Through analysis and research on the principle of neutron lifetime logging, the factors which affect the accuracy and technique are dec-scribed in detail in this paper.

Gadolinium neutron lifetime logging (GNLL) is a new technique used for detecting reservoir performance, which is developed by the improvement of boron neutron logging.

With proper designs of tool configuration,neutron burst sequence,as well as acquisition of energy and time spectra of gamma ray,an integrated pulsed-neutron gamma ray logging tool,which involves carbon/oxygen logging,neutron lifetime logging and oxygen activation logging,is constructed.

This paper analyzes the technological factors which might influence hit rate.

A Web cache-cluster system with higher throughput and hit rate was proposed.

The authors discuss in detail how to construct a native resource mechanism for improving the hit rate of fetching data from the server side.

Boron-injected neutron lifetime logging thchnology for evaluating cement channeling;

By applying Gadolinium-injected Neutron lifetime logging Technology and according to region characteristic,the multilevel logging-injecting-logging technique have developed,the law of imbibitions and diffusion is summarized and optimal logging time is determined.

We establish a model of torpedo hit probability under pure evasive maneuver situation by analyzing the organization of search area of two torpedoes salvo,possible target position area,selection of salvo aiming point,and the submarine evasive maneuver model.

Based on the characteristic of awaiting fire in the fire control theory,the problem of period hit probability to a maneuver target with properties of randomly passing through shot area was studied,that is,many hit probability under the condition of shooting time limited.

Because of the earth curvature,target data need to be detected by the friend unit and sent to ship,but data errors affect the hit probability.