Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capit...Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capital and the social capital structure.The results show the following:first,social capital can expand the household income gap,and the effect of this index on the household income gap is 7.54%.Second,the indexes of the social capital dimension can expand the household income gap,and the structural effects of the household income gap on social networks,social trust,and social participation are 3.17%,3.64%,and 0.65%,respectively.Third,no dimension of the path is the same as the effect on the household income gap.展开更多
In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a b...In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a block design. This paper shows that a circular block design neighbor-balanced at distances up toγ≤k - 1, where k is the block size, is universally optimal for total effects under the linear models containing the neighbor effects at distances up toγamong the class of all circular binary block designs. Some combinatorial approaches to constructing these circular block designs neighbor-balanced at distances up to k - 1 are provided.展开更多
For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be ev...For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD （chemical oxygen demand）, TSS （total suspend solid）, TP （total phosphorus）, TN （total nitrogen） and BOD （biochemical oxygen demand）. The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters： rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 （mass first flush ratio） and FF30 （first 30% of runoff volume） can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs （best management practices） facilities.展开更多
Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific d...Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific discovery approach.The total ionizing dose(TID)effects usually cause gain degradation of bipolar junction transistors(BJTs),leading to functional failures of bipolar integrated circuits.Currently,many experiments of TID effects on BJTs have been conducted at different laboratories worldwide,producing a large amount of experimental data which provides a wealth of information.However,it is difficult to utilize these data effectively.In this study,we proposed a new artificial neural network(ANN)approach to analyze the experimental data of TID effects on BJTs An ANN model was built and trained using data collected from different experiments.The results indicate that the proposed ANN model has advantages in capturing nonlinear correlations and predicting the data.The trained ANN model suggests that the TID hardness of a BJT tends to increase with base current I.A possible cause for this finding was analyzed and confirmed through irradiation experiments.展开更多
Annular gate nMOSFETs are frequently used in spaceborne integrated circuits due to their intrinsic good capability of resisting total ionizing dose （TID） effect. However, their capability of resisting the hot carrie...Annular gate nMOSFETs are frequently used in spaceborne integrated circuits due to their intrinsic good capability of resisting total ionizing dose （TID） effect. However, their capability of resisting the hot carrier effect （HCE） has also been proven to be very weak. In this paper, the reason why the annular gate nMOSFETs have good TID but bad HCE resistance is discussed in detail, and an improved design to locate the source contacts only along one side of the annular gate is used to weaken the HCE degradation. The good TID and HCE hardened capability of the design are verified by the experiments for I/O and core nMOSFETs in a 0.18 μm bulk CMOS technology. In addition, the shortcoming of this design is also discussed and the TID and the HCE characteristics of the replacers （the annular source nMOSFETs） are also studied to provide a possible alternative for the designers.展开更多
The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors （nMOSFETs） is investigated. Experimental results show that hot-carrier degradati...The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors （nMOSFETs） is investigated. Experimental results show that hot-carrier degradations on ir- radiated narrow channel nMOSFETs are greater than those without irradiation. The reason is attributed to radiation-induced charge trapping in shallow trench isolation （STI）. The electric field in the pinch-off region of the nMOSFET is enhanced by radiation-induced charge trapping in STI, resulting in a more severe hot-carrier effect.展开更多
This paper studies the total ionizing dose radiation effects on MOS （metal-oxide-semiconductor） transistors with normal and enclosed gate layout in a standard commercial CMOS （compensate MOS） bulk process. The lea...This paper studies the total ionizing dose radiation effects on MOS （metal-oxide-semiconductor） transistors with normal and enclosed gate layout in a standard commercial CMOS （compensate MOS） bulk process. The leakage current, threshold voltage shift, and transconductance of the devices were monitored before and after γ-ray irradiation. The parameters of the devices with different layout under different bias condition during irradiation at different total dose are investigated. The results show that the enclosed layout not only effectively eliminates the leakage but also improves the performance of threshold voltage and transconductance for NMOS （n-type channel MOS） transistors. The experimental results also indicate that analogue bias during irradiation is the worst case for enclosed gate NMOS. There is no evident different behaviour observed between normal PMOS （p-type channel MOS） transistors and enclosed gate PMOS transistors.展开更多
