Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution lea...Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.展开更多
Background: We recently showed HER2-positive breast cancers are less likely to respond to neoadjuvant anthracycline chemotherapy. Here, we investigated whether HER2-positive breast cancers responded to sequential neo...Background: We recently showed HER2-positive breast cancers are less likely to respond to neoadjuvant anthracycline chemotherapy. Here, we investigated whether HER2-positive breast cancers responded to sequential neoadjuvant anthracycline followed by paclitaxel plus carboplatin regimen in the absence of trastuzumab. Methods: Women (n=372) with operable primary breast cancer initially received two cycles of neoadjuvant anthracyclines, the clinical tumor response was assessed, then patients were received four cycles of paelitaxel plus carboplatin regimen. All the patients did not received trastuzumab treatment in the neoadjuvant setting. HER2 status was determined by immunohistochemistry and/or by fluorescence in situ hybridization in core- biopsy breast cancer tissue obtained before the neoadjuvant chemotherapy. Results: Eighteen percent (67/372) of patients achieved a pathologic complete response (pCR) in their breast. HER2-positive tumors had a significant higher pCR rate than HER2-negative tumors (33.0% versus 13.5%, P〈0.001) in this cohort of 372 patients, and positive HER2 status remained an independent favorable predictor of pCR in a multivariate analysis [odds ratio (OR), 2.26; 95% confidence interval (CI), 1.18 to 4.36, P=0.015]. Furthermore, patients who responded to initial anthracycline regimens were more likely to respond to paclitaxel plus carboplatin than patients who did not (pCR, 27.2% versus 14.6%, P=0.005). Patients with HER2-positive tumors exhibited a significant higher pCR rate than did patients with HER2- negative tumors in both anthracycline response group (40.5% versus 20.0%, P=0.025) and anthracycline non-response group (28.3% versus 11.3 %, P=0.002). Conclusions: Under the circumstance of no trastuzumab treatment, women with HER2-positive cancers derive a large benefit from paclitaxel-carboplatin-based neoadjuvant chemotherapy.展开更多
A new type of beam called the NPEP-BG(a Bessel-Gaussian(BG)beam with a spiral phase term of a new powerexponent-phase(NPEP))is theoretically studied in this paper.The results show that the number of singularities of t...A new type of beam called the NPEP-BG(a Bessel-Gaussian(BG)beam with a spiral phase term of a new powerexponent-phase(NPEP))is theoretically studied in this paper.The results show that the number of singularities of the phase and side lobes of the intensity of this beam were equal to the topological charges(TCs)and the beam has the characteristics of self-healing during propagation.The NPEP-BG beam combined the partial characteristics of the new power-exponentphase vortex(NPEPV)and the Bessel-Gaussian beam.At the focus of the beam,the characteristic like a perfect vortex beam was present,in which the focal radius is stable and independent of the topological charge.There are multi-focal spots around a ring in the focal plane,meaning that the NPEP-BG beam has a potential for application in multi-particle manipulation.展开更多
Earth’s magnetic field is generated in the fluid outer core through the dynamo process.Over the last decade,data assimilation has been used to retrieve the core dynamics and predict the evolution of the geomagnetic f...Earth’s magnetic field is generated in the fluid outer core through the dynamo process.Over the last decade,data assimilation has been used to retrieve the core dynamics and predict the evolution of the geomagnetic field.The presence of model errors in the geomagnetic data assimilation is inevitable because current numerical geodynamo models are still far from realistic core dynamics.In this paper,we investigate the effect of model errors in geomagnetic data assimilation based on ensemble Kalman filter(EnKF).We construct two dynamo models with different control parameters but exhibiting similar force balance and magnetic morphology at the core surface.We then use one dynamo model to generate synthetic observations and the other as the forward model in EnKF.Our test experiments show that the EnKF approach with the pre-setting model errors can nevertheless recover large-scale core surface flow and make a rough short-term(5-year)prediction.However,the data assimilation in the presence of model errors cannot keep improving the core state even though new observations are available.Motivated by the planned Macao Science Satellite-1,which is expected to provide improved internal geomagnetic field model,we also perform a test experiment using synthetic observations up to spherical harmonic degree l=18.Our results indicate that high-resolution observations are crucial in reconstructing small scale flow.展开更多
Objective: Early assessment of response to neoadjuvant chemotherapy (NAC) for breast cancer allows therapy to be individualized. The optimal assessment method has not been established. We investigated the accuracy ...Objective: Early assessment of response to neoadjuvant chemotherapy (NAC) for breast cancer allows therapy to be individualized. The optimal assessment method has not been established. We investigated the accuracy of automated breast ultrasound (ABUS) to predict pathological outcomes after NAC. Methods: A total of 290 breast cancer patients were eligible for this study. Tumor response after 2 cycles of chemotherapy was assessed using the product change of two largest perpendicular diameters (PC) or the longest diameter change (LDC). PC and LDC were analyzed on the axial and the coronal planes respectively. Receiver operating characteristic (ROC) curves were used to evaluate overall performance of the prediction methods. Youden's indexes were calculated to select the optimal cut-off value for each method. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) and the area under the ROC curve (AUC) were calculated accordingly.Results: ypT0/is was achieved in 42 patients (14.5%) while ypT0 was achieved in 30 patients (10.3%) after NAC. All four prediction methods (PC on axial planes, LDC on axial planes, PC on coronal planes and LDC on coronal planes) displayed high AUCs (all〉0.82), with the highest of 0.89 [95% confidence interval (95% CI), 0.83-0.95] when mid-treatment &BUS was used to predict final pathological complete remission (pCR). High sensitivities (85.7%-88.1%) were observed across all four prediction methods while high specificities (81.5%-85.1%) were observed in two methods used PC. The optimal cut-off values defined by our data replicate the WHO and the RECIST criteria. Lower AUCs were observed when mid-treatment ABUS was used to predict poor pathological outcomes. Conclusions:ABUS is a useful tool in early evaluation of pCR after NAC while less reliable when predicting poor pathological outcomes.展开更多
