群体中的个体:王世贞的多重文学维度——以苏轼批评为视角

王世贞是一个拥有多维文学面貌的人,这并不是因为他的“晚年自悔”,其本质是他身上的群体意志和个体意识不完全重合。从表现上来看,他从未抛弃复古的根本立场,同时却又有中晚明时期文学发展大势由复古转向革新的影子。这种特性在其对苏轼的接受态度上得到了完整的投射。在不同的人生阶段、在文盟领袖角色与纯粹个人感受之间,王世贞给外界传达出的对苏轼的态度有所不同。另外,王世贞并非保守的复古者,他在复古立场之上一直寻求与性灵革新的平衡,这在他对苏轼文学创作思想的承继上也多有体现。表面来看,王世贞的崇苏与复古派的抑宋似有矛盾,但抑宋的本质实际是反道统性理文学,这与苏轼的文学性格反而是统一的。

Short Baseline Positioning with an Improved Time Reversal Technique in a Multi-path Channel

The existence of a multi-path channel under the water greatly decreases the accuracy of the short baseline positioning system.In this paper,the application of a time reversal mirror to the short baseline positioning system was investigated.The time reversal mirror technique allowed the acoustic signal to better focus in an unknown environment,which effectively reduced the expansion of multi-path acoustic signals as well as improved the signal focusing.The signal-to-noise ratio（SNR） of the time reversal operator greatly increased and could be obtained by ensonifying the water.The technique was less affected by the environment and therefore more applicable to a complex shallow water environment.Numerical simulations and pool experiments were used to demonstrate the efficiency of this technique.

A novel zero-payload downlink CSI feedback scheme for closed-loop beamforming system

A novel downlink channel state information(CSI)feedback scheme is proposed for the closed-loopbeamforming system.In the proposed scheme,mobile terminal(MT)superposes the uplink pilot on thereceived downlink pilot,forms the hybrid pilot(HP),and then transmits the HP to base station(BS)viathe uplink pilot channel.Because downlink CSI can be recovered from HP at BS side without consumingextra uplink bandwidth,the proposed scheme can achieve zero-payload CSI feedback,effectively solvingthe traditional bottleneck problems,i.e.,the heavy burden for transmitting CSI.Moreover,both MT'scomplexity and feedback delays can be reduced since the downlink channel needs not to be estimated atMT any more.Simulations verify that the proposed scheme can achieve the better MSE performance forthe uplink channel estimation than the traditional scheme,and the cost for the zero-payload CSI feedbackis some acceptable loss of feedback precision.

A Limited Feedback Transmission Scheme Based on MS Compensation in the 3D MIMO System

In a three-dimensional （3D） multiple- input multiple-output （MIMO） system, the base station can use both horizontal and vertical spaces, transmitting spatial beam to users more accurately. This system has caught the attention of researchers in recent years. The existing research on the 3D MIMO technology is based on the assumption that the base station can acquire the ideal channel state information （CSI）, which is not actually the case in real systems. Therefore, this paper introduces a limited feedback transmission scheme based on mobile station （MS） compensation in the 3D MIMO system. In this scheme, the vertical antenna gain of the 3D MIMO system compensation is assigned to the MS. Two CSI-RS ports are configured at the base station, omnidirectional CSI-RS port and partial CSI-RS port. The MS can calculate the horizontal CSI and the vertical beam gain according to omnidirectional CSI-RS port and partial CSI- RS port, respectively. Partial CSI-RS resources are used to calculate the channel after being weighted by the vertical beam vector, MS selects the optimal vertical precoding vector. Simulations show that compared with the reference strategy, the transmission scheme with limited feedback based on the MS compensation proposed in this article has more advantages. The average spectral efficiency of the system and the cell edge spectral efficiency can be greatly improved.

Biomaterial Scaffolds with Biomimetic Fluidic Channels for Hepatocyte Culture

Biomaterial scaffolds play an important role in maintaining the viability and biological functions of highly metabolic hepatocytes in liver tissue engineering. One of the major challenges involves building a complex microchannel network inside three-dimensional （3D） scaffolds for efficient mass transportation. Here we presented a biomimetic strategy to generate a mi- crochannel network within porous biomaterial scaffolds by mimicking the vascular tree of rat liver. The typical parameters of the blood vessels were incorporated into the biomimetic design of the microchannel network such as branching angle and diameter. Silk fibroin-gelatin scaffolds with biomimetic vascular tree were fabricated by combining micromolding, freeze drying and 3D rolling techniques. The relationship between the micro-channeled design and flow pattern was revealed by a flow experiment, which indicated that the scaffolds with biomimetic vascular tree exhibited unique capability in improving mass transportation inside the 3D scaffold. The 3D scaffolds, preseeded with primary hepatocytes, were dynamically cultured in a bioreactor system. The results confirmed that the pre-designed biomimetic microchannel network facilitated the generation and expansion of hepatocytes.

Elastic-plastic seismic response of CRTS II slab ballastless track system on high-speed railway bridges

China railways track structure II (CRTS II) slab ballastless track on bridge is one kind of track structures unique to China. Its main bearing component of longitudinal force is the continuous base plate rather than rail. And the track-bridge interaction is weakened by the sliding layer installed between base plate and bridge deck. In order to study the dynamic response of CRTS II slab ballastless track on bridge under seismic action, a 3D nonlinear dynamic model for simply-supported bridges and CRTS II track was established, which considered structures such as steel rail, fasteners, track plate, mortar layer, base plate, sliding layer, bridge, consolidation, anchors, stoppers, etc. Then its force and deformation features under different intensities of seismic excitation were studied. As revealed, the seismic response of the system increases with the increase of seismic intensity. The peak stresses of rail, track plate and base plate all occur at the abutment or anchors. Both track plate and base plate are about to crack. Besides, the rapid relative displacement between base plate and bridge deck due to the small friction coefficient of sliding layer is beneficial to improve the seismic performance of the system. During the earthquake, a large vertical displacement appears in base plate which leads to frequent collisions between stoppers and base plate, as a result, stoppers may be damaged.

ROBUST OUTPUT FEEDBACK STABILIZATION OF NONLINEAR NETWORKED SYSTEMS VIA A FINITE DATA-RATE COMMUNICATION CHANNEL

This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer and a control law for the systems in the absence of any finite data-rate communi- cation channel. Based on the observer and the control law, the authors constructs an encoder/decoder pair and provides a sufficient condition, including suitable sampling period and data rate, which will guarantee the stability of the closed-loop systems when a finite data-rate communication channel is introduced.