The synergistic effect of total ionizing dose（TID） on single event effect（SEE） in SiGe heterojunction bipolar transistor（HBT） is investigated in a series of experiments. The SiGe HBTs after being exposed to 60 C...The synergistic effect of total ionizing dose（TID） on single event effect（SEE） in SiGe heterojunction bipolar transistor（HBT） is investigated in a series of experiments. The SiGe HBTs after being exposed to 60 Co g irradiation are struck by pulsed laser to simulate SEE. The SEE transient currents and collected charges of the un-irradiated device are compared with those of the devices which are irradiated at high and low dose rate with various biases. The results show that the SEE damage to un-irradiated device is more serious than that to irradiated SiGe HBT at a low applied voltage of laser test. In addition, the g irradiations at forward and all-grounded bias have an obvious influence on SEE in the SiGe HBT, but the synergistic effect after cutting off the g irradiation is not significant. The influence of positive oxide-trap charges induced by TID on the distortion of electric field in SEE is the major factor of the synergistic effect. Moreover, the recombination of interface traps also plays a role in charge collection.展开更多
Because of the discrete charge storage mechanism, charge trapping memory（CTM） technique is a good candidate for aerospace and military missions. The total ionization dose（TID） effects on CTM cells with Al2O3/HfO2/...Because of the discrete charge storage mechanism, charge trapping memory（CTM） technique is a good candidate for aerospace and military missions. The total ionization dose（TID） effects on CTM cells with Al2O3/HfO2/Al2O3（AHA） high-k gate stack structure under in-situ 10 keV x-rays are studied. The C-V characteristics at different radiation doses demonstrate that charge stored in the device continues to be leaked away during the irradiation,thereby inducing the shift of flat band voltage（V（fb））. The dc memory window shows insignificant changes, suggesting the existence of good P/E ability. Furthermore, the physical mechanisms of TID induced radiation damages in AHA-based CTM are analyzed.展开更多
The analytical method of total resource reallocation effect is an evolution of the analytical method of the factors of economic growth. Since the marketization reform in China in 1978, market mechanism has played a mo...The analytical method of total resource reallocation effect is an evolution of the analytical method of the factors of economic growth. Since the marketization reform in China in 1978, market mechanism has played a more and more important role in resource allocation, and Chinese economy has developed greatly, which is called "the Chinese Miracle". This paper analyzes the economic growth in China from 1978 to 2004 with the analytical method of total resource reallocation effect. The result shows that the annual growth rate of total resource reallocation effect was 0.2%, which was 5.1% of the comprehensive productivity and 0.21% of the gross output growth, i.e. the total resource allocation played a weak role in the economic growth in China. When analyzing it in Chenery's multinational model, we find that Chinese comprehensive productivity growth rate was higher than that in all the income phases of the model, but the total resource allocation effect was obviously lower than that in all the income phases of the model. It indicates that the total resource allocation in China has a great potential, and that to accelerate marketization reform is one of the important issues for Chinese economic development.展开更多
We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is ...We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is demonstrated numerically that electrons emitting from a point source in the n ＋ region will experience total internal reflection through the interface of the junction. The reflection becomes stronger and the transmission becomes weaker with decrease of the local potential in the right graphene ribbon. It is also found that when a nonideal interface is considered in the junction, the electron-reflection effect is enhanced due to interracial backseattering.展开更多
In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiat...In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiation of three bias conditions. It has been found experimentally that back gate threshold shift and leakage current were greatly reduced during irradiation for hardened transistors, comparing to control ones. It has been confirmed that the improvement of total-dose properties of SOI devices is attributed to the silicon nanocrystals (nanoclusters) in buried oxides introduced by ion implantation.展开更多
