Abstract A suitable thermal environment is important for the economy, society and public health in urban areas. However, understanding of relationship between heat island (UHI) effect background temperature (T-UHI) very limited. In this study, UHI induced by urbanization megacity Beijing was investigated using weather research forecasting model. Urban expansion heatwaves both considerably enhanced over areas summer. The strengthened during heatwave period can be clearly explained positive...

Abstract The High-Intensity Heavy-ion Accelerator Facility (HIAF) is a leading platform for heavy-ion scientific research in China with advanced beam current indicators. In these experiments, Low-Gain Avalanche Detectors (LGAD) have become the detector of choice, and readout circuit LGAD requires time-to-digital converters (TDC) to convert time measurement results into digital signals. Since smaller pixel area conducive improving positional resolution spatial resolution, TDC using...

We present an approach for the highly sensitive photon detection based on quantum dots (QDs) operating at temperature of 77K. The structure is AlAs∕GaAs∕AlAs double barrier resonant tunneling diode combined with a layer self-assembled InAs QDs (QD-RTD). A rate 115 photons per second had induced 10nA photocurrent in this structure, corresponding to photoexcited carrier multiplication factor 107. This high achieved by dot memory effect and tuning QD-RTD structure.

There is an increasing demand for a land surface temperature (LST) dataset with both fine spatial and temporal resolutions due to the key role of LST in Earth’s land–atmosphere system. Currently, technique most commonly used meet thermal infrared (TIR) remote sensing. However, cloud contamination interferes TIR transmission through atmosphere, limiting potential space-borne sensors provide complete spatio-temporal coverage. To solve this problem, we developed two-step integrated method to:...

This article presents a review of some latest advances in rheology measuring techniques. Consideration is given to the modification and approaches conventional techniques also development specialty instruments. A number sensing technologies such as nuclear-magnetic-resonance imaging ultrasonic pulse Doppler mapping have recently been adopted produce viscoelastic measurements for both Newtonian non-Newtonian materials. The working principles these their applications are described. Other...

This paper presents an AC-coupled, incremental analog-to-digital converter (ADC) based on two-step quantization for high-density implantable neural recording. It achieves a rail-to-rail electrode DC offset (EDO) rejection, low noise, small area, and power consumption. Fabricated in 180 nm CMOS process, the prototype ADC high input impedance, 24 mVpp linear range, 58.9 dB signal-to-noise distortion ratio (SNDR). Its core circuit has consumption of 12 μW area 0.0192 mm2. The referred-to-input...

This paper presents a system for simultaneous wireless power and data transfer (SWPDT) over single inductive link. We design the frequency-splitting link to address trade-off between high efficiency (PTE) rate (DR). An active rectifier is designed conversion efficiency. Forward communication based on frequency-shift keying (FSK) modulation support DR transmission while delivering uninterrupted power. Moreover, we proposed low-power FSK demodulation circuits further improve energy of...

Noise-shaping (NS) successive approximation register (SAR) analog-to-digital converters (ADCs) using passive integrators have drawn increasing attention owing to their simplicity and power efficiency. However, a capacitor array with integrator result in huge number of unit capacitors consumption. This paper presents second-order fully NS-SAR ADC segmented hybrid switching procedure. We use most-significant-bit(MSB) sampling-segmented reduce the capacitors, common mode voltage(VCM)-based...

A field effect enhanced quantum dot resonant tunneling diode is proposed and demonstrated to improve the detection dynamic range for low light imaging application. Using cross-wire device geometry, a lateral two dimensional electron gas (2DEG) current formed in well channel together with normal modulation. peak photoresponsivity of order 1010 A/W saturation level up 105 photons per second at 77 K are achieved when 2DEG makes main photocurrent contribution.

Micro-Pirani vacuum sensors usually operate at hundreds of microwatts, which limits their application in battery-powered sensor systems. This paper reports a diode-based, low power consumption micro-Pirani that has high sensitivity. Optimizations to the were made regarding two aspects. On one hand, greater temperature coefficient was obtained without increasing by taking advantage series diodes; on other structure and geometries redesigned enlarge variation. After that, fabricated tested....

The 256×1 linear array of multiple quantum wells infrared photodetector (QWIP) is designed and fabricated for the peak response wavelength at λ P = 14.6 μm. spectral width bigger than 2.2 two-dimensional (2D) diffractive coupling grating has been formed on top QWIP photosensitive pixel radiation to detective layers. performance device V B 3 T 45 K responsibility 4.28×10−2 (A/W), blackbody detectivity D b* 5.14×109 (cm·Hz1/2/W), * 4.24× 1010 (cm·Hz1/2/W). sensor pixels are connected with CMOS...

Environmental models have been regarded as a key method to study the complex conditions of environmental systems. Sensitivity analysis (SA) is vital step, which aims investigate impact model inputs on outputs. During application models, SA plays significant role in simplifying structure and improving precision reliability simulation. Consequently, identification sensitivity parameters an important issue. This paper provides introduction functions models. Mathematical theories methods used...

We have studied experimentally and theoretically the effects of series parallel resistances on current-voltage (I-V) characteristics resonant tunneling diode (RTD) in format a small-area freestanding air bridge. It has been shown by standard quantum mechanical considerations that I-V consists simple current peak (without bistability) voltage at is quite low, whereas experiments show not only much high current-peak voltage, but also bistability. Furthermore, experimental peak-to-valley ratio...

It was shown experimentally that charging InAs quantum dots (QDs) embedded in a small-area GaAs/AlAs double-barrier resonant tunneling diode (RTD) effectively modified the carrier transport properties of RTD. By adopting and comparing one-dimensional plane-wave three-dimensional (3D) wave-packet theories we show electron transports QDRTD device are form 3D wave packets, which strongly affected by long-range Coulomb potential induced charged QDs. This explains well experimental data indicates...

Uncooled infrared (IR) detectors are widely used in industry and civil imaging fields. Moreover, thermal parameters have a strong impact on detectors’ performance, especially under the trend towards higher spatial resolution. Therefore, evaluating them is important for improvement. In this work, inspired by traditional optical frequency-domain concept, self-test method of an uncooled IR focal plane array (FPA) proposed. Utilizing frequency-adjustable pulsed Joule heating power...

Thermopile infrared (IR) sensors based on the thermoelectric effect are widely applied in industrial and civil fields. Researchers urgently need to develop a technique for situ online extraction of sensor's thermal parameters, order allow better analysis performance improve its structure. In this work, pulse-voltage-based self-test method is proposed. The pulse voltage can be generated easily, only few data points required, with simple processing. measured results close theoretical values...

In this article, an active rectifier with pulse width modulation (PWM) mode on- and off-delay compensation technique is proposed. Conventional delay modes: current mode, voltage delay-based are discussed respectively. Also, the adaptive potential disturbance problems analyzed. To achieve wide flexible range, proposed adopts methods to eliminate off-delay. Moreover, PWM feedback loops built compensate circuit delays adaptively under various process, voltage, temperature (PVT) loading...