Objective To investigate the role of multi-detector computed tomography(CT) in the diagnosis and classification of isolated spontaneous superior mesenteric artery dissection(ISSMAD). Methods From July 2012 to December...Objective To investigate the role of multi-detector computed tomography(CT) in the diagnosis and classification of isolated spontaneous superior mesenteric artery dissection(ISSMAD). Methods From July 2012 to December 2016,30 consecutive patients with ISSMAD underwent CT scan at least two times. We retrospectively summarized the clinical characteristics and CT findings of them. The stenosis ratio of true lumen was compared between the patients without bowel ischemia and ones with bowel ischemia. Results There were 5 cases of type I ISSMAD,14 cases of type Ⅱ,1 case of type Ⅲ,7 cases of type Ⅳ and 3 cases of type V. Intestinal ischemia occurred in 5 patients. The stenosis ratio of true lumen in the patients without bowel ischemia was lower than that with bowel ischemia(45.6% vs. 76.0%,t=–14.5,P=0.000). Five patients with intestinal ischemia underwent superior mesenteric artery stenting and others received conservative therapy. The abdominal pain was alleviated for all the patients after treatment. Follow-up was complete in 30 cases. Follow-up CT angiography of superior mesenteric artery showed dissection remodeling in 12 patients. Conclusion Multi-detector CT is a valuable method in diagnosis and classification of ISSMAD and monitoring the changes of dissection.展开更多
Background- To compare two types of therapy for primary breast carcinoma, breast-conserving therapy (BCT) and modified radical mastectomy (MRM), in a matched cohort study. Methods: A series of 1,746 patients with...Background- To compare two types of therapy for primary breast carcinoma, breast-conserving therapy (BCT) and modified radical mastectomy (MRM), in a matched cohort study. Methods: A series of 1,746 patients with primary breast cancer treated with BCT or MRM in a single Chinese institute between January 2000 and February 2009 were analyzed retrospectively to compare their outcomes with respect to the incidence of local recurrence (LR), distant metastasis, and survival. The patients were matched with regard to age at diagnosis, spreading to axillary lymph nodes, hormone receptor status, the use of neoadjuvant chemotherapy and maximal tumor diameter. The match ratio was 1:1, and each arm included 873 patients. Results: The median follow-up period was 71 months. The 6-year disease-free survival (DFS) and 6-year distant disease-free survival (DDFS) rates differed significantly between two groups. The 6-year local recurrence-free survival (LRFS) rates were 98.2% [95% confidence interval (CI): 0.973-0.989] in the BCT group and 98.7% (95% CI: 0.980-0.994) in the MRM group (P=0.182), respectively. DFS rates in BCT and MRM groups were 91.3% (95% CI: 0.894-0.932) and 86.3% (95% CI: 0.840-0.886) (P〈0.001), respectively, whereas the DDFS rates in BCT and MRM groups were 93.6% (95% CI: 0.922-0.950) and 87.7% (95% CI: 0.854-0.900) (P〈0.001), respectively. Conclusions: BCT in eligible patients is as effective as MRM with respect to local tumor control, DFS and DDFS, and may result in a better outcome than MRM in Chinese primary breast cancer patients.展开更多
The objective of this study is to investigate the feasibility of using chitosanesodium alginate(CSeSA)based matrix tablets for extended-release of highly water-soluble drugs by changing formulation variables.Using tri...The objective of this study is to investigate the feasibility of using chitosanesodium alginate(CSeSA)based matrix tablets for extended-release of highly water-soluble drugs by changing formulation variables.Using trimetazidine hydrochloride(TH)as a water-soluble model drug,influence of dissolution medium,the amount of CSeSA,the CS:SA ratio,the type of SA,the type and amount of diluents,on in vitro drug release from CSeSA based matrix tablets were studied.Drug release kinetics and release mechanisms were elucidated.In vitro release experiments were conducted in simulated gastric fluid(SGF)followed by simulated intestinal fluid(SIF).Drug release rate decreased with the increase of CSeSA amount.CS:SA ratio had only slight effect on drug release and no influence of SA type on drug release was found.On the other hand,a large amount of water-soluble diluents could modify drug release profiles.It was found that drug release kinetics showed the best fit to Higuchi equation with Fickian diffusion as the main release mechanism.In conclusion,this study demonstrated that it is possible to design extended-release tablets of watersoluble drugs using CSeSA as the matrix by optimizing formulation components,and provide better understanding about drug release from CSeSA matrix tablets.展开更多
Objective: To determine the predictive ability of biomarkers for responses to neoadjuvant endocrine therapy (NET) in postmenopausal breast cancer. Methods: Consecutive 160 postmenopausal women with T 1-3 N 0-1 M 0...Objective: To determine the predictive ability of biomarkers for responses to neoadjuvant endocrine therapy (NET) in postmenopausal breast cancer. Methods: Consecutive 160 postmenopausal women with T 1-3 N 0-1 M 0 hormone receptor (HR)-positive invasive breast cancer were treated with anastrozole for 16 weeks before surgery. New slides of tumor specimens taken before and after treatment were conducted centrally for biomarker analysis and classified using the Applied Imaging Ariol MB-8 system. The pathological response was evaluated using the Miller & Payne classification. The cell cycle response was classified according to the change in the Ki67 index after treatment. Multivariable logistic regression analysis was used to calculate the combined index of the biomarkers. Receiver operating characteristic (ROC) curves were used to determine whether parameters may predict response. Results: The correlation between the pathological and cell cycle responses was low (Spearman correlation coefficient =0.241, P〈0.001; Kappa value =0.119, P=0.032). The cell cycle response was significantly associated with pre-treatment estrogen receptor (ER) status (P=0.001), progesterone receptor (PgR) status (P〈0.001), human epidermal growth factor receptor 2 (Her-2) status (P=0.050) and the Ki67 index (P〈0.001), but the pathological response was not correlated with these factors. Pre-treatment ER levels [area under the curve (AUC) =0.634, 95% confidence interval (95% CI), 0.534-0.735, P=0.008] and combined index of pre-treatment ER and PgR levels (AUC =0.684, 95% CI, 0.591-0.776, P〈0.001) could not predict the cell cycle response, but combined index including per-treatment ER/PR/Her-2/Ki67 expression levels could (AUC =0.830, 95% CI, 0.759-0.902, P〈0.001). Conclusions: The combined use of pre-treatment ER/PgR/Her-2/Ki67 expression levels, instead of HR expression levels, may predict the cell cycle response to NET.展开更多
