车载自组网络下基于量子随机数的高效组密钥分发方案

针对车载自组网络近场通信中密钥分发通信开销大、安全性低的问题,本文提出了一种基于量子随机数的高效量子组密钥分发方案。在该方案中:(1)通过车端和云端的量子随机数共同生成车辆的匿名凭证,并采用零知识证明方式实现车辆与路端的身份互认,保护了车辆隐私;(2)通过一种两段式的组密钥,即路端和云端的两个关键参数实现了组密钥的更新。组密钥在保证前向安全和后向安全的前提下,信令开销减少了一半,大大缩短了组密钥下发时间。最后,通过安全性和性能分析证明了该方案的安全性。

Data-and management-driven metaverse research

The metaverse has become a very important phenomenon in society because of the emergence of new technologies. The widespread adoption of the metaverse has generated significant discussions about the challenges and opportunities it presents. We invited three panelists to present their personal viewpoints on the metaverse in the 2022 AIS-SIG-ISAP Workshop on Information Systems in Asia-Pacific (ISAP). The discussion indicated that metaverse research is being conducted. Furthermore, it highlighted new research directions and offered research topics related to the advantages or disadvantages of the metaverse. The proposed research topics will offer new insights to academics and practitioners.

Experimental investigation of engineered geopolymer composite for structural strengthening against blast loads

The recent increase in blast/bombing incidents all over the world has pushed the development of effective strengthening approaches to enhance the blast resistance of existing civil infrastructures.Engineered geopolymer composite(EGC)is a promising material featured by eco-friendly,fast-setting and strain-hardening characteristics for emergent strengthening and construction.However,the fiber optimization for preparing EGC and its protective effect on structural elements under blast scenarios are uncertain.In this study,laboratory tests were firstly conducted to evaluate the effects of fiber types on the properties of EGC in terms of workability,dry shrinkage,and mechanical properties in compression,tension and flexure.The experimental results showed that EGC containing PE fiber exhibited suitable workability,acceptable dry shrinkage and superior mechanical properties compared with other types of fibers.After that,a series of field tests were carried out to evaluate the effectiveness of EGC retrofitting layer on the enhancement of blast performance of typical elements.The tests include autoclaved aerated concrete(AAC)masonry walls subjected to vented gas explosion,reinforced AAC panels subjected to TNT explosion and plain concrete slabs subjected to contact explosion.It was found that EGC could effectively enhance the blast resistance of structural elements in different scenarios.For AAC masonry walls and panels,with the existence of EGC,the integrity of specimens could be maintained,and their deflections and damage were significantly reduced.For plain concrete slabs,the EGC overlay could reduce the diameter and depth of the crater and spallation of specimens.

Uncertainty and disturbance estimator-based model predictive control for wet flue gas desulphurization system

Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution removal.The desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system robustness.To address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this paper.The UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed for optimal feedback regulation of the resultant dynamics.By viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control framework allows to locally treat the considered nonlinear plant as a linear one.The obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small,even in the presence of unmodeled dynamics.In the conducted comparison study,the introduced control scheme outperforms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of transient performance and robustness.Furthermore,the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.

Influence of the Atlantic Multidecadal Oscillation and Interdecadal Pacific Oscillation on Antarctic surface air temperature during 1900 to 2015

The importance of the Atlantic Multidecadal Oscillation(AMO)and Interdecadal Pacific Oscillation(IPO)in influencing zonally asymmetric changes in Antarctic surface air temperature(SAT)has been established.However,previous studies have primarily concentrated on examining the combined impact of the contrasting phases of the AMO and IPO,which have been dominant since the advent of satellite observations in 1979.This study utilizes long-term reanalysis data to investigate the impact of four combinations of+AMO+IPO,–AMO–IPO,+AMO–IPO,and–AMO+IPO on Antarctic SAT over the past 115 years.The+AMO phase is characterized by a spatial mean temperature amplitude of up to 0.5℃over the North Atlantic Ocean,accompanied by positive sea surface temperature(SST)anomalies in the tropical eastern Pacific and negative SST anomalies in the extratropical-mid-latitude western Pacific,which are indicative of the+IPO phase.The Antarctic SAT exhibits contrasting spatial patterns during the+AMO+IPO and+AMO–IPO periods.However,during the–AMO+IPO period,apart from the Antarctic Peninsula and the vicinity of the Weddell Sea,the entire Antarctic region experiences a warming trend.The most pronounced signal in the SAT anomalies is observed during the austral autumn,whereas the combination of–AMO and–IPO exhibits the smallest magnitude across all the combinations.The wavetrain excited by the SST anomalies associated with the AMO and IPO induces upper-level and surface atmospheric circulation anomalies,which alter the SAT anomalies.Furthermore,downward longwave radiation anomalies related to anomalous cloud cover play a crucial role.In the future,if the phases of AMO and IPO were to reverse(AMO transitioning to a negative phase and IPO transitioning to a positive phase),Antarctica could potentially face more pronounced warming and accelerated melting compared to the current observations.