The total ionizing dose radiation effects in the polycrystalline silicon thin film transistors are studied. Transfer characteristics, high-frequency capacitance-voltage curves and low-frequency noises (LFN) are measur...The total ionizing dose radiation effects in the polycrystalline silicon thin film transistors are studied. Transfer characteristics, high-frequency capacitance-voltage curves and low-frequency noises (LFN) are measured before and after radiation. The experimental results show that threshold voltage and hole-field-effect mobility decrease, while sub-threshold swing and low-frequency noise increase with the increase of the total dose. The contributions of radiation induced interface states and oxide trapped charges to the shift of threshold voltage are also estimated. Furthermore, spatial distributions of oxide trapped charges before and after radiation are extracted based on the LFN measurements.展开更多
The influences of total ionizing dose （TID） on the single event effect （SEE） sensitivity of 34-nm and 25-nm NAND flash memories are investigated in this paper. The increase in the cross section of heavy-ion single...The influences of total ionizing dose （TID） on the single event effect （SEE） sensitivity of 34-nm and 25-nm NAND flash memories are investigated in this paper. The increase in the cross section of heavy-ion single event upset （SEU） in memories that have ever been exposed to TID is observed, which is attributed to the combination of the threshold voltage shifts induced by 7-rays and heavy ions. Retention errors in floating gate （FG） cells after heavy ion irradiation are observed. Moreover, the cross section of retention error increases if the memory has ever been exposed to TID. This effect is more evident at a low linear energy transfer （LET） value. The underlying mechanism is identified as the combination of the defects induced by 7-rays and heavy ions, which increases the possibility to constitute a multi-trap assisted tunneling （m- TAT） path across the tunnel oxide.展开更多
Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facil...Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.展开更多
<b>Background & Aims:</b> The multimodal analgesia provides superior pain relief and reduces opioid consumption and its side effects. Gabapentin has been used successfully in multi-modal analgesia in d...<b>Background & Aims:</b> The multimodal analgesia provides superior pain relief and reduces opioid consumption and its side effects. Gabapentin has been used successfully in multi-modal analgesia in different doses. We designed a double-blind randomized control trial to find the minimal effective dose of gabapentin in multimodal analgesia for postoperative pain following total abdominal hysterectomy. <b>Material & Methods:</b> After informed consent, total of 87 patients were randomly assigned to A, B & C groups to receive gabapentin orally 300 mg, 600 mg, and 900 mg respectively one to two hours before surgery. Postoperatively pain was managed by patient-controlled analgesia (PCA) using pethidine. Pain score, opioid consumption, and side effects of gabapentin were monitored. Rescue analgesia was given and monitored. <b>Results:</b> There was no statistically significant difference among the groups with respect to age, weight, height, pethidine consumption, and rescue analgesia. Mean pain scores were statistically insignificant at baseline, 8, 12, and 24 hours postoperatively. Only at 4 hours, the highest pain score (mean) was found in group A, which is statistically significant. The side effects of gabapentin like nausea, vomiting, somnolence, and dizziness were also statistically insignificant. <b>Conclusion:</b> A single preoperative oral gabapentin 300 mg was found to be minimal effective dose in multimodal analgesic regimen for reducing post-operative pain and analgesic requirement following total abdominal hysterectomy.展开更多
This study developed a population pharmacokinetic model for sodium tanshinone IIA sulfonate(STS) in healthy volunteers and coronary heart disease(CHD) patients in order to identify significant covariates for the pharm...This study developed a population pharmacokinetic model for sodium tanshinone IIA sulfonate(STS) in healthy volunteers and coronary heart disease(CHD) patients in order to identify significant covariates for the pharmacokinetics of STS. Blood samples were obtained by intense sampling approach from 10 healthy volunteers and sparse sampling from 25 CHD patients, and a population pharmacokinetic analysis was performed by nonlinear mixed-effect modeling. The final model was evaluated by bootstrap and visual predictive check. A total of 230 plasma concentrations were included, 137 from healthy volunteers and 93 from CHD patients. It was a two-compartment model with first-order elimination. The typical value of the apparent clearance(CL) of STS in CHD patients with total bilirubin(TBIL) level of 10 μmol×L^(–1) was 48.7 L×h^(–1) with inter individual variability of 27.4%, whereas that in healthy volunteers with the same TBIL level was 63.1 L×h^(–1). Residual variability was described by a proportional error model and estimated at 5.2%. The CL of STS in CHD patients was lower than that in healthy volunteers and decreased when TBIL levels increased. The bootstrap and visual predictive check confirmed the stability and validity of the final model. These results suggested that STS dosage adjustment might be considered based on TBIL levels in CHD patients.展开更多