The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to i...The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to increase its solubility.Stability constant(Kc)was used for host selection.Factors influencing properties of the inclusion complex was investigated.Formation of the inclusion complex was identified by solubility study and DSC analysis.The brain targeting effect of the complex after intranasal administration was studied in rats.It was demonstrated that properties of the inclusion complex was mainly influenced by cyclodextrin type,organic acids type,system pH and host/guest molar ratio.Multiple component complexes can be formed by the addition of citric acid,with solubility improved for more than 23 times.Furthermore,In vivo study revealed that after intranasal administration,the absolute bioavailability of vinpocetine inclusion complex was 88%.Compared with intravenous injection,significant brain targeting effect was achieved after intranasal delivery,with brain targeting index 1.67.In conclusion,by intranasal administration of VIN inclusion complex,a fast onset of action and good brain targeting effect can be achieved.Intranasal route is a promising approach for the treatment of CNS diseases.展开更多
Aluminum nitride(AlN)is the promising substrates material for the epitaxial growth ofⅢ-nitrides devices,such as high-power,high-frequency electronic,deep ultraviolet optoelectronics and acoustic devices.However,it is...Aluminum nitride(AlN)is the promising substrates material for the epitaxial growth ofⅢ-nitrides devices,such as high-power,high-frequency electronic,deep ultraviolet optoelectronics and acoustic devices.However,it is rather difficult to obtain the high quality and crack-free thick AlN wafers because of the low surface migration of Al adatoms and the large thermal and lattice mismatches between the foreign substrates and AlN.In this work,the fabrication of AlN material by hydride vapor phase epitaxy(HVPE)was summarized and discussed.At last,the outlook of the production of AlN by HVPE was prospected.展开更多
The stereo matching method based on a space-aware network is proposed, which divides the network into threesections: Basic layer, scale layer, and decision layer. This division is beneficial to integrate residue netwo...The stereo matching method based on a space-aware network is proposed, which divides the network into threesections: Basic layer, scale layer, and decision layer. This division is beneficial to integrate residue network and densenetwork into the space-aware network model. The vertical splitting method for computing matching cost by usingthe space-aware network is proposed for solving the limitation of GPU RAM. Moreover, a hybrid loss is broughtforward to boost the performance of the proposed deep network. In the proposed stereo matching method, thespace-aware network is used to calculate the matching cost and then cross-based cost aggregation and semi-globalmatching are employed to compute a disparity map. Finally, a disparity-post processing method is utilized suchas subpixel interpolation, median filter, and bilateral filter. The experimental results show this method has a goodperformance on running time and accuracy, with a percentage of erroneous pixels of 1.23% on KITTI 2012 and1.94% on KITTI 2015.展开更多
Fueled by the booming online games,there is an increasing demand for monitoring online games in various settings.One of the application scenarios is the monitor of computer games in school computer labs,for which an i...Fueled by the booming online games,there is an increasing demand for monitoring online games in various settings.One of the application scenarios is the monitor of computer games in school computer labs,for which an intelligent game recognition method is required.In this paper,a method to identify game processes in accordance with private working sets(i.e.,the amount of memory occupied by a process but cannot be shared among other processes)is introduced.Results of the W test showed that the memory sizes occupied by the legitimate processes(e.g.,the processes of common native windows applications)and game processes followed normal distribution.Using the T-test,a significant difference was identified between the legitimate processes and C/S-based computer games,in terms of the means and variances of their private working sets.Subsequently,we derived the density functions of the private working sets of the considered game processes and those of the legitimate processes.Given the private working set of a process and the derived probability density functions,the probability that the process is a legitimate process and the probability that the process is a game process can be determined.After comparing the two probabilities,we can easily determine whether the process is a game process or not.As revealed from the test results,the recognition accuracy of this method for C/S-based computer games was approximately 90%.展开更多
Recrystallization behavior during optimized heat treatments provides a potential to obtain desirable grain structure,which significantly improves the mechanical properties of aluminum alloys.The influence of grain str...Recrystallization behavior during optimized heat treatments provides a potential to obtain desirable grain structure,which significantly improves the mechanical properties of aluminum alloys.The influence of grain structures on fatigue crack propagation(FCP)behaviors of Al-Cu-Li alloy with hot-rolled(HR)and cold-rolled(CR)was investigated.Subgrain boundaries have a significant impact on small crack growth rates,which is reflected in the pronounced fluctuation of fatigue crack growth of HR specimens after solution treatment.Moreover,the specific cellular structure within grains can improve the deformation capacity of alloys due to their accommodation of plastic deformation,which contributes to the lower fatigue crack growth rates and higher threshold values in HR specimens.The intragranular deflection also decelerates the FCP rate and occurs in these regions of large grain without subgrain boundaries.Recrystallization occurs in the CR specimens,resulting in small anisotropy on the fatigue resistance for the different orientations in the Paris stage due to the recrystallization texture.Fatigue cracks can be deflected and tend to propagate along the grain boundaries when it goes into the grain with a relatively low Schmidt factor value.展开更多