Convolution-Transformer for Image Feature Extraction

This study addresses the limitations of Transformer models in image feature extraction,particularly their lack of inductive bias for visual structures.Compared to Convolutional Neural Networks(CNNs),the Transformers are more sensitive to different hyperparameters of optimizers,which leads to a lack of stability and slow convergence.To tackle these challenges,we propose the Convolution-based Efficient Transformer Image Feature Extraction Network(CEFormer)as an enhancement of the Transformer architecture.Our model incorporates E-Attention,depthwise separable convolution,and dilated convolution to introduce crucial inductive biases,such as translation invariance,locality,and scale invariance,into the Transformer framework.Additionally,we implement a lightweight convolution module to process the input images,resulting in faster convergence and improved stability.This results in an efficient convolution combined Transformer image feature extraction network.Experimental results on the ImageNet1k Top-1 dataset demonstrate that the proposed network achieves better accuracy while maintaining high computational speed.It achieves up to 85.0%accuracy across various model sizes on image classification,outperforming various baseline models.When integrated into the Mask Region-ConvolutionalNeuralNetwork(R-CNN)framework as a backbone network,CEFormer outperforms other models and achieves the highest mean Average Precision(mAP)scores.This research presents a significant advancement in Transformer-based image feature extraction,balancing performance and computational efficiency.

What induced the trend shift of mixed-layer depths in the Antarctic Circumpolar Current region in the mid-1980s?

An obvious trend shift in the annual mean and winter mixed layer depth(MLD)in the Antarctic Circumpolar Current(ACC)region was detected during the 1960–2021 period.Shallowing trends stopped in mid-1980s,followed by a period of weak trends.The MLD deepening trend difference between the two periods were mainly distributed in the western areas in the Drake Passage,the areas north to Victoria Land and Wilkes Land,and the central parts of the South Indian sector.The newly formed ocean current shear due to the meridional shift of the ACC flow axis between the two periods is the dominant driver for the MLD trends shift distributed in the western areas in the Drake Passage and the central parts of the South Indian sector.The saltier trends in the regions north to Victoria Land and Wilkes Land could be responsible for the strengthening mixing processes in this region.

Hybrid Multi-Infeed Interaction Factor Calculation Method Considering Voltage Regulation Control Characteristics of Voltage Source Converter

Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluate its influence on the voltage interaction between VSC-HVDC and line commutated converter based high voltage direct current(LCC-HVDC),this paper proposes a hybrid multi-infeed interaction factor(HMIIF)calculation method considering the voltage regulation control characteristics of VSC-HVDC.Firstly,for a hybrid multi-infeed high voltage direct current system,an additional equivalent operating admittance matrix is constructed to characterize HVDC equipment characteristics under small disturbance.Secondly,based on the characteristic curve between the reactive power and the voltage of a certain VSC-HVDC project,the additional equivalent operating admittance of VSC-HVDC is derived.The additional equivalent operating admittance matrix calculation method is proposed.Thirdly,the equivalent bus impedance matrix is obtained by modifying the alternating current(AC)system admittance matrix with the additional equivalent operating admittance matrix.On this basis,the HMIIF calculation method based on the equivalent bus impedance ratio is proposed.Finally,the effectiveness of the proposed method is verified in a hybrid dual-infeed high voltage direct current system constructed in Power Systems Computer Aided Design(PSCAD),and the influence of voltage regulation control on HMIIF is analyzed.