Background Data on retrograde recanalization of epicardial collateral channels in patients with chronic total occlusion(CTO) undergoing percutaneous coronary intervention(PCI) are limited. Fearing about the complicati...Background Data on retrograde recanalization of epicardial collateral channels in patients with chronic total occlusion(CTO) undergoing percutaneous coronary intervention(PCI) are limited. Fearing about the complications of perforation, few CTO patients have chosen retrograde recanalization of epicardial collateral channels. Methods A retrospective analysis was conducted in this study. We followed up eligible patients who underwent continuous CTO via epicardial CCS from August 2011 to October 2018 in our center, and analyzed the detailed clinical baseline and angiographic data, surgical success rate and hospital complications to determine the efficacy and safety. The Cox model was used to compare major adverse cardiac events(MACE) and related co-variables between CTO patients with epicardial CCS perforation and non-perforated PCI patients. Results The study enrolled 191 patients with epicardial CCs PCI of CTO and the long term follow-up time was 24.03±19.18 months.Successful CCs PCI of CTO was achieved in 161(84.8 %) patients. Procedural collateral perforation occurred in23(12.0%) patients. MACEs occurred in 18 patients(9.4%) at 1-year follow-up. Kaplan-Meier curves showed no significant difference in MACEs between perforating recanalization of CCs PCI of CTO and non-perforating PCI of CTO.( adjusted hazard ratios(HR): 0.467; 95% confidence intervals(CI): 0.13 to 1.69, P=0.245). The multivariate Cox regression analysis identified the Werner score=0/1(HR: 5.80; 95% CI: 1.89 to 17.8; P=0.002) as significant independent predictors of perforation of CCs PCI of CTO. Conclusions The major complication of the procedure is collateral perforation. Recanalization of CTOs through epicardial collateral channel is safe and effective. It may be a available choice for recanalization of complex CTO.[S Chin J Cardiol 2019;20(1):37-43]展开更多
Background Aortic dissection（AD） is a life-threatening surgical emergency. Total arch replacement combined with stent trunk has gradually become the standard procedure for De Bakey type Ⅰ AD in China, but the compl...Background Aortic dissection（AD） is a life-threatening surgical emergency. Total arch replacement combined with stent trunk has gradually become the standard procedure for De Bakey type Ⅰ AD in China, but the complication and mortality rates are still relatively high due to surgical technical difficulties and complexity. In principle, AD should be treated with emergency surgery once the diagnosis is confirmed, but the operation time varies greatly in China due to the restriction of medical conditions. Therefore, analyzing and comparing the surgical mortality and complications rate between acute and chronic phase may facilitate the clinicians to comprehensively evaluate the patient＇s condition, and thus select an appropriate operation timing. Methods A total of330 De Bakey type Ⅰ AD patients admitted and treated with total arch replacement combined with stent trunk procedure in Guangdong Cardiovascular Institute from Jan 2010 to Jan 2014 were retrospectively analyzed. According to whether the onset was longer than 2 w, patients were divided into acute phase group and chronic phase group. There were 231 cases in acute phase group（≤ 2 w）, and the average length from onset to operation was 5.6± 3.8 d; while 99 cases in chronic phase group（〉 2 w）, and the average length from onset to operation was 20.6 ±14.7 d. Results The total mortality rate was 13%. Acute renal failure, neurological dysfunction, and wound healing were the major complications after operation. The in-hospital morality rate was 16.0%（37/231） in the acute group, while 6.1 %（6/99） in the chronic group. The surgical data of the ratio of CABG, cardiopulmonary bypass（CPB） time, aortic cross clamp time, intra-operative RBC infusion were significant higher in the acute phase group（P 〈 0.05）. The postoperative data of ICU stay, mechanical ventilation time, the incidences of neurological dysfunction, CRRT-dependent acute renal failure, hepatic insufficiency, and poor wound healing were significant higher in the acute phase group（P 〈 0.05）. Conclusions The total arch replacement combined with stent trunk for De Bakey type Ⅰ aortic dissection is safe and effective. Patients in the acute phase show higher postoperative mortality and complications. The acute phase is associated with relatively higher risk of surgical treatment.展开更多
基金supported by the Natural Science Foundation of China(grant No.71173174)
文摘Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capital and the social capital structure.The results show the following:first,social capital can expand the household income gap,and the effect of this index on the household income gap is 7.54%.Second,the indexes of the social capital dimension can expand the household income gap,and the structural effects of the household income gap on social networks,social trust,and social participation are 3.17%,3.64%,and 0.65%,respectively.Third,no dimension of the path is the same as the effect on the household income gap.