Image sparse representation is a method of efficient compression and coding of image signal in the process of digital image processing.Image after sparse representation,to enhance the transmission efficiency of the im...Image sparse representation is a method of efficient compression and coding of image signal in the process of digital image processing.Image after sparse representation,to enhance the transmission efficiency of the image signal.Entropy of Primitive(EoP)is a statistical representation of the sparse representation of the image,which indicates the probability of each base element.Based on the EoP,this paper presents an image quality evaluation method-Difference of Visual Information Metric(DVIM).The principle of this method is to evaluate the image quality with the difference between the original image and the distorted image.The comparative experiments between DVIM&PSNR&SSIM are carried out.It was found that there was a great improvement in the image quality evaluation of geometric changes.This method is an effective image quality evaluation method,which overcomes the weakness of other quality evaluation methods for geometrically changing images to a certain extent,and is more consistent with the subjective observation of the human eye.展开更多
The wireless network is limited by the transmission medium,and the transmission process is subject to large interference and jitter.This jitter can cause sporadic loss and is mistaken for congestion by the congestion ...The wireless network is limited by the transmission medium,and the transmission process is subject to large interference and jitter.This jitter can cause sporadic loss and is mistaken for congestion by the congestion control mechanism.The TCP Westwood protocol(referred to as TCPW)is such that it cannot distinguish between congestion loss and wireless jitter loss,which makes the congestion mechanism too sensitive and reduces bandwidth utilization.Based on this,the TCPW protocol is modified based on the estimate of the Round-Trip Time(referred to as RTT)value-called TCPW BR.The algorithm uses the measured smooth RTT value and divides the congestion level according to the weighted average idea to determine congestion loss and wireless jitter loss.The simulation results show that the TCPW BR algorithm enhances the wireless network’s ability to judge congestion and random errors.展开更多
Parkinson disease (PD) is a neurological disorder with huge destruction to human body, which affects approximately 2% of the population aged 65 years or older. As antioxidants in the stress defence systems, glutathion...Parkinson disease (PD) is a neurological disorder with huge destruction to human body, which affects approximately 2% of the population aged 65 years or older. As antioxidants in the stress defence systems, glutathione S-transferases (GSTs) are dimeric cytosolic enzymes with an important role in the pathogenesis of PD. The aim of this study was to evaluate the association between the polymorphisms of GST genes and PD. Meta-analyses were conducted from 17 studies (38 stages) among 3419 cases and 5686 controls between four polymorphisms (GSTT1 deletion polymorphism;GSTM1 deletion polymorphism;GSTP1-104: rs1695;GSTP1-114: rs1799811) and PD. There is no significant association between the four GST gene variants and PD. A further subgroup study by ethnicity observed a risky role of GSTM1 deletion polymorphism with PD in Europeans (p = 0.013, OR = 1.126, 95% CI = 1.025-1.236), and a protective role of GSTM1 deletion polymorphism with PD in Latin Americans (p = 0.032, OR = 0.750, 95% CI = 0.577-0.975). Our meta-analysis suggested that GSTM1 deletion polymorphism increased the risk of PD in Europeans, but reduced the risk of PD in Latin Americans. Future large-scale studies might be needed to confirm the ethnic difference of GSTM1 deletion polymorphism, and to check whether there was significant association of PD for other GST genetic polymorphisms.展开更多
Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0...Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.展开更多
Organic light-mitting transistors(OLETs)integrate the functions of light-emitting diodes and field-effect transistors into a unique device,opening a new door for optoelectronics.However,there is still a challenge due ...Organic light-mitting transistors(OLETs)integrate the functions of light-emitting diodes and field-effect transistors into a unique device,opening a new door for optoelectronics.However,there is still a challenge due to the absence of high quality organic semiconductors for OLETs.Herein,we reported a novel molecule 2,6-di(anthracen-2-yl)naphthalene(2,6-DAN),which exhibited mobility of up to 19 cm2:V'-s'and an absolute fluorescence quantum yield of 37.09%,which are good values for organic semiconductors.Moreover,OLETs based on 2,6-DAN single crystals showed bright yellowish-green emission and well-balanced ambipolar charge transport.The excellent ratio of hole to electron mobilty can reach up to 0.86,which is superior to most single component OL ETs in typical device configurations reported so far.展开更多
Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone (O3), NO2 and total oxidant (Ox) were analyzed by both linear regres...Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone (O3), NO2 and total oxidant (Ox) were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations (non-urban) and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime (13%/yr referred to 2006 level) was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds (VOC)-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.展开更多
基金financially supported by the National Natural Science Foundation of China(U1707601)project of Youth Innovation Promotion Association,Chinese Academy of Sciences(2021430)+1 种基金project of Innovation Academy for Green Manufacture,Chinese Academy of Sciences(IAGM2020C26)project of Bureau of International Cooperation,Chinese Academy of Sciences(122363KYSB20190033)。
文摘Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.