血糖控制不佳2型糖尿病视网膜病变患者外周血VEGF、HIF-1α和ET-1水平及其临床意义

目的探讨血糖控制不佳的2型糖尿病视网膜病变(DR)患者外周血中血管内皮生长因子(VEGF)、缺氧诱导因子-1α(HIF-1α)和内皮素-1(ET-1)水平与视网膜病变的关系。方法选取2012年1月-2018年2月在首都医科大学附属复兴医院住院并符合WHO 2型糖尿病(T2DM)诊断标准的T2DM患者195例为研究对象,分为3组:血糖控制较好且无DR的患者62例作为观察1组,血糖控制较好的DR患者65例作为观察2组,以及血糖控制不佳的DR患者68例作为观察3组。选择同期健康体检者64例为正常对照组。检测所有受试者的动态血糖和VEGF、HIF-1α和ET-1,考察VEGF、HIF-1α和ET-1与动态血糖的关系。结果与正常对照组比较,3个观察组的空腹血糖(FBG)、餐后2 h血糖(2 hPBG)、血糖水平标准差(SDBG)、日内血糖平均波动幅度(MAGE)、日间血糖平均绝对差(MODD)、日内血糖波动次数(NGE)、VEGF、HIF-1α和ET-1均提高(P<0.05),与观察1组比较,观察2和3组的SDBG、MAGE、MODD、NGE、VEGF、HIF-1α和ET-1均提高(P<0.05),与观察2组比较,观察3组的SDBG、MAGE、MODD、NGE、VEGF、HIF-1α和ET-1均提高(P<0.05),观察1、2组的FBG、2 hPBG差异无统计学意义(P>0.05),观察3组的FBG、2 hPBG均高于观察1、2组(P<0.05)。VEGF、HIF-1α和ET-1与SDBG、MAGE、MODD和NGE均呈正相关(P<0.05)。结论按T2DM发病、DR发生及伴随DR的血糖控制不佳的顺序,VEGF、HIF-1α和ET-1表达逐渐升高,可能参与血糖控制不佳的DR的发生、发展过程。

Association of caveolin-3 and cholecystokinin A receptor with cholesterol gallstone disease in mice

AIM: To investigate the role of caveolin-3 (CAV3) and cholecystokinin A receptor (CCKAR) in cholesterol gallstone disease (CGD).

Effects of Ligustrum robustum on gut microbes and obesity in rats

AIM: To investigate the anti-obesity and antibacterial effects of Ligustrum robustum(L. robustum) in vivoand in vitro and its possible mechanisms. METHODS: The effects of L. robustum aqueous extract(LR) on various gut bacteria in vitro were evaluated. The effects of LR on high-fat diet-fed(HFD) rats in vivo were also assessed. Culture methods,quantitative polymerase chain reaction,and terminalrestriction fragment length polymorphism were used to analyze the effects of LR on gut bacteria. Biochemical tests were also performed to detect the changes in obesity-related indicators after LR treatment. RESULTS: LR treatment lowered adipose weight and decreased Lee's index,blood glucose,total cholesterol,and lipid in the tested groups relative to control(P < 0.05). To determine the reasons for these changes,we assessed the potential bacteriostatic and bactericidal effects of LR on specific bacterial species in vitro. LR affected the richness,diversity,and evenness of gut bacteria,increased fecal Lactobacillus,and decreased Enterococci in HFD rats(P < 0.05). CONCLUSION: L. robustum may be a safe and effective food for weight loss and obesity control,and the effects of L. robustum might be mediated by the regulation of gut bacteria.

