The modelling of volumetric errors of machine tools has been widely used by the method of Homogeneous Transformation Matrix (HTM) based on rigid body kinematics analysis for a long time. Without ...spindle induced errors and thermal errors, to establish a closed-loop HTM for a three-axis machine tool, the total of 21 geometric errors are the primary elements to be known. It is well known that the measured points of translational errors are directly related to the volumetric error at the tool cutting point through rigid body kinematics. In the generalized HTM method, however, this relationship is missing. This report, therefore, proposes a new comprehensive approach to formulate the volumetric errors based on the famous Abbe principle in order to derive the error term in the motion direction, and Bryan principle to derive the error terms in orthogonal to the motion direction. The proposed methodology is simple in concept, rational in physical meaning and easy in implementation. Experimental results, including faster multi-degree-of-freedom error measurements, volumetric error analysis and compensation on a testbed of small machine tool, validate the correctness and effectiveness of this method.
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•This new method is more physically reasonable than the popular Homogeneous Transformation Matrix method.•An embedded sensor system for detecting 5-DOF geometric errors of a linear stage has been developed and equipped into an investigated small NC machine tool.•Through error measurement and compensation experiments, the correctness and feasibility of this new model have been verified.
The 3D vertical ferroelectric tunneling junction (FTJ) of bilayer antiferroelectric (AFE) Hf 1-x Zr x O 2 (HZO) and Al 2 O 3 has been demonstrated for NAND-compatible feasibility. A bilayer-type FTJ ...is explored for the designs of the dielectric interlayer Al 2 O 3 0 nm to 4 nm and the ferroelectric type, while the current mechanism is revealed. The multilevel AFE-FTJ is exhibited for both the Program and Erase operations and realizes a synaptic device. High-density emerging memory and computing-in-memory (CiM) are in high demanded for the future era and can be feasible by the proposed vertical FTJ.
Asymmetric field cycling recovery (AFCR) with alternating opposite low <inline-formula> <tex-math notation="LaTeX">{E} </tex-math></inline-formula>-field cycling is proposed to restore a fatigued ...ferroelectric (FE) capacitor and is experimentally demonstrated for up to <inline-formula> <tex-math notation="LaTeX">10^{{12}} </tex-math></inline-formula> switching cycles, thereby extending the endurance of FeRAM. Positive and negative asymmetric minor loops (AmLs) with AFCR exhibit nondegradation and complete restoration of <inline-formula> <tex-math notation="LaTeX">\Delta 2{P}_{\text {r}} </tex-math></inline-formula> toward unlimited endurance operation. Furthermore, an FE random access memory (FeRAM) array circuit with an inverting amplifier is designed to simultaneously execute Write/Read and Recovery procedures via the AFCR scheme.
Opposite polarity cycling recovery (OPCR) is proposed to completely restore a fatigued antiferroelectric (AFE) capacitor back to its initial state, thereby extending the endurance number of switching ...cycles for AFE-RAM. A comprehensive model exclusive to AFE with unipolar cycling is revealed to achieve unlimited endurance, and the unipolar cycling with OPCR is experimentally demonstrated to accumulate Formula Omitted cycles, while achieving the nondegradation and complete restoration of the remnant polarization (Formula Omitted). Furthermore, the proposed OPCR achieves a recovery time ratio of 0% (Formula Omitted), which indicates no extra time to spend for the recovery procedure.
The bilayer-based Antiferroelectric Tunneling Junction (AFTJ) with ferroelectric (FE) HfZrO 2 (HZO) and dielectric (DE) Al 2 O 3 demonstrates a current ratio of <inline-formula> <tex-math ...notation="LaTeX">> 100\times </tex-math></inline-formula>, a TER (tunneling electroresistance) of <inline-formula> <tex-math notation="LaTeX">> 50\times </tex-math></inline-formula>, multilevel states, <inline-formula> <tex-math notation="LaTeX">> 10^{4} </tex-math></inline-formula> sec retention, and a cycling endurance as high as 10 8 . The concept of tunneling current through DE in an antiferroelectric (AFE) system enhances the capacity to modulate the current/TER ratio and makes the AFTJ feasible for low-power crossbar eNVM (embedded nonvolatile memory) applications.
Asymmetric Field Cycling Recovery (AFCR) with a low E-field is proposed for the first time to extend the endurance cycles of a ferroelectric (FE) capacitor and is experimentally demonstrated for 200 ...periods and accumulated to 10 12 switching cycles. Positive and negative Asymmetric minor loops (AmL) with AFCR achieve the nondegradation and complete restoration of \triangle 2 \mathrm{P}_{\mathrm{r}} toward the prospect of unlimited operation. Furthermore, an FeRAM array circuit with an inverting amplifier is designed to execute the Write/Read and Recovery procedures simultaneously by AFCR scheme.