基金supported by grants from the National Natural Science Foundation of China (No.81302330,No.30973436 and No.81071629)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (No.2014BAI09B08)the 973 project 2013CB911004 and the 985-Ⅲ project
文摘Background: We recently showed HER2-positive breast cancers are less likely to respond to neoadjuvant anthracycline chemotherapy. Here, we investigated whether HER2-positive breast cancers responded to sequential neoadjuvant anthracycline followed by paclitaxel plus carboplatin regimen in the absence of trastuzumab. Methods: Women (n=372) with operable primary breast cancer initially received two cycles of neoadjuvant anthracyclines, the clinical tumor response was assessed, then patients were received four cycles of paelitaxel plus carboplatin regimen. All the patients did not received trastuzumab treatment in the neoadjuvant setting. HER2 status was determined by immunohistochemistry and/or by fluorescence in situ hybridization in core- biopsy breast cancer tissue obtained before the neoadjuvant chemotherapy. Results: Eighteen percent (67/372) of patients achieved a pathologic complete response (pCR) in their breast. HER2-positive tumors had a significant higher pCR rate than HER2-negative tumors (33.0% versus 13.5%, P〈0.001) in this cohort of 372 patients, and positive HER2 status remained an independent favorable predictor of pCR in a multivariate analysis [odds ratio (OR), 2.26; 95% confidence interval (CI), 1.18 to 4.36, P=0.015]. Furthermore, patients who responded to initial anthracycline regimens were more likely to respond to paclitaxel plus carboplatin than patients who did not (pCR, 27.2% versus 14.6%, P=0.005). Patients with HER2-positive tumors exhibited a significant higher pCR rate than did patients with HER2- negative tumors in both anthracycline response group (40.5% versus 20.0%, P=0.025) and anthracycline non-response group (28.3% versus 11.3 %, P=0.002). Conclusions: Under the circumstance of no trastuzumab treatment, women with HER2-positive cancers derive a large benefit from paclitaxel-carboplatin-based neoadjuvant chemotherapy.
基金Project supported by the Program of Shanghai Academic/Technology Research Leader(Grant No.20SR014501)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB1603)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2019247)。
文摘A new type of beam called the NPEP-BG(a Bessel-Gaussian(BG)beam with a spiral phase term of a new powerexponent-phase(NPEP))is theoretically studied in this paper.The results show that the number of singularities of the phase and side lobes of the intensity of this beam were equal to the topological charges(TCs)and the beam has the characteristics of self-healing during propagation.The NPEP-BG beam combined the partial characteristics of the new power-exponentphase vortex(NPEPV)and the Bessel-Gaussian beam.At the focus of the beam,the characteristic like a perfect vortex beam was present,in which the focal radius is stable and independent of the topological charge.There are multi-focal spots around a ring in the focal plane,meaning that the NPEP-BG beam has a potential for application in multi-particle manipulation.
基金supported by the Macao Foundation and preresearch project on Civil Aerospace Technologies of CNSA(D020308,D020303)the Macao Science and Technology Development Fund(0001/2019/A1)the National Natural Science Foundation of China(41904066,42142034)。
文摘Earth’s magnetic field is generated in the fluid outer core through the dynamo process.Over the last decade,data assimilation has been used to retrieve the core dynamics and predict the evolution of the geomagnetic field.The presence of model errors in the geomagnetic data assimilation is inevitable because current numerical geodynamo models are still far from realistic core dynamics.In this paper,we investigate the effect of model errors in geomagnetic data assimilation based on ensemble Kalman filter(EnKF).We construct two dynamo models with different control parameters but exhibiting similar force balance and magnetic morphology at the core surface.We then use one dynamo model to generate synthetic observations and the other as the forward model in EnKF.Our test experiments show that the EnKF approach with the pre-setting model errors can nevertheless recover large-scale core surface flow and make a rough short-term(5-year)prediction.However,the data assimilation in the presence of model errors cannot keep improving the core state even though new observations are available.Motivated by the planned Macao Science Satellite-1,which is expected to provide improved internal geomagnetic field model,we also perform a test experiment using synthetic observations up to spherical harmonic degree l=18.Our results indicate that high-resolution observations are crucial in reconstructing small scale flow.
文摘Objective: Early assessment of response to neoadjuvant chemotherapy (NAC) for breast cancer allows therapy to be individualized. The optimal assessment method has not been established. We investigated the accuracy of automated breast ultrasound (ABUS) to predict pathological outcomes after NAC. Methods: A total of 290 breast cancer patients were eligible for this study. Tumor response after 2 cycles of chemotherapy was assessed using the product change of two largest perpendicular diameters (PC) or the longest diameter change (LDC). PC and LDC were analyzed on the axial and the coronal planes respectively. Receiver operating characteristic (ROC) curves were used to evaluate overall performance of the prediction methods. Youden's indexes were calculated to select the optimal cut-off value for each method. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) and the area under the ROC curve (AUC) were calculated accordingly.Results: ypT0/is was achieved in 42 patients (14.5%) while ypT0 was achieved in 30 patients (10.3%) after NAC. All four prediction methods (PC on axial planes, LDC on axial planes, PC on coronal planes and LDC on coronal planes) displayed high AUCs (all〉0.82), with the highest of 0.89 [95% confidence interval (95% CI), 0.83-0.95] when mid-treatment &BUS was used to predict final pathological complete remission (pCR). High sensitivities (85.7%-88.1%) were observed across all four prediction methods while high specificities (81.5%-85.1%) were observed in two methods used PC. The optimal cut-off values defined by our data replicate the WHO and the RECIST criteria. Lower AUCs were observed when mid-treatment ABUS was used to predict poor pathological outcomes. Conclusions:ABUS is a useful tool in early evaluation of pCR after NAC while less reliable when predicting poor pathological outcomes.