Upregulation of caveolin-1 and SR-B1 in mice with non-alcoholic fatty liver disease

BACKGROUND:Non-alcoholic fatty liver disease(NAFLD)is one of the most frequent causes of liver diseases,with markedly increased prevalence.However,its mechanisms are not clear.The present study was undertaken to illustrate the role of caveolin-1(cav1)and the scavenger receptor class B type 1(SR-B1)in NAFLD.METHODS:Adult male C57BL/6 mice were fed with a normal diet or high fat and cholesterol(HFC)diet for 14 weeks.The mice were sacrificed to collect plasma and harvest the liver;their plasma lipid concentration was measured.Hepatic cav1and SR-B1 mRNA and protein expression were determined by real-time quantitative polymerase chain reaction(qPCR)and Western blotting,respectively.In order to study cav1 and SR-B1distribution and change in hepatocytes,immunohistochemical analysis was performed.RESULTS:HFC diet increased plasma lipids,induced NAFLD and increased the liver/body weight ratio.Compared to the control mice(n=6),the mRNA and protein levels of cav1 and SR-B1 in liver tissue of the NAFLD mice(n=12)increased significantly(cav1 mRNA:1.536±0.226 vs 0.980±0.272,P【0.05;protein:0.643±0.240 vs 0.100±0.130,P【0.01;SR-B1 mRNA:1.377±0.125 vs 0.956±0.151,P【0.01;protein:2.156±0.507vs 0.211±0.211,P【0.01).Furthermore,both cav1 and SR-B1immunoreactivity increased and their distribution was also changed,mainly in the plasma membrane of hepatocytes,cytoplasm and membrane of lipid droplets and around.CONCLUSION:NAFLD is associated with increased concentration of plasma lipids and upregulation of hepatic cav1 and SR-B1 gene and protein expressions,which indicate that cav1 and SR-B1 might play crucial roles in the pathogenesis of NAFLD.

泪小管炎主要临床特征及致病菌分析

目的:探讨泪小管炎的主要临床特征、致病菌分布及其药物敏感性特征,为临床诊治提供依据。方法:回顾性研究。选择2016-12/2020-10于河北省眼科医院确诊为泪小管炎的患者45例45眼,分析患者的一般资料、临床表现及治疗史、细菌培养及药物敏感性试验结果。结果:纳入的45例患者均单眼发病,其中21眼表现为流泪、分泌物增多、内眦部结膜充血,14眼表现为内眦部红肿,6眼表现为类似眼睑囊肿,行常规术前检查时发现并诊断4眼。既往被诊断为其他眼部疾病27眼,误诊率为60.0%。细菌培养阳性率为80.0%(36/45),以表皮葡萄球菌最为常见,其次为链球菌属;多重耐药菌感染患者占52.8%(19/36)。细菌对氟喹诺酮类抗生素敏感率(82.9%,97/117)高于氨基糖苷类(70.1%,68/97)和头孢菌素类(68.1%,111/163)抗生素;除万古霉素以外,利福平、左氧氟沙星、氯霉素对革兰氏阳性菌的敏感性较高。结论:表皮葡萄球菌是泪小管炎最常见致病菌、其次为链球菌属;左氧氟沙星、利福平可作为局部抗感染的首选抗生素,合理用药可减少多重耐药菌形成;行泪小管切开成形术彻底清除结石,可提高治愈率。

Recent advances in solid-state metal-air batteries

Solid-state metal-air batteries have emerged as a research hotspot due to their high energy density and high safety.Moreover,side reactions caused by infiltrated gases(O_(2),H_(2)O,or CO_(2))and safety issues caused by liquid electrolyte leakage will be eliminated radically.However,the solid-state metal–air battery is still in its infancy,and many thorny problems still need to be solved,such as the large resistance of the metal/electrolyte interface and catalyst design.This review will summarize some important progress and key issues for solid-state metal-air batteries,especially the lithium-,sodium-,and zinc-based metal-air batteries,clarify some core issues,and forecast the future direction of the solid-state metal-air batteries.

A Triterpenoid Inhibited Hormone-Induced Adipocyte Differentiation and Alleviated Dexamethasone-Induced Insulin Resistance in 3T3-L1 adipocytes

6a-Hydroxylup-20(29)-en-3-on-28-oic acid(1),a natural triterpenoid,was found to possess the ability in a dose-dependent manner inhibiting hormone-induced adipocyte differentiation in 3T3-L1 preadipocytes,and restoring glucose consuming ability in dexamethasone(DXM)-induced insulin resistant 3T3-L1 adipocytes.Compound 1 was also found to ameliorate DXM-induced adipocyte dysfunction in lipolysis and adipokine secretion.Mechanistic studies revealed that 1 inhibited adipocyte differentiation in 3T3-L1 preadipocytes via down-regulating hormone-stimulated gene transcription of peroxisome proliferator-activated receptor c and CCAAT-enhancer-binding protein alpha which are key factors in lipogenesis,and restored DXM-impaired glucose consuming ability in differentiated 3T3-L1 adipocytes via repairing insulin signaling pathway and activating down-stream signaling transduction by phosphorylation of signaling molecules PI3K/p85,Akt2 and AS160,thus leading to increased translocation of glucose transporter type 4 and transportation of glucose.