基金This work was partially supported by the National Natural Science Foundation of China (Grant Nos. 10671007,10471127)Zhejiang Provincial Natural Science Foundation of China (Grant No. R604001)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China and a CERG grant from Research Grants Council of Hong Kong
文摘In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a block design. This paper shows that a circular block design neighbor-balanced at distances up toγ≤k - 1, where k is the block size, is universally optimal for total effects under the linear models containing the neighbor effects at distances up toγamong the class of all circular binary block designs. Some combinatorial approaches to constructing these circular block designs neighbor-balanced at distances up to k - 1 are provided.
基金supported by the Key Project of Chinese Ministry of Education(No.108177)the National Natural Science Foundation of China(No.50679049)
文摘For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD （chemical oxygen demand）, TSS （total suspend solid）, TP （total phosphorus）, TN （total nitrogen） and BOD （biochemical oxygen demand）. The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters： rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 （mass first flush ratio） and FF30 （first 30% of runoff volume） can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs （best management practices） facilities.
基金supported by the National Natural Science Foundation of China (Nos. 11690040 and 11690043)。
文摘Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific discovery approach.The total ionizing dose(TID)effects usually cause gain degradation of bipolar junction transistors(BJTs),leading to functional failures of bipolar integrated circuits.Currently,many experiments of TID effects on BJTs have been conducted at different laboratories worldwide,producing a large amount of experimental data which provides a wealth of information.However,it is difficult to utilize these data effectively.In this study,we proposed a new artificial neural network(ANN)approach to analyze the experimental data of TID effects on BJTs An ANN model was built and trained using data collected from different experiments.The results indicate that the proposed ANN model has advantages in capturing nonlinear correlations and predicting the data.The trained ANN model suggests that the TID hardness of a BJT tends to increase with base current I.A possible cause for this finding was analyzed and confirmed through irradiation experiments.
基金supported by the Key Program of the National Natural Science Foundation of China(Grant No.60836004)the National Natural Science Foundation of China(Grant Nos.61006070 and 61076025)
文摘Annular gate nMOSFETs are frequently used in spaceborne integrated circuits due to their intrinsic good capability of resisting total ionizing dose （TID） effect. However, their capability of resisting the hot carrier effect （HCE） has also been proven to be very weak. In this paper, the reason why the annular gate nMOSFETs have good TID but bad HCE resistance is discussed in detail, and an improved design to locate the source contacts only along one side of the annular gate is used to weaken the HCE degradation. The good TID and HCE hardened capability of the design are verified by the experiments for I/O and core nMOSFETs in a 0.18 μm bulk CMOS technology. In addition, the shortcoming of this design is also discussed and the TID and the HCE characteristics of the replacers （the annular source nMOSFETs） are also studied to provide a possible alternative for the designers.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11475255,U1532261 and 11505282
文摘The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors （nMOSFETs） is investigated. Experimental results show that hot-carrier degradations on ir- radiated narrow channel nMOSFETs are greater than those without irradiation. The reason is attributed to radiation-induced charge trapping in shallow trench isolation （STI）. The electric field in the pinch-off region of the nMOSFET is enhanced by radiation-induced charge trapping in STI, resulting in a more severe hot-carrier effect.
基金Project supported by the National Natural Science Foundation of China （Grant No 6037202/F010204）.
