Two-parameter estimation with three-mode NOON state in a symmetric triple-well potential

We propose a scheme to realize two-parameter estimation via Bose–Einstein condensates confined in a symmetric triple-well potential. The three-mode NOON state is prepared adiabatically as the initial state. The two parameters to be estimated are the phase differences between the wells. The sensitivity of this estimation scheme is studied by comparing quantum and classical Fisher information matrices. As a result, we find an optimal particle number measurement method. Moreover, the precision of this estimation scheme means that the Heisenberg scaling behaves under the optimal measurement.     

Local times of continuous N-parameter strong martingales

Let M be a 4N-integrable, real-valued continuous N-parameter strong martingale. By extending Itô-type formulas for M to a function whose 2Nth derivative is Dirac's δ-distribution, Tanaka-type formulas for M are obtained. They represent local time of M with respect to occupation time scaled by the N-fold product of the Stieltjes measure defined by the quadratic variation of M and its kth derivatives in space, where k ≤ N − 1. Applications of Doob's and Burkholder's inequalities give continuity properties: space time continuity for local time, space continuity for the derivatives. In case N is even, for the continuity of the (N − 1)st derivative an additional condition on M is needed which may have a relation to the existence of local times of M w.r.t. different occupation time scales.     

Liminf results on the increments of an (N,d)-Gaussian process

We establish some liminf theorems on the increments of a (N,d)-Gaussian process with the usual Euclidean norm, via estimating upper bounds of large deviation probabilities on the suprema of the (N,d)-Gaussian process. This revised version was published online in June 2006 with corrections to the Cover Date.     

用束流位置监测器测量上海光源束流寿命

通过理论分析研究了电磁耦合型束流位置探测器（BPM）用于束流寿命测量的可行性,并在上海光源储存环上进行了束流实验,对其性能进行了评估。实验结果表明,与目前常用的直流流强变压器（DCCT）系统相比,BPM给出的束流寿命具有更高的带宽和分辨力,有利于进行不同时间尺度的束流寿命评估,而且可以通过多个平均的方式来进一步提高测量精度。     

糖尿病多参数生物传感器

新型糖尿病多参数传感器是针对糖尿病及其并发症的监控而设计的,可实现血糖、乳酸、胆固醇、β—羟丁酸等血液生化参数的同时检测。它将酶法分析技术与微腔技术相结合,以印刷碳糊电极为基础,通过生物固定化方法将检测所需的酶固定在碳糊电极表面,添加多糖物质作为酶稳定剂,保证传感器响应的稳定性。传感器的检测梯度范围为：血糖1～30mmol／L,检测时间20s;胆固醇1．0—4．0g／L,检测时间180s;乳酸1～15mmol／L,检测时间50s;β—羟丁酸20～700mg／L,检测时间50s。传感器的检测结果与大型生化分析仪的常规方法检测结果相关系数大于0．92。     

半导体特性的调制自由载流子吸收变距频率扫描方法研究

根据调制自由载流子吸收（modulated free carrier absorption,MFCA）检测技术的三维理论模型,采用变间距频率扫描方式测量单晶硅样品的电子输运参数,进行了仿真与实验,对结果进行了分析;通过多参数拟合,获取了测试样品的载流子扩散系数、少数载流子寿命和前表面复合速度.仿真与实验都表明,变间距频率扫描结合多参数拟合,可以提高输运参数的测量精度. 关键词： 调制自由载流子吸收 电子输运参数 变间距频率扫描 多参数拟合     

Necessary and Sufficient Fracture Criteria for a Composite with a Brittle Matrix. Part 2. High-Strength Reinforcement

Experimental results on fracture of composite specimens with a brittle matrix are given. A modification is proposed for the shear model that describes deformation of a composite with failed matrix. A three-parameter sufficient criterion of quasibrittle strength of the composite is constructed, based on the equations of an orthotropic medium. Simple analytical expressions that relate the macrocrack length to the loading, structural, stiffness, and strength parameters of the composite medium are obtained. An approach for constructing multi-parameter criteria that take into account special features of deformation of the materials of the composite components is discussed.     

Hausdorff Dimension for Range and Graph of Multi-Parameter Operator Stable L\'{e}vy Processes

??The lower Hausdorff dimension results for the range and the graph of multi-parameter operator stable L\'{e}vy processes are established. The consequences are completely determined by the eigenvalues of its exponent matrix.     

Quantum multiparameter estimation with multi-mode photon catalysis entangled squeezed state

We propose a method to generate the multi-mode entangled catalysis squeezed vacuum states (MECSVS) by embedding the cross-Kerr nonlinear medium into the Mach−Zehnder interferometer. This method realizes the exchange of quantum states between different modes based on Fredkin gate. In addition, we study the MECSVS as the probe state of multi-arm optical interferometer to realize multi-phase simultaneous estimation. The results show that the quantum Cramer−Rao bound (QCRB) of phase estimation can be improved by increasing the number of catalytic photons or decreasing the transmissivity of the optical beam splitter using for photon catalysis. In addition, we also show that even if there is photon loss, the QCRB of our photon catalysis scheme is lower than that of the ideal entangled squeezed vacuum states (ESVS), which shows that by performing the photon catalytic operation is more robust against photon loss than that without the catalytic operation. The results here can find applications in quantum metrology for multiparatmeter estimation.     

二阶p-Laplace多参数离散周期边值问题三个解的存在性

研究了二阶p-Laplace含多个参数的非线性离散周期边值问题,获得了非线性项在更一般的情形下三个解的存在性定理.主要结论的证明基于临界点理论.