文摘Objective To investigate the role of multi-detector computed tomography(CT) in the diagnosis and classification of isolated spontaneous superior mesenteric artery dissection(ISSMAD). Methods From July 2012 to December 2016,30 consecutive patients with ISSMAD underwent CT scan at least two times. We retrospectively summarized the clinical characteristics and CT findings of them. The stenosis ratio of true lumen was compared between the patients without bowel ischemia and ones with bowel ischemia. Results There were 5 cases of type I ISSMAD,14 cases of type Ⅱ,1 case of type Ⅲ,7 cases of type Ⅳ and 3 cases of type V. Intestinal ischemia occurred in 5 patients. The stenosis ratio of true lumen in the patients without bowel ischemia was lower than that with bowel ischemia(45.6% vs. 76.0%,t=–14.5,P=0.000). Five patients with intestinal ischemia underwent superior mesenteric artery stenting and others received conservative therapy. The abdominal pain was alleviated for all the patients after treatment. Follow-up was complete in 30 cases. Follow-up CT angiography of superior mesenteric artery showed dissection remodeling in 12 patients. Conclusion Multi-detector CT is a valuable method in diagnosis and classification of ISSMAD and monitoring the changes of dissection.
文摘Background- To compare two types of therapy for primary breast carcinoma, breast-conserving therapy (BCT) and modified radical mastectomy (MRM), in a matched cohort study. Methods: A series of 1,746 patients with primary breast cancer treated with BCT or MRM in a single Chinese institute between January 2000 and February 2009 were analyzed retrospectively to compare their outcomes with respect to the incidence of local recurrence (LR), distant metastasis, and survival. The patients were matched with regard to age at diagnosis, spreading to axillary lymph nodes, hormone receptor status, the use of neoadjuvant chemotherapy and maximal tumor diameter. The match ratio was 1:1, and each arm included 873 patients. Results: The median follow-up period was 71 months. The 6-year disease-free survival (DFS) and 6-year distant disease-free survival (DDFS) rates differed significantly between two groups. The 6-year local recurrence-free survival (LRFS) rates were 98.2% [95% confidence interval (CI): 0.973-0.989] in the BCT group and 98.7% (95% CI: 0.980-0.994) in the MRM group (P=0.182), respectively. DFS rates in BCT and MRM groups were 91.3% (95% CI: 0.894-0.932) and 86.3% (95% CI: 0.840-0.886) (P〈0.001), respectively, whereas the DDFS rates in BCT and MRM groups were 93.6% (95% CI: 0.922-0.950) and 87.7% (95% CI: 0.854-0.900) (P〈0.001), respectively. Conclusions: BCT in eligible patients is as effective as MRM with respect to local tumor control, DFS and DDFS, and may result in a better outcome than MRM in Chinese primary breast cancer patients.
基金supported by Liaoning Institutions excellent talents support plan(No.LR2013047).
文摘The objective of this study is to investigate the feasibility of using chitosanesodium alginate(CSeSA)based matrix tablets for extended-release of highly water-soluble drugs by changing formulation variables.Using trimetazidine hydrochloride(TH)as a water-soluble model drug,influence of dissolution medium,the amount of CSeSA,the CS:SA ratio,the type of SA,the type and amount of diluents,on in vitro drug release from CSeSA based matrix tablets were studied.Drug release kinetics and release mechanisms were elucidated.In vitro release experiments were conducted in simulated gastric fluid(SGF)followed by simulated intestinal fluid(SIF).Drug release rate decreased with the increase of CSeSA amount.CS:SA ratio had only slight effect on drug release and no influence of SA type on drug release was found.On the other hand,a large amount of water-soluble diluents could modify drug release profiles.It was found that drug release kinetics showed the best fit to Higuchi equation with Fickian diffusion as the main release mechanism.In conclusion,this study demonstrated that it is possible to design extended-release tablets of watersoluble drugs using CSeSA as the matrix by optimizing formulation components,and provide better understanding about drug release from CSeSA matrix tablets.