同步放化疗联合每周多西他赛与顺铂治疗局部晚期鼻咽癌的比较：一项倾向性评分匹配分析

背景与目的基于多西他赛的同步放化疗(concurrent chemoradiotherapy,CCRT)治疗头颈部肿瘤疗效显著且毒性可控。CCRT联合顺铂和/或5-氟尿嘧啶治疗局部晚期和转移性/复发性鼻咽癌(nasopharyngeal carcinoma,NPC)疗效确切。但是,CCRT联合多西他赛治疗局部晚期NPC尚无明确报道。本研究旨在比较CCRT联合每周多西他赛与3周1次顺铂治疗局部晚期NPC的疗效及毒性。方法评估2010年1月至2014年12月新确诊为局部晚期NPC患者的临床资料,患者均接受了CCRT联合每周1次多西他赛(15mg/m^2)或3周1次顺铂(80–100 mg/m2)的治疗。为平衡基线特征,进行了1∶1的特征评分匹配。比较两组间的不良事件和生存期。结果本研究共纳入962例患者,对其中448例患者进行了匹配并认定为匹配队列。整体队列的平均随访持续时间为48个月。在整体队列[风险比(hazard ratio,HR)=0.37,95%置信区间(confidence interval,CI):0.19–0.72,P=0.030]和匹配队列(HR=0.33,95%CI:0.14–0.79,P=0.023)两组中,接受多西他赛治疗患者的3年淋巴结无复发生存率均显著提高。然而,在2个队列中,总生存期、无局部复发生存期,无远端转移生存期均无显著差异。多西他赛组中患者的3级放射性皮炎(6.7%vs.1.8%,P=0.001)、黏膜炎(74.5%vs.37.9%,P<0.001)的发生率显著增高,而顺铂组患者多发任意级别的肾损伤(1.8%vs.15.1%,P<0.001)、呕吐(18.8%vs.88.3%,P<0.001)和ALT升高(19.2%vs.31.3%,P=0.027)及白细胞减少(2.2%vs.11.6%,P<0.001)。结论CCRT联合每周低剂量多西他赛对局部NPC患者是一种有效且可耐受的治疗方案。尤其是针对治疗前EBV DNA水平较低的患者,该方案可主要通过提高控制局部淋巴结转移进而使患者获得良好的生存获益。

A transformer generative adversarial network for multi-track music generation

This study proposes a new generation network based on transformers and guided by the music theory to produce high-quality music work.In this study,the decoding block of the transformer is used to learn the internal information of single-track music,and cross-track transformers are used to learn the information amongst the tracks of different musical instruments.A reward network based on the music theory is proposed,which optimizes the global and local loss objective functions while training and discriminating the network so that the reward network can provide a reliable adjustment method for the generation of the network.The method of combining the reward network and cross entropy loss is used to guide the training of the generator and produce high-quality music work.Compared with other multi-track music generation models,the experimental results verify the validity of the model.

The establishment of Boron nitride@sodium alginate foam/polyethyleneglycol composite phase change materials with high thermal conductivity, shape stability, and reusability