CeOs_{4}Sb_{12} (COS) and PrOs_{4}Sb_{12} (POS) are two representative compounds that provide the ideal vantage point to systematically study the physics of multi-f-electron systems. COS with Ce ...4f^{1}, and POS with Pr 4f^{2} configurations show distinct properties of Kondo insulating and heavy fermion superconductivity, respectively. We unveiled the underlying microscopic origin by angle-resolved photoemission spectroscopy studies. Their eV-scale band structure matches well, representing the common characters of conduction electrons in ROs_{4}Sb_{12} systems (R=rare earth). However, f electrons interact differently with conduction electrons in COS and POS. Strong hybridization between conduction electrons and f electrons is observed in COS with band dependent hybridization gaps, and the development of a Kondo insulating state is directly revealed. Although the ground state of POS is a singlet, finite but incoherent hybridization exists, which can be explained by the Kondo scattering with the thermally excited triplet crystalline electric field state. Our results help us to understand the intriguing properties in COS and POS, and provide a clean demonstration of the microscopic differences in heavy fermion systems with 4f^{1} and 4f^{2} configurations.
CeOs4Sb12 (COS) and PrOs4 Sb12 (POS) are two representative compounds that provide the ideal vantage point to systematically study the physics of multi- f -electron systems. COS with Ce 4f1, and POS ...with Pr 4f2 configurations show distinct properties of Kondo insulating and heavy fermion superconductivity, respectively. We unveiled the underlying microscopic origin by angle-resolved photoemission spectroscopy studies. Their eV-scale band structure matches well, representing the common characters of conduction electrons in ROs4Sb12 systems ( R = rare earth ). However, f electrons interact differently with conduction electrons in COS and POS. Strong hybridization between conduction electrons and f electrons is observed in COS with band dependent hybridization gaps, and the development of a Kondo insulating state is directly revealed. Although the ground state of POS is a singlet, finite but incoherent hybridization exists, which can be explained by the Kondo scattering with the thermally excited triplet crystalline electric field state. Our results help us to understand the intriguing properties in COS and POS, and provide a clean demonstration of the microscopic differences in heavy fermion systems with 4f1 and 4f2 configurations.
Experimental insights into a reverse switching charge for antiferroelectric (AFE) Hf 0.1 Zr 0.9 O 2 are validated by pulse measurement and capacitance-voltage (C-V). The difference between saturation ...polarization (<inline-formula> <tex-math notation="LaTeX">\text{P}_{\mathrm {S}} </tex-math></inline-formula>) and remnant polarization (<inline-formula> <tex-math notation="LaTeX">\text{P}_{\mathrm {r}} </tex-math></inline-formula>) plays an important role in the model and is confirmed by the steep and gradual slope of the P-V loop, which is made by AFE and antiferroelectric-dielectric (AFE-DE), respectively. AFE capacitor yield far superior released charge (<inline-formula> <tex-math notation="LaTeX">\text{Q}_{\mathrm {D}} </tex-math></inline-formula>) than capacitor of AFE-DE bilayers due to strong reverse switching of <inline-formula> <tex-math notation="LaTeX">\text{P}_{\mathrm {S}} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">\text{P}_{\mathrm {r}} </tex-math></inline-formula> difference. A nonhysteretic <inline-formula> <tex-math notation="LaTeX">\text{Q}_{\mathrm {D}} </tex-math></inline-formula> scheme is proposed by alternating bipolar AFE operation without a DE to achieve a bidirectional enhancement. This work demonstrates an experimental <inline-formula> <tex-math notation="LaTeX">\text{Q}_{\mathrm {D}} </tex-math></inline-formula> enhancement by an AFE system and supports the reverse switching concept.
Diagnosis of hypertension in adolescents is complicated because blood pressure values vary with age, gender and height. How can we simplify the diagnostic criteria for hypertension in adolescents? In ...2006, anthropometric measurements were assessed in a cross-sectional population-based study of 3136 Han adolescents aged 13-17 years. Hypertension was defined according to the 2004 National High Blood Pressure Education Program Working Group definition. The following equations for blood pressure-to-height ratio (BPHR) were used: systolic BPHR (SBPHR)=SBP (mm Hg)/height (cm) and diastolic BPHR (DBPHR)=DBP (mm Hg)/height (cm). Receiver-operating characteristic curve analyses were performed to assess the accuracy of SBPHR and DBPHR as diagnostic tests for elevated systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. After the cutoff points were determined, hypertension was defined by SBPHR/DBPHR, and the sensitivity and specificity were calculated. The accuracy of SBPHR and DBPHR (assessed by area under the curve) for identifying elevated SBP and DBP was >0.85 (0.989-1.000). The optimal thresholds of SBPHR/DBPHR for defining hypertension (stages 1 and 2) were 0.75/0.48 for boys and 0.78/0.51 for girls, and for defining hypertension (stage 2) were 0.81/0.57 for boys and 0.84/0.63 for girls. In identifying hypertension, the sensitivity and specificity were both >90% (91.0-99.1%). In identifying stage 2 hypertension, when the sensitivity was 100%, the specificity was 98.6% for boys and 99.1% for girls. BPHR is a simple, accurate and non-age-dependent index for screening hypertension in Han adolescents, especially for stage 2 hypertension.
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