JAVA main features

 JAVA main features


Java language has distinct characteristics, making it a convenient and efficient tool in the development of distributed network applications, multi-platform applications, graphical user interfaces, Web applications, multi-threaded applications and other software development. The following options to be introduced.

        (1) development and use of simplicity. Java Basic syntax style is very similar to the C + + language, but cut the pointer in C + +, operator overloading and some easy to confuse the place. In memory management and provides a garbage collection. This allows the programmer to make more effort in implementing program functionality without having to worry about minor issues such as memory release. C + + in the complex and flexible pointer operation often leads to serious errors, has always been the development of debugging staff is very difficult issues, which does not exist in Java. The Java Virtual Machine can also link local or even remote libraries to programs, so developers do not have to worry about their details. All these provide a simple application development.

        (2) distributed. Java's support for TCP / IP protocols such as HTTP and FTP makes it easy for Java programs to establish network connections and access remote files through the Uniform Resource Locator (URL), as well as accessing local files. Java's runtime system dynamically loads the bytecodes over the network, dynamically using the new protocol control software.

        (3) object-oriented. Unlike C ++, Basic syntax in Java is very strict with object-oriented and does not allow you to define variables and methods (functions) that are independent of the class. Java class and object-based, any variables and methods can only be included in a class of internal. This makes the structure of the program clearer for inheritance and reuse to bring convenience.

        (4) security. For network applications, this is extremely important. Java security as a first consideration, set up a layer of prevention. First of all compile-time syntax, semantic checks. Link, but also to re-class over and over again the type of inspection, elimination of indirect object access. At runtime, Java's run-time system will perform bytecode checking and record the object's storage to limit access to the security context. Local classes run separately from remote classes, preventing the remote system from destroying the local system. Java-enabled browsers also allow users to control Java software access to the local system. The combination of the various measures to ensure the safety of Java programs.

        (5) platform independence and portability. Java's Application Programming Interface (API) and run-time system are key to portability. Java provides a consistent API for the various operating systems that support it. In the API interface, all Java programs will not depend on the platform. Java runtime system in the interpretation of the implementation process, the bytecode into the current machine code machine. Program developers do not need to consider the application of the hardware conditions and operating system structure, the user only needs a Java runtime system, you can run compiled bytecode.

        (6) multi-threaded. Java provides built-in multi-threaded support, the program can easily create multiple threads, each thread to perform different work. This makes the program work simple. For example, with different threads, respectively, control the sound and image, you can easily build the complexity of the effect of audio and video intertwined, and programming as long as the work of the respective threads, do not care about their cooperation, which also greatly contributed to the dynamic program interactivity and real-time.

        In order to control the action of each thread, Java also provides a thread synchronization mechanism. The internal implementation of this mechanism is based on management. This mechanism allows different threads to access shared resources to cooperate with each other to ensure data consistency, to avoid errors.

        (7) explain the implementation. Java programs are compiled to form bytecodes, which are then interpreted and executed on the virtual machine. This is the Java program can be run independently of the platform. This also makes the program beneficial for incremental linking, thereby speeding up the development process

US scientists to complete the most complex human brain directly connected experiments

About 100 billion neurons in the brain communicate with each other, forming 100 trillion synapses, the number of dense, better than the stars of the Milky Way. We can explore galaxies beyond the light-years, but we do not know much about the brain.
In 2013, the European Union and the United States have launched the "brain project" and "brain plan", respectively, within 10 years plans to invest 1 billion euros and 4.5 billion US dollars to the "final science fortress and the ultimate frontier" - "brain science"
In September, researchers at the University of Washington used a brain-to-brain approach that allowed five pairs of subjects to pass brain signals over the Internet to play quizzes. For the first time, this experiment proves that the two brains can be directly connected, and without the need for vocalization, one can accurately guess the other's ideas.
This is one of the most complex brain-brain experiments that humans have ever performed: the respondent wears an electroencephalograph (EEG) recording EEG activity. When he sees an object on the computer screen, such as a dog, Another interrogator also sees a set of possible objects and related problems. Click the mouse to ask the questioner to send a question, the respondent will answer yes or no by staring at the LEDs with different frequencies of flash on the monitor. Both answers send a signal to the interrogator via the Internet, activating the magnetic coil placed behind the head. But only the answer is "yes" to generate enough to stimulate the interrogator visual cortex of the signal, and let it see a wavy or fine linear flash, this phenomenon is called "vision." Through this feedback, the interrogator can confirm and point out the correct object.
The use of non-invasive connection, and invasive (such as implanted electrodes to the cortex) means, although the signal reception is relatively straightforward, but the signal transmission process is indeed circuitous and complex. However, brain - brain direct connection is the future of deep emotions, knowledge, memory and other "interactive" one of the bases, so even if only to achieve a Zhuopu "game", still gives people unlimited hope.
Thus, although the brain of the subject is only showing a temporary "yes" flash, but no less than 1866 Mendel in the famous pea hybridization test, was used to represent the different traits, and later on behalf of the gene group Upper and lower case letters.

The first close observation of human Pluto

The largest solar system members of the ups and downs to Pluto. Since 1930, Clyde Thompson found that Pluto's controversy has been relevant, even if the global textbooks have been known as the "ninth planet" name, and finally was kicked out in 2008, downgraded to " Dwarf planet ".
NASA launched a new field of vision in 2006, the target went straight to Pluto, 9 years later, the United States Eastern time at 14:45 on July 14, 2015, "New Horizons" close range Flying Pluto, became the first to detect the distant dwarf planet of human detectors.
"New Horizons" shaped like a grand piano, carrying a 77 kg propellant, including 10.9 kg of plutonium dioxide as a power source. It is by far the fastest detector, in less than 10 years, flying 4.8 billion kilometers. Its counterparts, as part of Pluto discoverer Clyde Thompson's ashes, and NASA solicitation of 450,000 signatures. On the road, it also visited the Saturn and Neptune.
Pluto had little knowledge of Pluto, the "meeting" to make the understanding of human Pluto revolutionary changes - its diameter is 2370.6 km (± 19.3 km), the density lower than previously thought, the internal may have More ice and less rock, scientists also confirmed that the Arctic is indeed as speculated by the ice composition, but also rich in methane and nitrogen ice.
At present, the "new horizon" probe is still on the line, will enter the mysterious edge of the solar system Kuiper belt, Kuiper belt object is considered to be formed during the solar system has not yet time to grow into a planet's wreckage, recording the solar system initially formed history , So the future "Kuiper Belt" trip, in a sense, is also a glimpse of the origin of the solar system.
"New Horizon" to visit Pluto, in the global media, astronomy, as well as the majority of science and technology enthusiasts of the carnival. There is no doubt that the first human close observation of Pluto, marking the golden age of the planet to explore the arrival of the summit.