Adopting organic phase change materials(PCMs) for the management of electronic devices is restricted by low thermal conductivity. In this paper, the composite PCMs are established by freeze-drying and vacuum impregnation. Herein, polyethylene glycol(PEG) is induced as heat storage materials, boron nitride(BN) is embedded as filler stacking in an orderly fashion on the foam walls to improve thermal conductivity and sodium alginate(SA) is formed as supporting material to keep the shape of the composite stable. X-ray diffractometry, scanning electron microscopy-energy dispersive spectrometer, thermal gravimetric analysis, thermal conductivity meter, differential scanning calorimeter, and Fourier transform infrared were used to characterize the samples and thermal cycles were employed to measure the shape stability. The results exhibit the BN@SA/PEG composite PCMs have good chemical compatibility, stable morphology, and thermal stability. Due to the high porosity of foam, PEG endows the composite PCMs with high latent heat(149.11 and 141.59 J·g^(-1)). Simultaneously, BN@SA/PEG shows an excellent heat performance with high thermal conductivity(0.99 W·m^(-1)·K^(-1)), reusability, and shape stability, contributing the composite PCMs to application in the energy storage field. This study provides a strategy to manufacture flexible, long-serving, and shape-stable PCMs via introducing BN@SA foam as a storage framework, and these PCMs have great potential in thermal management in the electronic field.

A Comparison of Shale Gas Fracturing Based on Deep and Shallow Shale Reservoirs in the United States and China

China began to build its national shale gas demonstration area in 2012.The central exploration,drilling,and development technologies for medium and shallow marine shale reservoirs with less than 3,500m of buried depth in Changning-Weiyuan,Zhaotong,and other regions had matured.In this study,we macroscopically investigated the development history of shale gas in the United States and China and compared the physical and mechanical conditions of deep and shallow reservoirs.The comparative results revealed that themain reasons for the order-ofmagnitude difference between China’s annual shale gas output and the United States could be attributed to three aspects:reservoir buried depth,reservoir physical and mechanical properties,and engineering technology level.The current engineering technology level of China could not meet the requirements of increasing production and reducing costs for deep shale gas reservoirs;they had reached the beneficial threshold development stage and lacked the capacity for large-scale commercial production.We identified several physical and mechanical reasons for this threshold development stage.Deep shale reservoirs were affected by the bedding fracture,low brittleness index,low clay mineral content,and significant areal differences,as well as by the transformation from elasticity to plasticity,difficulty in sanding,and high mechanical and strength parameters.Simultaneously,they were accompanied by six high values of formation temperature,horizontal principal stress difference,pore pressure,fracture pressure,extension pressure,and closure pressure.The key to deep shale gas horizontal well fracturing was to improve the complexity of the hydraulic fracture network,formadequate proppant support of fracture surface,and increase the practical stimulated reservoir volume(SRV),which accompanied visual hydraulic discrete network monitoring.On this basis,we proposed several ideas to improve China’s deep shale gas development involving advanced technology systems,developing tools,and supporting technologies in shale gas exploration and development in the United States.These ideas primarily involved stimulation technologies,such as vertically integrated dessert identification and optimization,horizontal well multistage/multicluster fracturing,staged tools development for horizontal wells,fractures network morphology monitoring by microseismic and distributed optical fiber,shale hydration expansion,soak well,and fracturing fluid flow back.China initially developed the critical technology of horizontal well large-scale and high-strength volume fracturing with a core of“staged fracturing with dense cutting+shorter cluster spacing+fracture reorientation by pitching+forced-sand addition+increasing diameter perforating+proppant combination by high strength and small particle size particles”.We concluded that China should continue to conduct critical research on theories and technical methods of horizontal well fracturing,suitable for domestic deep and ultra-deep marine and marine-continental sedimentary shale,to support and promote the efficient development of shale gas in China in the future.It is essential to balance the relationship between the overall utilization degree of the gas reservoir and associated economic benefits and to localize some essential tools and supporting technologies.These findings can contribute to the flourishing developments of China’s deep shale gas.

Raman scattering from highly-stressed anvil diamond

The high-frequency edge of the first-order Raman mode of diamond reflects the stress state at the culet of anvil, and is often used for the pressure calibration in diamond anvil cell(DAC) experiments. Here we point out that the high-frequency edge of the diamond Raman phonon corresponds to the Brillouin zone(BZ) center Γ point as a function of pressure. The diamond Raman pressure gauge relies on the stability of crystal lattice of diamond under high stress. Upon the diamond anvil occurs failure under the uniaxial stress(197 GPa), the loss of intensity of the first-order Raman phonon and a stressdependent broad Raman band centered at 600 cm^(-1) are observed, which is associated with a strain-induced local mode corresponding to the BZ edge phonon of the L1 transverse acoustic phonon branch.