification.

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Fully memristive neural networks for pattern classification with unsupervised learning

Solid-state electronics

There has been an enormous infusion of new ideas in the field of solar cells over the last 15 years; discourse on energy transfer has gotten much richer, and nanostructures and nanomaterials have revolutionized the possibilities for new technological developments. However, solar energy cannot become ubiquitous in the world's power markets unless it can become economically competitive with legacy generation methods such as fossil fuels. The new edition of Dr. Stephen Fonash's definitive text points the way toward greater efficiency and cheaper production by adding coverage of cutting-edge topics in plasmonics, multi-exiton generation processes, nanostructures and nanomaterials such as quantum dots. This book's new structure improves readability by shifting many detailed equations to appendices, and balances the first edition's semiconductor coverage with an emphasis on thin-films. Further, it now demonstrates physical principles with simulations in the well-known AMPS computer code developed by the author. This classic text is now updated with new advances in nanomaterials and thin films that point the way to cheaper, more efficient solar energy production and, many of the detailed equations from the first edition have been shifted to appendices in order to improve readability. It carries important theoretical points are now accompanied by concrete demonstrations via included simulations created with the well-known AMPS computer code.

太阳电池器件物理 = Solar cell device physics

Integrated Development Environment

In this study, the in situ sol–gel method has been deployed to prepare the titanium dioxide/multiwalled carbon nanotubes (TiO2/MWCNTs) nanocomposite (NCs) powders with varying content of MWCNTs (0....

/pdf/structural-and-optical-properties-of-nanocrystalline-tio2-1ywu9u9udi.pdf

Structural and Optical Properties of Nanocrystalline TiO2 with Multiwalled Carbon Nanotubes and Its Photovoltaic Studies Using Ru(II) Sensitizers.

Bipolar resistive switching and memristive properties of hydrothermally synthesized TiO2 nanorod array: Effect of growth temperature

The unique nonlinear relationship between charge and magnetic flux along with the pinched hysteresis loop in I-V plane provide memory with resistance combinations of attribute to Memristor which lead to their novel applications in non volatile memory, nonlinear dynamics, analog computations and neuromorphic biological systems etc. The present paper reports development of Ag/WO3/ITO thin film memristor device using spray pyrolysis method. The structural, morphological and electrical properties of the thin film memristor device are further characterized using x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and semiconductor device analyzer. The memristor is simulated using linear dopent drift model to ascertain the theoretical and experimental conformations. For the simulation purpose, the width of doped region (w) limited to the interval [0, D] is considered as a state variable along with the window function characterized by the equation f (x) = w (1 − w). The reported memristor device exhibits the symmetric pinched hysteresis loop in I-V plane within the low operating voltage (±1 V).

Development of Ag/WO 3 /ITO thin film memristor using spray pyrolysis method

As leading sensors of ambient conditions, temperature sensors act as important sensing devices. They are essential in a large variety of products. A variety of temperature sensors is available on the market to meet specific application needs. The most common include thermocouples, resistive temperature detectors (RTD), thermistors, and silicon‐based sensors. But of all of these temperature sensors, the thermistor is the only one that holds the esteemed position owing to its high sensitivity, accuracy and low cost. Temperature measurement systems utilizing thermistors are less expensive to produce because few additional components are required, especially in the present era of embedded systems. With the recent advances in manufacturing techniques, the drawbacks of conventional thermistors, like aging, interchangeability, unreliability etc., are almost eliminated. Booming demand for DVD players and portable communication appliances have pushed up the popularity of NTC thermistors. This article reviews the latest trends in thermistor manufacturing and the associated applications.

Rajanish K. Kamat

Papers

Integrated Development Environment

Structural and Optical Properties of Nanocrystalline TiO2 with Multiwalled Carbon Nanotubes and Its Photovoltaic Studies Using Ru(II) Sensitizers.

Bipolar resistive switching and memristive properties of hydrothermally synthesized TiO2 nanorod array: Effect of growth temperature

Development of Ag/WO 3 /ITO thin film memristor using spray pyrolysis method

Thermistors – in search of new applications, manufacturers cultivate advanced NTC techniques