文摘This paper studies the total ionizing dose radiation effects on MOS （metal-oxide-semiconductor） transistors with normal and enclosed gate layout in a standard commercial CMOS （compensate MOS） bulk process. The leakage current, threshold voltage shift, and transconductance of the devices were monitored before and after γ-ray irradiation. The parameters of the devices with different layout under different bias condition during irradiation at different total dose are investigated. The results show that the enclosed layout not only effectively eliminates the leakage but also improves the performance of threshold voltage and transconductance for NMOS （n-type channel MOS） transistors. The experimental results also indicate that analogue bias during irradiation is the worst case for enclosed gate NMOS. There is no evident different behaviour observed between normal PMOS （p-type channel MOS） transistors and enclosed gate PMOS transistors.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61704127 and 61574171)the Fundamental Research Funds for the Central Universities,China(Grant No.XJS17067)
文摘The synergistic effect of total ionizing dose（TID） on single event effect（SEE） in SiGe heterojunction bipolar transistor（HBT） is investigated in a series of experiments. The SiGe HBTs after being exposed to 60 Co g irradiation are struck by pulsed laser to simulate SEE. The SEE transient currents and collected charges of the un-irradiated device are compared with those of the devices which are irradiated at high and low dose rate with various biases. The results show that the SEE damage to un-irradiated device is more serious than that to irradiated SiGe HBT at a low applied voltage of laser test. In addition, the g irradiations at forward and all-grounded bias have an obvious influence on SEE in the SiGe HBT, but the synergistic effect after cutting off the g irradiation is not significant. The influence of positive oxide-trap charges induced by TID on the distortion of electric field in SEE is the major factor of the synergistic effect. Moreover, the recombination of interface traps also plays a role in charge collection.
基金Supported by the National Natural Science Foundation of China under Grant No 616340084the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2014101+1 种基金the International Cooperation Project of Chinese Academy of Sciencesthe Austrian-Chinese Cooperative R&D Projects under Grant No 172511KYSB20150006
文摘Because of the discrete charge storage mechanism, charge trapping memory（CTM） technique is a good candidate for aerospace and military missions. The total ionization dose（TID） effects on CTM cells with Al2O3/HfO2/Al2O3（AHA） high-k gate stack structure under in-situ 10 keV x-rays are studied. The C-V characteristics at different radiation doses demonstrate that charge stored in the device continues to be leaked away during the irradiation,thereby inducing the shift of flat band voltage（V（fb））. The dc memory window shows insignificant changes, suggesting the existence of good P/E ability. Furthermore, the physical mechanisms of TID induced radiation damages in AHA-based CTM are analyzed.
文摘The analytical method of total resource reallocation effect is an evolution of the analytical method of the factors of economic growth. Since the marketization reform in China in 1978, market mechanism has played a more and more important role in resource allocation, and Chinese economy has developed greatly, which is called "the Chinese Miracle". This paper analyzes the economic growth in China from 1978 to 2004 with the analytical method of total resource reallocation effect. The result shows that the annual growth rate of total resource reallocation effect was 0.2%, which was 5.1% of the comprehensive productivity and 0.21% of the gross output growth, i.e. the total resource allocation played a weak role in the economic growth in China. When analyzing it in Chenery's multinational model, we find that Chinese comprehensive productivity growth rate was higher than that in all the income phases of the model, but the total resource allocation effect was obviously lower than that in all the income phases of the model. It indicates that the total resource allocation in China has a great potential, and that to accelerate marketization reform is one of the important issues for Chinese economic development.
基金Supported by the Science Research&Train Program of(SRTP)Southeast University for Undergraduates
文摘We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is demonstrated numerically that electrons emitting from a point source in the n ＋ region will experience total internal reflection through the interface of the junction. The reflection becomes stronger and the transmission becomes weaker with decrease of the local potential in the right graphene ribbon. It is also found that when a nonideal interface is considered in the junction, the electron-reflection effect is enhanced due to interracial backseattering.