文摘Objective: To determine the predictive ability of biomarkers for responses to neoadjuvant endocrine therapy (NET) in postmenopausal breast cancer. Methods: Consecutive 160 postmenopausal women with T 1-3 N 0-1 M 0 hormone receptor (HR)-positive invasive breast cancer were treated with anastrozole for 16 weeks before surgery. New slides of tumor specimens taken before and after treatment were conducted centrally for biomarker analysis and classified using the Applied Imaging Ariol MB-8 system. The pathological response was evaluated using the Miller & Payne classification. The cell cycle response was classified according to the change in the Ki67 index after treatment. Multivariable logistic regression analysis was used to calculate the combined index of the biomarkers. Receiver operating characteristic (ROC) curves were used to determine whether parameters may predict response. Results: The correlation between the pathological and cell cycle responses was low (Spearman correlation coefficient =0.241, P〈0.001; Kappa value =0.119, P=0.032). The cell cycle response was significantly associated with pre-treatment estrogen receptor (ER) status (P=0.001), progesterone receptor (PgR) status (P〈0.001), human epidermal growth factor receptor 2 (Her-2) status (P=0.050) and the Ki67 index (P〈0.001), but the pathological response was not correlated with these factors. Pre-treatment ER levels [area under the curve (AUC) =0.634, 95% confidence interval (95% CI), 0.534-0.735, P=0.008] and combined index of pre-treatment ER and PgR levels (AUC =0.684, 95% CI, 0.591-0.776, P〈0.001) could not predict the cell cycle response, but combined index including per-treatment ER/PR/Her-2/Ki67 expression levels could (AUC =0.830, 95% CI, 0.759-0.902, P〈0.001). Conclusions: The combined use of pre-treatment ER/PgR/Her-2/Ki67 expression levels, instead of HR expression levels, may predict the cell cycle response to NET.
文摘The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to increase its solubility.Stability constant(Kc)was used for host selection.Factors influencing properties of the inclusion complex was investigated.Formation of the inclusion complex was identified by solubility study and DSC analysis.The brain targeting effect of the complex after intranasal administration was studied in rats.It was demonstrated that properties of the inclusion complex was mainly influenced by cyclodextrin type,organic acids type,system pH and host/guest molar ratio.Multiple component complexes can be formed by the addition of citric acid,with solubility improved for more than 23 times.Furthermore,In vivo study revealed that after intranasal administration,the absolute bioavailability of vinpocetine inclusion complex was 88%.Compared with intravenous injection,significant brain targeting effect was achieved after intranasal delivery,with brain targeting index 1.67.In conclusion,by intranasal administration of VIN inclusion complex,a fast onset of action and good brain targeting effect can be achieved.Intranasal route is a promising approach for the treatment of CNS diseases.
基金partly supported by Beijing Municipal Natural Science Foundation (No. 4182046)the National Natural Science Foundation of China (No. 61874007)+3 种基金the Fundamental Research Funds for the Central Universities (Nos. buctrc201802, buctrc201830)the Funding for Bagui Talent of Guangxi province (Nos. T31200992001 and T3120097921)ASEAN Young Talented Scientist Program (No. Y312001913)Talent Model Base, China (No. AE31200065)
文摘Aluminum nitride(AlN)is the promising substrates material for the epitaxial growth ofⅢ-nitrides devices,such as high-power,high-frequency electronic,deep ultraviolet optoelectronics and acoustic devices.However,it is rather difficult to obtain the high quality and crack-free thick AlN wafers because of the low surface migration of Al adatoms and the large thermal and lattice mismatches between the foreign substrates and AlN.In this work,the fabrication of AlN material by hydride vapor phase epitaxy(HVPE)was summarized and discussed.At last,the outlook of the production of AlN by HVPE was prospected.
基金This work was supported in part by the Heilongjiang Provincial Natural Science Foundation of China under Grant F2018002the Research Funds for the Central Universities under Grants 2572016BB11 and 2572016BB12the Foundation of Heilongjiang Education Department under Grant 1354MSYYB003.
文摘The stereo matching method based on a space-aware network is proposed, which divides the network into threesections: Basic layer, scale layer, and decision layer. This division is beneficial to integrate residue network and densenetwork into the space-aware network model. The vertical splitting method for computing matching cost by usingthe space-aware network is proposed for solving the limitation of GPU RAM. Moreover, a hybrid loss is broughtforward to boost the performance of the proposed deep network. In the proposed stereo matching method, thespace-aware network is used to calculate the matching cost and then cross-based cost aggregation and semi-globalmatching are employed to compute a disparity map. Finally, a disparity-post processing method is utilized suchas subpixel interpolation, median filter, and bilateral filter. The experimental results show this method has a goodperformance on running time and accuracy, with a percentage of erroneous pixels of 1.23% on KITTI 2012 and1.94% on KITTI 2015.
基金This work is funded in part by the National Nature Science Foundation of China(File Nos.61872451 and 61872452)in part by the Science and Technology Development Fund,Macao SAR(File Nos.0098/2018/A3 and 0076/2019/A2).Li Feng is the corresponding author.
文摘Fueled by the booming online games,there is an increasing demand for monitoring online games in various settings.One of the application scenarios is the monitor of computer games in school computer labs,for which an intelligent game recognition method is required.In this paper,a method to identify game processes in accordance with private working sets(i.e.,the amount of memory occupied by a process but cannot be shared among other processes)is introduced.Results of the W test showed that the memory sizes occupied by the legitimate processes(e.g.,the processes of common native windows applications)and game processes followed normal distribution.Using the T-test,a significant difference was identified between the legitimate processes and C/S-based computer games,in terms of the means and variances of their private working sets.Subsequently,we derived the density functions of the private working sets of the considered game processes and those of the legitimate processes.Given the private working set of a process and the derived probability density functions,the probability that the process is a legitimate process and the probability that the process is a game process can be determined.After comparing the two probabilities,we can easily determine whether the process is a game process or not.As revealed from the test results,the recognition accuracy of this method for C/S-based computer games was approximately 90%.
