In this paper,the concept of grantfree non-orthogonal multiple access(NOMA) for uplink data transmission is elaborated.NOMA in combination with grant-free can be applied to ultra reliability low latency communication(...In this paper,the concept of grantfree non-orthogonal multiple access(NOMA) for uplink data transmission is elaborated.NOMA in combination with grant-free can be applied to ultra reliability low latency communication(URLLC),massive machine type communication(m MTC),enhanced mobile broadband(e MBB) small packet and two-step random-access channel(RACH) scenarios.The advantages of grant-free NOMA are low latency and signaling overhead,high access capability and efficient resource utilization.Candidate uplink NOMA schemes are summarized and preliminary comparison among a subset of schemes are presented.Furthermore,design aspects for grant-free NOMA are discussed,with special notes on particular issues such as blind UE identification and transmitter/receiver(Tx/Rx) impairments in realistic deployment.展开更多
建立了液相色谱-四极杆飞行时间质谱(LC-Q-TOF/MS)对饲料中非目标污染物(兽药)的筛查方法,以及未知物的判定和确认技术。饲料样品经0.1%EDTA-乙腈-甲醇(1∶1∶1,含0.1%甲酸)混合溶液提取,Q-TOF全扫描模式采集数据,数据经过峰对齐...建立了液相色谱-四极杆飞行时间质谱(LC-Q-TOF/MS)对饲料中非目标污染物(兽药)的筛查方法,以及未知物的判定和确认技术。饲料样品经0.1%EDTA-乙腈-甲醇(1∶1∶1,含0.1%甲酸)混合溶液提取,Q-TOF全扫描模式采集数据,数据经过峰对齐(质量误差5 m Da以内)、噪音过滤、自动排除无用峰等处理后,进行正交偏最小二乘判别分析(OPLS-DA)处理,根据Score图、S-Plot图和VIP图判定出特征离子,结合二级信息与自建谱库比对,进行结构式确认,或通过同位素丰度比例和分子式生成功能,确认分子式,结合二级断裂信息,判定特征离子的结构式,从而判定未知物的成分。结果显示:16份饲料样品共筛查出27种兽药。采用液相色谱-三重四极杆串联质谱法对其中的12种兽药进行定性定量分析,验证结果仅出现2个假阳性,兽药含量在12.5~152.0 mg/kg之间。通过LC-Q-TOF/MS结合OPLS-DA的方法能够对饲料中的非目标物进行筛查分析,方法准确度高。展开更多
文摘In this paper,the concept of grantfree non-orthogonal multiple access(NOMA) for uplink data transmission is elaborated.NOMA in combination with grant-free can be applied to ultra reliability low latency communication(URLLC),massive machine type communication(m MTC),enhanced mobile broadband(e MBB) small packet and two-step random-access channel(RACH) scenarios.The advantages of grant-free NOMA are low latency and signaling overhead,high access capability and efficient resource utilization.Candidate uplink NOMA schemes are summarized and preliminary comparison among a subset of schemes are presented.Furthermore,design aspects for grant-free NOMA are discussed,with special notes on particular issues such as blind UE identification and transmitter/receiver(Tx/Rx) impairments in realistic deployment.
文摘建立了液相色谱-四极杆飞行时间质谱(LC-Q-TOF/MS)对饲料中非目标污染物(兽药)的筛查方法,以及未知物的判定和确认技术。饲料样品经0.1%EDTA-乙腈-甲醇(1∶1∶1,含0.1%甲酸)混合溶液提取,Q-TOF全扫描模式采集数据,数据经过峰对齐(质量误差5 m Da以内)、噪音过滤、自动排除无用峰等处理后,进行正交偏最小二乘判别分析(OPLS-DA)处理,根据Score图、S-Plot图和VIP图判定出特征离子,结合二级信息与自建谱库比对,进行结构式确认,或通过同位素丰度比例和分子式生成功能,确认分子式,结合二级断裂信息,判定特征离子的结构式,从而判定未知物的成分。结果显示:16份饲料样品共筛查出27种兽药。采用液相色谱-三重四极杆串联质谱法对其中的12种兽药进行定性定量分析,验证结果仅出现2个假阳性,兽药含量在12.5~152.0 mg/kg之间。通过LC-Q-TOF/MS结合OPLS-DA的方法能够对饲料中的非目标物进行筛查分析,方法准确度高。