文摘In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiation of three bias conditions. It has been found experimentally that back gate threshold shift and leakage current were greatly reduced during irradiation for hardened transistors, comparing to control ones. It has been confirmed that the improvement of total-dose properties of SOI devices is attributed to the silicon nanocrystals (nanoclusters) in buried oxides introduced by ion implantation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61574048 and 61204112the Science and Technology Research Project of Guangdong Province under Grant Nos 2015B090912002 and 2014A030313656the Pearl River S&T Nova Program of Guangzhou
文摘The total ionizing dose radiation effects in the polycrystalline silicon thin film transistors are studied. Transfer characteristics, high-frequency capacitance-voltage curves and low-frequency noises (LFN) are measured before and after radiation. The experimental results show that threshold voltage and hole-field-effect mobility decrease, while sub-threshold swing and low-frequency noise increase with the increase of the total dose. The contributions of radiation induced interface states and oxide trapped charges to the shift of threshold voltage are also estimated. Furthermore, spatial distributions of oxide trapped charges before and after radiation are extracted based on the LFN measurements.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11690041,11675233,U1532261,and 11505243)
文摘The influences of total ionizing dose （TID） on the single event effect （SEE） sensitivity of 34-nm and 25-nm NAND flash memories are investigated in this paper. The increase in the cross section of heavy-ion single event upset （SEU） in memories that have ever been exposed to TID is observed, which is attributed to the combination of the threshold voltage shifts induced by 7-rays and heavy ions. Retention errors in floating gate （FG） cells after heavy ion irradiation are observed. Moreover, the cross section of retention error increases if the memory has ever been exposed to TID. This effect is more evident at a low linear energy transfer （LET） value. The underlying mechanism is identified as the combination of the defects induced by 7-rays and heavy ions, which increases the possibility to constitute a multi-trap assisted tunneling （m- TAT） path across the tunnel oxide.
基金This work was financially supported by the National Natural Science Foundation (DistinguishedYouth Fund 29925204) Fok Ying Tung Education Foundaiton (Fund 71012).
文摘Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.
文摘<b>Background & Aims:</b> The multimodal analgesia provides superior pain relief and reduces opioid consumption and its side effects. Gabapentin has been used successfully in multi-modal analgesia in different doses. We designed a double-blind randomized control trial to find the minimal effective dose of gabapentin in multimodal analgesia for postoperative pain following total abdominal hysterectomy. <b>Material & Methods:</b> After informed consent, total of 87 patients were randomly assigned to A, B & C groups to receive gabapentin orally 300 mg, 600 mg, and 900 mg respectively one to two hours before surgery. Postoperatively pain was managed by patient-controlled analgesia (PCA) using pethidine. Pain score, opioid consumption, and side effects of gabapentin were monitored. Rescue analgesia was given and monitored. <b>Results:</b> There was no statistically significant difference among the groups with respect to age, weight, height, pethidine consumption, and rescue analgesia. Mean pain scores were statistically insignificant at baseline, 8, 12, and 24 hours postoperatively. Only at 4 hours, the highest pain score (mean) was found in group A, which is statistically significant. The side effects of gabapentin like nausea, vomiting, somnolence, and dizziness were also statistically insignificant. <b>Conclusion:</b> A single preoperative oral gabapentin 300 mg was found to be minimal effective dose in multimodal analgesic regimen for reducing post-operative pain and analgesic requirement following total abdominal hysterectomy.
基金supported by the Science and Technology Commission of Shanghai Municipality(12DZ1930300,12DZ1930302,12DZ1930303)the Weak Discipline Construction Project(No.2016ZB0301–01)the 2016 Key Clinical Program of Clinical Pharmacy of Shanghai Municipal Commission of Health and Family Planning.cdh3
文摘This study developed a population pharmacokinetic model for sodium tanshinone IIA sulfonate(STS) in healthy volunteers and coronary heart disease(CHD) patients in order to identify significant covariates for the pharmacokinetics of STS. Blood samples were obtained by intense sampling approach from 10 healthy volunteers and sparse sampling from 25 CHD patients, and a population pharmacokinetic analysis was performed by nonlinear mixed-effect modeling. The final model was evaluated by bootstrap and visual predictive check. A total of 230 plasma concentrations were included, 137 from healthy volunteers and 93 from CHD patients. It was a two-compartment model with first-order elimination. The typical value of the apparent clearance(CL) of STS in CHD patients with total bilirubin(TBIL) level of 10 μmol×L^(–1) was 48.7 L×h^(–1) with inter individual variability of 27.4%, whereas that in healthy volunteers with the same TBIL level was 63.1 L×h^(–1). Residual variability was described by a proportional error model and estimated at 5.2%. The CL of STS in CHD patients was lower than that in healthy volunteers and decreased when TBIL levels increased. The bootstrap and visual predictive check confirmed the stability and validity of the final model. These results suggested that STS dosage adjustment might be considered based on TBIL levels in CHD patients.