文摘Recrystallization behavior during optimized heat treatments provides a potential to obtain desirable grain structure,which significantly improves the mechanical properties of aluminum alloys.The influence of grain structures on fatigue crack propagation(FCP)behaviors of Al-Cu-Li alloy with hot-rolled(HR)and cold-rolled(CR)was investigated.Subgrain boundaries have a significant impact on small crack growth rates,which is reflected in the pronounced fluctuation of fatigue crack growth of HR specimens after solution treatment.Moreover,the specific cellular structure within grains can improve the deformation capacity of alloys due to their accommodation of plastic deformation,which contributes to the lower fatigue crack growth rates and higher threshold values in HR specimens.The intragranular deflection also decelerates the FCP rate and occurs in these regions of large grain without subgrain boundaries.Recrystallization occurs in the CR specimens,resulting in small anisotropy on the fatigue resistance for the different orientations in the Paris stage due to the recrystallization texture.Fatigue cracks can be deflected and tend to propagate along the grain boundaries when it goes into the grain with a relatively low Schmidt factor value.
基金This research was financially supported by Guangdong Provincial Department of Education major scientific innovation project characteristics(natural sciences)No.2014KTSCX210Also it was supported by Youth Program No.GKY-2016KYQN-3 and NO.GKY-2017KYQN-1College Students Innovation Training Program No.1611007 of Guangdong University of Science and Technology.
文摘Image sparse representation is a method of efficient compression and coding of image signal in the process of digital image processing.Image after sparse representation,to enhance the transmission efficiency of the image signal.Entropy of Primitive(EoP)is a statistical representation of the sparse representation of the image,which indicates the probability of each base element.Based on the EoP,this paper presents an image quality evaluation method-Difference of Visual Information Metric(DVIM).The principle of this method is to evaluate the image quality with the difference between the original image and the distorted image.The comparative experiments between DVIM&PSNR&SSIM are carried out.It was found that there was a great improvement in the image quality evaluation of geometric changes.This method is an effective image quality evaluation method,which overcomes the weakness of other quality evaluation methods for geometrically changing images to a certain extent,and is more consistent with the subjective observation of the human eye.
基金The paper is funded by Guangdong Provincial Department of Education major scientific innovation project characteristics(natural sciences),project number:2014KTSCX210。
文摘The wireless network is limited by the transmission medium,and the transmission process is subject to large interference and jitter.This jitter can cause sporadic loss and is mistaken for congestion by the congestion control mechanism.The TCP Westwood protocol(referred to as TCPW)is such that it cannot distinguish between congestion loss and wireless jitter loss,which makes the congestion mechanism too sensitive and reduces bandwidth utilization.Based on this,the TCPW protocol is modified based on the estimate of the Round-Trip Time(referred to as RTT)value-called TCPW BR.The algorithm uses the measured smooth RTT value and divides the congestion level according to the weighted average idea to determine congestion loss and wireless jitter loss.The simulation results show that the TCPW BR algorithm enhances the wireless network’s ability to judge congestion and random errors.
文摘Parkinson disease (PD) is a neurological disorder with huge destruction to human body, which affects approximately 2% of the population aged 65 years or older. As antioxidants in the stress defence systems, glutathione S-transferases (GSTs) are dimeric cytosolic enzymes with an important role in the pathogenesis of PD. The aim of this study was to evaluate the association between the polymorphisms of GST genes and PD. Meta-analyses were conducted from 17 studies (38 stages) among 3419 cases and 5686 controls between four polymorphisms (GSTT1 deletion polymorphism;GSTM1 deletion polymorphism;GSTP1-104: rs1695;GSTP1-114: rs1799811) and PD. There is no significant association between the four GST gene variants and PD. A further subgroup study by ethnicity observed a risky role of GSTM1 deletion polymorphism with PD in Europeans (p = 0.013, OR = 1.126, 95% CI = 1.025-1.236), and a protective role of GSTM1 deletion polymorphism with PD in Latin Americans (p = 0.032, OR = 0.750, 95% CI = 0.577-0.975). Our meta-analysis suggested that GSTM1 deletion polymorphism increased the risk of PD in Europeans, but reduced the risk of PD in Latin Americans. Future large-scale studies might be needed to confirm the ethnic difference of GSTM1 deletion polymorphism, and to check whether there was significant association of PD for other GST genetic polymorphisms.
基金supported by the National Natural Science Foundation of China,Nos.82204360(to HM)and 82270411(to GW)National Science and Technology Innovation 2030 Major Program,No.2021ZD0200900(to YL)。
文摘Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.
基金the National Key R&D Program of China(Nos.2017YFA0204503 and 2016YFB0401100)the National Natural Science Foundation of China(Nos.91833306,21875158,51633006,51703159,51725304,and 51733004).
文摘Organic light-mitting transistors(OLETs)integrate the functions of light-emitting diodes and field-effect transistors into a unique device,opening a new door for optoelectronics.However,there is still a challenge due to the absence of high quality organic semiconductors for OLETs.Herein,we reported a novel molecule 2,6-di(anthracen-2-yl)naphthalene(2,6-DAN),which exhibited mobility of up to 19 cm2:V'-s'and an absolute fluorescence quantum yield of 37.09%,which are good values for organic semiconductors.Moreover,OLETs based on 2,6-DAN single crystals showed bright yellowish-green emission and well-balanced ambipolar charge transport.The excellent ratio of hole to electron mobilty can reach up to 0.86,which is superior to most single component OL ETs in typical device configurations reported so far.
基金supported by the National Natural Science Foundation of China(No.21190052,41121004)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB05010500)+1 种基金the National Public Benefit Special Fund for Environmental Protection Research(No.201009001-4)the Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.13Z02ESPCP)
文摘Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone (O3), NO2 and total oxidant (Ox) were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations (non-urban) and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime (13%/yr referred to 2006 level) was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds (VOC)-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.