基金supported by Science and Technology Planning Project of Guangdong Province(No.2016A020216022)
文摘Background Data on retrograde recanalization of epicardial collateral channels in patients with chronic total occlusion(CTO) undergoing percutaneous coronary intervention(PCI) are limited. Fearing about the complications of perforation, few CTO patients have chosen retrograde recanalization of epicardial collateral channels. Methods A retrospective analysis was conducted in this study. We followed up eligible patients who underwent continuous CTO via epicardial CCS from August 2011 to October 2018 in our center, and analyzed the detailed clinical baseline and angiographic data, surgical success rate and hospital complications to determine the efficacy and safety. The Cox model was used to compare major adverse cardiac events(MACE) and related co-variables between CTO patients with epicardial CCS perforation and non-perforated PCI patients. Results The study enrolled 191 patients with epicardial CCs PCI of CTO and the long term follow-up time was 24.03±19.18 months.Successful CCs PCI of CTO was achieved in 161(84.8 %) patients. Procedural collateral perforation occurred in23(12.0%) patients. MACEs occurred in 18 patients(9.4%) at 1-year follow-up. Kaplan-Meier curves showed no significant difference in MACEs between perforating recanalization of CCs PCI of CTO and non-perforating PCI of CTO.( adjusted hazard ratios(HR): 0.467; 95% confidence intervals(CI): 0.13 to 1.69, P=0.245). The multivariate Cox regression analysis identified the Werner score=0/1(HR: 5.80; 95% CI: 1.89 to 17.8; P=0.002) as significant independent predictors of perforation of CCs PCI of CTO. Conclusions The major complication of the procedure is collateral perforation. Recanalization of CTOs through epicardial collateral channel is safe and effective. It may be a available choice for recanalization of complex CTO.[S Chin J Cardiol 2019;20(1):37-43]
基金supported by The Medical Scientific Research Foundation of Guangdong Province(No.A2016028/No.A2015458)
文摘Background Aortic dissection（AD） is a life-threatening surgical emergency. Total arch replacement combined with stent trunk has gradually become the standard procedure for De Bakey type Ⅰ AD in China, but the complication and mortality rates are still relatively high due to surgical technical difficulties and complexity. In principle, AD should be treated with emergency surgery once the diagnosis is confirmed, but the operation time varies greatly in China due to the restriction of medical conditions. Therefore, analyzing and comparing the surgical mortality and complications rate between acute and chronic phase may facilitate the clinicians to comprehensively evaluate the patient＇s condition, and thus select an appropriate operation timing. Methods A total of330 De Bakey type Ⅰ AD patients admitted and treated with total arch replacement combined with stent trunk procedure in Guangdong Cardiovascular Institute from Jan 2010 to Jan 2014 were retrospectively analyzed. According to whether the onset was longer than 2 w, patients were divided into acute phase group and chronic phase group. There were 231 cases in acute phase group（≤ 2 w）, and the average length from onset to operation was 5.6± 3.8 d; while 99 cases in chronic phase group（〉 2 w）, and the average length from onset to operation was 20.6 ±14.7 d. Results The total mortality rate was 13%. Acute renal failure, neurological dysfunction, and wound healing were the major complications after operation. The in-hospital morality rate was 16.0%（37/231） in the acute group, while 6.1 %（6/99） in the chronic group. The surgical data of the ratio of CABG, cardiopulmonary bypass（CPB） time, aortic cross clamp time, intra-operative RBC infusion were significant higher in the acute phase group（P 〈 0.05）. The postoperative data of ICU stay, mechanical ventilation time, the incidences of neurological dysfunction, CRRT-dependent acute renal failure, hepatic insufficiency, and poor wound healing were significant higher in the acute phase group（P 〈 0.05）. Conclusions The total arch replacement combined with stent trunk for De Bakey type Ⅰ aortic dissection is safe and effective. Patients in the acute phase show higher postoperative mortality and complications. The acute phase is associated with relatively higher risk of surgical treatment.
